Smoothing Car Frame/chassis

I have a 57 Chevy frame that has been blasted. Still has minor pitting from rust prior to blasting. I want to smooth everything and paint the frame. The frame is in SPI epoxy primer. Any suggestions for products to get it smooth? Not sure any poly spray filler will be thick or durable enough, but also prefer not to spread filler all over frame just because of time involved. Pics attached...first pic is not mine, but that’s kinda what I’m going for. I think that guy used Z Glass and bondo for his frame.



I would think it would be faster and better to spread a layer of filler on it and DA that down then it would be to spray large mills of primer to fill that, more then likely you would be priming and sanding more then once because you didn't get them all out the first time. Either way your gonna have to sand it smooth, you might as well start with filler then sand that the same day and prime with Epoxy. Just my 2 cents.

old soul

Agree 100% with Datec. If you want your frame to look anything like the one in the picture, you've got to put in the time.


Active Member
I can’t even imagine applying and sanding filler on a frame with all those holes, brackets etc. Two coats of Rust Defender, sand and done. Even has a built in guide coat.

But I’ll defer to the experienced guys who know better than me.

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John Long

If you don't take the time to smooth the frame and decide to just spray it with epoxy, it will look good one time. That will be the day you paint it. After that day it will be impossible for you to ever clean the frame and/or detail the bottom of the car. The rust pits that are left will collect dirt and it will be impossible to get it out. The frame will always look dirty as well as it being obvious it was rusty when you started.

I find it is worth putting in the time. If for no other reason, it will pay off in the value of the car down the road.