What causes adhesive to set rapidily?

[carryoncamping]

Just mixed a bag of drywall adhesive (for dot & dab) and it set like a rock in 20 minutes I used clean fresh water in a 'bath' that was reasonably clean (slightly dusty and the odd 'crumb' of old adhesive, and the use by date was Jul 2008.

What would cause it to set so quickly? Can mixing too long do it? Poorly stored adhesive?

Cheers

 

[Richard C]

Are you referring to Gyproc Bonding (plaster) or Drywall Adhesive; I always use proprietary adhesive for dot & dab as it stays workable for longer. Storage conditions are important; with all the rain we’ve had this year, storing in a damp garage or shed for a couple of months won’t help. I've had a couple of bags of plaster & adhesive stored in my fairly dry garage (left over since January) & I’m about to finish off an en-suite, it’s still well in date but I won't take a chance on it as I’ve been caught out in the past; it’s going in the skip & I’ll get some fresh. Over mixing & aeration will also cause it to go off more quickly as will traces of old plaster/adhesive in the tub.

 

[carryoncamping]

I mixed another bag today with a very clean tub and fresh water and the same thing happened. So, I'm taking the rest of the bags back to buildbase to exchange. I wouldn't mind if I'd stored them for weeks in a damp garage, but I only bought them on Tuesday!

 

[diyisfree]

Carryon,

I always buy my plaster from one of the big sheds. B&Q turn over vasts amounts so you are always sure to get fresh gear.

I got some the other week and it was still warm

Lot of the smaller builders merchants seem to store in some run down shack with a leaky roof and they always have their pallets under visqueen.

 

[noseall]

bonding compound should hold off for ages. certainly more than 20 mins. knauf or lafarge is workable for ages.
too long sometimes.

old or exposed gear will go off pretty rapid. it may even produce heat if it goes off quickly enough.

are you using clean water or water from a dirty bosh?

 

[carryoncamping]

bonding compound should hold off for ages. certainly more than 20 mins. knauf or lafarge is workable for ages.
too long sometimes.

old or exposed gear will go off pretty rapid. it may even produce heat if it goes off quickly enough.

are you using clean water or water from a dirty bosh?

I'm using a brand new tub and fresh tap water. Just mixed a bag I bought a month ago and it stayed 'gooey' for at least 90 minutes.

I took my remaining bags back to Buildbase and they said there had been other complaints. So it looks like I got a duff batch.

Cheers