Checking my burl drying technique

[RedShirtGuy]

In the next few days I'll be harvesting a couple of small Eucalypt burls (pics of the tree tomorrow maybe) to turn into small simple bowls about 4-6" in diameter and 3-4" in depth from each individual burl (already in a bowl shape).

After a bit of reading it's been difficult finding a "one size fits all" method of drying for an Aussie burl so I thought I'd run this by the gurus (that's you lot ) and see what you think.


Option 1:
Cut burl, clean, seal end, leave in bucket of saw dust for few years, turn dry and finish.

Option 2:
Cut burl, rough turn to shape (walls 1/2"-3/4" thick for final 1/4"ish thickness), low temp oven/microwave to dry, turn dry, wait a month or so for final movement, re-turn if necessary and finish.


Option 2 sounds good because I'm excited to get them done soon, but I am worried about excessive warping because all I want to achieve is a simple round bowl. I expect cracks and cavities, and they will be filled with an epoxy mix during the process, but wild flaring of green timber isn't desired.


Are there any votes for or against, or additional notes, for either option from those in the know?

Thanks in advance

[rod1949]

I've got a dozen or so burls that in part I've done your option 2 with ie. rough cut out, buried them in saw dust for a year or two (I won't be microwaving them). I check then every now and then to see if the bark is easy to remove but so far its not so they remain buried.

[Willy Nelson]

Hello Mate
By way of authority, I season hundreds of burls each. This is what I do.

Cut em, preferable in winter

Write the date, type of burl and where I got it. Seal it with bondcrete. Store in the garage racks, alphabetically under B for Burl.

Wait two to three years, blast the bark off the burl if I intend to carve it. Or just go ahead and turn it
Sincerely
Willy
Jarrahland

[RedShirtGuy]

Bondcrete...that's a new one!

Perhaps I could try different methods with the few burls that I'll be getting. Curse my impatience for trying something new

[hughie]

Well I have never really worried too much about whether its dry or wet. I find that no matter how dry it seems to be, its always damp in the centre. I have never really had an issue with cracking or warping. I just simple fix it or work around if it does.
There several well know turners who specialize in turning wet burls and claim that its never a problem. What does concern me if its a burl off a long dead tree, then its likely to be hard, damn hard . But like all burls you have to persevere and its generally worth in the end.

[Drillit]

Hello Redshirtguy,
I rough turn to about 3/4". Then place in a large plastic container of water with a bottle of (cheap) dish washing liquid.
Leave for 2 weeks. Remove, wash and let dry (and drain) for another 2 weeks. Then good to go. The liquid strips
the tannin out of the piece, believe me. Burl will not crack. I have also used Willie's idea of bondcrete. It is as good
as end grain sealer, but many use old plastic paints which work OK as well, which I have also used. I have also seen
Guilio Marcolongo turn green wood and finish it, then smother the piece with thin super glue. While the piece dries it
may warp, but it will not crack. Hope this helps. Drillit.

[dai sensei]

If you are in a hurry, you can rough turn, then stick in a dehydrator for ~120 hours and you will be probably right to finish. I continually measure weight to be sure, when it stops losing weight it will be 4-6% MC. Get the rectangular ones with drawers, that are normally perfect for pen blanks, but the drawers can be removed to make room for larger blanks. I have one like this 8 Food Dehydrator Commercial Preserve Yogurt Fruit Dryer Jerky Maker | eBay and regularly do bowls and pepper grinder blanks.

Drying this fast does NOT removed stresses though, so I would still do final shape but then leave it for a week to settle and equalise before final turning and finishing.

[RedShirtGuy]

Thanks again all. Most helpful, as always and you've given me a few different methods to experiment with.


Here's a few pics of the tree (any idea on species?), the shoots it's growing and the burls.

The tree is pretty much knackered. Most of it is long dead/dying, but no doubt still green.

[Willy Nelson]

Some of those burls may not be worth harvesting, especially the four you have circled as they are quite small. Remember, there will also be at least and inch or two of bark
Hope I am wrong
Cheers
Willy

[RedShirtGuy]

Thanks for the heads up Willy.
I'm kind of hoping they are only small ones...I'd hate to bugger up my first efforts on big ones
As long as they're mountable, I'll be happy.

[Drillit]

Hello dai sensei,
What is the approximate size of the dehydrator and about what temperature do you dry at, please. I noticed that the thermometer regulates from 35-68c.
In using dishwashing liquid what I have found is that some cracks disappear in the process for reasons I do not understand, but readily accept. I should also mention
that Guilio often dyes his pieces, lets that dry and then seals with thin super glue. Thin is the operative word here. Thick is disastrous. Thanks, Drillit.

[Wood Collector]

The green vertical shoots are epicormic shoots, the tree has put them up due to it being stressed e.g. drought. my guess would be flooded gum or candle bark.

[dai sensei]

What is the approximate size of the dehydrator and about what temperature do you dry at, please. I noticed that the thermometer regulates from 35-68c.

Mine is pretty similar to the one that is in the link I provided above. I use the 145F most of the time but 125-135F for the more sensitive crack prone stuff. For burl the 145F is fine.

[Willy Nelson]

After just returning from the workshop, I was reminded of my preferred method of sealing timber, but usually bowl blanks, but this work just as well from burls which are under 40 cm.
I have an frypan full of old candle wax, I simply heat it up and plunge the burl into the wax for 30 seconds or. Cheap, easy and works very well
Sincerely
Willy
jarrahland

[Rodneywt1180b]

You might look at boiling wood too. I've just started testing the method for myself but others have reported good results. Boiling will remove some of the tannins and helps relieve some of the internal stresses in the wood.
I agree with Willy. Those burls are pretty small on the outside. There might be more burl wood inside the tree but unless you're taking the whole tree down they may not give you any usable blanks.
Rodney