Bonding coat getting got to the touch

[perky416]

**getting hot to the touch

Hi guys,

Just has a strange thing happen, getting a bonding coat on the wall and i noticed it had gone rock hard within less than an hour. I then noticed the next bag i mixed had gone hard in the bucket after around 15 minutes of mixing.
I started to pull it off the wall (it was impossible to level as it was so hard) and noticed it was warm to the touch.
Then i put my hand in the bucket and everything had gone rock hard and was hot. Its 13 degrees in the room however the temperature of the bonding in the bucket was 33 degrees.

The bag says to mix it 14L of water per 25kg bag which i normally do. This mix i did it maybe 14L to 20kg so it was a little wet if anything as it looked a little thick in the bucket.

Has anybody ever had this happen? Just trying to understand what went wrong so i can prevent it from happening again.

Thanks

 

[Nige F]

Maybe the bag was out of date ?

 

[perky416]

Maybe the bag was out of date ?

Both bags i used this morning said use by september.

 

[lostinthelight]

Did you over mix it

 

[perky416]

Did you over mix it

Was literally about to ask this very thing. We put water in the bucket...half the bag...more water...more bonding...more water...more bonding...more water...more bonding.

Is it ok to put all the water in and then the whole bag all at once?

 

[lostinthelight]

WARNING!! I am not a plasterer, just someone who does a bit through necessity
I keep a little water back and add the bulk if the plaster never letting it get on the drier side.
First mix, wall too dry, room too warm?
Your second mix, could you possibly have seeded it by not cleaning thoughly between mixes?

 

[Tigercubrider]

I believe that you should add plaster to water, not the other way around? You can hold a bit back but plaster first causes lumps?
Certainly plaster of Paris generates a lot of heat when mixed.

Setting plaster is exothermic
You probably made it too strong.

 

[lostinthelight]

Setting plaster is exothermic
You probably made it too strong.

Op said second mix was too wet if anything .
You can't mix it too strong only too dry, unless thats what you meant?

 

[Alastairreid]

If the bonding is setting in the bucket in 15min its went off...how was it stored? Don't mix it too long either as you are introducing air into the mix which makes it go off faster as well.
Mix the plaster into the water.