In prepping blanks for bowl turning, I cut them out of logs for face turning. I am using a freshly felled American Elm stump and a year old Walnut trunk for stock (felled a year ago). The blanks range in size from 6-8″ inches round and 4-6″ thick.
Both the Elm and Walnut blanks are cracking against the grain as they sit in my garage. It’s been very humid and rainy since I’ve cut these out. As a test, I put half of them in my basement (50-60% humidity) and they cracked the same as the garage-stored blanks.
I don’t even have time to rough them out, they crack so quickly. What is causing this cracking? How can I prevent it?
Submitted by TroyM
Answer:The problem is that the wood is drying. If the drying is not controlled very carefully, the blanks will be prone to cracking. This is especially true on thick pieces such as you’re probably cutting for your bowl blanks.
The best way on how to stop wood from cracking is to seal the blanks as soon as you cut them. A commercially made product such as Anchorseal is the perfect answer for this problem. It’ll completely seal the blank and keep it wet until you’re ready to work with it. You can brush it on or, if you want to make it really easy, pour the Anchorseal in a tub and dip your blanks. This is my approach. Brush off the excess, let the sealer dry, and you’re blanks will remain sound for a long time.
You can purchase Anchorseal from woodworking specialty stores like Woodcraft.
George
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Be carefully “sealing” ends of logs / blocks. If it is much over 60° your wood will quickly become “dodie” or soft… in winter you can get by with sealing pretty well but when the temp gets above 60 mother nature is the boss, not us.
If I’m making several blocks and won’t be working them for several days I simply place them in a pan (I have several 3’x15″x 2″deep) and have 1/4″ of 250 – 500 weight mineral oil in them. I stand the blocks on end (end grain in the oil and up)… then also keep the top grain painted in mineral oil for as long as needed before working. I’ve kept them for up to 3 weeks like this with no problems.
Just holler if I can help.
I’ve been making bowls from freshly cut “green” wood for over 35 years. Mostly from maple, but black walnut and cherry at times too.
I try to only cut logs when the sap is “down” but that isn’t always possible. Cutting trees late November and December and trying to get all I need by early January greatly helps with the cracking problem.
But even if I cut a log in June – I can do pretty well keeping them from cracking.
I buy mineral oil from STE-OIL.COM it’s food safe but far heavier than what you’ll get from a pharmacy or grocery store. The local stuff is 70 weight (like water) I buy 250, 350 and 500 weight and mix my own “weight”. When I was a paid display artist for the NC State Fair I did shows outside so I was not in a controlled setting as far as wind and temperature go.
I would use 500 weight, applying it with a brush as I was chipping out the bowl. But in a shop setting – I would wait until the bowl was completed and sanded to 80 grit – coat it with 250 weight… then place on a metal pan upside-down for 24 hours. Then after that – right-side up for 10-12 weeks (maple) and around 6 months for walnut. I check the bowls daily, and apply a light coating on the end grain inside and out for around a week, then “only if needed” after that. The 250 sinks in well but evaporates at a much slower rate than the 70 Wright you buy local. If it’s hotter weather – the 350 weight sinks in pretty good but remains on the surface better to prevent surface drying prematurely and causing cracks.
This method works very well and I will only run across a hard to get along with piece of wood on rare occasions… hope this helps. Feel free to contact me if I can help. JP Madren
I have 8″x8″ blocks of wood used to shore up walls for sewer construction workers. I grinded it to the shape I wanted. I dyed it the color I wanted but didn’t seal it. Within a week or so it cracked. How can I prevent cracking in that situation,
If it’s structural and you don’t care about appearance, apply 2-3 coats of paint to the end grain on both sides, and that will help a lot as well. If you want to preserve the look of the wood, I have a couple suggestions that you can try. First, apply this product per the directions: https://www.amazon.com/gp/product/B003DL118S/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&tag=vondriskawood-20&camp=1789&creative=9325&linkCode=as2&creativeASIN=B003DL118S&linkId=7e82d17b510a8b6f4bba336b018292cf. Also, place the piece in a paper grocery bag and store it in a cool place to slow the rate of drying. Those two steps should increase your chances of reducing cracking. 8×8 is still a large chunk of wood, so unless you are removing a lot of material (which you can’t because it’s structural) there will still be a good chance of cracking. Another way to reduce cracking is to paint the ends.
Paul
Am a beginner in bowl coring so this interesting
Does this anchor seal slow the drying, or suspend it? Hate to “pause” time just to have it crack when worked later, especially on a lathe! Whoa… What time is req’d for your 3-4″ thick junks example? We have tropical hardwoods growing onsite here, and would hate to waste them.
Hello Gunther. It slows the drying time; doesn’t stop it from drying entirely. If you want to let it crack before you use it, then do not apply anything. Some people take that approach, and apply resin to patch the cracks, which is a valid approach. I seal my turning blanks to keep them from cracking prior to turning. When I turn green, I rarely have cracks form when the bowl dries. When a crack does appear, I simply patch with epoxy (sometimes I’ll add some dye or pigment powder for effect), then sand and finish.
Paul
Woodworkers Guild of America
I have a question not a commment hope it’s ok, can I use red cedar to crave spoons and bowls that will be in contact with food
Hello,
Here’s what the experts had to say about your question:
There are multiple species of cedar. Some will impart an unpleasant flavor on food, some are not food safe, and some have both problems. I would not recommend using it for food contact items.
Sincerely,
Paul
Wood Workers Guild of America
A cap on top of a 4 x 4 post (treated wood cap) is showing cracks. What can be done to keep them from going further?
Hello Ken,
Here’s what the experts had to say about your question:
You can try to patch it up with some epoxy. If the wood has become dry to the point of equilibrium, the resin should help.
Sincerely,
Paul
Wood Workers Guild of America Expert
I’m making wood cookies for our wedding! I applied anchorseal 2 to both sides of nearly 40 cookies! Its been 2 months and I planned on sanding them before applying epoxy resin to them. They all look good no cracking bark is still attached on the black walnut 1 inch cuts. The wood sealer however is eating through all my sand paper. Will it dry enough to sand or do I need to use another technique to remove the anchorseal?
Hi Phil,
Thank you for the question, here is the reply:
Anchorseal is a wax emulsion, so even after it has dried, it will clog up your sandpaper. I’d suggest using a putty knife or cabinet scraper to remove as much of it as possible before trying to sand it.
Anchorseal is a great product for protecting bowl blanks or other wood that is in raw format and will be machined into a project. For what you are doing, cutting green wood to final dimensions and then preserving it so that it won’t crack as it dries, you would have wanted to use this product, as it can easily be sanded after the piece dries: https://amzn.to/3olrdN8.
Paul
Woodworks Guild of America
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Hi. I do a lot of woodworking, woodturning, woodcarving, and furniture making. I made a small door from oak recently from 7 boards at different widths. The door is 48 inch high by 23 inches wide and 3/4 inch thick, with 3 coats of varnish on both sides. I also put a batten on the top and the bottom. I fitted the door to the oak frame and hung it. But a few days after, the door started to warp. I forgot to varnish the sides. Would that be the reason why it’s warped? Regards, Vincent Murphy.
It’s always a good idea to finish all surfaces, and it’s possible that it was a contributing factor. It’s also possible that the boards had some stresses in them that were released during the milling process, particularly if more material was removed from one side than the other. Good building practices will minimize the potential for this, but sometimes it will still just happen in spite of us doing everything correctly.
Paul
Woodworkers Guild of America
I have a 1 inch thick pine disc, about 2.5 feet in diameter. I want to make a table top out of it. The problem is that the disc is starting to crack. It was cut about 3 weeks ago. Should I start sanding and apply varnish, or should I wait till it dries out. I’d hate for it to crack. Any advice would be appreciated. thanks.
I would suggest letting it dry first. Hopefully you’ve already applied Pentacryl, as that is your only chance at preventing it from cracking.
Paul
Woodworkers Guild of America
What keeps your turning from cracking after you have turned it?
Hi Robert. I find that if you turn green wood thin enough, perhaps 1/2″ or thinner, it doesn’t seem to crack very much unless you’ve captured the pith in your piece. It will distort as it dries, but it won’t usually crack too much. Some species crack a bit; red oak seems to be prone to it from my experience. But for the most part most species seem to hold up ok.
Thanks
Paul-Woodworkers Guild of America
My pergola wood is splitting. It was sealed with Thompson water sealer last year. How can I stop it from splitting even more.
Hi Luann. I’m not aware of a way to stop the splitting once it has begun. It should stop on its own once the wood reaches moisture equilibrium. For future reference, the best way to minimize cracking to seal the ends right away after the boards are cut. Applying 2-3 coats of Thompson sealer to the end grain would likely help to minimize the cracking.
Thanks
Paul-Woodworkers Guild of America
I sculpt using basswood. What is the desirable humidity to start s ulpting?
Hi Gerry. I’m not sure what is ideal. I’ve done a bit of sculpting, not a ton, and I haven’t paid close enough attention to what the humidity has been when I’ve done it. By doing a lot of it you will probably develop a good sense of what is ideal.
Thanks
Paul-Woodworkers Guild of America
The correct moisture content for your piece is a function of local climate. What will work in Florida will shrink, crack or twist in Nevada. Here we look for approx 10% moisture content. Wet or green wood will take around 1 year per inch of thickness to reach this condition.
I Am mfr of willow clefts and keep them for drying in open for so many months the clefts get cracked please tell me any remedy
Hi Rashid. I would suggest trying this product: https://amzn.to/2T8xu3N
Thanks
Paul-WWGOA
I am a woodcrafter to a unique field of making musical instruments and tables from branches. I’m used to working with finished wood from the lumber yard but recently within the last two months started working with live wood. We have to dry them to bend them on a bow like a bow and arrow except we attach a wire and play an instrument. We also clap them together in two wooden 21 inch sticks for a stick dance. How can I dry the branches from 1 to 2 inches in thickness to work with so that they don’t dry brittle?
Hi Tiffany. I’m not aware of a way to dry wood that doesn’t result in the wood becoming brittle.
Thanks
Paul-WWGOA
try looking for ASH or HICKORY branches The native Americans used them for making stringed weapons and were quite effective and long lasting
Is that work with sandal wood sculptures? Does it remove the smell of sandal wood?
Sorry but I do not have any experience with Sandalwood. I’m guessing that this approach would work for reducing cracking, but I doubt that it would help much to remove the smell. I would suggest contacting the manufacturer to get their guidance on this.
Thanks
Paul-WWGOA
I have 10 gallons of pentacryl for sale for $100. Is it possible for me to make this known to the readers of your website?
Where r u located and is it still available
I do a lot of green wood carving this was great advise
I can`t purchase the anchorseal in Winnipeg to coat fresh cut wood to prevent cracks will wax melted on the malpe cutoff work as well
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Paint the ends with wood glue.
A good latex paint will do wonders on hard wood to keep it from splitting. It worked well on my walnut and my brother used it on his maple.