I have several slabs of oak that has been air dried and has lovely figure and grain. My customer wants to have a table made but it can only be managed as veneer. I am thinking of resawing it and using plastic resin glue to veneer it to 1″ MDF. Any opinions on how thick the veneer should be? I want to avoid cupping, creep but allow enough thickness for refinishing over time.
Thanks.
Replies
The usual wisdom is that veneer should be 3/32" or less. With veneer that thick, and with 1" MDF for the substrate, I'd think very seriously about veneering the bottom too, to make a balanced panel. The backer veneer doesn't need to be your high-class oak. It could be cheaper oak, or even some other species. It just should be roughly the same thickness as the top veneer.
1/8" should be no problem and is easier to produce and work such a thicknesshttp://www.metmuseum.org/explore/studiolo/studiolo.html
The Gubbio Studiolo was done in the 1400's with 1/8" veneers and John Cederquist has been using 1/8" veneers on his pieces for years now. Thin is cheaper and yields more material. As long as you back it with a suitable thickness it should be stable. I've seen lots of thick vneered pieces in museums. I don't know of any documentation that it can't be done based on all the real examples I've seen.
Thick veneers worked in environments, pre central heating, where there was little change in seasonal relative humidity, but in a modern home in many climates, very thick veneer will definitely have problems with cracking.
Many of the pieces you see in museums must be kept in very tightly, and expensively, regulated environments to prevent the furniture from self destructing.
From experience I concur that 3/32 is about as thick as can be used. The panel must have a backing veneer, with the grain direction matching the show surface's grain.
John White, Yestermorrow School
John
I respectfully disagree with your assessment of 1/8" veneer. I've got pieces in customers homes, as well as my own, veneered with shop sawn veneer (which, by the way, I prefer to the 1/40" stuff they're selling commercially) that are as old as 15 years, and I haven't had a single call back. I prefer the thicker veneer to work with, as its easier to joint for edge joining, and it also leaves a little extra wood for smoothing and scraping, etc.... I wouldn't dare take a smoother to a commercial veneer.
To the op
You definately want to veneer BOTH sides of your substrate, regardless of the thickness. Not doing so will cause your work to be unstable, and the panel WILL warp.
Jeff
What are you using for a substrate?
John W.
John
apple ply or baltic birch ply. As I stated to sapwood, this may be the difference, and I may also be scraping off that last critical 1/32" which everyone seems to be worrying about as a part of the final prep for finish. I don't know, as I don't measure it.
Jeff
Whenever this topic of max. veneer thickness comes up, two camps always seem to emerge: the 3/32"+ crowd and the 3/32"- group. We all stand on our respective sides wildly shaking fists and calipers and shout out either horror stories or tales of calm/content happy veneer. I always wonder what makes the difference between success and failure in regards to veneer thickness. Why have you had fifteen years of veneer stability and I've had two failures in seven years? Like yourself and others, I like the idea of a nice thick veneer.... one that I can plane and repair if necessary. I like the idea of taking a nice board and stretching it out to cover a table top. It's nice to know that if some kid carves his initials in the kitchen table, the substrate won't show through. But, bottom line, it (the veneer) has to stay attached to the substrate. And my experience says that anything over 3/32 won't. Why? Why can you do it and I can't? Or have you simply not had your failure yet?Maybe I'll make up a few test panels, with thick veneer. Maybe I can answer the question for myself. At least, maybe, I'll further confirm what I already believe.
Personally, I don't think that 1/32" makes that much difference, either way. I wouldn't use 1/4" veneer, as I then believe that the strength of the movement of the wood will overpower the bond of the glue.
Also, I can easily see that when I use 1/8" shop cut veneers, I definately remove a little with smoothing and/or scraping for final finish. I'm not one of those guys who walks around with a vernier caliper measuring down to the last .00001, so I can't tell you exactly what the final thickness is. I get em' smooth and flat by sight and touch, and I move on to the next panel. I start out cutting them at 5/32" at the bandsaw, and remove just enough from one side on the drum sander to make em' smooth. Edge glue, tape, vacuum bag, scrape, next.....
Perhaps the strength of the glue, as well as the substrate used, is part of the equation. I always use Baltic or apple ply, and I always use plastic resin glue. Maybe other glues and/or mdf are the cause for the failures you have discussed.
Jeff
See the answer to this question or this debate is this. Those that i the 3/32 or less camp are right. lol This is because anything thicker than that shouldn't be classed as veneer. It should be classed as solid timber.lol Kaleo
http://www.kalafinefurniture.blogspot.com
I have personally had two failures in 1/8" veneer. One in honduras mahogany and the other in ash. We have very long and dry winters here. Both cases had the veneer cupping with edges coming up.... surface drying. I no longer use any veneer over 3/32 and prefer to keep it to 1/16" max.
Chances are your veneer will not be of perfect thickness after resawing so you will have to surface it in some way to get it to a consistent thickness. I suggest sawing the veneer just under .125 and then drum sand it till all the pieces have the saw marks cleaned up. It may clean up at .094, however you may find that you go down to .062 to get all the saw marks off of some pieces. Compared to most commercial veneers .062 is quite thick and in oak it would take someone a long time to sand thru on veneer that thick.
Ron
I agree with most here that 3/32 is about as thick as you want to go. I have used 1/8 before and had failures also. I would go for 3/32 and after final sand it'll be around 1/16 which is perfect. The thicker you go the more strength the wood has.
Also like everyone else have said, veneer the other side. And I would use a solid lipping around the edges instead of an edgeband. I just thinking it looks nicer.
http://www.kalafinefurniture.blogspot.com
http://www.veneersupplies.com/product_info.php?cPath=40&products_id=186
Try this glue...it's made for thicker bandsawn veneer.
Ultra-CAT™ is a high-solid content, precatalyzed plastic powdered urea-formaldehyde resin (P-PPR) veneer glue developed using catalyzed adhesive technology. Designed exclusively for vacuum press veneering, Ultra-CAT™ cures rock-hard and leaves a glue line that withstands heat and moisture. Ultra-CAT™ is highly sand-able and works particularly well with wood types that are prone to bleed-through such as burls and open-pore woods.ultracat veneer glue
Due to the rigid nature of this superb adhesive, veneers do not 'creep' with seasonal movement and seam lines are forever kept tight. Ultra-CAT™ will permanently lock-in the form of curved and contoured veneer projects making it ideal for all custom furniture projects and bent laminations. Those who are familar with Dap Glue #00204 (as used by David Marks) will find Ultra-CAT to be an excellent alternative. Ultra-CAT is also comparable to Pro-Glue and Vak Bond adhesives.
Highly Recommended For Bandsawn Veneers
If you bandsaw your own veneer and it's a bit on the thick side, you'll find that Ultra-CAT™ is the only veneer adhesive that cures hard enough to prevent creeping.
That's great glue hype but I think any urea formaldahyde glue will do the same. The problems I had in my thick veneer failures didn't reside in the glue. The cupping veneer actually broke the substrate. Just like in edge gluing, the glue proved to be stronger than the wood.
Thanks for your input. I am curious, what was the substrate that failed?
mdf
No one has mentioned the factor of the width of the veneer. If it is less than say 2" then any thickness is unlikely to split.
Also, the cut of the substrate is important. If it is timber that is backsawn then the risk of cupping is increased. If it is quarter sawn then... I'm not sure what will be the risk to veneer above 3/32".
Another factor that has be alluded to is the material of the substrate, MDF and partical boart will have movement due to humidity. Plywood is unlikely to move at all. Then if substrate movement due to humidity is significantly different to the material of the thick veneer, larger thickness will increase the risk. In the last case, orientation of the timbers can have an effect.
Anyway, my point is that there are other factors to thickness of veneers that have not been discussed in this thread.
Nevertheless, the thinner the veneer, there will be less likelihood of cupping/splitting occuring,
Like everything else in life, it is "multi-factorial".
But it is worth the effort.
Bevin
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