Fresh Burl wood

[Mark]

To get active on the forum again, I'll pose the following question.

Just purchased 70lb of freshly cut Madrone Burl wood from a guy that salvages on logging jobs, then sells from the bed of a twenty foot trailer to our local club. Does it need to be "sealed" on the saw-cut surfaces to keep it from cracking? I've learned all about checking in logs, but how about Burls? Is the grain already so mixed-up that it won't check/crack? I hope to be turnin' this over the next three to six months.

It's got some really good figure from what I can see. The retail burl blanks I see are sealed 100%, but I figure that's 'cause the store might have them around for quite awile, and that they likely do alot of traveling to get there. One of the other club members highly recommended boiling before turning in order to stabilize as well.

Thanks,
Mark

Patience and positive results are mutually inclusive.

[sdb777]

I would AnchorSeal the end grain anyway.

I just wish I knew more to be of help.




Scott (someone smart is comin' soon) B

[fredbelknap]

Mark I don't have any experience with burls. I have used crotch oak blocks. Boiling helps to stabilize the wood. I turn it green till it is about what I want then let it dry for a couple months. It will twist and curl and it might crack. I have a couple white oak bowls that I have drying wrapped in newspaper as I don't have any paper bags. It will be more stable and will dry faster if it is boiled. I boil mine an old canner for about two hours. Not sure if I have to do it that long but I assume that it won't hurt. It is suppose to be better to put it in a paper bag for a while till it dries out.
I'm sure that others will have varying opinions but that is what I have done. I don't have a lot of experience but I have researched the boiling process on line. Some people use denatured alcohol instead of boiling. I have heard of some using microwave oven but I haven't tried any of those ideas.
If you rough turn it be sure to leave enough to round everything back after it distorts and it will distort somewhat.

[TDHofstetter]

I'd personally seal it... but I've known a lotta' guys who didn't & everything came out OK. I HAVE seen one huge cherry burl (neighbor's house) shot clear through with teeny checks from drying in his well-wood-heated basement, so I know they're not checkproof.

I'd just seal it (as I've done before) with either paint or liquified paraffin (cut into little chunks & thinned with mineral spirits at near-boiling temperature in a double boiler). I use the wax for really special blanks, the cheap latex paint for run-of-the-mill blanks.

EDIT: I'm one of the boilers, though - I boil mine after rough-turning green. That gives me a big jumpstart on the drying process, and I have yet to see a bowl crack after boiling.

[Mark]

Thanks Fred, I tried boiling a small piece earlier in my learning to turn phase, and have also used DNA. Have still not done enough, or paid close enough attention to cause vs effect, to understand either process, so will continue my experimentation.

Pressure washed the pieces today, and they are gorgeous. Just don't want them to split before I can get the nerve to cut into 'em and start the process.

And thanks Tim. I bought the AnchorSeal today, as I've not stepped up to makin' the stuff from scratch as you described. Once they dry from the washing, I'll coat 'em to slow their loss of internal moisture.

Thanks,
Mark

[Doug B]

Mark,

It sounds like you need to send us all a sample of that wood to see how well our different methods work on it ;D

I use the DNA method for rough turned green bowls as well as for bottle stopper and pen blanks too. Air dried wood takes one year per inch of thickness to dry out...a bowl blank will take a long, long time Burl might be shorter,,,I dunno bout that stuff.

[triplefreak]

I belong to a wood turning club in my area. There's an old guy there who's been turning for 40+ years. I watched him turn a huge fresh burl on a Stubby lathe one weekend. It was amazing how he did it.
He only turned the edges to "sort of" round, then took it off the lathe & sealed it up with Anchor Seal. I asked him why he stopped, & he told me you can only do so much at a time on a burl without splitting it.

I never found out exactly why, but I suspect it has to do with heat buildup.

Maybe something to think about.

[Mark]

Well, I've cut a small portion of the haul, and submitted it to the DNA method of "drying". The first piece was 1.5" sq x 7" long (skinny scoop-handle size), with no bark. It went directly into the DNA bath, and four days later was transferred into a brown paper bag with the top twisted closed. After three days there, it has cracks in two opposite faces, that extend visually perhaps 1/4" into the stock. The moisture meter said 26% before DNA, and says 23% after coming out of the bag.

Another portion was cut into both stopper-size and scoop-handle-size (bigger than other one) blanks and put in the DNA. They were there just two days before going in the paper bag. After three days in paper, none of those show cracks. Moisture content before and after were the same as in the other piece with longer DNA soak. Some of these pieces still have areas of bark intact.

I'm sure bowl blanks will likely behave differently still, due to their size and typical shape. I'll have to see. My next experiment will be to boil a couple of pieces that were in DNA only two days, to see how much I can get the moisture content to change with that method, and if it causes cracking.

Thanks,
Mark

[Doug B]

Some pieces are going to crack no matter what you do. And the bark will amost always come off when it soaked in DNA (and of course boiling too). Make sure you cut the pith out (the very center) as it will almost always crack.

I only soak in DNA for 24 hours, then place on cardboard to dry. I do not know if it makes a difference if you soak longer than that in DNA Maybe, but I would not think so.

[Mark]

Well, here's the first sample from the Madrone Burl. Interesting stuff. I've DNA'd it and boiled it, and it's still got a ton of moisture trapped in the wood. So, decided to turn some to see what would happen. Turned beautifully, and it has taken on much more character after removal from the mandrel.

it was absolutely round and symmetrical at the moment of last cutting. I gave this a complete sanding, then a good soak in BLO before detooling it.





As it has slowly continued to lose moisture, it is shriveling up in random fashion. Very neat results I think.

Just wonderin' what a bowl size piece might do . . . . .

Thanks for lookin', and any comments welcome.

[Doug B]

Holy cow. I'm sober but it doesn't seem like it the way that looks Maybe I'll have a couple and look again and it will seem right then ;D

That is beautiful wood Mark, but it sure is still warping a lot on you even though you gave it a double treatment of boiling and DNA. FWIW, I usually still wait 3 weeks or so after the DNA treatment and that seems to keep the warpage to a minimum. How thick is that piece? Maybe that is the issue...

Still, very interesting looking piece.

[Mark]

Oh it's relatively small - 1 7/8 tall by 1 1/4 diameter. There were readily apparent bands of wet grain, and those are where most of the wrinkles are forming. Perhaps a new twist on the old-man and old-lady dolls that were made out of skinned apples some years ago. Haha ....

Thanks Doug,
Mark

[boodrow]

Mark I agree with Doug , beautiful wood , ive had my share of warping , crackin and such. I would be the last one to advise u on how to get the wood dry without probs.
Boodrow