zinc phosphate outdrive primer ?
 

i'm going to sandblast and repaint my trs drives, k-planes and water pick up's. they have been chewed up pretty good by corrosion and being 17 years old and in the water all summer doesn't help. i was wondering if anyone has tried that primer ? boat u.s. carries it for 9$ a can. is there a better option? someone suggested a two part epoxy to seal the drives before the anti-fouling paint, also, i think there is a saltwater zink kit for those drives. anybody know where to get it? thanks for the help. Fran

That is the only stuff to prime aluminum with. It will hold up better than anything else.

what Tinker said!:cool: :D

I used A self etching primer made by dupont
named Vara Prime(sp.) it is a two part epoxy.
The Emron has been on three years and looks new.

I am getting ready to squirt my drives with Imron. I don't have a corrosion problem, just 14 year old paint that looks crappy. The Imron guy told me to simply scuff the existing paint and spray. Do I need to use self etching primer if I am not going over bare aluminum?

BT

I used the zinc on my transom housings, and an etching primer on my drives. In both cases I used a Sherwin Williams product called "Sunfire" for the color coating. In a few years I should be able to tell you which primer worked best...
:D :D :D :D

You only need etching primer if you have bare aluminum.

I prefer to use zinc chromate.

EXCALEAGLE, I have been trying to page you after seeing one of your posts. Do you have your old 81 series O/D? I would be interested in any parts you have left. I have a 80 series. I did find a company here in the northwest that has parts and knows where ALL the nos is wharehoused.
thanks Geo 100

geo,
i do have some parts left over, flywheel, clutch, shifter, oil cooler, a solid bronze prop, and other things. the people i was getting parts through was marysville marine in michingan a believe. i think i still have their # if you need it. click on my profile and send me an e-mail if you need some parts or info. i'd be glad to help you out if i can.

Zinc chromate is better than zinc phosphate, but may be harder to find since it is considered a professional product. Use a respirator with any of this stuff - especially zinc chromate.

Used Dupont DP90 primer over bare aluminum, followed by black Imron. So far, it has held up nicely. Even survived a 40 MPH whack against a submerged stump without a scratch or a chip. :eek: Good stuff!

Thank Tinderboat. Any thoughts on the need for a clear coat after the Imron? Paint guys says not needed.

BT

The clear coat isn't needed and boaters world has the zink chromate primer.

Well just to give you a little different slant from someone who has painted more aluminum in worse applications than most...

If the aluminum is bare clean and RIGHT AWAY treat with Dupont's Alodine (225S & 226S)

Then use an two component epoxy primer (you can use zinc chromate first, but it is not necessary).

Then use Imron, but we strongly prefer the Industrial Dupont coatings (web site shows industrial dealers). They have 30% solids and are much more like the thickness of the original powder coating than regular Imron. Lastly we do use the high solids clear also. You don't have to but there is no down side as you get a real protective coating with respect to gloss retension and thickness. Respect recoat times on the can.

My $.02. What has been previously recommended is fine also, just giving you a best approach in my opinion.

Ted

any thoughts on what to to fill the little pits in with that were caused by the corrosion? it's not necessary but it will make it look nicer. i was thinking titanium putty. i just picked up a quart of the "variprime" two part self etching epoxy primer. it does have zinc chromate and titanium dioxide in it already. must be good stuff, thanks for the tip.;)