I confess that I’ve not read the links about using the paint stripper to break-up and/or remove modern white and yellow carpenter’s pva glue, BUT:

Many have the fantasy that real hide glue is “easy” to reverse in taking things apart, and that PVA glues are practically modern “waterproof” ones. The later versions of Titebond will be more robust than original PVA, but the latter is in some cases easier to disassemble than well-applied hide glue.

A simple application of a strong solution of alcohol in warm water will often degrade PVA glue enough to pull pieces apart in a fraction of the time it would take to thoroughly soak and heat hide glue. A colleague on this list once presented at my shop with a rescued ZHI Flemish harpsichord whose amateur builder had attempted to glue in place the 8’ hitchpin rail with PVA and inadequate clamping. It was failing, but not failing enough to pop out cleanly.

Because PVA glue is reputed not to bond well with cured residues of itself, we were obliged to remove the rail (in one piece to avoid having to make a replacement) and to remove as close to all of the original glue residue as possible, before regluing the rail using hide glue and trenails for insurance.

We applied a warm mixture of about half-and-half water and alcohol and in fairly short order the glue started turning into something resembling ricotta or cottage cheese, and within the hour we had the rail out, cleaned up ready for re-gluing, and the gluing area stripped almost perfectly clean. All went swimmingly.

How the alcohol would attack something like Titebond II or III is another matter.

But I think the alcohol solution would be a bit less unhealthy than paint stripper.

owen


> 
> 
> 
> Date:    Wed, 13 Apr 2016 08:30:13 -0500
> From:    Borys Medicky <[log in to unmask]>
> Subject: Safe removal of dried carpenter's glue
> 
> Hello all... I have been reading blog posts written by those that restore or conserve antiques, since it occurs to me that some of the problems they deal with are not unlike those faced by us in the harpsichord world.  Specifically, both groups must sometimes make minimally invasive repairs, as well as deal with previous repairs that were poorly done and are now interfering with the successful resolution of new problems.
> 
> I thought it might be of interest to give a link to several posts which talk about the use of a specific formulation of paint stripper to safely remove dried carpenter's glue (i.e. white or yellow PVA glue).  The blog author was, earlier in his career, chief conservator at the Smithsonian in Washington, D.C.
> 
> http://donsbarn.com/weeds/
> http://donsbarn.com/using-safest-stripper-in-furniture-conservation-i/
> http://donsbarn.com/my-favorite-safest-stripper-application/
> 
> In a nutshell, a dibastic-ester (DBE) formulation of paint stripper will remove dried carpenter's glue residue, and interestingly enough, has essentially no impact on natural oil or resin finishes (i.e. shellac).
> 
> I know it's possible to remove glue by soaking, scraping and/or applying heat, but there might be situations where such techniques won't be entirely successful, so the above information might prove useful.  I, for one, was not aware that there was a chemical means of removing such glues.
> 
> BM
> 

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