Painting Your Underside

[Bluescrawler]

I just had the underside of my Duster sand blasted and now I am wondering what is the best way to keep it from rusting while I work on it and what is the best way to finish it (paint, rust encapsulator, type of primer, etc.)

I scraped all the undercoating off with a torch and scrapers and had a buddy come over and sand blast it in my driveway. Which makes me top on the most wanted list for my HOA. Holy cow I hate living in the subs, HOA's are no place for a redneck like me.

Anyway, I have seen so many methods for prepping the underside and protecting it that I am now officially confused as to what to use.

So what have you all done to finish the underside of your ride from bare metal to finished coating??

Thanks for any help you can offer,
Joe

 

[Aaron]

I would use an epoxy primer to seal it up. A couple good coats should make it last. You will want to paint over the primer at some point (typically the same color as the body), but the epoxy will protect the metal from flash rust. For any rusty areas, I like to use the Eastwood rust encapsulator, it works well, and can be easily topcoated.

- So, paint the rust areas, then seal it with epoxy, then scuff the primer and apply color of choice.

 

[71produster]

I put Chassis Saver part # UCP970 on mine when I did the underside of my Duster! It took 2 quarts to do it.

 

[Bluescrawler]

I would use an epoxy primer to seal it up. A couple good coats should make it last. You will want to paint over the primer at some point (typically the same color as the body), but the epoxy will protect the metal from flash rust. For any rusty areas, I like to use the Eastwood rust encapsulator, it works well, and can be easily topcoated.

- So, paint the rust areas, then seal it with epoxy, then scuff the primer and apply color of choice.

I have always intended to paint the underside the same color as the body, I am assuming this is the normal practice. At any rate I like the look of it. So the Rust Encapsulator can be painted over with the Epoxy Primer right?

I am assuming that since it has been sand blasted there is no need for any etching primer or anything like that either, is that right?

Thanks for your input.

Joe

 

[OneOfMany]

Funny as it sounds, I use a two-component industrial green zinc epoxy primer on the undersides/floors/inner firewall etc. It is used on exposed structural steel with no topcoat. Of course it can be coated with anything. I have one underside with this stuff on it that I blasted ten years ago, stored outside, and it looks like I sprayed it yesterday.

Once cured, it can be roughed fairly easily for automotive epoxy primer like the body.

Grant

 

[Longgone]

I just got a hell of a visual when I read the title of this thread. Lol!

 

[OneOfMany]

Ok.. Ok..

 

[1969GTS]

I've used rust mort on any surface rust, then RM EP80 epoxy primer with a couple of good coats of POR15 on top. If you wait till the EP80 flashes down and paint right away you don't have to sand the primer. Its called wet on wet application and you get a very strong chemical bond while saving a ton of work.

Dave

 

[Longgone]

I just got a hell of a visual when I read the title of this thread. Lol!

Ok.. Ok..

I was thinking more along the lines of something this:

 

[Bluescrawler]

I was thinking more along the lines of something this:

A bird in the hand is worth 2 in the .. what? That woman has a cat peeking out of her azzcrack!

 

[Bluescrawler]

I've used rust mort on any surface rust, then RM EP80 epoxy primer with a couple of good coats of POR15 on top. If you wait till the EP80 flashes down and paint right away you don't have to sand the primer. Its called wet on wet application and you get a very strong chemical bond while saving a ton of work.

Dave

Is this the Rust Mort your talking about?

http://www.sjdiscounttools.com/sem69508.html

I am assuming that this would take care of any flash rusting or mild surface rust before applying the Epoxy Primer, correct?

Then based on the previous post; if there are any areas with a bit more surface rust than the flash rust the encapsulator will take care of them. I hope I got that right. I am a noob to restoration and painting business and I want to get it right.

Thanks for your help.

Joe

 

[BobsDart]

I would recommend cleaning any flash rust, sanding the really rough areas and use either POR 15 or a 2k epoxy primer 2 good coats. PPG DP epoxys... Most epoxy primers are not recommended over a self etch primer. I have customers using bedliner kits on the underside, interior and trunks for extra protection and sound deadening. We sell catalysed tintable and black kits for around $125 that includes the applicator gun... This is might not be a option on a full 100pt resto, but on something you are going to have fun with why not???

Bob

 

[1969GTS]

Thats the rust mort. Turns rust into a weird black grey carbon and seals it. I used it on the frame of a 1960 Land Rover I restored and never had an issue with it. Just follow the instructions and don't get in in your eyes.

Dave