ms87iroc

I am in need for some advice, i have a rusty underbody and chassis, and i am not sure what to use, I would like to paint underbody gray and the chassis black. I am trying to keep it looking original. I was going to use POR-15, but some people says it peels. please help

haps

iTrader: (4)

I've heard a few good things about Rust Bullet. I've purchased a quart and intend to do my undercarriage. It comes in metallic silver and you can purchase a gloss black topcoat. If you want a black matte finish, topcoat the Rust Bullet or POR15 with Eastwood Chassis Black. I've used POR15 in the past and it worked fine. Follow the directions carefully. If you are not equipped for spraying paint, Eastwood sells rust encapsulators in spray bomb form.

http://www.eastwood.com/rust-solutions/treatment.html

401kfirebird

iTrader: (1)

its not exactly factory looking but my car has rhino lining on the whole underside. the original owner was a saint!! ill never have to worry about my underside rusting....EVER!

FueledSoul

iTrader: (18)

got any pics of the underside?

ms87iroc

Thanks guys for the advice, i thought about the rhino, but like you said its not the original look i am looking for, but maybe i could use it in the wheel wells. I also was thinking of the por-15 but it doesnt seem to come in gray, i would consider it for chassis parts, since i am painting them black. I think gray would be the original color of under-body. (any suggestions?) Also i heard that the por-15 will peel if its not on a rough surface, i have a good bit of rust but there is many areas that are not. Thanks for the suggestions. I will send pics.

ms87iroc

Sorry i have'nt been able to post pics yet, been working the graveyard shift, me and my project are suffering. I have been interested in possibly using the Eastwood rust converter and then rust encapsulator and painting over that with automotive paint, i want the underbody to be painted not undercoated. Has anyone had any luck with this system?

skinny z

I've just been through this.
There are a couple of approaches depending on what you're after.
In my case, I wanted an OEM look. That would be the gray e-coat.
First get all the crud off the underside and get it grease free. The factory black undercoating is the hardest to remove. I've solvent soaked mine and then sand blasted critical areas to remove the rust. On bare metal a self etching primer is needed. Over that I applied an enamel that was a suprisingly close match the factory e-coat. So close in fact that it's difficult to tell where the original paint ends and the new paint starts.
All the work was done with spray bombs.
If that represents too much work (and it IS labour intensive) an option to consider would be any of the new formulations of rust paint. POR-15, Rust Bullet or Chassis Saver all fall into this category. Unfortunately, I'm only aware of it's availability in various black tints and aluminum. However it can be topcoated with a compatible colour coat. Grease free is still very important however you can brush or spray over rust that isn't flaking or peeling. Once you're happy with the coverage of the rust paint, apply the top coat colour of choice.
I have more pics but you get the idea. The most work was the removal of the old undercoating.

ms87iroc

Thanks skinny z, thats exactly what i am looking for, i am trying to keep original gray color and black chassis parts. My underbody is much more rusty than yours, my floor pans are completely covered in surface rust, but i have no areas with holes. I was going to try to sand blast all the rusty areas, spot prime rust with that rust converter andthen prime with rust encapsulator and then paint gray. What 2 part epoxy primer did you use and what finish coat did you use? do you think i should just use gray 2 part epoxy primer and paint over that. I wonder if that converter stuff works.

skinny z

If you forego the OEM gray look, you can use any of the "rust encapsulator" products and brush/spray right over the bare metal or slightly rusty surfaces. The satin black is an excellent choice for the rear axle, control arms (front and rear) etc. It looks best if you can spray it although the brush gives acceptable results. If you wanted to, you can top coat the rust paint (which only comes in black and aluminum IIRC) with your choice of colour matching gray.
I didn't use a two stage primer or top coat on the underside. A spray bomb of self etching primer and another of a close colour match (Duplicolor Federal Gray) took care of the underside sheet metal. Right off the shelf at the local body shop/parts store.
I did use a 2 part 2K urethane primer and 3 part urethane top coat for the engine bay though. I wanted better results but didn't want to go to the trouble of a base/clear application.

J.Prock

Not to hijack but if there is just some surface rust and small pin holes (very simillar to shiney z's) would I need to replace the rusted places I want to replace the floor pans but if I dont have to then I wont they arnt bad but I dont want it do come back and bite me in the @$$.

skinny z

Surface rust is ok. You can even paint right over it with the new rust paint formulations.
Pinholes will have to be repaired. I've found one small area where the rust has perforated the floor pan under the passenger seat. That'll mean I have to cut out the rusted bit (not much more than 2" by 3") and weld in a new piece. More prep and paint after that.