Which glue ? (for a backside veneer repair)

[Henry W]

I think I know the answer, but I want to hear it anyways.

Here's the repair - a backing 'veneer' from a table leaf. It was starting to warp and I suggested to my friend that this was clearly water absorption - and was he sure he did not have roof leaks and mold in this closet where the leaf was stored (no evidence of mold on the leaf itself). He did not have leaks or mold, and I took the piece home. Uppn more careful examination I realized that 80% of the backing veneer had lost glue contact with the core, and so the piece was warping. I removed the veneer in its entirety rather gingerly (I did not want to have to refinish anything here).

SO what I have it the original piece, and the backing veneer, all in usable shape (front is without issue; the multi-layer backing veneer is 95% intact, and there is 1005 coverage of the glued area). There is/was no tear out with veneer removal. Glue residues on both sides (?) - I can't recall exactly.

So maybe a 60+ year old table. I am assuming this is hide glue. Am I correct?
If so, is heat activation with an iron 'enough' to re-glue this? Or do I add some of the modern versions of hide glue (Old brown glue?) - or something like that? Do I scrape away the old glue or re-activate it?

Advice welcome.

Goal here is to restore the leaf to flatness with minimal (NO) refinishing.

THanks

 

[Chris C]

New hot hide glue will reactivate the old hide glue. Liquid hide glue will not.

You could gently steam the old and scrape it off. You could probably gently heat with a heat gun and do the same. Or you could just add new to the old... but I'm not sure what the effect of the added glue would be on the finished veneer.

 

[Tarhead]

I would put together a press whichever direction you go with the glue. Unibond (Urea Formaldehyde) in a warm environment(>70f) is what I would use after removing the old glue. Lots of open time and no creeping joint. I would be surprised if it had hot hide glue on it if it came out of a factory in the 40s-50s. Probably resorcinol-formaldehyde.

 

[walnutjerry]

I think I know the answer, but I want to hear it anyways.

Here's the repair - a backing 'veneer' from a table leaf. It was starting to warp and I suggested to my friend that this was clearly water absorption - and was he sure he did not have roof leaks and mold in this closet where the leaf was stored (no evidence of mold on the leaf itself). He did not have leaks or mold, and I took the piece home. Uppn more careful examination I realized that 80% of the backing veneer had lost glue contact with the core, and so the piece was warping. I removed the veneer in its entirety rather gingerly (I did not want to have to refinish anything here).

SO what I have it the original piece, and the backing veneer, all in usable shape (front is without issue; the multi-layer backing veneer is 95% intact, and there is 1005 coverage of the glued area). There is/was no tear out with veneer removal. Glue residues on both sides (?) - I can't recall exactly.

So maybe a 60+ year old table. I am assuming this is hide glue. Am I correct?
If so, is heat activation with an iron 'enough' to re-glue this? Or do I add some of the modern versions of hide glue (Old brown glue?) - or something like that? Do I scrape away the old glue or re-activate it?

Advice welcome.

Goal here is to restore the leaf to flatness with minimal (NO) refinishing.

THanks

I have been told denatured alcohol will reactivate hide glue. May want to spritz a little on a small area and see what happens. I was told it softens the old glue and then the glue adheres as the alcohol evaporates.

 

[Oka]

Heat will loosen real hide glue ... assuming it is real hide glue needs to be around 150 deg

Biggest problem you have is the potential of warping out the veneer. On instrument repair we heat the scraper and slowly remove the glue that way minimizing the trauma to the material you want to reuse.