Tanalising and PVA

[Steve Maskery]

Morning all,
One for Scrit, probably.

My neighbour and I are making some replacement sashes for his house. We have to cut an angled double rebate in the bottom after the sahs has been assembled. Given that Tanalising is essentially a surface treatment, there doesn't seem much point in having them dipped, then gluing up only to cut a load of it away. Better to glue up, rebate, then tanalise the finished sash. But will the waterproof PVA (the blue Evo-Stick bottle) be affected by the dipping?

Cheers
Steve

 

[Scrit]

Hi Steve

This begs the question of how waterproof is weatherproof PVA I suppose. Being me I probably wouldn't trust a D3 (cross-linked) PVA in this situation and would opt for a UF (urea formaldehyde) glue such as Extramite or Cascophen as they are really good in wet environments. That's what living in the Pennines does for you! Given that I've seen some softwood sash windows put together with hide glues which have done 100+ years without preservatives - but they were painted regularly with the right paints (i.e. not latex) and they weren't facing into the weather, either.....

If you are going to treat then do it after assembling as tanalith (and other commercial preservatives) are essentially all oil/petrochemical derivatives and I don't think that oiling the joint is going to enhance the quality of the glue bond!

Probably the best person to ask would be Mr Grimsdale as he builds/repairs sash windows - Jacob, are you there?

Scrit

 

[Steve Maskery]

Thank you Scrit. Much appreciated.

We've decided to glue them up, rebate the bottoms and then dip. The tank can submerge 20", which is a tad over our maximum width.

We have glued up 10 frames this afternoon. We are havving to do it all in fairly short sessions (today's has been the longest for months) as Brian is still recovering after falling off a ladder.

We've made these frames using the new Festool Domino machine. It doesn't half speed up the joinery! Twin tenons at each corner. But that's 16 mortices to glue up simultaneously, we have to be quick.

I just hope he's measured up correctly!

 

[lugo35]

hi i assume that the tanalising you are useing is the cupranol type stuff(like white spirit). i have used that in joinery used to work at for 12yrs, painted on with a brush and never had a prob's with PVA. hope this helps