Chassis Paint Options?

[brrian]

While I redo my front suspension, I'm cleaning the frame for refinishing - just back to the doors for now. My car was undercoated & once removed i'm left with a (suprisingly) clean, bare steel frame. It's a driver & I'm not too concerned with originality or perfection. I want a satin finish, and I want to brush it on. The frame isn't 'sandblast' clean... no doubt there's some leftover undercoating in the crevices & hard to get to places, but it's pretty clean.

Since there's almost no rust, sticking to / sealing / converting rust is less important than sticking in general to an occasionally imperfect surface. And yes, I know how important surface prep is, and I'll do my best but there's a limit to what can be done with the car on the frame.

I feel like an undercoating product that stays flexible (like Rusfre & many others) would hold better than a paint-based product like Magnet Paint's Chassis Saver that could chip or flake off if not adhered properly. Any thoughts or opinions to share?

 

[oldsofb]

I used this for my frame.
https://magnetpaints.com/underbody.asp

Hutch

 

[Clone TIE Pilot]

The frames were dipped in hot wax baths at the factory. This means there is wax in the steel pores that will interfere with paint adhesion if not cleaned really well. So you have two options, properly sandblast the whole frame clean for proper paint adhesion or recoat it with frame wax, not Fluid Film. GM recommends Daubert Nox-Rust X-121 to repair damaged frame coatings. Fluid Film type coatings will attack the remaining wax coating. Its also why anytime you do welding repairs on the frame you want to use flux core MIG wire.

 

[brrian]

So glad I asked! I had no idea. I'll use the X-121. Only issue is that it's only available in spray cans or a 5 gallon bucket. I'm not buying 5 gallons, so it looks like i'll be spraying. Crap.

Thanks!

 

[08Malibu]

The frames were dipped in hot wax baths at the factory. This means there is wax in the steel pores that will interfere with paint adhesion if not cleaned really well. So you have two options, properly sandblast the whole frame clean for proper paint adhesion or recoat it with frame wax, not Fluid Film. GM recommends Daubert Nox-Rust X-121 to repair damaged frame coatings. Fluid Film type coatings will attack the remaining wax coating. Its also why anytime you do welding repairs on the frame you want to use flux core MIG wire.

Why flux core over regular mig?

 

[Clone TIE Pilot]

Why flux core over regular mig?

Flux core flows contaminants out of metal which makes it a better choice for wax coated steel which is difficult to clean out of the pores. It can tolerate less than completely clean metal better. Also flux core can weld thicker metals than solid core at the same voltage.

 

[08Malibu]

Flux core flows contaminants out of metal which makes it a better choice for wax coated steel which is difficult to clean out of the pores. It can tolerate less than completely clean metal better. Also flux core can weld thicker metals than solid core at the same voltage.

I see. I only ask, because I did all the frame repairs on my 05 Sierra using regular MIG, without any issues. I have a large Miller welder so that probably helped.

 

[1KWIKSIX]

Here’s what was used on my chassis / engine bay clean up.
It’s been used by many before me & stands the test of time.
If your prep / clean up the surface with lacquer thinner , it will stick like glue .

 

[1KWIKSIX]

Here’s what was used on my chassis / engine bay clean up.
It’s been used by many before me & stands the test of time.
If your prep / clean up the surface with lacquer thinner , it will stick like glue .

More pics

 

[Josepht94]

I agree with 1kwiksix, VHT roll bar and chassis paint looks great and sprays awesome. I believe it will hold up but I haven't had it in there very long.