Darryl Keil Last Activity 2026-01-12 8:29 AM
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Ken Krawford

 
Subject : Veneer adhesive problem
Posted : 2000-07-31 9:10 PM
Post #30671
I am a hobbyist doing a first time veneer project and need a little advice. I'm applying Birdseye veneer to MDF panels. The panels are clamped for 24 hours. I have experienced varying degrees of bubbling after the glue dries. I tried Titebond and WEST epoxy with similar results. The bubbles became most noticeable after applying a water based lacquer finish (Hydrocote) but are sometimes visible before finishing. Any suggestions would be appreciated. Thanks!



 
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William Tandy Young

 
Subject : Veneer adhesive problem
Posted : 2000-08-02 9:13 PM
Post #30678 - In reply to #30671
The source of the problem might also be the MDF. Different brands of MDF have different densities. Your board may be a lower density brand, and if so could be absorbing too much glue when you press your veneer, leaving areas that are glue-starved. This is particularly a problem with marine epoxy systems like the WEST system, because as mixed, they are really too thin to be used for gluing wood. You have to thicken them up with silica or microballons in order to use them effectively as wood adhesives. The best way to veneer MDF using epoxy is to mix up an unthickened batch of epoxy and "wet-out" the surface of the MDF. This pre-loads the porous surface with epoxy. Then, mix up a batch of thickened epoxy and use that to press your veneer with. Do the veneering before the wet-out coat hardens. A vacuum system is highly advisable. If you use one, cut back on the amount of vacuum you pull. 7-12 in. of mercury ought to be enough. More pressure will drive out too much epoxy and starve the bond line. Epoxy requires a thicker bond line than ureas or PVA's.Final note: if you think you have problem veneer, be sure to scuff sand the glue side before pressing it, to help promote optimal adhesion. Every little thing helps.




 
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Darryl Keil

 
Subject : Veneer adhesive problem
Posted : 2000-07-31 9:51 PM
Post #30672 - In reply to #30671
Dear Ken,Without some question I cant be sure what the problem is, but I suspect you are not getting uniform pressure. I am assuming you are using clamps to press with. If you are using a vacuum press be sure you have a caul between the bag and the veneer, a caul being a sheet of 1/4" or thicker material, usually masonite.The bubbles show up when you applied finish because the water in the hydrocote swells the veneer revealing unglued spots, but they were already there just waiting to be discovered. In fact, wiping a veneered piece lightly with water after pressing is an excellent way to locate unglued areas.SincerelyDarryl Keil: I am a hobbyist doing a first time veneer project and need a little : advice. I'm applying Birdseye veneer to MDF panels. The panels are : clamped for 24 hours. I have experienced varying degrees of bubbling : after the glue dries. I tried Titebond and WEST epoxy with similar : results. The bubbles became most noticeable after applying a water : based lacquer finish (Hydrocote) but are sometimes visible before : finishing. Any suggestions would be appreciated. Thanks!




 
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Ken Krawford

 
Subject : Veneer adhesive problem
Posted : 2000-08-01 11:53 AM
Post #30674 - In reply to #30672
: Dear Ken,: Without some question I cant be sure what the problem is, but I suspect you are not getting uniform pressure. I am assuming you are using clamps to press with. If you are using a vacuum press be sure you have a caul between the bag and the veneer, a caul being a sheet of 1/4" or thicker material, usually masonite.: The bubbles show up when you applied finish because the water in the hydrocote swells the veneer revealing unglued spots, but they were already there just waiting to be discovered. In fact, wiping a veneered piece lightly with water after pressing is an excellent way to locate unglued areas.: Sincerely: Darryl KeilThanks for the quick reply. I'm clamping a 2x4 framework covered with 3/4 melamine and as many clamps as I can muster. Is Titebond just as good as epoxy given the price differences?Do you sell your adhesive in anything smaller than gallons?Thanks again.Ken Krawford




 
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Darryl Keil

 
Subject : Veneer adhesive problem
Posted : 2000-08-01 7:41 PM
Post #30675 - In reply to #30674
: : Dear Ken,: : Without some question I cant be sure what the problem is, but I suspect you are not getting uniform pressure. I am assuming you are using clamps to press with. If you are using a vacuum press be sure you have a caul between the bag and the veneer, a caul being a sheet of 1/4" or thicker material, usually masonite.: : The bubbles show up when you applied finish because the water in the hydrocote swells the veneer revealing unglued spots, but they were already there just waiting to be discovered. In fact, wiping a veneered piece lightly with water after pressing is an excellent way to locate unglued areas.: : Sincerely: : Darryl Keil: Thanks for the quick reply. I'm clamping a 2x4 framework covered with 3/4 melamine and as many clamps as I can muster. : Is Titebond just as good as epoxy given the price differences?: Do you sell your adhesive in anything smaller than gallons?: Thanks again.: Ken KrawfordDear Ken,Although I am not a big fan of epoxy for veneer because it bleeds through so heavily, in your case it may be better than a yellow glue because it has some ability to fill the areas on your piece that are not receiving adequate pressure. Also, I would double up on your melamine cauls so you get 1 1/2" each side, this may solve your problem. Uniform pressure is a must for successful pressing.To your second question, we do carry Unibond 800 in half gallons.SincerelyDarryl Keil
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