1 Attachment(s)
Drying LARGE bowl blanks.
Quote:
Originally Posted by
Thomas Wilson80
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!
Attachment 404441
I'll try to get some pictures of the types of larger blanks currently on my drying and dry shelves.
JKJ