I have sourced over 60 burls in the Santa Cruz mountains that have been dugout and sitting on the ground for over a year. these are oak, redwood,madrone,manzinita mostly.
I brought a small one home, (manzinita) and sliced it into 2 inch cookies (that was a mistake, I think I should have gone with the grain.)
within 2 days it split to high heaven.
I was planning on sawing all this burl on site but if (becuase its been out of the ground for a year) its all going to split like this perhaps I should pass. what do you think?
I would coat them completely with Anchorseal as soon as they are sawn.
Not a lot of burl experience, but what I have is turning them on the lathe. Experimenting with the manzinita is a tough way to start. That stuff is like a red rock, and dries about as easily. Also from what I've read, madrone starts to crack as soon as it's cut off the tree. I'd call some woodturners and sell by the pound. No worries about the cracking then, just count the money. Here's some reading on turning bowls from madrone burl that talks about storing them under water till used, and then boiling the bowl blank.
http://www.serioustoolworks.com/wood-turning-a-madrone-bowl-01.php
Due to the wild grain in a burl, which means wild shrinkage (warp) and lots of it, a burl must be dried slower than "very slow." Add to this general statement that some species are very check-prone and have to be dried even slower. And then some species, like redwood, have water pockets that also require slow drying to avoid collapse. Coating the burl with Anchorseal is certainly a good idea, but a thick coating will mean that in a year, the wood is still soaking wet, so do not get carried away. You can also dry the wood slowly by putting them in a freezer, burying them in a pile of manure, and covering each one with burlap, etc.
Most commonly, burl is either turned green or sliced for veneer and press dried. I'm most familiar with the latter. I saw my burl into a useable block (no larger than about 10"x12", but usually smaller). I then coat it in wax. and then throw it in a garbage can filled with sawdust. When I need a few slices, I take one out and resaw it on my shop bandsaw (usually), rewax the exposed wood and put it back. The slices are about 1/8" thick and I "press dry" it using an iron. you have to keep flipping it as it starts to curl up after a few moments with the warm Iron. takes about 15 min for a 6x9 leaf. afterward, I usually glue them up right away. Also, some burls are more forgiving than others. walnut is usually ok, but Apple can really give you fits. >:(
Thank you gentleman
lifes funny, since I got my sawmill I have thought of cutting burl and indeed cut some olive burl.
now that I have this opportunity I might just pass...
cheers!