# Primer for mud to plaster



## jennifertemple (Oct 30, 2011)

Someone here, a long way back, posted a comment about a special primer that causes drywall mud to adhere to plaster. Could you name the product again?
Until now I've just been using the superior adhesion, Aqua Lock by Insulex but I want to see if the special product performed better or differently.


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## TJ Paint (Jun 18, 2009)

Raw plaster?


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## daArch (Mar 15, 2008)

All purpose mud? (USG green top)

What issues are you having where mud is NOT adhering to plaster?


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## Big Hoss (Jul 7, 2012)

Plaster weld.


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## Lazerline (Mar 26, 2012)

I've never had a problem with hot mud sticking to plaster.


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## RH (Sep 7, 2010)

We're talking painted plaster right? I mud over it frequently and paint as usual. I can't imagine a scenario where you would put joint compound over fresh, unpainted plaster.


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## jennifertemple (Oct 30, 2011)

daArch said:


> All purpose mud? (USG green top)
> 
> What issues are you having where mud is NOT adhering to plaster?


I had been told that any of the usual tapping muds do not adhere to pl;=aster so before patching I have always primed the area under repair. I have now SEEN where patching over plaster failed because no prime was applied first. So, my take is that plaster needs prep before repair or it won't hold up. The job I am presently looking at was a mud skim coat over raw plaster. It held until a piece broke away, now it looks like a thin separate sheet over the plaster.


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## jennifertemple (Oct 30, 2011)

Gibberish45 said:


> We're talking painted plaster right? I mud over it frequently and paint as usual. I can't imagine a scenario where you would put joint compound over fresh, unpainted plaster.


Holes or breakage in the plaster exposes some raw plaster. Or when I need to remove broken plaster and resurface. I see a lot of that in old houses and have always used a good high adhesion primer.


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## Epoxy Pro (Oct 7, 2012)

Unless it's fresh plaster compound should bond fine. If it's falling off in chunks there is most likely an underlying issue with the wall or they used dura-bond and some how messed it up while mixing it.


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## mudbone (Dec 26, 2011)

cdpainting said:


> Unless it's fresh plaster compound should bond fine. If it's falling off in chunks there is most likely an underlying issue with the wall or they used dura-bond and some how messed it up while mixing it.


:yes:


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## Sir Mixalot (Sep 8, 2009)

The drywall mud could have bonding issues due to an old oil paint on the plaster or heavy sheen.


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## mudbone (Dec 26, 2011)

Sir Mixalot said:


> The drywall mud could have bonding issues due to an old oil paint on the plaster or heavy sheen.


I have to hand it to you Sir, you seem to not only Mixalot but you also seem to know alot! Good point!


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## 1963 Sovereign (Dec 14, 2011)

I think the product you want is called plaster weld ,made by Larsen,works great paint it on lath,or over other areas of plaster to insure a chemical bond between the two.


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## Sir Mixalot (Sep 8, 2009)

mudbone said:


> I have to hand it to you Sir, you seem to not only Mixalot but you also seem to know alot! Good point!


:laughing:......:thumbup:


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## RH (Sep 7, 2010)

Sir Mixalot said:


> The drywall mud could have bonding issues due to an old oil paint on the plaster or heavy
> 
> I'm Priming a kitchen today for just that reason. Skim coat goes on tomorrow.


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## ces (Jul 18, 2013)

Use Gardz by Zinnser to seal up the surface and then durabond for repair.


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## Masterpiece (Feb 26, 2008)

Some joint compounds could possibly not have enough glue in them to apply over plaster, topping or perhaps "lite" mud for example. They're generally not even recommended for taping though some will anyway.

I've never used all purpose so I can't comment on it but with "hot mud" I've never had any issues. In fact, I just repaired an art deco painted plaster ceiling in a historic theater that I previously repaired about 6 years ago with USG Easy Sand. It help up great with no primer until a water line burst above the ceiling.

Jeremy


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## mudbone (Dec 26, 2011)

Masterpiece said:


> Some joint compounds could possibly not have enough glue in them to apply over plaster, topping or perhaps "lite" mud for example. They're generally not even recommended for taping though some will anyway.
> 
> I've never used all purpose so I can't comment on it but with "hot mud" I've never had any issues. In fact, I just repaired an art deco painted plaster ceiling in a historic theater that I previously repaired about 6 years ago with USG Easy Sand. It help up great with no primer until a water line burst above the ceiling.
> 
> Jeremy


Been there done that! No fun when that happens.


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## Gough (Nov 24, 2010)

1963 Sovereign said:


> I think the product you want is called plaster weld ,made by Larsen,works great paint it on lath,or over other areas of plaster to insure a chemical bond between the two.


Just curious, is there a nickname for this in other parts of the country? Around here, it's universally called "moose milk".

We use it when we're patching plaster with plaster.


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## Big Hoss (Jul 7, 2012)

This stuff works great!


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