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Thread: Questions regarding turning platters

  1. #1
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    Questions regarding turning platters

    Hi

    I have a few beginner questions regarding turning platters. I have some logs from some recent storms and wondering the best section of the wood to use for turning a platter.

    First, I assume you never want the pith to be in your platter blank, is that correct (due to splitting, etc).

    Next do you normally create a platter blank from a vertical slice of the log (i.e. going with the grain) and not across the log (horizontally across the tree log)?

    Lastly, for turning green wood, is this recommended for platters and do you then leave the platter turned down to say 10X the desired thickness to dry out for 3-6 months?

    thanks very much,

    'mark

    p.s. it would be really cool and helpful for beginners if there was a diagram available which shows what can be turned from different portions of a tree. I've only seen this for bowls.

  2. #2
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    Think of a platter as a flat bowl and you'll have a starting point. Experience will fill in the blanks. Every log, every blank will react to drying uniquely to a degree within a wood species and across wood species.

  3. #3
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    Mark did you sign up for the Woodturners Worldwide Symposium? I gave a demo last night on making dinner plates (same thing as platters only smaller), and everything I covered applies to plates and platters.

    1. Correct, you never want the pith in your blank.

    2. Always take a plate/platter blank from side grain (typical bowl orientation), never cut across the log as that would be an end grain platter. A lot of people cut slices or "cookies" off the end of logs to make side table tops. This is fine for tables or display pieces, not for plates/platters.

    3. I cut my dinner plate blanks to 1.5 thick, smaller appetizer plates you can get by with 1" to 1.25" thick, platter blanks I like 2" thick. Thicker means if there is any warping during the drying process you have plenty of wood to straighten things out. If you cut it too thin and it warps too much, your platter might end up as a plate!

    The rule of thumb is for every inch of thickness allow 1 year to air dry, some even say for every inch allow a year plus a year. Going by this rule a 2" blank could take 2 years before it's completely dry in the middle. If you rush it and turn it too soon the platter can warp as you remove wood and it dries out more. My moisture meter will only measure 3/4" deep, but if I measure from both sides I can get an idea how things are going. I plan for this length of time to dry and probably have 100 plate/platter blanks drying in my basement, so I'll just grab a blank that's been drying long enough. It's dry with low humidity in CO where I live and you might be able to get by with a shorter length of time in other dry environments but I never turn anything that's only been drying 3 months.

    Here's a diagram where I show the best place to get plate stock. Trunk sections are preferred over limbs because it is the most stable wood. Limbs can be under a lot of compression and extension and the wood can move more. In this diagram you are looking straight down at the end grain. The black dot represents the pith, the red rectangles are the best place to cut plate blanks from. These will be quartersawn blanks where the growth rings are perpendicular to the surface of the plate and will be the most stable. Note that in this diagram if you want 10" plates, the tree will have to be at least 22"-25" across to allow for waste and drying.
    plate stock_lg.jpg
    This diagram shows where I cut my platter blanks. If I want a 15" platter then the tree only needs to be 16" or 17" across. This is also my 2nd choice for plate blanks as again if I want 10" plates my blank only needs to be maybe 12" across, and it's a lot easier to handle a 12" log than a 25" log. The growth rings are not at 90 degrees to the surface but are still pretty much up and down.
    platter stock_lg.jpg
    You'll have to click on this picture to blow it up and see it better. The top diagram again shows where I get plates (green), and platters (red). The bottom diagram shows that you should not cut more platter blanks next to the first ones (black X) as now the growth rings for these blanks will be too flat and too parallel to the surface. You'll get a lot of wood movement in your plates/platters even if the wood is seasoned and dry. If it's just a display piece then maybe it's OK, but I make items that will be used and washed and I don't want them to rock on the table so I want the most stable wood. The wood between the platter blank and outside of the log is what I use for bowls.
    platter stock.jpg

  4. #4
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    Thanks much for your help.

  5. #5
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    THanks much Pat, For some reason (I think forum rules) I cannot see the images you posted.
    Is it possible to email me them? email is "mahlenius 720 at gmail.com" (take out the spaces and substitute)

    I did not sign up for that symposium, did not even know about it. I'd love to learn more about making them both. Plus would like to see those pix.

    thanks again

    'mark

  6. #6
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    Quote Originally Posted by Pat Scott View Post
    Pat's post is excellent! True quartersawn is, of course, the most stable however that takes a huge tree and some big sawing. Pat's second diagram is what I do for larger platters or for smaller logs. It gives you the best diameter with a blank very close to true quartersawn. Any further away from true quartersawn almost guarantees cupping while drying and movement in service.

    Note: I do NOT turn platters from green wood - I cut the blanks, seal the end grain, and put them up to dry inside the shop. Monitoring the weight over time will prove when it is dry. A 1.5 to 2" platter blank doesn't take all that long to dry, depending on the type of wood and the environment. Wood like Eastern Red Cedar (great for large platters) will dry quickly and warp little. Walnut is usually not too bad, oak, maple, and cherry can be worse. Including sapwood in some blanks can make drying more challenging.

    Mark, if you do turn it green, besides allowing a little extra thickness to allow for cupping, allow extra width to any rim to allow for truing the inevitable oval shape from cross-grain shrinkage. As for 3-4 months drying for a roughed out platter, that also depends on the wood, the thickness, and the environment. You can monitor the drying of a rough-turned piece by the weight method too. I put a piece of tape on the wood and write the date and the weight in grams. Periodically, I weigh again and write down the date and weight. When the weight quit changing the piece is dry. Note that with the change of seasons, a dry piece might first stabilize then even gain a little! (I am monitoring hundreds of blanks like this now. If I have a number of similar sized blanks, I usually monitor just one or two with the expectation they will all dry about the same rate.)

    JKJ

  7. #7
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    Thanks John

    this is very very helpful. I’ll try to cut some blanks and set them aside to dry. I’ve been using Anchor seal, and guessing you just seal the outside circumference of the round blank

    best

    mark

  8. #8
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    Quote Originally Posted by mark ahlenius View Post
    Thanks John

    this is very very helpful. I’ll try to cut some blanks and set them aside to dry. I’ve been using Anchor seal, and guessing you just seal the outside circumference of the round blank

    best

    mark
    I generally don't cut platter blanks round. I usually cut the blanks square, a little longer than the desired platter so any minor checks can be cut away. If possible, it's best to keep and dry the entire slab instead of cut it into individual platter blanks since any degrade is likely to be on the end grain and the middle is often perfect. Another reason for keeping blanks square or rectangular is to give flexibility to turn bowls or platters or cut them up to make other things such as boxes, hand mirrors, ornaments, even pen blanks!

    At minimum I seal the end grain. If the blank contains wild grain and/or sapwood and heartwood (in some species) I might seal the entire blank or at least the unusual places. I like to use AnchorSeal thickened by partially evaporating - I pour some into a plastic coffee can and leave the lid off for a few days. Brush on with a cheap disposable brush - the same brush lasts for years.

    Unless I'm air drying a stack of slabs from my sawmill I don't sticker outside and apply weight. I usually set individual blanks on edge or end on wire shelves indoors with a little space between the blanks but sometimes make a stack with small spindle squares between for air flow. I stand short slabs and planks vertically. Keeping wood cooler rather than hotter can help, especially in the initial drying. (My shop has heat and air set to 80 in the summer and 65 in the winter.) A lot of the water leaves in the first few weeks so after that I inspect each blank for checks in the end grain and other defects. If I see checks I cut them away and reseal. If I see cracks elsewhere I'll probably cut the bowl or platter blank up into spindle squares. If I decide to leave minor cracks in the blank I mark them with red sharpie so I won't be unpleasantly surprised when turning. Staying a bit away from the pith can avoid cracks down the center of the blank.

    As for time to air dry, you've probably heard the "rule of thumb" of 1 inch per year plus one inch. This may be true for some species dried outdoors but based on my measurements this is almost never true for drying indoors. Depending on the species, some 1" turning squares are dry in a few weeks and some 8/4 blanks in a couple of months. Other species might take a year or so. (All mine are inside in heated and cooled space which probably makes a big difference.)

    All in all, this type of processing is quite successful. I probably lose fewer than 1 in 50 blanks, whether platter (usually 6/4 or 8/4), bowl (often 3-6" deep), or spindle blanks typically 1x1 up to 8x8 and occasionally larger. I've been processing and drying wood like this for almost 20 years so I have a good supply, perfect for my use since I almost never turn green wood. (I find turning large bowls kind of boring.) I now have so much dry turning wood I give a lot away but my Lovely Bride wants me to start selling it instead!

    BTW, not much in these piles for platters, but this is some of the wood I've taken to an annual woodturning club auctions, typical of many of the blanks I cut from green wood and dry. The more small and medium pieces I take the more people can go home with wood! All these are cut up on the shop bandsaw - I usually cut up wide platter blanks on my WoodMizer behind the barn - a lot easier!

    ambrosia_maple_IMG_20171202_175649_933.jpg auction_wood_2018.jpg

    I do cut some green bowl blanks round if they are going to the auction - some people don't have a good bandsaw and they can mount blanks like this on the lathe and turn immediately!

    bandsaw_blank_IMG_20180312_161447_777.jpg

    If you live nearby stop in and I'll give you a dry platter ambrosia maple, walnut, or cedar platter blank. I gave one from ambrosia maple to a friend just a couple of days ago for a small (12") platter.

    JKJ

  9. #9
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    My first attempt at a platter came about because of a void in the blank. It was larger than the radius and not near the pith. Needless to say I did a great job at making a Pringles potato chip. But I learned and kept the blank (vs throwing it in the wood stove where all my other failures go, lol). You've gotten good advise. Best I can add is go try and don't worry too much about failing. Being able to laugh at your mistakes can be very entertaining.

  10. #10
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    Pat, (off-topic)

    Loved your presentation at the Woodturners Worldwide Symposium. You were prepared, relaxed, informative, and fun. Thanks, David G

  11. #11
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    Quote Originally Posted by John K Jordan View Post
    I generally don't cut platter blanks round. I usually cut the blanks square, a little longer than the desired platter so any minor checks can be cut away. If possible, it's best to keep and dry the entire slab instead of cut it into individual platter blanks since any degrade is likely to be on the end grain and the middle is often perfect. Another reason for keeping blanks square or rectangular is to give flexibility to turn bowls or platters or cut them up to make other things such as boxes, hand mirrors, ornaments, even pen blanks!" JKJ
    The bigger the piece the more wood there is to dry and the longer it’s going to take, especially in the center. If you know you want plate or platter blanks, cut it round and knock off the corners. The corners add more wood that has to dry, and air has to “go through the corner” to reach the platter (red arrows). If I want spindle blanks I cut spindle blanks, I don’t repurpose platter blanks into spindles. If I want boxes or mirrors I cut pieces for them. Worst case scenario if I get cracks in plate or platter blanks is I can make a smaller plate.

    In this picture air has to travel through the corner to reach the platter outline. That’s going to slow down the drying for all 4 corner areas.
    Cut circles not squares.jpg

    In this picture if I leave the slab long, the whole center (blue circle) is going to dry much slower than the rest. The ends of the slab will dry out before the middle which can lead to cracks.
    Cut to size don't leave long_1.jpg

    I stack my plate blanks in a column with spacers in between, or stand them on end. What you can't see is everything has wood spacers to keep them off the floor. Platter blanks get stacked on end like in the 3rd photo (although these are plates). Fresh cut blanks go on the bottom of the stack to minimize airflow and air temperature, and as the plates dry they work their way to the top as fresh ones are placed under them. In the 2nd photo these blanks are dry and waiting to be turned and don't have spacers between them.
    20200928_105602.jpg 20200928_105634.jpg 20200928_105658.jpg

  12. #12
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    Quote Originally Posted by Pat Scott View Post
    ...

    The rule of thumb is for every inch of thickness allow 1 year to air dry, some even say for every inch allow a year plus a year. Going by this rule a 2" blank could take 2 years before it's completely dry in the middle. If you rush it and turn it too soon the platter can warp as you remove wood and it dries out more. My moisture meter will only measure 3/4" deep, but if I measure from both sides I can get an idea how things are going. I plan for this length of time to dry and probably have 100 plate/platter blanks drying in my basement, so I'll just grab a blank that's been drying long enough. It's dry with low humidity in CO where I live and you might be able to get by with a shorter length of time in other dry environments but I never turn anything that's only been drying 3 months.

    ...
    Allow a comment on this rule of thumb: It may be accurate somewhere, with some species of wood, but it is inaccurate in lots of other places with other kinds of wood. Each of us need to learn what works in our shop with the kinds of wood we frequently use. My shop is near Phoenix, Arizona. Until this summer, it was without air conditioning and was uninsulated. Believe me, it takes no where near 1 year for each inch of thickness for wood to dry in my shop! (Now that my shop has A/C, it might take longer. Which is why I stress we need to learn what works in our own shop. What works for a friend across town may not work as well for you.) Is there any harm in letting the wood dry for longer than necessary? No, not if you have plenty of room to store blanks.

    Instead of relying on a this rule of thumb, weigh your blanks regularly. When they stop losing weight, they're dry (for your shop). With some experience weighing blanks, you'll pretty much know how long you need to wait. In my shop, a plate blank would be dry within 6 months. But, then, I live in Arizona, where if a tree is cut down in the morning it's too dry to turn by afternoon.

    None of this means we cannot learn from each other. We just need to learn to adapt what others do to our circumstances. Does someone on the internet recommend putting a rough turned blank inside a paper bag filled with fresh savings? That may work for you, too. Just apply anchorseal to the end grain? That, too, works for some and might for you. Others swear by coating the entire blank. Experiment and find what works for you, with the wood you use, in your shop.
    David Walser
    Mesa, Arizona

  13. #13
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    Quote Originally Posted by David Gilbert View Post
    Pat, (off-topic)

    Loved your presentation at the Woodturners Worldwide Symposium. You were prepared, relaxed, informative, and fun. Thanks, David G
    Thanks David, I appreciate it!

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