burls (again)

[TheKid]

sorry to perhaps misplace this post, but again; I like the opinions here on the milling side. I have several burls of cherry, alder and maple, most under basketball size. i've already learned the hard way of drying them too fast once the bark was peeled. I had them in my friends unheated garage and they began to crack after a week! i've been reading up on PEG-polyethelene glycol i believe. basically wax that permeates the wood? does anyone have direct experience with this stuff and a good method to work with this and mostly under basketball size burls? thanks in advance.

 

[aquan8tor]

I think the idea is basically that once the PEG is in there, it doesn't go anywhere. PEG is considered food safe, and it keeps the burl from taking on or shedding water and therefore expanding & contracting. I know that it takes a fair amount of time, and some warm temps, if I'm not mistaken. I have a big block of it and a burl still on a tree that I'm going to have a go at this spring. BTW, you have a PM.

 

[BlueRider]

look into Pentacryl

Before you take the plunge into PEG you should also check out Pentacryl. PEG has a lot of undsireable charicteristics such as bleeding PEG long after it is supposed to be dryalong with darkening the color. Pentacryl takes a bit longer but dosent have the problems associated with PEG.

 

[zopi]

Two thing that i have heard, but not tried yet...one is boiling the wood..old timers used to boil smaller pieces of wood then let dry, mostly for tool handles that needed to be stable in order to sy in their sockets...I guess the idea is to boil the sap out and the water will leave evaporate at its own pace..dunno what this means as far as checking and stress relief though.

the other is something I have heard of turners doing...soaking wood in
denatured alcohol to bring out the moisture..again, i don't know how this will affect the structure of the wood.

my favorite idea, if impractical for large pieces, is to place the piece in a
vacuum chamber with a bit of epoxy, and place it under vacuum...some knife makers stabilise wood this way for handles...dunno how deep the penetration
is tho...

hope there is something there you can use.

 

[woodshop]

Two thing that i have heard, but not tried yet...one is boiling the wood..old timers used to boil smaller pieces of wood then let dry, mostly for tool handles that needed to be stable in order to sy in their sockets...I guess the idea is to boil the sap out and the water will leave evaporate at its own pace..dunno what this means as far as checking and stress relief though...

I'd like to hear some one who is more of an expert on wood technology address the boiling wood option. Wood is my passion, and I've studied it to a point, but it's still only a hobby. One way to take very thin sections from a piece of wood using a microtome for studying it's microstructure is to boil the wood for a long period of time first. However, the purpose is to soften the wood and saturate it with water so the knife slices it's super thin sections easier. How this saturated piece would then be more stable once it dried, I'd like to know.

When I was a kid, my Grandfather used to tell me that on the farm they would take chunks of hardwood and bury them in tubs of pig fat for a year. I guess the fat and oils would impregnate the wood? They would then use these for wagon wheel hubs. He didn't say whether the wood was already dried or not. If it was wet wood right off the saw, I can't see the fat replacing the water. In fact, I would think that would keep the wood from drying if anything.

 

[zopi]

Got me...that is straight from the Foxfire book..and several old codgers I knew as a kid...all I really know is they did it to accelerate the wood curing..I will try this one at some point when I haven't anything else going on >snort<

it may be a difference in the length of time the wood is boiled? dunno.

How long do you boil wood to slice it like that?

and how do you boil a 16 ft 2x6?:jawdrop: :hmm3grin2orange:

 

[rayvil01]

What I always heard for tool handles, such as a hammer or hatchet handle, was to dry the wood out in an oven on low, install it on the hammer, then soak the head in boiled Linseed oil for a week. The Linseed oil would swell up and lock in the head. It's worked well for me over the years.

I was down Williamsburg last winter and watched them put a wagon wheel hub together. It was bone-dry piece of White Oak. The interpreter said something about oiling it when it was assembled. But, I didn't pursue it.

 

[woodshop]

How long do you boil wood to slice it like that?

and how do you boil a 16 ft 2x6?:jawdrop: :hmm3grin2orange:

The length of time you need to boil the wood depends on the species. For slicing sections for study on the microtome you only need a small cube, say half and inch on each side. Some of the tropical hardwoods if I recall had to be boiled for more than 24 hours before they were soft enough for the microtome. I think it had more to do with the density of the wood rather than how hard or soft it was, although those two properties often go hand in hand.

 

[zopi]

What I always heard for tool handles, such as a hammer or hatchet handle, was to dry the wood out in an oven on low, install it on the hammer, then soak the head in boiled Linseed oil for a week. The Linseed oil would swell up and lock in the head. It's worked well for me over the years.

I was down Williamsburg last winter and watched them put a wagon wheel hub together. It was bone-dry piece of White Oak. The interpreter said something about oiling it when it was assembled. But, I didn't pursue it.

I live just a few miles from Williamsburg...nice place to visit..in the off season..too many turistas..

I use linseed oil on my good axe handles..

 

[zopi]

The length of time you need to boil the wood depends on the species. For slicing sections for study on the microtome you only need a small cube, say half and inch on each side. Some of the tropical hardwoods if I recall had to be boiled for more than 24 hours before they were soft enough for the microtome. I think it had more to do with the density of the wood rather than how hard or soft it was, although those two properties often go hand in hand.

I got the impression that it was only for a couple hours for something the size of an axe handle..say in ash...

Maybe there is nothing to it..

i'll cut up a couple of pieces of green crotchwood the same shape and size,
boil one for a couple hours and then air dry them in the same place and see what happens...guess i'll need a moisture meter soon huh?:greenchainsaw:

 

[NJANDPA]

Here's what I have found from 5 years of working with my lathe, drying wood different ways and burls. By far the best is using denatured alcohol. It is the best and quick and easy. Do a search on the web and you will find great directions. It works great!

 

[aquan8tor]

I'd like to hear some one who is more of an expert on wood technology address the boiling wood option. Wood is my passion, and I've studied it to a point, but it's still only a hobby. One way to take very thin sections from a piece of wood using a microtome for studying it's microstructure is to boil the wood for a long period of time first. However, the purpose is to soften the wood and saturate it with water so the knife slices it's super thin sections easier. How this saturated piece would then be more stable once it dried, I'd like to know.

When I was a kid, my Grandfather used to tell me that on the farm they would take chunks of hardwood and bury them in tubs of pig fat for a year. I guess the fat and oils would impregnate the wood? They would then use these for wagon wheel hubs. He didn't say whether the wood was already dried or not. If it was wet wood right off the saw, I can't see the fat replacing the water. In fact, I would think that would keep the wood from drying if anything.

I've heard of people boiling green bowls to not only speed up drying, but it supposedly reduces drying problems; checks, warping, etc. I have my doubts as to whether it works on the really crazy grain in burls; It doesn't seem like the water would have much place to go through the burled grain; I mean, it all would steam out through the end grain in straight grained wood, but in a burl, it seems like it would make it crack more. It makes sense that it would work, because the heat of the water boiling, as it gets the wood itself up to 212F or 100C, the water is converted into steam. This works its way out through the end grain, as thats the only place it can go through the vascular tissue of the wood; whats left inside will dry a heck of a lot quicker is the idea. I personally have yet to try the boiling thing with my bowls; I'm not a pro so I don't mind waiting to dry to finish turn them, but I found a website of a profesional turner that boils his bowls:


http://www.woodturningvideosplus.com/boiling-protocol.html