Paint Hardener

I used Rust Oleum Self Etching Primer coated with 2+ coats of Rust Oleum Enamel from spray cans on the interior of my boat. Long story short a few places were a little soft and very easy to scratch off with my fingernail. I sanded the soft spots back down to the bare aluminum and plan to re-paint when the weather clears up here in NE PA (Rain for 7 days...I will need my boat to get to work.)

I then went out and bought a quart of the brush on Rust Oleum to put a thicker coat on in the hopes that it won't be as soft the second time around. I also bought a can of industrial paint hardener from Tractor Supply Co. It seems like some pretty serious stuff from reading the warning label. I have a respirator from working pest control in the summer time and painting outside is a definite.

My question is has anyone used this on their build before? How well does it work? Will the paint chip off over time from being too hard and having the hull of the boat flex? I also bought Easypoxy by Pettit to paint the outside this weekend...is this safe to add to this as well? I would hate to ruin a $25 quart of paint if they aren't meant to mix. Any input would be awesome from your experience or opinion.

You said the etching primer was soft and scratched off easy. From what I read you did it right, it is meant to be like that so that you can lay whatever paint you need on top of it to make it adhere good. That etching primer is suppose to chemicaly bond on both sides.

As for he hardener I have read on other forums that hardener is the way to go. I myself was gonna use hardener and some implement paint from rural king. The hardener makes it dry faster and makes the paint thicker.

hope that answer helped you

but just to let you know you did do the primer right, it just kind o sets the stage to paint over aluminum with a final coat

You are on the right track. I used brush on rustoleum and the hardener you are speaking of....hardens much quicker. Rustoleum is notorious for taking forever to harden...but eventually it does and works out well. You cannot add hardener to the petit easypoxy. The epoxy has its own hardener...or catalyst if you will. The hull flex has not been a problem for me....I structurally overdid mine and now instead of flexing I'm breaking rivits on my deck framing in really choppy water at WOT. Guess I could slow down eh. Back to subject: rustoleum is cheap and you will be touching up spots here and there....not a huge deal for the price of rustoleum huh.

Awesome...thanks guys. I painted the boat last weekend. I sanded and roughed up the old coat on the inside and re-painted with the Rust-Oleum brush on w/ hardener. It came out great I accidently dropped a ratchet on the floor when I was putting the decking on this week and not even a scratch [-X . It is the best way to go. As for the Easypoxy, I didn't use the hardener since I read that the hardener is only for enamels and the Easypoxy is an oil infused urethane. It came out great as well. After 3 coats it's not as hard as I would like but it still has a day or two to cure yet. (minimum of 7 days before using and 16 hours inbetween coats.) The high gloss finish was awesome I will have pics posted on my build soon. The build is finally done though and this weekend though is what it is all about. Time to go fishing! =D>