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Is it possible to unglue PVA joints?

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Anonymous

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Hi,
I messed up the clamping on a frame containing some mortice and tenon jointed rails. Result is it is not perfectly rectangular. The glue was Evostick PVA. Is there any way to rescue the situation?
 

Chris Knight

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Hi Jimmy,

Welcome to the forum. Sorry about your frame - we've all done it at one time or another I guess.

It is very difficult to unglue the modern glues but if not the so-called waterproof kind, PVA bonds can be broken through the application of moisture and heat. Sometimes vinegar helps too.

Your problem is getting the hot moisture to the M/T joint. I guess I would try steaming it first or wetting it and using a domestic iron on high to heat it. Try sliding in a hot wet spatula or knife (if there is enough shoulder on the joint) once you get any movement, to help lever the joint apart.

If you have used "waterproof" PVA you can still stry this but chances of success are reduced.

An altogther easier solution would be to cut the joints apart, cut new mortises and use loose tenons. This would be my preferred way of tackling it.
 
A

Anonymous

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Thanks for the advice Chris. I suspected the answer would be to cut it all up again!

What are loose tenons?

Jimmy
 

ProShop

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jimmyd":1i0yf0l3 said:
What are loose tenons?

Jimmy
If you decide to cut it apart, drill or chop out the filled in mortice, then make another mortice where the tenon was. and then shape a single piece of wood to fit into both mortices and glue up again.

Hope this helps
 

samlarsen

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I recently had the same problem with a window frame. The problem was caused by leaving it to dry on an uneven floor :roll: .

I had to remedy as above, cut the joint out, rebuild tenons as loose ones.

Needless to say I'll not be doing that again....................

Cheers
 
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