Wet Sanding

[Fred Belknap]

I see the term used quite frequently with the inference that everyone knows what they are talking about. I have tried different ways of wet sanding with less than stellar results. I mostly end up with a mess and ruined sandpaper. So for me and maybe another one or two I would like to start a thread on wet sanding.
What is wet sanding, water, mineral oil, mineral spirits, tung oil etc.??
How do you do it? Do you apply the wet to the piece and then sand, or in general how do you get whatever you use under the sandpaper?
What grits do you use wet sanding?
What is it's advantage if any over regular sanding?
Does it fill up open grain and minor defects in the turning like some tear out?
Do I need a special kind of sandpaper?
What is the effect on the final finish that is applied as can I apply an oil finish after wet sanding?
Dang I didn't know how much I didn't know. I might even have a few other questions. I was sanding a Cherry NE bowl and the thought crossed my mind, "There has got to be a better way."

[William Tanner]

Good questions Fred. I'll be watching for the answers myself.

[Richard Coers]

I started out by listing these answers, then realized that there are two kinds of wet sanding to describe here, based on your questions. One to sand in a thin oil to form a slurry, then the other is to level or remove orange peel defect from a film finish. Never wet sand raw wood, unless it is with oil, for an oil finish.
1)all of those except tung oil. Well some oils can be wet sanded into the wood when applied, but not used for wet sanding a film finish.
2) dip the sandpaper in the liquid, or spritz bottle
3) 400 or 600
4)sandpaper last longer, lets you get on the finish before it is completely cured, and finish "dits" won't build up on sandpaper
5)fill tear out? not even close.
6) silicone carbide (black), or anything that says wet/dry on the back
7) wet sanding is usually reserved for sanding a film finish only, not wood. You can sand in a coat of thinned oil, WATCO was an advocate of wet sanding up a slurry of finish and sawdust to fill pores, but they better be small pores.

[Dennis Ford]

I have done "wet sanding" with water.
* Wet the paper and the piece, use enough water to keep it wet (it is very messy)
* It allows you to rough sand a piece that is turned to final thickness while wet (before it warps)
* It will not fill defects (wet sanding with oil is a completely different process and may fill some minor defects)
* cloth backed paper is better but not necessary
* my method using water requires the wood to be dried and final sanded later before finishing (no effect on finish)

[Tom Wilson66]

If you are wet sanding wood with lots of water, you will get a mess. Most wet sanding refers to sanding "plastic" pen blanks or waterproof finishes, such as lacquer. This is to keep the heat down while sanding these materials. On these wet sanding can get a mirrorlike finish.

"Wet" sanding on wood might refer to lightly moistening the wood surface before using the final grit to raise the grain to get rid of small fibers which will show up when the wood dries. But this is usually called "raising the grain". This is typically done when using a water based finish.

If it is compatible with the finish, you can use wax and mineral oil as a lubricant to reduce dust when sanding wood.

[robert baccus]

Good question Fred. In my misspent youth I painted cars and hot rods and they were always wetsanded with slightly soapy water and waterproof 220-440 grit. This was followed by wetsanding the finish laquer with 440 and buffing with liquid compounds and then wax. Applied this to woodworking and found that green wood, dry hard tropicals and especially dry laquers, shellacs wet sand very well with soapy water. Oil finishes get really pretty wet sanded with finish oils(messy). Tropicals with a lot of oil, heart lighter pine ect love it. The advantages are your paper stays clean, fast cutting and does not seem to scratch. If it gums up use more liquid and yes it can be messy. Helps much if you have a variable speed lathe. WS on laquer or sanding sealer I use only good quality sanding sponges, the 1/4" 3M is my favorite in medium and fine. For a semigloss finish I merely follow with a scotch-brite and good wax. For a gloss 3 minutes with an auto compound & wax on the lathe and you are finished. On unfinished wood you may have to scrub the goop from the open pores. Just my experience.

[Marvin Hasenak]

I wet sand walnut and most other woods that have large pores that need filling. I dry sand to about 500, and then I soak the item in oil, either teak or Tru-Oil, then sand using the next grit. I add oil as needed as I sand with 600 grit to create a sludge or slurry always keeping it in a muddy state. After I figure I have sanded enough I let the sludge sort of dry, then add a little oil and slowly hand rub the oily sludge mess into the pores. I wait 24 hours and I usually repeat the process the again wait 24 hours. Next step is apply a coat of oil and lightly wet sand with 800 grit trying not to sand back to bare wood. Wait 24 hours and repeat the prior step, wait 24 hours and then apply another coat of oil.

For some wood with large pores I dry sand to 500, then I start the wet sanding with 320 or 400 grit and go through the above steps. In a few cases I start with wet sanding, and sand all the way through the grits all in one setting. Leave the sludge on and let it dry for 24 hours, then wet sand starting at 600 grit and wipe it down and let dry for 24 hours. Then hand rub in a a coat of oil.

The 24 hours is what I can use, I live in a low humidity area with pretty nice weather. Your time may vary up to a week. Also the age of the finish can affect drying times, old finishes sometimes take forever. This is not a fast finish process. For more info Google "Frank Whiton gunstock finish".

[Roger Chandler]

Great thread, Fred..........I hope to learn a good bit from the responses. I hope John Keeton will post here.......he wet sands often and his finish is usually flawless and high caliber.........

Calling John Keeton........Are ya' listening John? :D;)

[Reed Gray]

Well, our illustrious AAW president Dale Larson sands out all of his bowls with walnut oil. Paper lasts longer, and there is no dust. The oil keeps the paper from clogging up. Mike Meridith of The Doctor's Wood Shop also does this. You can get some build up on the abrasives, but they will clean up easily with the eraser sticks, and the abrasives are almost as good as new. I don't really like it because it takes more time, and I tend to get the slurry all over the place. However, I can manage to get dirty in a sterile room.... Mike also likes it for oily woods like cocobolo. No dust, and it cuts well, and again, the sludge that builds up on the abrasives cleans off easily. This is done with the entire range of grits. I did find that the sludge would work into some of the defects, like tear out to the point that I could not see them and I never got them sanded all the way out and had to go back. I am guessing that is some thing I would get better at if I did it all the time. This is the rough sanding method. Finishes can also be wet sanded and leveled using water, soapy water, and oil.

robo hippy

[Vince Welch]

Hi Fred,
Good questions! For as many people turning and sanding there is probobly as least as many different ways to sand and finish a piece. In reference to your questions...
1. On a bowl or platter I wipe oil on the piece I am working on before I begin to sand with my lowest grit. Some folks condition the piece before they take therir final finishing cut with their cutting tool "IE gouge". This helps with tearout, crossgrain and overall helps me get a good sanding surface as I continue my sanding process. This also helps keep dust down but it does clog the first sanding disc. Not to worry this can be corrected with compressed air or a rubber crep block. Also once the residue drys it just crumbles off the next time you use the disc. I think of it like this... when I shave I use something to condition my face...why?... because I know from experence I will get a better shave. So with that in mind why my "condition the wood fibers" you are shaving off the surface! I generally only do this with the first grit I use. It may seem a bit extreme but hopefully you get the point and I can tell from experience doing this will greatly reduce your continued sanding as you will not struggle cleaning up trouble areas.
2. On smaller items I may dip the discs in water if I am working with acrylic. I also have a spray bottle close at hand.
3. Depends on the application.. pens and small items I might wet sand through all the grits with either my BlueFlex or my BlackFlex discs. The Blackflex are a Silicon Carbide (SC) which is a sharper discs great for hard surfaces and hard finishes such as poly or laquer. YOu can wet sand in between coats.
4. Wet sanding helps keep things cooler. Years ago people were using SC and dipping it in wax. That works well because the wax helps the discs stay cool and because SC is a harder more brittle mineral the grainial will fracture faster when it becomes heated. Again, wax helps keeps things cool.
5. I would be thinking of filling in with sanding.
6. WnD/Black material works or a film backed abrasive also works well. CLoth back works but generally does not go up to 2000 or 2500 grit. Paper is your least expensive option and the backing tends to tear because it is usually a cotton blend.
There is alot of misinformation concerning sanding and finishing. I talk to hundreds of people concerning this topic and I am producing a DVD that will discuss much of this and more. I am hoping will be completed in the next 8 weeks. As always reach out to me if I can help you more. Thanks, Vince

[Fred Belknap]

Thanks guys, and great response. I like the idea of wet sanding, less dust and hopefully less time. There seems to be two types of WS, bare wood done with oil as Vince has described and WS a waterproof finish like lacquer with water and/or soapy water. I realize there is many ways to sand and I'm looking for a better way. You have given me some good tools to work with.
Vince your method would seem to work best with what I do which is mostly bowls and hollow forms. You said you use an oil with the lower grits, is it a drying oil like tung or Antique Oil, or a slower drying oil like BLO or mineral oil.
With my method of dry sanding it seems like I will sand through the grits and when I get to the higher grits I see tool marks I didn't see at lower grits so back down to the lower grits and start over. Seems like I spend hours sanding with the DC,window fan and pressure type face shield going. I don't like to compromise on a finish but sometimes I do.
Again thanks for the great ideas.

[Greg Bolton22]

Vince,

Put me down for the first copy of your DVD!

Greg

[Faust M. Ruggiero]

I wet sand any once turned pieces I think will change texture after drying. For example, a burl will form lots of little indentations when it dries. Imagine trying to sand madrone burl after it dries. I use foam backed pads that I buy by the foot from 80 grit through 320 grit. The foam backing holds the water. I sand on the lathe and lay a piece of plastic across the bedways to protect them. I keep the speed low enough not to sling the water, even though I usually have a streak up my front and face mask. It's only water with a bit of wood dust. The water process makes the abrasive last longer and cut faster. If I want to sand past 320, I go to Abralon up to 1000 grit.
The other wet sanding process I use is to sand a lacquer finish with mineral oil. I use oil because it slows down the cutting process and makes it more gentile. I use wet/dry paper with a pad for flat surfaces and Abralon for bowls.
faust

[Harvey M. Taylor]

Vince, put me down for your dvd. Hpw will I know when it is out? Max

[Mike Meredith]

Fuast, I have the same streak on my jacket. I've started putting a strip of clear food wrap on the lathe shield i use for demonstrations to keep from ruining the plexiglass. The idea of using a sanding lubricant is old as the hills, at least some of the younger hills. Wet sanding for metal and plastic is standard procedure. With the rise of the resin turning material (Alumalite is the one i prefer) the little used, but essential, method will become more common. With resins, water is an acceptable lubricant, though oil has a greater heat capacity. For wood, I find, as my grandfather did, that an oil lubricant allows you to sand at a higher speed without heat checking, and sand more efficiently. We forget that sandpaper is a cutting tool (the 80 grit gouge). The sawdust trapped in the oil becomes a burnishing compound so we are cutting and polishing at the same time. During demonstrations, I routinely sand a surface with walnut oil lubricant and ask an observer to touch the piece and tell me what grit of sandpaper I used. The answer is always 400 or 600 grit. The correct answer is always 220 grit. With a sanding lubricant, we can sand faster and more effectively, and who likes to sand. A second, equally important, point is that it keeps the dust our of the air and out of your lungs. I would never use cocobolo or ebony in a public demonstration without the sanding oil. Even padauk can be sanded without sneezing.

[Michael Stafford]

I frequently "wet sand" the end grain of exotics with wax as a lubricant. But when I don't have any wax I use water and the results are almost as good and cleanup does not require a solvent to remove the sanding sludge. Water is certainly cheaper. When you are through sanding you will need to wait for the surface to dry and remove any fine hair/raised grain that might pop up but that is usually easily done with a quick swipe with some very fine paper or a 3M pad.

I saw Richard Raffan wet sand ash cross grain boxes with water because the dust was irritating him.

I have tried mineral oil and walnut oil for sanding and both worked just fine. You just have to remember to remove the sanding sludge between grits or you will go backwards with your scratches.

Personally I prefer wax as a sanding lubricant because of how effective it is in picking up the sanding offal and keeping it out of the air. Your final finish has to be taken into consideration when using a lubricant. Most solvent based finishes, not alcohol based, can be used over the residues left by most waxes. Sometimes the wax residue can interfere with lacquers. I always try to wipe out as much wax as I can before attempting a finish. On exotics such as cocobolo, kingwood, tulipwood, etc. wax can be the final finish as no other topcoat besides some microcrystalline wax is really needed.

[Reed Gray]

Well, as far as making the sanding easier, the few times I tried it, I didn't notice any difference. This is most likely because I use the soap soak, which acts as a lubricant even when it is dry. It really makes a bid difference. With an efficient sanding hood, there is no escaping dust.

robo hippy

[Stew Hagerty]

OK, to start with, I am not a turner.

BUT... I have wet sanded many of my projects.

I tried wet sanding with water, but was not very happy with it. The I discovered a secret wet sanding weapon: Paraffin Oil

It's designed for use with pumice and rottenstone but it sure works great with wet/dry paper. It's thicker than water and really slippery, yet at the same time it it's sort of "sticky". What I mean is, it seems to want to cling to the surface and the sandpaper. But it is also quite slippery, and so it makes wet sanding extremely easy, clean, and produces wonderfully glass smooth results. When I'm done, a quick wipe with a soft dry cloth cleans everything up.

I use Behlen Paraffin Oil. If I remember right, I've gotten it from Rockler and T4WW, but you can get it pretty much anywhere they sell Behlen products.



All that said, I have absolutely no idea how it would work on a lathe.

[Wally Dickerman]

Well, I'll have to say that I'm surprised at the different answers about wet sanding.

I've been wet sanding for almost as long as I've been turning. Way back in the 50's when the NRA sold thousands of military Springfield and Enfield rifles for $15 there were many people "sporterizing" them. As a sideline I made quite a few custom walnut stocks. I finished them with oil, wet sanding each coat until the pores were level full. It occurred to me that that might work on my turned bowls. It did and I've been doing it ever since.

I only wet sand with the first grit and it's hand sanding. I very seldom power sand. I use the same oil that I'm using for finishing. The results are so good that I'm surprised that not everybody does it. Cuts my sanding time considerably. It's sometimes amazing how easy it is to quickly get problem wood smooth with a minimum of scratches. If I have a small problem area I stop the lathe and hand sand with the grain, using oil.

[Roger Chandler]

Personally I prefer wax as a sanding lubricant because of how effective it is in picking up the sanding offal and keeping it out of the air. Your final finish has to be taken into consideration when using a lubricant. Most solvent based finishes, not alcohol based, can be used over the residues left by most waxes. Sometimes the wax residue can interfere with lacquers. I always try to wipe out as much wax as I can before attempting a finish. On exotics such as cocobolo, kingwood, tulipwood, etc. wax can be the final finish as no other topcoat besides some microcrystalline wax is really needed.

Mike........may I inquire what type of wax you use most of the time when sanding? I have regular paste wax like one would use on hardwood floors and renwax........I have seen Carl Jacobson use wax when sanding, but he never states in his youtube videos what kind of wax he uses. I like the idea of keeping the dust out of the air and getting better results..........any help is appreciated!

Do you mix it with mineral spirits or anything else to thin it?

[robert baccus]

Like Wally I am amazed at all the methods used. One thing I strongly recommend if you are sanding with water is to add a small amt. of liquid soap. Won't make your wood any cleaner but breaks the surface tension and makes the water wetter and floats the dust--sorta makes a lather and lubricates. Gee you guys love to sand--cool. A hollow form here gets 3-4 minutes of 80-100 grit, the same with 180 and finish with 220--all power sanded on a spinning lathe. Torn grain may get a bit of handsanding. This is for a SS and Laq. finish and 3 minutes of wet 220 to level the laquer. I have quick changes on glueblocks and frequently get a daisy chain going of 4-8 pieces and there's always a dry one ready for something coming around. Any foulups go to the end of the line.

[Vince Welch]

Hi Fred,
I suggest using something that is plentiful and nothing real expensive. Mineral oil, Antique oil, whatever as long as it is not something that is going to get gummy or hard real fast. Again the goal is create a surface that allows you to sand/remove your project surface tear out, deep scratches and tool marks.

Addressing your marks/scratches when you get to the higher grits. Always use a firm pad when sanding with the lower grits!!! Preferably an inner face pad! This give the pad the support needed to flatten your surface even on a curve. If you start sanding with a soft pad the soft pad will follow the slight undulations left on the wood from the tool. Again, a firm pad allows the lower grit discs to sand out and flatten the surface. With this said... some folks start sanding at a higher grit such as 150 or higher. IMO...you really have to be careful when doing so because you risk losing the benefits of using the lower grits. When I am working at the lathe I get a pretty good tool finish yet I understand that if I start sanding with grit above 120 I am risking my sanding success. I start at a low grit take small steps (and it is not more costly because I spend far less time with each grit) on average 3-4 passes with each grit not including my starting grit of usually 80-100 grit. As you progress through the grits progress to softer pads and slower speeds. When I get to 280-320 grit my lathe speed is 50-100RPM. All I am doing is clouding or fogging the piece. I have very little heat if any. You can always call with questions and/or get the Sanding Suggestion Form from my website which is free. Thanks, Vince


Thanks guys, and great response. I like the idea of wet sanding, less dust and hopefully less time. There seems to be two types of WS, bare wood done with oil as Vince has described and WS a waterproof finish like lacquer with water and/or soapy water. I realize there is many ways to sand and I'm looking for a better way. You have given me some good tools to work with.
Vince your method would seem to work best with what I do which is mostly bowls and hollow forms. You said you use an oil with the lower grits, is it a drying oil like tung or Antique Oil, or a slower drying oil like BLO or mineral oil.
With my method of dry sanding it seems like I will sand through the grits and when I get to the higher grits I see tool marks I didn't see at lower grits so back down to the lower grits and start over. Seems like I spend hours sanding with the DC,window fan and pressure type face shield going. I don't like to compromise on a finish but sometimes I do.
Again thanks for the great ideas.

[Bernie Weishapl]

I must say thanks to all suggestions and ideas. Lots of ideas.

[John Keeton]

I am a bit late in responding, Roger, but most of it has been covered. Like Wally, my wet sanding is a natural carryover from gun building days. All of the longrifles I built were either walnut or curly maple, and for different reasons, all were wet sanded - the walnut to get some grain fill, and the curly maple to sand out the multi-step dying/staining process I used.

As has been said, there are two types of wet sanding - bare wood and leveling applied finishes. I do few bowls, and nowadays only use walnut oil as a finish on them. Using walnut oil to wet sand is simply a part of the finishing process and is started at the lower grits. The reduction in sanding time is significant as it greatly reduces sanding marks. I usually sand bowls to 400 - all by wet sanding, initially applying a very heavy coat of the walnut oil prior to sanding at 150, and then re-wetting the bowl with each grit.

If I am using a film finish, then I will sand with either BLO or mineral spirits, depending on the final look desired. I have also used a mixture of WOP and either BLO or tung oil for wet sanding at higher grits.

When I wet sand a film finish, I typically use mineral spirits, though I have also used mineral oil. The mineral oil can obscure the true level of polish one achieves and can result in failing to observe areas that may need a bit more sanding.

On a film finish, I wet sand to higher grits than some have mentioned - usually to 1200 - as I find it reduces buffing time and effort.

There is certainly not just "one-way" to do this, and many of you have put forth some great ideas!

[Thom Sturgill]

I am late to the discussion, but noticed few covered the use of water to raise the grain. This is not truly 'wet sanding' as the wood is allowed to dry after water is applied. but may be confusing to the newcomer.

I use Mineral Spirits to sand when a hard finish is desired, starting with the sealer coat and progressing up to 8-12000, sanding between coats of rattle can lacquer. Dip the sandpaper/polishing cloth into a small dish of MS and change it every grit or at least every other grit. As an aside, my brother once worked as a finisher at a guitar factory where they wet sanded with MS and BLO. They had two fires attributed to the drying rags not being stored properly before they changed to using soapy water.

I am using much less lacquer as I find the fumes bothersome. On bowls I use an oil finish on the inside (walnut oil) and sand with it from about 180 grit up. I sometimes apply a hard finish to the outside of bowls and wet sand that with MS.

[paul vechart]

Mike........may I inquire what type of wax you use most of the time when sanding? I have regular paste wax like one would use on hardwood floors and renwax........I have seen Carl Jacobson use wax when sanding, but he never states in his youtube videos what kind of wax he uses. I like the idea of keeping the dust out of the air and getting better results..........any help is appreciated!

Do you mix it with mineral spirits or anything else to thin it?

Carl Jacobson uses a brand of wax called Crystal Clear paste wax...I found it at Woodcraft. It works well when mixed with walnut or mineral oil.

[Faust M. Ruggiero]

A word of warning when you buy mineral oil. I buy mine at the local drug store. The first time I bought it I had to ask which isle it was in. As I was scrounging around the isle, a kindly old lady who had heard me ask the clerk where to find it took my hand and pointed it out on the bottom shelf. I thanked her and she commented that she knew how important finding the mineral oil was because, as she said, "When you need it, you need it. Don't worry, it will work quickly". I was looking for the words to explain my need and decided just to smile and say thanks. That's why I lubricate with water.... the sanding that is! :)
faust