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Disolving PVA glue?

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Forum topic by Bill White posted 02-15-2017 04:28 PM 1563 views 0 times favorited 6 replies Add to Favorites Watch
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Bill White

4799 posts in 3793 days


02-15-2017 04:28 PM

Topic tags/keywords: question

A very good friend has asked me to repair what WAS a nice walnut pedestal side table. Quite small, but with some nice features.
Problem is that at some time, an idiot slathered PVA glue all over the leg (3) joints and the tenon/mortice joint holding the small top to the column. This glue is all over the would-be joints and other surfaces.
The table will undoubtedly have to be refinished which is not the issue. I just need to figure a way to get all this crap out of (and off of) the joints so I can proceed with the real resto.
Once I get it clean, I will have to repair dowels, surfaces, and re-glue.
Any ideas as to how to get this old glue off without changing the color of the walnut?
Operators are standing by for your learned answers.
Bill

-- bill@magraphics.us


6 replies so far

View HokieKen's profile

HokieKen

4503 posts in 971 days


#1 posted 02-15-2017 04:51 PM

I have heard that methylated spirits dissolve PVA but that you have to use a syringe or something similiar to get it into the joints thoroughly. Never tried it, just remember reading it. I wouldn’t think it would affect the color of the wood but I’d put some on a piece of scrap first to be sure.

Good luck!

-- Kenny, SW VA, Go Hokies!!!

View JBrow's profile

JBrow

1269 posts in 753 days


#2 posted 02-15-2017 06:37 PM

Bill White,

A non-water resistant PVA glue can be softened with water. I have also heard that methylated spirits, acetone, and vinegar can also weaken and/or remove PVA glue.

I have not tried methylated spirits, but I have recovered from major glue-up blunder with PVA (indoor, i.e. non-water resistant) glue. I let the 6” long dado and tongue joint soak in a bucket of water for I think about 6 hours. That was enough for the glue to soften and joint to come apart. I observed some staining on the wood along the water line but the staining was easily removed with normal sanding. Since a lot of water can enter wood setting in a bucket, I do not necessary recommend my bucket approach; but if water can be kept in a joint long enough it should come apart.

I have tried acetone and vinegar to remove cured non-water resistant PVA glue from the surface of a walnut scrap. The scrap walnut was where I mixed some of my own wood filler with PVA glue and wood dust. This left a layer of clearly visible glue that had cured for at least a week on the surface.

I soaked a paper towel with acetone and rubbed across an area of the glue (as if hand sanding). Some glue was removed but it was a slow go. When I soaked a paper towel with white vinegar and then rubbed the glue spot I was surprised to see the glue disappear from the surface. My conclusion is that both acetone and vinegar are effective agents for removing non-water resistant PVA glue on an unfinished wood surface but white vinegar works faster. But then I am not sure whether it was the acetic acid dissolved in water (that mixture constitutes white vinegar) or simply the water in the vinegar that was the effective agent. Since I did not try plain water, plain water might be worth a first try. If you try plain water, distilled water would reduce the chances of any mineral staining problems that might otherwise emerge if tap water is used.

Probably obvious; any finish that was applied over the glue would have to be removed to expose the glue before water, acetone, or white vinegar would be effective.

View Gene Howe's profile

Gene Howe

9745 posts in 3261 days


#3 posted 02-15-2017 07:18 PM

Vinegar will soften even Tite Bond lll.

-- Gene 'The true soldier fights not because he hates what is in front of him, but because he loves what is behind him.' G. K. Chesterton

View Loren's profile

Loren

9602 posts in 3481 days


#4 posted 02-15-2017 07:36 PM

hot knife. I’ve removed guitar bridges and
fingerboards this way. Also works on hide
glue.

The issue with solvents is they may damage
adjacent finished surfaces.

Steam also softens pva glue. I used to make
barrels (for conga drums) and experimented
a lot with steam and glue.

View wseand's profile

wseand

2796 posts in 2875 days


#5 posted 02-15-2017 08:09 PM

Acetone will pretty much eat any glue.

View Tennessee's profile

Tennessee

2587 posts in 2347 days


#6 posted 02-15-2017 09:04 PM

Agree with Loren.
Hot knife will soften and loosen without all the water, chemicals, and other liquids possibly allowing it to flow into areas before you get it off.

-- Tsunami Guitars and Custom Woodworking, Cleveland, TN

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