which prep? Longterm

If you were going to prime or protect everything, what would you do? I 've heard talk of 409 and hot water and scotchbrite etc and self etch etc......... I think I like PPG 1791/1792. What are peoples favorite for long time corrosion protection and such...? (cause this will be a several year project) And no I'm not trying to start primers wars all over....(ducking for cover)... mebe ppg 1791/2 and then alodine when I drill?
I dont want to use Zinc Chromate because of it's hazardous properties.
Best
Brian Wallis
404-405-1315

On the stuff that I am going to prime that needs to be tough and have good protection, I use the (Stewart Systems) AFS waterborne system.

Drill, debur, dimple
Scrub with maroon scotchbrite with their EKOETCH (Non hazardous version of Alumiprep)

Then I shoot their Waterborne non hazardous primer on with an elcheapo HF suedo HVLP gun

Water cleanup

This stuff dries so you can work with it in about 2 hours, a little longer when it is cold. Full toughness overnight.

It is way tougher than rattle can self etching or other single stage stuff but not as tough as two part, close but not quite.

I skip the entire alodine step due to the fact that that stuff is nasty and I don't want to work with it.

Right now I'm using a wash primer. Very soon I'm switching to Strontium Chromate epoxy primer.

I just want to elaborate a bit more, since I have given this alot of thoughts (this doesn't mean I'm correct though). Alodine + zinch chromate give superior corrosion protection, but is not the industry standard. Zinc Chromate is illegal in Europe due to environmental/health reasons. Alodine is available but requires special disposal handling. The industry standard is:

* Clean/passivate with etching solution
* Non chromate wash primer (with zinc oxid)

OR

* Alodine

Then

* Strontium chromate epoxy primer
* Polyurethane top coat(s) (preferably, or some other)

On internal parts it is enough to clean/pasivate and a layer of Str Cr epoxy.

The "main ingredient" is the strontium chromate epoxy. This gives superb corrosion protection and superb strength, chemical resistance, is 100% water proof, stick like glue and act as an excellent base for top coats. It is vastly superior to zinc chromate rattle cans due to the properties of the epoxy, and strontium chromate is nowhere near as toxic as zinc chromate.

Water bourne systems have low VOC values, but is harder to apply. In industrial processes where all the fumes are captures and recycled anyway, the water based products really doesn't add any value.

But, what is a health/environmental risk in industrial processes may be insignificant in a garage shop. Also, what is a non-issue industrially may be very complicated and risky in a garage shop. No one is going to convince me that, considering I am wearing a good mask, I will run a greater health risk using zinc chromate rattle cans than I will by messing around with a two component non chromate etch primer using a spray gun.

Given the choice (if Zinc Chromate was available), I would use Zinc Chromate from rattle cans on all internal parts + alodine on all non-alclad pieces. On external parts I would use StrCr epoxy. Right now I'm using a two component wash primer for internal parts and a zinc chromate rattle can I got hold on for non-alclad pieces, but will be switching to the "industry solution" with StrCr epoxy when I get the goods.