Thread: What would you guys do in this situation? Bare metal

Tweet

I have sandblasted everything and ready for the next step. I have a 2 part epoxy primer or should I use por15 since there was rust before I blasted? I also am going to do a 2 part metal prep. First is to take care of any leftover rust and the next step etches a zinc coating on the metal.

This piece is outside and its cool outside but there is also rain in the forecast for Sat. So this is getting done tonight or in the morning. I will be leaving town for about 2 weeks on Sun. So what ever has to be done it will be DONE Fri night. I have not had a chance to do the filler work so it will be done later, right now I have only time to cover the metal. Can I add to the epoxy in a couple of weeks , filler and a top coat? Or does this have to be done within a certain time period?

I'd just shoot it with epoxy primer and get it covered. You can scuff it up and do all your repairs later. I hate having bare metal, it starts to surface rust almost instantly. Was the rust on it just surface rust or deeper? Wouldn't hurt to coat those areas first with some Por 15...

I treated the metal with a 2 part chemical treatment from DuPont. The first step calls for soaking everything with the part A then rinse with water. After that the whole thing turned a light bronze color. Was this rust or the zinc color coming out?

Man ,it looks like rust What should I do to paint the epoxy?? I am going to paint the seams and fender wells with the por15 but use the epoxy for the engine compartment. What should I do about the light rust?

Heres some pics after the treatment.....

Looks like a typical phosphoric acid based material reaction. It could be that in the areas that are rusting already the material was used too sparingly or without allowing sufficient reaction time. If it were me I'd go back over the rusted spots with the rust conversion material by hand (gloved of course) as a touch up. Then if you had any doubts about the success of the conversion process spray a coat of etch primer before topping with epoxy primer. If you're good with the conversion process then go straight to the epoxy primer/sealer.

I agree with Bob.

A thorough re-work with something like metal prep (phosphoric acid base) should clean it up. Most of the paint stores have it. Use it per the instructions, then hit it immediately with an etching primer. Some ideas.

http://www.hirschauto.com/acb/showde..._ID=16&CATID=2

http://www.halonmarketing.com/mall/R...tal%20Prep.php

Just to give you an idea of how effective phosphoric acid conversion is here are a couple pics of a chassis in bare metal I've got in process. The first is the frame shortly after delivery with areas of surface rust. The second is the chassis today, four months after doing the process as you described; acid wash followed by wash with water to neutralize, followed by drying. You can even see some finger prints that haven't gotten rusty yet.

I would call it good , I followed the directions. BUT, I have never used the metal prep from DP to compare. Damn, the more I look at your photos and compare to mine I think I did something wrong. I will take photos to the paint shop tomorrow and see what they say.

I always metal prep any bare metal. Why take a chance??? It's cheap and easy.

I have had metal preps leave a "bronzey" color behind, before.

According to the "experts", you are not supposed to use both metal prep, and self etch primer. Use one or the other.

So what you think HotRod? I did use metal prep from DP it was a 2 step deal.???
Step A metal conditioner, rust conversion and etches the metal.
Step B Steel and Galvanized refinishing system conversion coating, Leaves a zinc Phosphate coating on the metal ready for paint.

From what I have read what you want to prep rusted metal with a zinc "coating" to protect from future rust, or It protects better.

I think I might of used to much,lol. I sprayed it on the entire surface and before it could dry I rinsed with water,per insructions .Then did step B ,sprayed it on 5-10 minutes and rinsed. Only difference was instructions said wipe it on and might of went to 15 minutes,lol.

My advise does not include a guarantee.....but if you used it per the instructions, and it hasn't set too long, I'd paint it!

If it sits for more than a day, I would etch it again, blow out any areas that might trap moisture, and paint 30 minutes after it's dry.

Dang , now something else,lol No really I will paint it by noon tomorrow and it will sit over night. Do you really think I should etch it again?
How can I spray a thick coat of the epoxy? I tried it today at 35 psi, about 70 degrees outside ,and a 2 to 1 mix.

Rule of thumb that I have gone by is that you have to spray two coats of any catalyzed paint, for the hardener to work right. The cans or tech sheet should tell you how long to wait between coats.