[rwb647]

I made a large wall decoration which is made of solid pine and cheap luan plywood with veneer on all sides. The veneer is all large rectangles, at least 3" x 12". The veneer is glued with TB original with the iron-on method.

My first veneer project was similar, with veneer rectangles over luan. I only put glue on the plywood. Then I ironed on the veneer and finished with shellac. The shellac made the veneer swell up and i got a lot of bubbles!

This time I put glue on both the workpiece and the veneer sheets, so the bond should be a lot better. But still, how can I make sure to avoid any swelling upon finishing? The veneer is 8 different species. Some are burl. So basically what is the absolute safest finish?

 

[lacman]

Speaking from experience, a water base finish is not the choice to start with. Instead I would use an alcohol based dye to color the piece and then you can apply waterborne or solvents based coatings. You can purchase trans-tints dye from Jeff Jewitt. His website is www.homesteadfinishingproducts.com. Buy the dye and mix in alcohol you can customize as you please.

 

[rwb647]

thank you for the reply. i am not trying to stain or dye the piece, i would just like to give it a clear protective finish. I would like the finish to be somewhat thick, to fill some tiny gaps between veneer pieces.

maybe I should start out with a couple wipe on coats of tung oil, and then build up the finish with some type of lacquer or varnish?

 

[Steve Neul]

I'm wondering if your veneer was paper backed. A lot of paper backed veneer the paper is applied with hot melt glue and using an iron could damage the adhesive bonding the paper to the veneer. Also this type of veneer can easily be damaged by the solvents in oil stain or solvents. Some paper back veneers are marked "Do not use oil stains" for this reason. If it was real wood veneer it sounds like you didn't get enough glue on it. It should have held up to the shellac finish. Next time try using a resin glue. Sometimes gluing veneer with PVA glues the glue will harden around the edges and stay wet in the center. The resin glue will harden regardless.

 

[rwb647]

both times were with raw wood veneer, no backing. OK, i'm glad to hear that shellac usually would not cause problems. this time around i put glue on both surfaces, like you're supposed to, so i hope it will be better.

i have read that the alcohol in shellac swells wood almost the same way that water does (perhaps because it picks up atmospheric moisture). So I think I will stay away from shellac just to be safe.

 

[Steve Neul]

Any solvent or water will make the veneer bubble up if it is loose. You might do a test piece with some scrap veneer and if it bubbles take a chisel and cut the bubble off and see if there is wet glue under it. I think you are just not getting the veneer glued on completely. If there is wet glue under it the resin glue will solve that problem.

 

[Rick Mosher]

The problem was putting the glue on just one surface. The shellac will be fine just reduce the first coats more and spray 3 or 4 light passes (don't flood the surface) so that it dries very fast until it is sealed off then scuff sand and apply your normal full coats. You can fill any gaps with wax sticks or burn in sticks. I prefer burn in sticks myself either Mohawk or Konig.