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what to use for firewall/undercarriage

1K views 8 replies 7 participants last post by  AhX 
#1 ·
I plan on sandblasting my firewall and undercarriage soona nd have some conflicting info. I was under the impression that once you blast to bare you should epoxy it immediately. BUT, some people are using POR15, Zero Rust, Rust bullet on these areas. These products shoudl be applied over bare metal also. Which is the correct way?

TIA
 
#2 ·
Well when you ask that question you will get about 10 different answers from 10 different guys as everyone has their own favorite poison to use..

Mine happens to be the epoxy as I feel it gives a better base for the final paint..

The "rust mort" products will convert the rust to a hard black substance but then need to be painted over in order to prevent further corrosion..

So I get it as clean as I can as a practical matter..then use some rust mort in the areas I have a hard time getting to and then use the epoxy primer on the whole thing..I do try and limit the sand blasting as it creates a real mess to clean up..and I can get to most of the large areas with my power wire wheel and a flap disk..just blasting the tight areas that I cannot get to with the grinder..

That is the do-it-yourself way..

Of course if the budget runs to it you can send the work out to one of the pro strippers who do do a fine job as far as I can see..

OMT
 
#5 ·
AhX said:
I plan on sandblasting my firewall and undercarriage soona nd have some conflicting info. I was under the impression that once you blast to bare you should epoxy it immediately. BUT, some people are using POR15, Zero Rust, Rust bullet on these areas. These products shoudl be applied over bare metal also. Which is the correct way?

TIA
POR-15 is for rusted metal only, NOT bare

If you use POR-15 you dont have to use anything else. When you go to buy it, get a gallon of thier metal etcher. After sandblasting, and any bodywork. leave it outside, spray bottle the etcher on, hose it down. next day wire brush the scale off and coat with POR-15. It bonds to the rust and seals the steel.
 
#8 ·
Epoxy is good for every surface that is going to receive a finish paint coat. HOWEVER, it will chip and scratch when hit by debris just like any other paint. The advantage of POR is that it will not chip. You can hit it with a hammer and you can't chip it. That's why a lot of people use POR or other similar products on frames and under-bodies. Once you use the POR you never have to touch it again and because it won't chip and the product seals the metal it won't rust.

I would not use POR on any surface that will see direct sunlight on a regular basis. POR will chalk if subjected to UV for long periods but it doesn't effect the sealing or protecting power of the product only the color. And if you "sand blast" the metal you can use POR directly on the blasted metal.
 
#9 ·
I am using sand for firewall and floors. will use walnut shells for body or chemical removal. So basically from reading this thread, there is no best way LOL. Thanks for the info. i appreciate and respect all of yoru opinions so keep them coming.
 
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