Smelly PVA?

[Richard Perkin]

Rather than any special woodworking adhesive I usually use common or garden PVA bought in 5l or 2.5l tubs (depending on what other jobs I have on at the time) from Wickes, labelled as 'Building Adhesive'. I then decant some into a small bottle for woodworking use.

Doing a little woodworking project at the weekend with several biscuit joints. Went to the shed to top up with PVA from the big tub

- only to find it had 'gone off'. With the tub was opened, the PVA smelled 'funny' and had a small number of 'cloudy patches' on the surface, perhaps the early stages of mould growth.

The PVA was last used about 2 months ago for priming a small area of brickwork (approx 1 sq m) for plastering. To the best of my knowledge no 'unclean' tools have been used in it - I usually ladle it out into a bucket before diluting it for use (when priming / plastering, that is). The brush goes in the bucket, not into the virgin PVA. For the approx last two months it's been stored in the shed.

Anyone else experienced this 'smelly PVA? How can it be avoided? What have I 'done wrong'?

Aside: I went ahead and used a small quantity of the 'smelly' PVA without apparent problems...

[David in Normandy]

I do exactly the same as you, except I use the exterior quality PVA from Wickes. That has never gone off for me. Like you I always tip some into squeezy type bottle to use for woodworking. The only time I've ever seen any "go off" is when it had been mixed with some water to "size" some walls and what remained was left in a paint tin. I can't remember the exact details - it was a number of years ago, but I remember being surprised it had gone mouldy. Black mould as I remember.

Perhaps the exterior quality is less prone to go off?

[David in Normandy]

Just remembered something else. I once bought some PVA from Homebase and it had gone off while unopened in the tub! It had gone into a sort of jelly/cheese. They swapped it for another tub.

[Andy Dingley]

Frost will kill PVA pretty quickly. One hard night will do it.

Symptoms are that it goes like cottage cheese (curds and whey) and the whey is then much more prone to mould. Unfrozen PVA will mould too, but it takes more provocation.

[NoSpam]

Strangely I had exactly this problem last night with a pot of diluted PVA which I use for sealing floors, walls, etc. Black areas in it and a smell like a used soil pipe! It seemed to seal the floor but the rest is going in the bin.

Dave

[Richard Perkin]

Andy Dingley wrote in news: [e-mail] :

I don't think it's frost that has made it 'go off'. It hadn't separated or anything - just smelled 'funny'. But thanks for the warning - next mini-project is to fit that fan heater + thermostat in the shed, just in case.

Kind regards

[Stuart Noble]

It works just as well if you can stand the smell

[Mogga]

We had some with nice mouldy bits on recently - didn't smell though so we skimmed it off and used some. Worked fine.

[TheScullster]

"Stuart Noble" wrote

Leaving plenty of time to reply in rhyme!!

[Mary Fisher]

We once worked for an educational supplier, dealing mostly with primary schools. A popular product was pva based paint, ready mixed in screw topped bottles and in a variety of colours.

One day there were explosions in the warehouse - all the bottles of brown paint had exploded, more or less at the same time.

There was an interesting mess, guess who had to clean it ... :-(

Mary