[huesmann]

What's the skinny on drywall primer/sealer? Something that should be done, or a scam? If the former, what's its real purpose—sealing the drywall paper, or the joint compound, or both?

Reason I'm asking: I've got some spots on an existing wall where I skimmed over some dents and unevenness with joint compound, and I'm wondering if it's worth using (i.e. buying) drywall primer/sealer before painting.

TIA!

 

[Clutchcargo]

My process is...
I sand the joint compound as smooth as I can. When I'm satisfied, I hit it with primer. The sheen of the primer reveals how crappy of a mudding job I actually did. I then go back over the rough areas with mud and hit those again with primer. My end-results are arguably between a level 4 and level 5 finish.

 

[stick\shift]

Depending on how you apply the primer, it can also help if you have a lot of texture like roller stipple on the wall. If not using primer, usually an additional coat of paint will be needed.

 

[mark sr]

Depending on how many repairs they are, I might just spot prime the repairs with the finish paint. A dedicated primer is better. If the walls have a texture [or even roller stipple] you need to texture the repairs first so they blend in.

 

[ron45]

I just use two good coats of paint and have never had any problems.

If you find any drywall that will not take paint really good without primer, call the manufacturer and tell them because their going to lose a lot of business.

 

[woodco]

I will often skip the primer for spot repairs, and its almost never a problem, as long as you're using a decent paint.

Primer is not a scam by any means, but isnt always necessary, especially with Flat paint. Its not the best idea to put semigloss on raw mud or patches, so you want to use something to prime with, even if its some other flat paint, or your ceiling paint. decent quality eggshell shoulnt be a problem on small patches without primer. It might take a third coat, it might not.

 

[huesmann]

To clarify my question: is the stuff labeled specifically as "drywall primer/sealer" necessary for either drywall or joint compound, or is regular primer/sealer (not labeled as for use on drywall) acceptable for use on both surfaces?

 

[ClarenceBauer]

https://www.usg.com/content/dam/USG...eetrock-first-coat-primer-submittal-J1095.pdf

See if this info is helpful.

 

[mark sr]

If you are talking about PVA primers [which is pretty much only for drywall] they are the bottom of the barrel when it comes to priming bare drywall. Drywall can pretty much be primed with any primer. Which one to use depends both on your budget and the top coat you expect to use.

 

[Sdiver2489]

My reason for using a good primer is a sheen/monetary one. To get a completely even sheen you often need 3 coats of paint on new walls. Couple that with the fact that the first coat or two suck into the wall and use at least 2x more paint at $60 a gallon and you have good reason to use some $15 a gallon primer to save paint in the long run.