JohnnyNoName Posted March 30, 2011 Report Share Posted March 30, 2011 I am having an issue with some quarter-sawn white oak. I am making a bookcase with frame and panel sides. The problem that I am having right now is with the panels. The wood just won't settle down. It just keeps cupping. I take a little off of the thickness and let it sit. It continues to cup. I started out with 3/4" rough stock, hoping to end up with 1/2" panels. Right now I'm at 3/8" and the boards are still massively cupped. I'm really hoping to use these panels, because the ray flecks look so nice. One solution I thought was to just thickness them down to 1/8" thick, and then glue them to a stable base, but I've never used material that thick before for veneer. Will this work? Should I go thinner then 1/8"? Thicker? Should I just throw the pieces into the burn pile and use something else? Thanks in advance, Jonathan =================================== Quote Link to comment Share on other sites More sharing options...
PaulMarcel Posted March 30, 2011 Report Share Posted March 30, 2011 It seems odd they have so much motion. When you thickness, you're taking off equal amounts on both sides, correct? Otherwise, you'll get a lot of cup. When I use home-sawn veneer, I limit it to 1/8" thick at most. Haven't had a problem. You'll need a balance veneer at those thicknesses so be sure to veneer the other side of the base; doesn't have to be with more QS white oak... I pick on Poplar for that. Quote Link to comment Share on other sites More sharing options...
Salvadore Posted March 31, 2011 Report Share Posted March 31, 2011 Is that stuff kiln dried? I'm no expert but if it is kiln dried then you should be able to mill it up sand it and seal it up to prevent it from drying out to quick. where is it from? Can you test the moisture content? Unless it is soaking wet I think you should be able to mill the pieces and seal them up to lock in the moisture or maybe seal out the moisture if your in a damp climate. Good luck Quote Link to comment Share on other sites More sharing options...
JohnnyNoName Posted March 31, 2011 Author Report Share Posted March 31, 2011 Is that stuff kiln dried? I'm no expert but if it is kiln dried then you should be able to mill it up sand it and seal it up to prevent it from drying out to quick. where is it from? Can you test the moisture content? Unless it is soaking wet I think you should be able to mill the pieces and seal them up to lock in the moisture or maybe seal out the moisture if your in a damp climate. Good luck The wood is from a tree that a client had cut down in her yard. The wood is willow oak, and the tree had a lot of spalting, splitting and cracking. I'm making a glass door bookcase out of it and every little piece of wood is precious, because most of the wood is junk... for any large pieces of furniture anyway. Luckily the client understands this. The wood was in a solar kiln for two-and-a-half months, and it sat in my shop for another two. The moisture content is at 13%, which I think is high, but I have also tested many other pieces in my shop that have been in there for years, and they are around 11-13 percent too which was SHOCKING! Jonathan ============================ Quote Link to comment Share on other sites More sharing options...
Salvadore Posted March 31, 2011 Report Share Posted March 31, 2011 Like I said I'm no expert but to me it would seem like if you leave the freshly milled board flat on the table and the edges curled up it would indicate the board is drying out where as if the center cups up it is absorbing moisture. My hypothesis is based on the idea that the side against the table does no losing or absorbing while the face up is doing one or the other. I may be way off here. My guess is your boards are absorbing moisture? Do to high humidity in the area. Either way if you seal it up shortly after milling it should stay flat. Maybe just a coat of wax until you determine the finish. Quote Link to comment Share on other sites More sharing options...
Pete Bennett Posted March 31, 2011 Report Share Posted March 31, 2011 Hi 13% is a fairly good air dry moisture reading, depending on where you are. If its quarter sawn I'm surprised it's cupping so much. However, 1/8" veneers are common, and as Paul says no problem if you balance it with a similar thickness of virtually any other veneer, but, try to make sure they are both at 13% if poss. In the good old days a lot of furniture was veneered with 3/16" veneer on to solid Oak carcases and some of that stuff was done around 4,000 years ago and still survives. Admittedly it spent almost all that time in a very controlled environment beneath several thousand tons of stone Pyramid. I never use commercial veneers unless it's either a fantastic burr or truly exotic wood not available otherwise. I always cut at 3mm which is pretty near exactly 1/8" and the only problems I've ever had have been caused by me. So go for it and good luck. Quote Link to comment Share on other sites More sharing options...
JohnnyNoName Posted March 31, 2011 Author Report Share Posted March 31, 2011 Hi 13% is a fairly good air dry moisture reading, depending on where you are. If its quarter sawn I'm surprised it's cupping so much. However, 1/8" veneers are common, and as Paul says no problem if you balance it with a similar thickness of virtually any other veneer, but, try to make sure they are both at 13% if poss. In the good old days a lot of furniture was veneered with 3/16" veneer on to solid Oak carcases and some of that stuff was done around 4,000 years ago and still survives. Admittedly it spent almost all that time in a very controlled environment beneath several thousand tons of stone Pyramid. I never use commercial veneers unless it's either a fantastic burr or truly exotic wood not available otherwise. I always cut at 3mm which is pretty near exactly 1/8" and the only problems I've ever had have been caused by me. So go for it and good luck. So if I glued the 1/8" solid wood veneer to a 1/4" MDF core and DIDN'T put another 1/8" veneer on the other side, it would definitely cup or is the extra 1/8" veneer an insurance policy? Jonathan ============================== Quote Link to comment Share on other sites More sharing options...
PaulMarcel Posted March 31, 2011 Report Share Posted March 31, 2011 With 1/8" thick veneer, I think you'll have movement issues if you don't put the balance veneer. I was a big skeptic of that in the past and did some cheezy experiments in the shop. I now take any left over Poplar from projects/jigs/whatever and resaw it to 1/8" thick so it's ready when I use a hardwood veneer somewhere else. With commercial 1/42" thick veneers, the recommendation is to put the balance veneer although I'm still a big skeptic of that requirement. Sure, I'll do it on a panel because the backside can be seen and needs the veneer, too, but if the back wasn't visible, I might consider the joinery strong enough with that 1/42" case (oh, that depends, too, on the glue you choose). Quote Link to comment Share on other sites More sharing options...
jhl.verona Posted March 31, 2011 Report Share Posted March 31, 2011 I am having an issue with some quarter-sawn white oak. I am making a bookcase with frame and panel sides. The problem that I am having right now is with the panels. The wood just won't settle down. It just keeps cupping. I take a little off of the thickness and let it sit. It continues to cup. I started out with 3/4" rough stock, hoping to end up with 1/2" panels. Right now I'm at 3/8" and the boards are still massively cupped. I'm really hoping to use these panels, because the ray flecks look so nice. Reaction wood perhaps? How does it rip? If you have a piece to test a veneer cut, see if it pinches shut behind the band saw blade, or opens up dramatically. With 1/8" thick veneer, I think you'll have movement issues if you don't put the balance veneer. I was a big skeptic of that in the past and did some cheezy experiments in the shop. I now take any left over Poplar from projects/jigs/whatever and resaw it to 1/8" thick so it's ready when I use a hardwood veneer somewhere else. With commercial 1/42" thick veneers, the recommendation is to put the balance veneer although I'm still a big skeptic of that requirement. Sure, I'll do it on a panel because the backside can be seen and needs the veneer, too, but if the back wasn't visible, I might consider the joinery strong enough with that 1/42" case (oh, that depends, too, on the glue you choose). I'm no expert - never veneered anything in my life, but I think the problem is with the glue, not the veneer or thickness. One whole side gets a soaking of glue (hide or vinyl) usually applied with a roller. So if you don't wet the other side with glue, it'll cup - just as much as if the board were left on the bench, one side dries while the other stays wet. Though in this case it's the other way round - one side is dry while the other becomes wet. Does that make sense? John Quote Link to comment Share on other sites More sharing options...
PaulMarcel Posted March 31, 2011 Report Share Posted March 31, 2011 I'm no expert - never veneered anything in my life, but I think the problem is with the glue, not the veneer or thickness. One whole side gets a soaking of glue (hide or vinyl) usually applied with a roller. So if you don't wet the other side with glue, it'll cup - just as much as if the board were left on the bench, one side dries while the other stays wet. Though in this case it's the other way round - one side is dry while the other becomes wet. Does that make sense? John Yup, makes sense, which is why I sponge water on the other side Quote Link to comment Share on other sites More sharing options...
Pete Bennett Posted April 1, 2011 Report Share Posted April 1, 2011 I don't know about insurance policies. cos I utterly distrust each and every one of them. But, if I were veneering any substrate that thin I'd definitely back it off no matter what. On thick substrates it is often no problem but a 1/8" veneer on 1/4" MDF I've never bet on a horse in my life but I reckon distortion would be massive odds on favourite. Quote Link to comment Share on other sites More sharing options...
RenaissanceWW Posted April 6, 2011 Report Share Posted April 6, 2011 Someone mentioned briefly you may have reaction wood. I think this is worth reviewing, although there is really not much you could do about it. A close look at the distribution of the growth rings may tell you if you are dealing with a piece that was not part of the central bole or trunk. It may not be full on branch wood, but close enough that you are getting reaction and tension release unevenly across the board. In any case, resawing to a thinner section and veneering usually will solve your problem as the thinner piece will still move the same as a thicker one (maybe quicker as absorption is faster with thinner stock) but the thinner stock doesn't have the same strength and ability to break apart joints. In other words you can usually hold the wood in check. This of it as a momentum equation. The greater the mass the more force it can exert. If you have a widely moving piece of veneer exerting a weak force against a stable more massive substrate then the substrate will win. Unless you are dealing with a highly dense and brittle veneer species the veneer should flex without a problem. In your example you are not since you are dealing with something in the Quercus (oak) genus and they are highly bendy. As far as thickness, most antique furniture has veneer that was hand sawn in the 1/8th range. It may have been reduced through preparation but it is still substantially thicker than commercial stuff we see today. Quote Link to comment Share on other sites More sharing options...
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