Wondering if people are generally gluing both surfaces when using paper-backed veneer in a Vacuum press. I always have done this but I'm about to do A LOT of it and would like an excuse not to do that. Thanks
[OP]
Member
Wondering if people are generally gluing both surfaces when using paper-backed veneer in a Vacuum press. I always have done this but I'm about to do A LOT of it and would like an excuse not to do that. Thanks
Contributor
What glue? In a vacuum press I’d be using epoxy or PVA. Spreading glue only is n on the substrate is sufficient.
Contributor
I've glued up a few hundred sq ft of paper backed veneer in a vacuum press. All of it was done with Unibond 800. Apply glue only to the substrate. Zero issues. I've also done smaller pieces with contact cement w/o issue. In that case, you apply the cement to both surfaces. I'm pretty sure plain old yellow glue works fine with paper backed veneer, too, but I've never used it.
John
[OP]
Member
Sorry, PVA
Contributor
Substrate only. Pva is what I use on paperbacked veneer.
Second Unibond 800. When you buy some you will also feel better about calling them and asking them questions. The owner of Vacupress is a good guy (as far as I can tell) and is very smart when it comes to veneering. They have a forum on his site too which covers a lot of good veneer specific questions.
Contributor
I also use unibond 800 and only put the glue on the substrate. For smaller pieces or for something I need quick, I may use a PVA based veneer glue like better bond.
Contributor
I use pva for paperback because it requires no mixing, is relatively inexpensive, nontoxic, easy to clean up and rigid enough for the material. I save ppr and epoxy for jobs needing extra rigidity, working time or water resistance. I use contact rarely for small areas where clamping is impractical.
From https://www.oakwoodveneer.com/tips-info.html
4. WHAT TYPE OF GLUE SHOULD I USE TO HOLD THE VENEER IN PLACE?
The best glues to use are urea formaldehyde, white or yellow PVA (wood glue) or epoxy. With these glues, however, you must keep consistent pressure on the surface during the glue’s cure time by means of clamping or pressing in a hydraulic or vacuum press. If these pressing methods aren’t available to you, an instant bond can be achieved with contact cement and the appropriate veneer.
Contributor
Do you mean apply glue to both substrate or veneer (as everyone assumed you meant, and perhaps they're right..) or gluing veneer onto only one side of the substrate (which I know we're told to never do).
But I do it fairly often, and use polyurethane glue for those applications, so no water is involved causing differential moisture issues. I'd think particularly with paper backed veneer this would be fine. I think polyurethane glue (Titebond poly or Gorilla are what I've used) is underrated as a veneering glue. Use as thin a coat as your patience allows , spreading with a thin piece of wood used like a putty knife for spreading.
Contributor
Whether you use a water based glue or not, a balanced panel with veneer of similar characteristics on both sides is best practice to avoid warpage. Paperback is less prone to movement as the wood layer is typically so thin, but the potential can't be ignored. Most shops at least use a backer such as Gatorply to deal with the issue.Originally Posted by al ladd
Contributor
I'm not a fan of paperbacked veneer. All you are gluing to the substrate is paper. You have to rely on the bond from a vendor who glued the paper to the veneer. I've read about issues with applying a hot solvent finish like lacquer to the veneer and a couple bubbles appear since the solvent from the lacquer soaked through a section with vertical grain in the veneer and the bond released between them. If you must buy an assembled sheet of veneer, double ply (two layers of wood veneer) or phenolic backed, are far superior. I've also read about contact cement being used on an end table that was put in front of a south facing window. On an intense solar day, the contact cement softened and bubbles appeared. I had a personal disaster with contact cement too. Laid on a sheet on a desk with large radii on the ends. I thought my only option was contact cement. The humidity came way up over the weekend, and came in Monday morning to see the sheet has released in a couple of places on double ply. It took hours to rebound that sheet.
mahogany desk.jpg
Contributor
Paperback veneer is a compromise, for sure. You do, obviously, rely on the manufacturer for the glue bond. I prefer to have control over the leaf selection and arrangement that raw veneer allows, but the labor savings of sheet veneer are undeniable. I don't have experience with two ply or phenolic backed so can't comment. I have laid many hundreds of square feet of paperback with success. One problem with surface checking may have been due to a problem with the veneer/paper bond, but it was never definitely sussed out, otherwise the material I have used (mostly from Oakwood) has been reliable. Contact is not something I like to use, and would certainly avoid it on all but small areas.
One glue option that has not been mentioned is FSV, a high/fast tack pva that can be laid with a pinch roller or hammer/scraper. https://veneersystems.com/product/fs...neer-1-gallon/ My preference is for regular pva with a vacuum press.
Contributor
The other thing I don't like about paperback veneer is it usually telegraphs any joints in the substrate underneath it. Wood backed/two ply/NBL veneer hides the joints much better.
Contributor
I only apply to the substrate. You don't want it too thick as the glue will flow into pools and create high spots. Adhesion shouldn't be an issue. Despite what some say the glue actually does adhere to the wood because the paper is not water proof. The horror stories you hear about bubbling and peeling are from those who did something wrong along the way and think correlation is causation.
Posting Permissions
Reply With Quote