Hello,
Heard from a plasterer that if the plaster is on the job site too long, it may not work when it is time to put it on the wall board. Is this true? I can understand if the stuff absorbs moisture but if it is dry??? How long is too long to be on the job site?
Turtleboy
Replies
yeah that's correct
here (the UK ) they print a use before date on the bag.
I think it absorbs moisture from the air and that starts it setting so when you come to mix it up it sets much faster than when its fresh.
much the same as cement I assume.
cement is now becoming available in plastic bags instead of the old paper.
I saw a couple of bags on a manufactures stand last year that had been underwater all day and were still soft.
aleks
I have a little leftover portland stored in those nylon bags they give you for termite fumigation. Some day I'll try it and see if the bagging helped.
-- J.S.
i'm pretty sure its all to do with keeping the moisture at bay.
even a brand new unopened bag of cement if left in the garage will turn into a solid block if left long enough. probably about a year in my experience.
aleks
Plaster sold in the US has born on dates stamped on the bags. Provided it is stored in a dry area it has a shelf life of six months. You can use material past that date, but you risk that it will set prematurely or not trowel consitently. Quality plaster work must be smooth and polished the first time. Sam