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+-- Thread: veneer from end grain and burls (/showthread.php?tid=7351241)
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RE: veneer from end grain and burls - jteneyck - 11-15-2019
(11-15-2019, 11:39 AM)TomFromStLouis Wrote: They were fresh sliced from an air dry piece of burl and soon after glued down. Honestly I think I did everything right except I used the wrong glue.
The first time I ever used end grain veneers I think I used PVA glue and everything went fine. The piece is still intact. Next time same approach and some sections delaminated after a winter indoors. This looks like it might be harder than I thought... I switched to hide glue because the bleed through would not be an issue and thought I had this problem licked with veneers significantly under 1/8" thick. Not so.
Dang this hobby can be humbling. I've been doing this long enough that I truly should not be having these problems. I must be a slow learner.
Air dried doesn't mean it was dry enough. It is highly unlikely it was in the 6 - 8% range unless the drying conditions were at 30 - 40% RH. When I said I had seam splits when the RH in my house got down below 30%; that's 6% moisture content for wood. That's why I asked what the RH is in your house.
I don't see any benefit of crossbanding with burl. Which way would one run the cross banding?
Steve, Unibond 800 has water in it. It's in the liquid portion.
John
RE: veneer from end grain and burls - Steve Altman - 11-15-2019
(11-15-2019, 01:39 PM)jteneyck Wrote: Air dried doesn't mean it was dry enough. It is highly unlikely it was in the 6 - 8% range unless the drying conditions were at 30 - 40% RH. When I said I had seam splits when the RH in my house got down below 30%; that's 6% moisture content for wood. That's why I asked what the RH is in your house.Hi,
I don't see any benefit of crossbanding with burl. Which way would one run the cross banding?
Steve, Unibond 800 has water in it. It's in the liquid portion.
John
<< Steve, Unibond 800 has water in it. It's in the liquid portion. >>
I didn't know that. Thanks for the info!
<<I don't see any benefit of crossbanding with burl. Which way would one run the cross banding? >>
Either way. I don't think creating a two-ply with burl is necessarily an attempt to counteract shrinkage across the grain. It's more like creating a more stable, strong structure (burls are so often pretty fragile) to lay down on the core. I've never seen any burl delaminate from a two ply made with Unibond 800 and never seen any two-ply delaminate or show any signs of cracking or curling up from a core. I suppose its possible, or even likely with very wet burl or oysters. Never seen it happen, though. Unibond 800 used correctly seems just about foolproof if you're careful about following the instructions. Perhaps I've just been lucky...
RE: veneer from end grain and burls - TomFromStLouis - 11-15-2019
John,
I am aware that all the wood in my house gets to 6% in the winter. None of the wood I use in my unheated garage shop is ever at 6% when I build with it but it all has been there when kiln dried. I used the term air dry to indicate where it was when used.
RE: veneer from end grain and burls - jteneyck - 11-15-2019
(11-15-2019, 04:02 PM)Steve Altman Wrote: Hi,
<< Steve, Unibond 800 has water in it. It's in the liquid portion. >>
I didn't know that. Thanks for the info!
<<I don't see any benefit of crossbanding with burl. Which way would one run the cross banding? >>
Either way. I don't think creating a two-ply with burl is necessarily an attempt to counteract shrinkage across the grain. It's more like creating a more stable, strong structure (burls are so often pretty fragile) to lay down on the core. I've never seen any burl delaminate from a two ply made with Unibond 800 and never seen any two-ply delaminate or show any signs of cracking or curling up from a core. I suppose its possible, or even likely with very wet burl or oysters. Never seen it happen, though. Unibond 800 used correctly seems just about foolproof if you're careful about following the instructions. Perhaps I've just been lucky...
I see your point Steve. Makes a lot of sense. Thanks.
John