# Quickset / hot mud still wet after 24 hours?



## tolem (Oct 8, 2018)

I did a few patches around the house yesterday with USG easysand 45 (mixed in a small amount of elmers glue into the water first because the walls have glossy paint). 

Everything is dry but the garage is still grey / wet in spots even after 24 hours. Its raining and the humidity in the garage is 72% RH @ 70 degrees F.

The coat is not thick, maybe 1/8th" - 1/4" max?

I thought hot mud was a chemical drying process and wasnt reliant on the humidity in the room? I've never seen it take longer than an hour to turn white / dry so I am a little concerned. Should I be?


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## ClarenceBauer (Mar 4, 2005)

The setting compounds contain a large amount of Calcium Sulfate when mixed with some other chemicals the Calcium Sulfate will be affected & in most cases it will NOT set.
Also the high humidity will affect the set time but it will set.
THERE IS A STATEMENT ON THE PRODUCT " DO NOT MIX WITH OTHER CHEMICALS"
Some Chemicals that i know of that will KILL the setting compound.
Vinegar.
Sugar
Cream of Tartar
Coke cola & most anything that contains sugar.
There also things that will cause it to set faster.


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## siffleur (Aug 19, 2013)

tolem said:


> I did a few patches around the house yesterday with USG easysand 45 (mixed in a small amount of elmers glue into the water first because the walls have glossy paint).
> 
> Everything is dry but the garage is still grey / wet in spots even after 24 hours. Its raining and the humidity in the garage is 72% RH @ 70 degrees F.
> 
> ...


To add a few things to the good advice of ClarenceBauer:

Rolling thinned down Elmer's Glue was an old trick used to help new plaster or hot mud to adhere to questionable surfaces. There are products that are out now that are specifically designed for what you tried to use Elmer's Glue for, only they are better than thinned down Elmer's glue. Here is the spec sheet for a product by Larsen called Plaster Weld:

http://www.larsenproducts.com/wp-content/uploads/2017/04/plasterweld-spec.pdf

Here is an exerpt from the specs:

Application of bonding agent: Apply Plaster-Weld® uniformly
using brush roller, or spray to form a continuous pink film
over the entire surface. Allow to dry one hour. (NOTE: Painted
surfaces must be sound, washable and firmly adhered to the
substrate. Glossy painted surfaces should be dulled with an
abrasive. 

I would imagine that if you had just sanded down the surrounding areas of where you patched you would not have needed to use either Elmer's or Plaster Weld (If you planned on painting over the glossy paint on your walls you would have done well to sand all the glossy surfaces to dull them anyway, then you would have been able to patch without any glue and paint right away after priming your patches).

If you are really worried about hot mud adhering to your patches, do a 1st coat with USG Durabond. It has more glues in it than its lighter brother Easy Sand does. Try dropping a glob of both on a floor and let them dry. You will be able to scrape up the Easy Sand with a spackle knife, but you might damage the spackle kinfe trying to scrape up the Durabond!

Painting and its associated prep work is really like doing chemistry experiments. You have discovered what does not work when using Elmer's Glue with Easy Sand. 

siffleur


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## mark sr (Jun 13, 2017)

It would have been better to scuff sand the walls with 80 grit sandpaper prior to applying the mud. I've never added glue to any mud.


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## In Ontario (Oct 5, 2018)

Yes, I agree with Siffleur and Mark Sr. Adding glue is antiquated, the answer is Durabond.


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## jeffnc (Apr 1, 2011)

"Hot mud" or setting compound sets to get hard, it does not dry. It does dry as well, but that's different. People call it "drying" all the time, but that is not true.

So it's perfectly possible in high humidity conditions and thick layers of mud (1/4" is very thick) for the compound to not be dry yet. However if it's not hard, then you have a problem.


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