How long should I wait after metal etch before applying Epoxy primer? How long can I wait to apply? I want to apply the etch wash but won't be laying Epoxy primer for a week-OK or not? Just trying to cut down on flash rust.

What brand...which product?
Have you checked the tech sheets??

Do it now, and then do it again before you paint. It only takes 5 minutes to etch the car. Make sure it's all dry before priming. About 10 minutes should do.

The flash time for etches in general to prime are around 30 mins.
You MUST make sure that the etch is dry before you apply anything. With the etch I use I wait 45 mins.

Pretty much all etches have a time frame of topcoating within 24hrs. After that 24hrs has expired you need to rescuff and reapply etch.
Now not ALL etches are like that, PPG's 3 main etches are scuff and reapply.
Dupont's variprime is just scuff.
A red scuff pad will work fine when scuffing that etch.

Like mentioned before look on the tech sheets for specific information, or state what product you are using.

Using all S-W product and they don't really have tech sheets. I'd love to go elsewhere but they about it for 20 miles in any direction.

I have S-W final wipe, S-W triple-Etch, and S-W 5214 Epoxy Prime.

Sherwin Williams has some Great Products!
I used SW products for about 6 yrs, and it is still my first choice when I do my own stuff.
Should be able to find anything you need here:
http://www.sherwin-automotive.com/reference/pds_catalog.cfm

My bad, I was looking at S-W, but can't get it locally so I'm going with M-S, they have a terrible web site, no information.

Originally posted by dennis68:
My bad, I was looking at S-W, but can't get it locally so I'm going with M-S, they have a terrible web site, no information. Yea, Same stuff, different numbers....
If you can manage to figure out what the equivalent SW number is.........

The M-S web page is fine, here is the page to find the tech sheets. (Click here) (http://www.martinsenour-autopaint.com/refmaterials/refmaterials.html)

If you are using the "Vinyl wash" 8827 etch, you MUST recoat within 4 hours!! You can not sand it, you MUST recoat it with it's self if you let it go more than the 4 hours.

Trio/PRIME etch is much more forgiving, though it isn't a good an etch as the Vinyl Wash.

Originally posted by MARTINSR:
The M-S web page is fine, here is the page to find the tech sheets. (Click here) (http://www.martinsenour-autopaint.com/refmaterials/refmaterials.html)

If you are using the "Vinyl wash" 8827 etch, you MUST recoat within 4 hours!! You can not sand it, you MUST recoat it with it's self if you let it go more than the 4 hours.
Must re-coat within 4 hours and CANNOT sand-what would happen if it were to be sanded after application?I washed the whole car in etch about a week ago, I will be needing to scuff some off for welding/filler work.

Lets just clarify what you did. You sprayed 8827 Vinyl etch primer?

If you did you can sand the area off to metal work but you WILL need to reapply the 8827 over it's self where it is left prior to applying anything else. And you will need to apply that urethane primer or what ever you plan on using within the four hours.

NO spray, I just washed by hand with a red scotchbrite pad some triple etch.

Ahhhhhh, "Triple Etch" is not wash primer. So you didn't use 8827 Vinyl wash primer at all?

Triple Etch # 6877 leaves a layer of Zinc Phosphate on the metal. You leave it there to prime over.

Be sure you sand it all off before applying any body filler. Filler over the zinc is a no-no.

OK, thanks for the help.