[riccobo4]

I'm doing en experiment to test these 3 Zinsser primers and I'm looking for test suggestions.

I got a piece of drywall and spread a stripe of joint compound along its length to simulate a new wall.
Then I divided it into 6 Sections: 1 and 2 coats of each Zinsser Gardz, 123, and PVA drywall primer. See Picture.

Next I will apply 2 coats of Sherwin williams Cashmere Low Luster paint in light gray.

The question is, what is the best way to test this when done?

I can hold it up to light to check flashing
How should i test durability/adhesion? I figure I can apply different types of tape and pull it off.
Let me know what you think I should do and I'll report back with the results.

 

[riccobo4]

I just painted the board and 5 minutes later I made some observations:

The PVA (both 1 and 2 coat sections) appears significantly more dry than any of the other sections. This suggests the PVA does the worst job sealing and paint is getting absorbed.

The 2 coats of Gardz appears the most wet, suggesting it seals the best.

The 1 Coat of Gardz as well as both 123 sections are intermediate and are too close to rank.

Tomorrow I will photograph with 1 coat in the light, then put on a 2nd coat.

Who knew watching paint dry could be so exciting!

 

[cocomonkeynuts]

how do you expect to get 'flashing' on a 1x2 section of drywall?


PVA is well known to be crap. Not sure why bother to test a product thats not even worth the can they put it in.

 

[riccobo4]

how do you expect to get 'flashing' on a 1x2 section of drywall?


PVA is well known to be crap. Not sure why bother to test a product thats not even worth the can they put it in.

1) A larger sheet would be better, however each small section is half drywall paper and half joint compound so I'll be looking to see if there is a sheen difference at the transition. The test is also about adhesion/durability which I should have plenty of space to test. It's admittedly far from a perfect test but should still provide some good information.

2) It seems like the of all the professional opinions I've heard, half say its crap and the other half say for new drywall its just as good and there's no need to spend more. I even called Zinnser and they said their PVA would be just as good as their own more expensive options. Its not as settled a debate as you seem to imply.

 

[cocomonkeynuts]

2) It seems like the of all the professional opinions I've heard, half say its crap and the other half say for new drywall its just as good and there's no need to spend more. I even called Zinnser and they said their PVA would be just as good as their own more expensive options. Its not as settled a debate as you seem to imply.

The number of times PVA has caused an issue for my customers would say otherwise. Plenty of examples on DIY and PT as well.

 

[mark sr]

PVA primers are the bottom of the barrel, given a choice I won't use them. Any finish paint will preform better with a better grade of primer under it.

 

[jeffnc]

how do you expect to get 'flashing' on a 1x2 section of drywall?


PVA is well known to be crap. Not sure why bother to test a product thats not even worth the can they put it in.

Why are you even here? Just to throw in your cynical, negative, overbearing opinions over and over and over?

This is the best post in this forum in the past year. He's doing something you've never done here.

 

[jeffnc]

Good work riccobo, keep us posted. Ignore anyone too lazy to do any research themselves.

 

[jeffnc]

Standard tape test after 24 hours and again after 7 days would be good, IMO.

 

[cocomonkeynuts]

Why are you even here? Just to throw in your cynical, negative, overbearing opinions over and over and over?

This is the best post in this forum in the past year. He's doing something you've never done here.

Why would I bother to make samples of PVA? The only reason to use is it that its dirt cheap bottom tier stuff. Essentially its thinned white glue with some filler pigment. I've tested many drywall primers, spraying and brush/roll and PVA products ain't even worth the bucket the come in. I'm not going to write an entire book for information that has been rehashed 1000x on other forums like PT, but for various reasons generally vinyl acrylics and in particular PPG 6-2 and superspec 253 are the best primers I have used.



Regarding 1x2 samples boards: too small of a sample and not vertical surface, I would want to do at least an entire room with gardz make a judgement. Seems useful for large areas like ceilings.

 

[jeffnc]

I've tested many drywall primers

Then post the results rather than just shouting the first knee-jerk response that comes to your head. Hint "this one is good, this one is crap" is not very useful information, it's just noise pollution.

 

[cocomonkeynuts]

Then post the results rather than just shouting the first knee-jerk response that comes to your head. Hint "this one is good, this one is crap" is not very useful information, it's just noise pollution.

You wouldn't trust me anyway. Go spray some 123 or any other 100% acrylic then spray some PPG 6-2. One has good sheen hold out and doesn't sting your eye balls.


I have only used small amounts of gardz so I would be interested in how it sprays and how fast the odor dissipates.

 

[kwikfishron]

Some post were removed.

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https://www.diychatroom.com/f4/prim...s-pva-primer-678513/f114/diy...-rules-281002/

 

[riccobo4]

Standard tape test after 24 hours and again after 7 days would be good, IMO.

When you say standard tape test, Are you referring to the test I just now googled involving cutting an X then pressing on and pulling off masking tape?

I was originally planning to just stick different tapes on the paint (no cuts) and removing them. (yellow frogtape, green frog tape, 3m command strips, duct tape etc). I was also thinking of gluing something on permanent and ripping it off just to see where the failure point is.

 

[jeffnc]

Actually I wasn't aware of Xs, I was just talking about pressing it on and pulling it off. But if you've found a better test, go for it.

 

[cocomonkeynuts]

When you say standard tape test, Are you referring to the test I just now googled involving cutting an X then pressing on and pulling off masking tape?

I was originally planning to just stick different tapes on the paint (no cuts) and removing them. (yellow frogtape, green frog tape, 3m command strips, duct tape etc). I was also thinking of gluing something on permanent and ripping it off just to see where the failure point is.

http://www.galvanizeit.com/uploads/resources/ASTM-D-3359-yr-2010.pdf


There are certain approved tapes but regular scotch 3850 packing tape works.


Test method B (cross lattice cut) is more suitable for your test application.

 

[jeffnc]

That document is for metal substrates, but the test is used for other substrates as well. The problem with that method over a substrate like drywall is that you can't avoid cutting through either the paper, or the primer, or the joint compound, and doing any of those can invalidate the results (can't happen over metal). So, I was talking about simply putting masking tape on firmly and pulling it off.

 

[cocomonkeynuts]

That document is for metal substrates, but the test is used for other substrates as well. The problem with that method over a substrate like drywall is that you can't avoid cutting through either the paper, or the primer, or the joint compound, and doing any of those can invalidate the results (can't happen over metal). So, I was talking about simply putting masking tape on firmly and pulling it off.

Yes that is an issue however I'm unaware of any other standardized testing other than just using some 2060 tape. I would be surprised to see any adhesion issues to mud though. Only issue I ever heard of was a thread on PT and I think the consensus was it was due to an incompatibility with dust control mud.
https://www.painttalk.com/f2/gardz-problems-adhering-drywall-mud-82049/

 

[jeffnc]

Well that was an interesting thread. It's hard to believe Dust Control compound has any wax in it, because that's an obvious no-no to paint over. But for whatever reason, I don't rely on it anyway so I will avoid it for now.

 

[cocomonkeynuts]

Well that was an interesting thread. It's hard to believe Dust Control compound has any wax in it, because that's an obvious no-no to paint over. But for whatever reason, I don't rely on it anyway so I will avoid it for now.

https://patents.google.com/patent/US20170233293A1/en