Drying bowl blanks

[Roger Davis TN]

I have called every pet shop in town trying to find Silica Gel cat litter to us as a drying agent. It is hard to find. I think I will order it. Anyway I was just thinking why not use my vaccumn pump to pull out the water? Has anyone done this. I know when you stabilize pen blanks they tell you to run a vacum before adding the resin. Roger

[Dean S Walker]

I would not think a vacuum would be a good idea as it may pull the water too quickly and crack the bowl. If I want to dry them quickly I turn them as thin as I think I can get away with and seal the outside end grain, then take the wet shavings and full up the bowl and put saran wrap over it. but this still takes a couple months

[Brice Rogers]

Go to either Amazon or ebay - - they sell silica gel in all sizes and at decent prices. And better yet? You don't have to drive to pick it up. It'll be delivered.

Eventually the silica gel will absorb moisture and need to be dried out. Google the oven temps and time required.

[Reed Gray]

There are vacuum kilns. They do add a little heat to the process, usually through extruded aluminum sheets with antifreeze in them. Water, inside a vacuum boils at a much lower temperature than outside the vacuum. Not sure if the vacuum pump from the presses we use would work for that or not. The wood that comes out of vacuum kilns, and solar kilns works like air dried lumber. If you rip a board on your table saw, you get shavings, not dust. Also, I can rip a 8/4 board down to book match a table top, and get no spring, warp or cupping.

robo hippy

[Paul Gilbert]

I have considered building a vacuum kiln, however I am sure that I would need a refrigerated moisture trap ahead of my rotary vane vacuum pump. You can get a lot of water occluded in a stack of bowls and that could gum up you pump vanes.

The practice of pulling a vacuum on wood prior to pressure treating it is to pull the air out of the wood prior to flooding so that the preservative will penetrate deeply into the wood. It has nothing to do with drying.

[John K Jordan]

Roger,

Lots of people use an old fridge or freezer with gentle warming from a light bulb.
www.cindydrozda.com/handouts_Pdfs/handouts/demo%20handouts/drying_kiln.pdf

Also, of you can plug the front of the bowl (say with a piece of plywood and a gasket) or vessel you can put compressed air into it and blow out a lot of the free water and it will dry quicker. The other Jordan guy does this with his hollow forms - I was surprised at how much water bubbled out of the wood.

Walmart used to carry that type of cat litter. I wouldn't use it myself in fear of drying too fast. I might try it if the bottom and end grain (or maybe even the entire outside) were sealed with Anchorseal first.

JKJ

[Roger Davis TN]

Thanks guys for the information. I found 100% silica gel in Dr. Elsey's cat litter. Small grain in Senior, Medium in Respiratory relief and the largest grain in his longhair cat formula. Get it at Petsmart, Petco or on line at Chewy.com. People say this method works. I will coat the bowls with Anchorseal first, then cover with silica gel. The article says dry in 48 hours with little shrinking or cracking. https://m.youtube.com/watch?v=DaaTbDTUsg0 and https://m.youtube.com/watch?v=QpM_3uTNm5Y I will let you know my results. My old success rate is 75% of turntable bowls after air drying for a year. Thanks Roger

[Ron Borowicz]

Roger,

Sounds like it could be a solution for a bowl "that you can't wait to re-turn". I typically rough turn, anchor seal and record the weight periodically and re-turn one to two years or more later. I have on more than one occasion rough turned a crotch piece that I would like to re-turn "soon".

Just curious why you chose to use anchor seal and use silica gel? Wouldn't that just prolong the moisture removal?

As you say....please post your results.

Ron

[Reed Gray]

There is a method for using a dehumidifier, light bulb, and fan, with a moisture trap of some sort. It is some what similar to the fridge kilns. Even though I don't twice turn, it seems like a lot of extra work to speed dry when you can put them on a shelf and let them sit. Of course, some woods are a lot easier to dry than others...

robo hippy

[Roger Davis TN]

Hello Ron, I think maybe Anchorseal will give the bowl a uniform drying. I am just guessing. Maybe no seal will be better. Anyway my success rate with shelf drying is not very high. Some bowls are a little out of round others can only be scraped and sanded. I do not like to sand. I will try the kiln/light bulb in some type of enclosure also. Thanks for the reply,Roger.

[robert baccus]

Endseal (anchor seal is a brand name--there are many) all over, inside only on vases, toss in the corner and soon you will have an oversupply of dry pieces with almost no cracks. Remember the 10% thickness thumb rule.

[phil harold]

Roger,

Lots of people use an old fridge or freezer with gentle warming from a light bulb.

I use a old dishwasher and light bulb

[John K Jordan]

I use a old dishwasher and light bulb

I need to break down and build myself one of those. What wattage light bulb do you find best? Did you cut vents in the top?

I'm making a small one from a large roll-around cooler big enough to hold a 5-gallon bucket. Not for drying wood or bowls but to re-liquify a bucket of honey that crystalized from getting too cool.

JKJ

[Roger Davis TN]

I am going to use a metal garbage can with a 100 watt light bulb at the bottom. I stored incandescent bulbs before they were replaced with LED types. I also have a 150 watt reptile heater type bulb, may be too hot. I have four green bowls and will have two more tomorrow. All of them are going in for a week. I painted some with Anchorseal. I will report my findings then. Roger

[Alex Zeller]

if you don't mind spending a few extra bucks and you can do what I'm going to do. This is a Watlow brand temperature controller. I got it use off ebay for $20. While they have extra inputs/ outputs you can use them in basic form. It has a simple power cord you plug into any 120v outlet, an output (the gray wire going down to the bowl blank), and the orange wire that the end of which measure the temp. The green number is the temp set point and the red number is the current temp. The best thing is that you can set the temp low to start off at a lower temp then keep increasing the temps. Once you get a feel for how each wood dries you can come with a formula that works well. This one is set up to control a heat source up to 500 watts. It'll hold what ever temp you want (as long as the heat source can heat source is powerful enough) with in a degree or two of what you set it at. The heat source can be any 120v source. Light bulbs are getting harder to get but small ceramic heaters are easy to get. I'm trying to find a broken stainless commercial fridge or freezer to turn into a kiln.

402888

[Roger Davis TN]

Looks interesting Alex. I will check the temperature controller out? Looks like a good plan.I put six green bowls in a metal trash can tonight with a 100 watt light bulb. I coated some with Anchorseal some partially and two with nothing. We will see what warps or cracks. They are all one inch thick. Thanks for your help. Roger

[Roger Davis TN]

Alex, I found one about same price. I have 2 -150 watt reptile heaters. A controller that just cuts off will do, right? Would a ceramic heater be better with the fan? Thanks Roger

[John K Jordan]

I coated some with Anchorseal some partially and two with nothing. We will see what warps or cracks. They are all one inch thick. Thanks for your help. Roger

That's a good test but perhaps don't base your analysis solely on a half-dozen data points! The natural structure of wood varies so much you might need to dry 100 with one method to "prove" anything!

I didn't get to read the entire thread. Do you have gentle air circulation inside, some ventilation holes for moisture to escape, good separation and/or shielding so the bowl closest to the bulb doesn't overheat? Weigh before starting and periodically to track the drying?

JKJ

[Reed Gray]

Well, I don't use a kiln, and probably never will. I have never understood using an old fridge or freezer. I would think it would be easier to build a plywood box with some wire shelves in it to put bowl blanks on, and a bulb at the bottom. Convection currents should do an excellent job of moving air through the cabinet with no need for a fan as long as there is ventilation on both bottom and top of the box... Depending on woods and size of box, I would think smaller wattage bulbs would be safer to prevent more cracking.

robo hippy

[John K Jordan]

...I have never understood using an old fridge or freezer. I would think it would be easier to build a plywood box with some wire shelves in it to put bowl blanks on, and a bulb at the bottom. Convection currents should do an excellent job of moving air through the cabinet with no need for a fan as long as there is ventilation on both bottom and top of the box......

I think the idea of using a fridge or freezer is the insulation keeps the heat from escaping out through the sides. Maybe save on energy or maybe distribute the heat more evenly through the volume, I don't know.

JKJ

[Alex Zeller]

A plywood box would work just fine. Once you price out a couple sheets of plywood, insulation, hinges for the door, and wire racks it makes a free dishwasher or fridge seam more attractive. My main reason for a commercial fridge/ freezer is that they usually will be one or the other. A household fridge will be part fridge and part freezer. Household freezers often have fixed shelves. Not that it would be hard to drain the freon and make the shelves adjustable. Has anyone experimented with using a small fan to help keep the air circulating.

Those industrial heaters just turn on and off so I would think a reptile heater would work just fine. It might even work better as the industrial ones have extra settings you could mess with (but don't need to) as they can be used for applications where you want to control to 1 degree. If you know how to change a light switch you could just use a dimmer to control the heat the bulb puts out. You could use a digital oven temp meter to monitor it. I know some people just start off with lower wattage bulbs and keep going up in size but the engineer in me likes to be more precise.

[Roger Davis TN]

I only have a 100 watt incandescent bulb under a wire separation in the 30 or 40 gal can. I tried to place six bowls evenly to distribute the convection heat. There are holes in the bottom and the trouble light cord out the top crack. So far no warping after several days. The bowls were wringing wet as they were turned. I have to purchase a moisture meter or scale, which is better? Thanks for helping me, Roger.

[Alex Zeller]

I have both a scale and a cheap moisture meter. The scale is much more accurate. I'll write the weight and date on the bottom of the bowl that will get removed when I finish it. A food scale will work just fine and is cheap. If you get one with a stainless top it's easy to clean so you can use it for other things as well.

[John K Jordan]

I only have a 100 watt incandescent bulb under a wire separation in the 30 or 40 gal can. I tried to place six bowls evenly to distribute the convection heat. There are holes in the bottom and the trouble light cord out the top crack. So far no warping after several days. The bowls were wringing wet as they were turned. I have to purchase a moisture meter or scale, which is better? Thanks for helping me, Roger.

I air-dry a lot of wood blanks and I find a moisture meter good for a general check of dryness. The pin-less Wagner I use is far more expensive than a scale and can only be used on flat sides. A cheap pin-type meter can be used on curved wood. A search should show useful past discussion about moisture meters.

A scale works on anything and is far cheaper. I have several but this is one I use now when drying blanks: https://www.amazon.com/gp/product/B013WU0FUO For serious moisture testing with the oven-dry method I use smaller scales with more resolution, these: https://www.amazon.com/gp/product/B002SC3LLS and https://www.amazon.com/gp/product/B0012LOQUQ

The accuracy of the scale doesn't matter as much as having the appropriate resolution for the size of the sample - oven-dry samples can be pretty small.

A single weight tells you nothing, you need to periodically weigh the piece/blank/sample during whatever drying process you use and record the weight. When the weight doesn't change after several periods the piece is dry. When I air-dry blanks I write the weight and date on a piece of masking tape but could write it on the wood with a marker. Every month or two, depending on the thickness of the wood, I weigh again and record the weight.

I don't have experience with kiln drying but drying loads of lumber can take months. Perhaps the trashcan you use will be quicker, in which case you might want to weigh each piece every day or so. Different species, thickness, and positions in the kiln could dry differently.

You said you have ventilation holes in the bottom but don't mention the top except about the crack for the cord. I'm imagining it would be helpful to have vents near the top of about the same area as those in the bottom so the air could flow through. If you find your kiln dries too quickly and causes cracks you might adjust the wattage of the bulb or the size of the vents to slow down the air flow. Keep in mind that what works for walnut might not work for cherry, etc.

There is a lot of information available about large-scale kiln operation. There are careful tables for the temperature, humidity, and time for various species to get the best results. Maybe you can find similar parameters for a bowl kiln. If no one here has extensive experience, you might check Glenn Lucas's web site - he uses kilns for drying tons of bowl blanks. If his web site doesn't say, he might answer an email, or a phone call if you feel like calling Ireland. Also, Cindy Drozda might be a good person to ask.

Here is a good document on kiln drying if you are interested in getting an understanding of how complex it is to cover all bases:
https://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr81.pdf

JKJ

[Roger Davis TN]

Thanks Alex and John, Costco has a kitchen scale that will fit the bill. I will look up all the information offered. Tonight I worked on spalted/ punky maple bowls. Tear out is major. John I am trying to follow your use of 60 degree included angle NRS which is working great eliminating the holes. I notice that my skews look the same except for the burr. I am coating with tung oil and buffing out for a finish. I really like this look. God bless you and yours....thanks again for the help. Roger

[Kyle Iwamoto]

I built a fridge kiln, as many have already mentioned. I bought a cheap indoor/outdoor remote temp/humidity meter, and put the outdoor in the kiln. I use 40/53/72 watt bulbs (electricity, not light) I think they may be 60/75/100 watt lights. Anyways, when the humidity stops going down, I increase the wattage. For me, a week per light rating is good enough, if you want to make sure or you get old and forget, 2 weeks at the higher wattage does not hurt. I'm a weekend turner, so this is awesome. The biggest benefit is the fridge kiln also doubles as a storage locker that keeps the bugs away. At least they haven't found mine as of yet. Also a old age factor, when you open it up to load more roughs and see all the already dry roughs I had forgotten about.
I got my upright freezer free from an appliance recycler. I think they (commercial people) have to pay to properly dispose of them, so he was more than happy to help me load it up. No fan, just the cheap clamp on lamp from the Depot. From what I read, the low wattage to start helps raise the temperature slowly and supposedly less cracking. Some still do crack. I'm pretty sure that this is the cheapest alternative, and its pretty fast. Relatively I guess.

[John K Jordan]

Kyle, for those who might want to try this, could you provide some specifics? Details of what you found works for you might help someone get started.

For example, you said you use "bulbs". How many?
Are the bulbs at the bottom of the cabinet below a wire shelf?
Does the clamp on light fixture have a reflector and if so, is it aimed up?
Did you cut vents? Bottom, sides, top? Approximate area?
Do you have this in the shop or outside?

Thanks,

JKJ


I built a fridge kiln, as many have already mentioned. I bought a cheap indoor/outdoor remote temp/humidity meter, and put the outdoor in the kiln. I use 40/53/72 watt bulbs (electricity, not light) I think they may be 60/75/100 watt lights. Anyways, when the humidity stops going down, I increase the wattage. For me, a week per light rating is good enough, if you want to make sure or you get old and forget, 2 weeks at the higher wattage does not hurt. I'm a weekend turner, so this is awesome. The biggest benefit is the fridge kiln also doubles as a storage locker that keeps the bugs away. At least they haven't found mine as of yet. Also a old age factor, when you open it up to load more roughs and see all the already dry roughs I had forgotten about.
I got my upright freezer free from an appliance recycler. I think they (commercial people) have to pay to properly dispose of them, so he was more than happy to help me load it up. No fan, just the cheap clamp on lamp from the Depot. From what I read, the low wattage to start helps raise the temperature slowly and supposedly less cracking. Some still do crack. I'm pretty sure that this is the cheapest alternative, and its pretty fast. Relatively I guess.

[Kyle Iwamoto]

I essentially followed Cindys info, someone above posted the link.

I use a single bulb in the bottom. As mentioned I bought that cheapo clamp light. It has a shield, a switch and a plug. If you would price out components in Cindys page, you would need a 6 buck light fixture, an inline switch 3 bucks, box and cover about 10, plug another 3 bucks and wire. And you would need to fashion a shield for the light. For more heat, I have though of an additional light, an easy splice in. "Bulbs" meant more than 1 wattage rating. Have not had to add more heat. The single 72 watt gets the kiln over 100 degrees. I found that sufficient for my climate, since ambient "dry wood" is 12% or so here. Cooler drier places could use a pair at the end. I think for us, 100 kills all the bugs. Or maybe they just die from lack of water.

I built a small clamp stand for the clamp light, an upside down T with scrap. Clamp the light on, I face the shield and light down to keep the dried rubbish from hitting the light.

Per Cindy, drill 1/2" through holes, 5 on a side (10) at the top and same on the bottom. None on the very top as my kiln is outside. Seems to be adequate. I did have my doubts. That bit could be the most costly item, but I do have a good tool seection, so I already had one.

Easy easy build. Getting an upright freezer may not be that easy to find, that makes the build really easy. They have built in shelves, and no fridge freezer partition to deal with. I lucked out. Actual incandescent light bulbs are getting harder and harder to find. LED/CFL will not work. LOL. The bulbs do burn out, so get several. All you really need is is a cheap 6 buck outdoor thermometer to monitor the temperature. I got the temp/humidity remote monitor mostly because I'm lazy, and didn't want to open the door to look at the temperature. Wastes a lot of heat I would think. The monitor makes it easy and fun. Cheap ones run 30 bucks or so. That was the most expensive part.

That is about it I think. Good luck!

[Clint Bach]

For what it's worth... I have a STC-1000 temperature controller I tried to use on a sous vide conversion of a crock pot. It has too much lag for a sous vide crock pot (the pot not the controller) but would probably work great for a small drying kiln.

Controls heat and cool with 10 amp relays, -50 to 210 c control. Dirt cheap! Digital display.

Search STC-1000 and you get many results.

The usual, I'm not associated with any company related to this controller blah, blah, blah. Just a satisfied customer. I would buy it again.

Clint

[John K Jordan]

I essentially followed Cindys info, someone above posted the link.
...
Actual incandescent light bulbs are getting harder and harder to find. LED/CFL will not work. LOL. The bulbs do burn out, so get several. All you really need is is a cheap 6 buck outdoor thermometer to monitor the temperature.

Incandescent bulbs are still available from Amazon. I always buy the 130v bulbs instead of the more usual 120v bulbs. 130v lamps will put out a tiny bit less light/heat but can last a lot longer. I usually get "rough service" bulbs, just because. For example, https://www.amazon.com/CEC-Industries-Frosted-Silicone-Service/dp/B00JS9SAA6

Thanks for your notes. I was the one who posted the link to Drozda's page and it's fairly complete, but it's always great to hear ideas from others with experience.

JKJ

[tom lucas]

has anyone tried seedling heat pads?

[Clint Bach]

STC 1000 temperature controller.... Dirt cheap... Heat and cool 10amp relays... -50 to 210 degree C control range.... Search the net...

My previous post seems to be lost here somewhere....

Clint

[John K Jordan]

STC 1000 temperature controller.... Dirt cheap... Heat and cool 10amp relays... -50 to 210 degree C control range.... Search the net...
My previous post seems to be lost here somewhere....
Clint

Still here: https://sawmillcreek.org/showthread.php?271597-Drying-bowl-blanks&p=2897698#post2897698

[Clint Bach]

Huh... I wonder why it's eluding my browser?

Clint

[phil harold]

I need to break down and build myself one of those. What wattage light bulb do you find best? Did you cut vents in the top?

I'm making a small one from a large roll-around cooler big enough to hold a 5-gallon bucket. Not for drying wood or bowls but to re-liquify a bucket of honey that crystalized from getting too cool.

JKJ

just a hundred watt bulb
no vents
load it full
needs to dry real slow
say about two weeks

[Dennis Peacock]

I still use the denatured alcohol method for soaking and drying bowls. I've had too much success with the DNA method to stop using it. Maybe I'll have to try the other methods when I come across the right materials for free. :)

[Alex Zeller]

Too bad IPA is so expensive. Denatured is cheaper but still will add up over time.

[Dennis Peacock]

I tend to use a 5 gallon container of DNA for a year before dumping and starting over with a fresh batch.

[Alex Zeller]

I tend to use a 5 gallon container of DNA for a year before dumping and starting over with a fresh batch.

That's about $65 (from Zoro through Walmart with free shipping) for a 5 gallon jug. How many and what size bowls do you dry? How wet are they when you start? Enough of my blanks are too big to fit into a 5 gallon bucket so I've looked into something like a 15 gallon plastic barrel (old food container) with a screw on lid. Have you thought about using a hydrometer to check how much water is in your alcohol?

[Dennis Peacock]

No, I don't test it. I just use it until it doesn't work any longer and dump it. :)
I do have a large container that I put it in...which is larger than a 5 gallon bucket. I do turn several bowls every year that are too large to fit inside a 5 gallon bucket. I've also used a good heavy duty trash bag and padded the outside with shavings to make the DNA cover the bowl inside the bag. Takes less DNA that way too.

[Roger Davis TN]

Dennis, could you tell me the cheapest place to buy DNA. Roger

[Dennis Peacock]

A local lumber / building supply company near here sells it in 5 gallon cans. Last can I bought was about $64. Not cheap....but it's far cheaper for me than to end up with fancy firewood for my wood stove heater. :)

[Roger Davis TN]

Thanks Dennis, Roger.

[Alex Zeller]

I've looked into every option and I haven't found a good source to buy it local for a reasonable amount. But you can buy it by the 5 gallon can through WalMart (through a vendor called Zoro) with free shipping the last time I looked. It seamed tempting but I figured I would need at least 10 gallons and a container (like an old food grade plastic barrel) with a large sealed lid. I figured it would be about $200 to get started. I've even looked at ways to remove the water from the alcohol. Freezing seams like an easy one for me living up north. What I haven't found is a good idea as to how much you will loose per bowl. On a small scale basis it seams like a viable option.

But that's really exactly how everything is with turning. Other than the lathe and a few expensive attachments everything is a hundred or two here or there. Want to try turning something new, $100 will get you the correct tool for the job. Want to get multiple bowl blanks out of block of wood, a few hundred will get you a coring system. What tool junkie doesn't want it all right now?

[John K Jordan]

Alex, over the years there has been a lot of discussion and some controversy over using alcohol to aid in drying roughed out green bowls. Some say it works for them and that's fine. Some, like me, tried to do so fair comparison tests and saw no significant difference between the alcohol soaking and drying other methods, in either reduced drying time or reduced defects. I don't turn many bowls so admittedly my tests were not exhaustive. At one time there was so much processing with alcohol it almost reach a religious fervor - a few people got highly and vocally disturbed at any heathen who dared even question the process.

When considering the cellular structure of wood it does make me wonder how effective it can be, at least on some woods. Wood like red oak has open soda-straw pores that alcohol could easily enter. I can imagine internal free water and some bound water in adjacent cells mixing with the alcohol and being removed more rapidly as the alcohol evaporates. However, the free water will leave fairly quickly on its own - it's the bound water that can take years to migrate from the center of a thick piece of wood. And many species have their pores tightly sealed with tyloses - for example white oak, osage orange, locust - which would stop even alcohol from penetrating deeply. Others, such as diffuse porous woods such as dogwood and such, have extremely small pores, also an impediment to free exchange of liquid.

For those who have had success with alcohol soaking, I say more power to them, keep up what works. The same for those who have success with refrigerator kilns, wrapping in paper bags, the plastic bag regimen, burying in shavings, or coating with anchor seal - if it works why do anything different?

But if so inclined and if you have the time and energy for some tests I think you should try alcohol soaking for yourself. I recommend getting just a few gallons for a test rather than making a big investment. Perhaps use the plastic bag method instead of the large container dunking method. But don't just try a bowl or two and pronounce it worthwhile - how would you know if that particular wood and bowl geometry would have behaved differently if dried a different way?

One way to experiment: Make four or more roughed bowls from the same wood and store in water or plastic bags until ready for the test. Soak two in alcohol and dry two or more in other ways and compare the differences. For a more complete test, rough out a single bowl (or two) with thick walls and cut four quadrants, each with the same amount of end and side grain. Soak two, dry two another way. (The more data points, the better.) After some time cut a small sample from the center of each and use the oven dry method to determine the actual moisture content. This won't prove that one method will result in less loss from cracking and such but it might provide a good handle on how dry the wood is on the inside.

If you want a sure, time proven method to reduce drying defects and speed up drying you might consider boiling. An acquaintance who exported many bowls and blanks from Peru said without boiling he would not have a business. They boiled every bowl in 55 gallon drums over wood fires. Respected turner/teacher/writer Steven Russell investigated this years ago and wrote "Boiling Green Wood Overview: In the summer of 1999, several of my Internet woodturning friends urged me to begin a comprehensive series of timber drying tests. My goal was to reduce drying defects to the absolute minimum and to discover faster and more efficient ways to accelerate the drying process. This first article on boiling green wood will profile the results of my continuing drying tests with bowls, platters and hollow forms." His web site is gone now, only available on the Wayback Machine archive, but I have downloaded many of his articles and could email that one if you want it.

Some people still use boiling but I don't hear much about it these days. I suspect one reason is it's more trouble than many methods - you have to have a suitable container and heat source, work outside, and invest some time. There is the safety associated with fire and boiling water, even outside. And a few unthinking people have discovered to their dismay and injury that a round bowl the same diameter as the inside of a turkey fryer can plug the container and cause it to explode from trapped steam, spraying scalding water. Don't do that!

If you do decide to use alcohol, have fun. Keep in mind the real hazards of storing and working with large amounts of highly flammable liquid in or near the shop. And one other thing about denatured alcohol - read the MSDS sheet for any brand you might purchase. In recent years, I've noticed a trend for processors to mix methyl alcohol with ethyl alcohol, presumably to stretch it out and make more money (methanol is cheaper than ethanol). However, methyl is toxic. Read up on the difference. It is recommended to use gloves since it can be absorbed though the skin. I was surprised to find that one brand of DNA I've bought for years suddenly and quietly switched formulas to includ a huge percentage of methanol.

For me, I find a certain zen satisfaction to slowing down and letting things dry with time. In the larger scheme of things, what's a few months for a roughed bowl to dry? I'm turning wood blanks now drying since I cut them green, some in 2006 and earlier. These are small compared to big bowl blanks, of course, or they would be mostly firewood now.

JKJ


I've looked into every option and I haven't found a good source to buy it local for a reasonable amount. But you can buy it by the 5 gallon can through WalMart (through a vendor called Zoro) with free shipping the last time I looked. It seamed tempting but I figured I would need at least 10 gallons and a container (like an old food grade plastic barrel) with a large sealed lid. I figured it would be about $200 to get started. I've even looked at ways to remove the water from the alcohol. Freezing seams like an easy one for me living up north. What I haven't found is a good idea as to how much you will loose per bowl. On a small scale basis it seams like a viable option.

But that's really exactly how everything is with turning. Other than the lathe and a few expensive attachments everything is a hundred or two here or there. Want to try turning something new, $100 will get you the correct tool for the job. Want to get multiple bowl blanks out of block of wood, a few hundred will get you a coring system. What tool junkie doesn't want it all right now?

[Peter Blair]

Reed that was what I thought as well until I found a free upright freezer. The advantage that I see over plywood is that the plywood might hold moisture and it's inability to insulate to help maintain temperature. The freezer I found has great shelves so I didn't need to add any only removed the cooling equipment cut holes low in each side and one in the top all which have a small circular pad that I can rotate to limit the amount of air movement. I installed a ceramic light fixture and have lots and lots of light bulbs. I presently just use a 60 watt and weigh items two days in a row prior to turning them. If their weight doesn't change overnight the are ready to return for finishing. Works great for me here on the Wet Coast of BC.

[Alex Zeller]

I will be the first to admit that I don't like to wait. I get an idea in my head I want to try it. I have a number of bowl blanks that are drying but their shape is what I felt like at that time. Last week I decided to turn a box using a blank that I had sitting around. I cut into a round shape on the bandsaw and covered the end grain. The tree was one that snapped about 20' up off the ground back in fall of 2017 so a lot of the moisture was gone. I would love it if I had lots more blanks like this but most of what I have are like the sugar maple that I cut a couple months ago and is sitting in a snow bank. There's too much gravel on it to cut blanks off of it without hosing it off first. I did cut a couple (which required stopping several times to sharpen the chain). When I turned them into a bowl blank water was flying off of the blank as it spun on the lathe. Each time I see the log (actually it's almost a whole tree) I see all the potential it has. Once it warms up around here I should cut up all the blanks I want, protect them, and find a good place to store them. At the same time a part of me is going to say "waiting sucks".

I've looked into almost every way I could find on the internet to speed up and the success of getting a good dry bowl blank. Each has it's pluses and minuses. Boiling seamed interesting but a fair bit of work. I didn't look too far into it but it sounded like you turn the blank then boil it as quickly as possible. That would mean getting a fire going and trying to time when the water started to boil and when the blank was ready. It seamed like if you could do a half dozen blanks at a time it would make more sense. What would happen if you turned a bowl blank and then submerged it in the pot in just water and left it while you made the next blank. Then when you got 5 or 6 start the fire to bring the pot to a boil?

I've used the microwave to dry bowl blanks but found it doesn't really work well on wood that's really wet. But that's with only limited experience. I like the kiln idea and even hoped if I made one I would experiment with steam. Not sure if that would be practical as I have no clue how long the steam would be needed. Steam also changes the color of the wood. I work on semiconductor equipment and a lot of what we do is with vacuum pumps and RF equipment so vacuum drying sounds kind of fun. We've thrown away several pieces of equipment (pressure chambers made out of thick aluminum with channels for heating) that would of made a great vacuum kiln.

In the end it comes down to simplicity and what woods you work with often. A homemade light bulb kiln where you only need to check on it once every couple days sounds very simple. An alcohol dip that you can let them soak for a week seams like pretty easy way to go too. If anyone does try the alcohol approach I would recommend using something like an extra long glove rated for solvents like alcohol and a chemical respirator with the correct cartridge. I've never done it but I could see opening up the cover and getting hit with the fumes.

[John K Jordan]

I've looked into almost every way I could find on the internet to speed up and the success of getting a good dry bowl blank.
Boiling seamed interesting but a fair bit of work. I didn't look too far into it but it sounded like you turn the blank then boil it as quickly as possible.

Do you mean you want dry to thick green unturned bowl blanks then turn them dry? Or do you mean drying roughed out bowls instead of "blanks"? Big difference.

You may never dry a large unturned dry bowl blank successfully. Some chunks will say wet inside for years and crack like crazy as they dry and shrink, depending on the species. I have successfully dried some bandsawn round bowl blanks (up to about of 8-10" in diameter and maybe 6" deep) of a fairly stable species, sealed all the way around - have a couple on my shelf now maybe 12 years old, no cracks. Burls seem easier due the reinforcement from the twisty grain.

Blanks cut from a standing dead tree are sometimes fairly stable (if not full of bugs). The sap and a lot of the water is gone. I read that some tropical species are harvested that way - girdle the tree to kill it then cut it down a few years later. One trick at the sawmill is to stand planks on end to let the water run out before stickering.

You can easily dry roughed-out bowls with various techniques but the best bet I know for drying the whole blank is to boil the blank a good long time then dry slowly. The heat from the boiling apparently softens the lignum so it can dry and shrink without cracks. I was told by the dealer that a big block of Pink Flame I got from Peru was guaranteed to self destruct without boiling. (Instead I cut it up into small pieces which could dry OK) Madrone blanks are often boiled or steamed for the same reason - madrone will otherwise warp and twist and pucker and boiling prevents that (unless you like that, of course some do). All the madrone stock I have has been boiled.

You don't have to rough turn a bowl then boil it quickly. You can toss the rough turned bowl into water (completely submerged) and it will keep indefinitely as long as you occasionally change the water in warm weather before it gets nasty. You can look up "ponding", works as well on blanks that have been turned as it does on logs or chunks of wood. Timbers recovered from the bottom of cool lakes are still like new after many decades in the water.

After you accumulate enough roughed bowls to make it worthwhile, boil the whole batch. If you store them in a 55 gal drum full of water then boil them in that drum. You can put a roughed bowl in plastic to keep it wet for a few days - longer if you keep it cool. You can wrap in plastic and store in a chest freezer for a long time. I tested a blank like this and it was still fine after five years. I've had another in a freezer for about 10 years now I need to pull out and test.

Another way for the impatient to get dried roughed out bowls quickly is to buy them. Our club got hundreds from an estate of a local man who loved to rough-turn bowls. These are years old and well dried. Every year I auction a bunch off at a special club meeting. I bought a couple myself 14-18" in diameter.

JKJ

[Alex Zeller]

While I was waiting for delivery of my lathe I cut up some blanks with the chainsaw and then turned them round on the band saw. Those got a couple coats of end grain sealer. The tree sat down on the ground for 8 months before I did a thing with it other than lifting it off the ground. Around here most trees can sit on the ground for a year without bugs becoming an issue. The blanks were probably 6" to 8" thick and up to 12" diameter from the cherry tree and 8" thick and 16" diameter on the yellow birch. After about 2 years the MC was around 20%~25%.

Now my blanks go from the log, to the band saw, then to the lathe within hours then get dried. I normally will get two blanks from a round (do turners call short sections of logs rounds like we do with firewood?). I prefer not rough turning dry blanks. It feels harder to me, it's dusty, and I find I'm touching up the tools much quicker. But I do like to be inspired to try to do something and being able to go from log to finished form. I'm really hoping that once the club president returns from wintering down in Florida and the club meetings move to his house (a half hour from me) I can get to some. I'm sure I'm doing plenty of stuff the hard way and missing opportunities on how to turn something a different way.

[Thomas Wilson80]

You may never dry a large unturned dry bowl blank successfully. Some chunks will say wet inside for years and crack like crazy as they dry and shrink, depending on the species. I have successfully dried some bandsawn round bowl blanks (up to about of 8-10" in diameter and maybe 6" deep) of a fairly stable species, sealed all the way around - have a couple on my shelf now maybe 12 years old, no cracks.

JKJ

oy, I wasn’t aware of this.....I just got a larger bandsaw and am planning on getting my big lathe at the end of the year but was going to start making 15-18” round blanks (no pithe of course) in preparation. Obviously wouldn’t be able to rough turn.

Would blanks this size of walnut, maple, sycamore, or other common hardwoods not last if I cut them round, sealed end grain and stored in cool basement?

tom

[John K Jordan]

oy, I wasn’t aware of this.....I just got a larger bandsaw and am planning on getting my big lathe at the end of the year but was going to start making 15-18” round blanks (no pithe of course) in preparation. Obviously wouldn’t be able to rough turn.
Would blanks this size of walnut, maple, sycamore, or other common hardwoods not last if I cut them round, sealed end grain and stored in cool basement?


I don't know. I've only stored and dried a few blanks that size, one from Yellow Poplar and a few from soft Maple. As I mentioned in the message, I've had success in drying somewhat smaller round blanks from some woods. I usually don't turn large bowls I have no incentive (or the space!) to store a bunch of large blanks. I do cut large blanks for others but they turn them green.

Cutting them round does seem to be an improvement in some cases over leaving them square and certainly an improvement over leaving them in log form, even logs that have been sliced down the middle to remove the pith. As noted, I have some on my shelves that are still fine after over 10 years. I have no idea of the moisture content but I could measure with a pinless meter if needed.

The size might matter but more important are getting the pith and the nearby juvenile wood out of the blank. In some species removing the sapwood is a big help too. Rectangular blanks from some species have survived like this. Walnut is particularly stable, as is soft maple. Some other blanks, even much smaller, have cracked horribly, even some from the same species. For example I have two identical fairly large sycamore box blanks cut just a few months ago - one is fine and the other has a split down the side. For those that fail it may be there were invisible cracks or defects in the wood to start with or that particular part of the tree had more internal stress or tendency to shrink unevenly.

I usually seal blanks only on the end grain but for figured wood and bandsawn rounds I like to seal the entire blank (with Anchorseal). The moisture gradient inside the block creates the most stress - moisture escaping from the surface causes shrinkage at the surface in both end grain and side grain. If the inside is wetter, it shrink at the same rate so the wood checks and cracks to relieve the stress. Sealing all over helps slow the moisture escape at the surface enough to let the moisture migrating from the very center migrate to the outside and the entire blank slowly shrinks. That's why many wood dealers, especially those who sell exotic woods, dip the entire blank in paraffin wax.

Keeping the sealed blank in a cool or cold place helps slow the moisture escape too. Wrapping in plastic wrap and freezing works well. Or as mentioned before, just keep the entire blank immersed in water. (ponding) Your 18" blanks would keep fine, especially if the water was kept cool and changed before it got nasty.

However, the best advice I've heard from the experts is if you like to turn green wood simply don't collect wood until you are ready to turn! The usual advice is to not bring home more wood than you can process and turn within a couple of weeks. If you live where trees grow there is usually more wood available than you can use all year around.

So many people have gotten excited and accumulated piles of wood which just took up space until they fed the fireplace. The other John Jordan, the famous one, said he only turns green wood. He likes to get the entire log even if he has to pay to get it delivered, and stores it in the shade off the ground. Logs can stay in good condition for a long time like that unless you live in the desert - the bark helps to keep the outside from drying too fast and splitting. When he's ready to turn something he cuts about 6" off the end and throws it away then cuts a chunk big enough to turn.

I don't work like that since I prefer to turn dry wood and usually smaller things - most of the blanks I dry are for spindles and boxes and such, 4" square or less. Since you have a good bandsaw now and you might do the same. Smaller blanks are great for turning many things and good to give away or trade too. And if years from now you decide to turn smaller things you'll have a good stash of dry wood!

404441

I'll try to get some pictures of the types of larger blanks currently on my drying and dry shelves.

JKJ

[Alex Zeller]

oy, I wasn’t aware of this.....I just got a larger bandsaw and am planning on getting my big lathe at the end of the year but was going to start making 15-18” round blanks (no pithe of course) in preparation. Obviously wouldn’t be able to rough turn.

Would blanks this size of walnut, maple, sycamore, or other common hardwoods not last if I cut them round, sealed end grain and stored in cool basement?

tom

I'm certainly not an expert. I probably could have waited but a part of me wanted to jump right in. I had a couple trees down that I really didn't want to sit any longer than they had to. Plus I knew there would be a learning curve with cutting the blanks with a chainsaw and the band saw. I put two heavy coats of end sealer on the curved parts of the blanks and left the flat part uncovered. This is about 20 cherry blanks. None of them cracked. One of the 4 yellow birch blanks I made did crack.
404454

Where are you getting your wood? Is it standing trees you are planning on cutting down? If so then I would wait. If it's from logs then maybe you could get them off the ground and put end sealer on the logs and wait. Ponding sounds like an interesting idea as long as you don't have too many otherwise you might actually need a pond to hold them all.

[Thomas Wilson80]

Thanks for the replies and info John and Alex.

I will be visiting my in-laws in TN/NC in a couple of weeks. They live in the mountains and have had a lot of trees come down recently so I wanted to bring back a load of half-cuts and round them on my band saw and store until the end of the year.

Last winter I brought home 6 half-logs of black walnut and sealed the ends and faces and stored in my garage (large temp swings between summer and winter). I was only able to use 3 of them within a couple of months before the remaining 3 split (admittedly, I had only cut through the pith and hadn't removed the actual pith or the area around the pith - live and learn).

Here's a couple of those bowls turned on my jet 1014 (about 8.5 and 10 inches in diameter):
404457404458
Not the greatest bowls, but my first wet turnings. It was so much fun to turn wet and I learned a lot (is the brown streaking in the sapwood in the top of the natural edge bowl from sanding across the bark or is that part of the wood?)


I think I'll bring as much wood as I can fit again and give it another try - this time cut out the whole pith and round on the bandsaw before sealing and store in more temperate basement. We'll see what happens. Can't go wrong with free wood, right?

Thanks,
Tom

[Jeffrey J Smith]

My name is Jeff, and I’m a boiler. I started boiling about 15 years ago, just after I started turning seriously. I don’t understand the idea that its a pain, or time consuming. I bought a very large aluminum stack pot - its 24” diameter and 20” deep - can’t remember how many quarts. Heat is a jet burner from a turkey cooker. It takes about 10 minutes to setup.

On roughing day (I tend to spend a couple of days roughing when I do it...) the pot gets setup, preprocessed blanks are all stacked up, usually band sawn to roughly round. They go on the lathe, get roughed to outside shape, then cored with the Macnaughton. As the cores come off, each is reversed into the base and a tenon gets turned. Throw it into the boiling pot. Its right outside the shop doors which are usually open when I’m roughing. I only shoot for three cores from each blank

Depending on the size of the blanks, the pot holds between 10 and 15 blanks. That’s about a days work for me. If I’m unusually energetic, the pot can get filled twice, but...Usually, everything stays in the pot, slow boiling merrily away while the shop gets cleaned up and ready for tomorrows session. last thing I do is take everything out of the pot and stack it on edge on the shop floor or, if there’s too many for my shop space, on a piece of 2x12 on the gravel driveway just outside the shop to cool. By now its usually dark and I’m ready for a good meal and an adult beverage.

After a couple of days, the blanks are sticker stacked rim down with good air movement on wire shelves where they live until I’m ready to finish turm them - sometimes a couple of weeks, sometimes they’re there for months or even years. Some get turned to finish immediately if I can live with some movement/warpage.

The point is that altogether the boiling process adds perhaps 20 minutes total to the days routine (8 to 12 hours) from setup to take down. The only part thats even mildly troublesome is disposing of the water/extractives sauce that remains. We do live in the woods, and I’m pretty sure it does no environmental harm, but a pot that size gets heavy. I do stir the pot once in a while - a good excuse to take a short break and stretch a little before getting back to work

My wife has used the extractives to dye wool and some other fabric from time to time - usually a nice deep shade of reddish burgundy results (I turn a lot of local madrone and maple) we call it tree-hugger brown.

Perhaps I’m different from everyone else, but I can’t see the obsession with saving time. This has become part of a very enjoyable process for me. I look forward to getting new wood to rough out. The turning allows me to try different grinds, tool presentations, etc. without destroying anything too critical. I seldom lose a blank to cracking (unless I’ve done something stupid (read teaching moment) or skipped a step in the process. What’s the hurry - enjoy the prcess.

[John K Jordan]

...I put two heavy coats of end sealer on the curved parts of the blanks and left the flat part uncovered. This is about 20 cherry blanks. None of them cracked. One of the 4 yellow birch blanks I made did crack. ...


I don't see where you said how long they have been stored. (Tom wants to store his for almost a year). Storing them in a cool place may help.

A huge factor that can't be determined ahead of time is the actual tree. I've had cherry, for example, that cracked in to weeks. Cherry rounds from another tree refused to crack no matter what I did - I had one outside in the sun for years and it refused to crack. Making lots of blanks would be good insurance for any wood.

JKJ

[Reed Gray]

With my once turned bowls, the DNA did nothing except make the wood harder to sand out.Soap soak made the wood a lot easier to sand out.

robo hippy

[Alex Zeller]

.....I will be visiting my in-laws in TN/NC in a couple of weeks. They live in the mountains and have had a lot of trees come down recently so I wanted to bring back a load of half-cuts and round them on my band saw and store until the end of the year.

I think I'll bring as much wood as I can fit again and give it another try - this time cut out the whole pith and round on the bandsaw before sealing and store in more temperate basement. We'll see what happens. Can't go wrong with free wood, right?

Thanks,
Tom

If it's free then I would take as much as I could. If you are going to cut it while there I would cut the pith out with the chainsaw and then seal the end grain. Last fall I was down in Charlotte and a friend gave me a Walnut and Pin Oak stump. He had cut it months ago and it was sitting next to his firewood. Both were smaller trees. Even without any sealer I was still able to make him several bowls out of them.


My name is Jeff, and I’m a boiler. I started boiling about 15 years ago, just after I started turning seriously.........

............What’s the hurry - enjoy the prcess.

Thank you for the detailed information. It's a pain for me because it's 3 degrees out right now. From December to mid March is hit or miss on temperature. It does seam like an interesting option. I have a stream on my property that I could easily make a small pond to store the bowl blanks until I have enough to fill a pot. I don't have a turkey fryer but I'm sure I could find one to borrow for a day. How long do you leave them in the boiling water?


I don't see where you said how long they have been stored. (Tom wants to store his for almost a year). Storing them in a cool place may help.

A huge factor that can't be determined ahead of time is the actual tree. I've had cherry, for example, that cracked in to weeks. Cherry rounds from another tree refused to crack no matter what I did - I had one outside in the sun for years and it refused to crack. Making lots of blanks would be good insurance for any wood.

JKJ

I still have a few blanks that I haven't turned yet. I forget exactly when I did it last winter/ spring but we still had snow on the ground so probably March. I would guess that they sat for 4 months before I started turning them. I used one to make a box with last week and it's moisture content was under 20%. I kept them in my basement so cool and dry.