Repairing Bubbled Veneer
From contributor M:
Maybe you could also try poking a small hole in the veneer to let the air out before you reheat the glue.
From contributor W:
I've had this problem before. The advice so far is good. Poke a hole, re-heat and roll is about all you can do without re-veneering.
In the future, use a 2-ply veneer. The thicker your veneer, the less likely you'll get bubbles. Also, if you spray a lacquer finish, make sure you use a water based contact cement. What might have happened in your case is that the thinner in your finish coat loosened up your contact cement.
From contributor S:
The operative word here is phenolic. That is the same substrate as Formica laminate. There is absolutely no chance that any surface solvent is loosening the contact cement either by liquid or vapor penetration. Phenolic is impermeable. Also, it is even more stiff than a wood cross ply veneer. So the only culprit here is simple glue failure from either misapplication or contamination on the surface under the veneer.
From contributor K:
I agree with contributor S - the lacquer most likely did not loosen your contact cement. The fixes mentioned above are the way to go. The only thing I would not do is poke a hole. I would carefully slice with the grain and make sure you cut through the phenolic backer.
If the iron won't set the glue or after the glue cools, it releases again, you might have to inject a little more adhesive into the bubble and then use the iron again.
All this advice is assuming the failure is in the glue line that you applied and not in the manufactured product, i.e. in the glue line between the phenolic and the veneer face. If this proves to be the case you might have to re-veneer. Nine times out of 10, though, it is the contact cement. Sometimes the contact cement hasn't flashed off completely and as it gasses off after the veneer has been applied, it creates a bubble.
Try the incision and iron method first. Also, FYI when applying the veneer with this method - you should stay away from using a J roller to apply the pressure. Wood veneer and especially maple veneer moves a lot and the J roller does not give you enough PSI on that type of glue line. A veneer hammer or scraper is much better. A veneer that moves a lot will bubble if there is a weak spot in the glue line.
Out of curiosity, is the veneer backed with an actual phenolic regrind or a polyback backer? There is a difference, but some suppliers use the terms interchangeably. This might slightly alter your approach to your fix.
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