Frame undercarriage prep and paint

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71RAT

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I'm starting my K20/M1008 frame refurbishing. It will see some winter road salt and crap, although I usually can get it rinsed off fairly quick. Want it to look nice, it's not a show truck. Planning on using a satin or semigloss black, maybe gloss on the axles. I've used POR15 and Rustolum Pro on other smaller projects with good results. There are so many probucts to chose from!
So what did you do, what did you use for product? Negative feed back is welcome. Sure others would also like to know what not to do or use!
 

KilgoreTrout

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I've been wondering what I'm going to do, too.
I have the bed off and at least feel like I should do brake lines and clean up the frame, etc.
My plan was to pressure wash for dirt and loose stuff, then wire wheel, ospho, rinse and repeat. Then epoxy.

I'm not sold on por 15, honestly. I don't understand what it's supposed to do.
 

71RAT

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I've been wondering what I'm going to do, too.
I have the bed off and at least feel like I should do brake lines and clean up the frame, etc.
My plan was to pressure wash for dirt and loose stuff, then wire wheel, ospho, rinse and repeat. Then epoxy.

I'm not sold on por 15, honestly. I don't understand what it's supposed to do.

Ospho? Is that the product thst chemically converts the rust? I plan on trying some type of that on the axles and rusty stuff. If that doesn't work I'm going the sandblast route. I used POR15 on my inside floors 10+ years ago, no bleed through, still looks good.
I've talked with a couple experienced restoration guys. If you do the sandblast route, a good self etching primer and chassis paint or acrylic enamel is what they do. POR15 is pricey, but I'm 58yo, this is my last resto on this truck!
 

Old77

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Used POR15 on my '77 and it's held up great for 10 years or so. Eastwood also carries some decent undercoating products.
 

legopnuematic

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71RAT

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legopnuematic

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Have you used this paint before? No primer is used? I guess if no other product is required, the price isn't out of this world. Thanks, check it out.
I have not yet. If you get on Facebook or Instagram look up 'squarebody specialists' they do high end restoration/custom work and they primarily use Tamco products and seem to have excellent results with their products.

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KilgoreTrout

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Ospho? Is that the product thst chemically converts the rust? I plan on trying some type of that on the axles and rusty stuff. If that doesn't work I'm going the sandblast route. I used POR15 on my inside floors 10+ years ago, no bleed through, still looks good.
I've talked with a couple experienced restoration guys. If you do the sandblast route, a good self etching primer and chassis paint or acrylic enamel is what they do. POR15 is pricey, but I'm 58yo, this is my last resto on this truck!

Yeah, it's phosphoric acid stuff. Many swear by it, but there's some arguments about paint adhesion if you dont wash it all off.
Lots of arguments about por15, too, though.
I just dont really understand what por15 does that paints dont?


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CSFJ

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Yeah, it's phosphoric acid stuff. Many swear by it, but there's some arguments about paint adhesion if you dont wash it all off.
Lots of arguments about por15, too, though.
I just dont really understand what por15 does that paints dont?


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The por15 is supposed to be a kind of rust converter that bonds to the surface. I've never used it myself, and from what I understand, if you follow all the directions it works really well. My hesitation to use it stems from it forming a thicker covering than paint, and I worry about rust forming underneath where you wouldn't be able to see it. I'm more comfortable with primer and frame paint, where you can see if you need to get after it.
 

KilgoreTrout

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The por15 is supposed to be a kind of rust converter that bonds to the surface. I've never used it myself, and from what I understand, if you follow all the directions it works really well. My hesitation to use it stems from it forming a thicker covering than paint, and I worry about rust forming underneath where you wouldn't be able to see it. I'm more comfortable with primer and frame paint, where you can see if you need to get after it.

That's exactly my issue with it.

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Bennyt

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I have had great results with Eastwood Ceramic Chassis paint. Anything I can disassemble, I powder coat as it's easier and cheaper.
 

71RAT

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I'd also like to discuss blasting sand media etc vs rust converters and orthophosphoric acid products. That maybe considered rust converter.
Again this is not a show truck, I have a dirt driveway, and the carport has a dirt floor also. Willing to trade off some appearance for durability.
 

Donald

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Me being of Scottish descent , I have done several cars and trucks with Rustolum satin and had very good results just make sure the surface is clean . If you don't have or want to spray the paint on , use a brush and when the paint is still wet take a foam brush torn it sideways and pat the painted surface it will give it a texture of a sprayed finish . Por 15 is great stuff but pricey and if the part is exposed to sun light it will fade badly . Make sure you us the UV protected type .
 

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The por15 is supposed to be a kind of rust converter that bonds to the surface. I've never used it myself, and from what I understand, if you follow all the directions it works really well. My hesitation to use it stems from it forming a thicker covering than paint, and I worry about rust forming underneath where you wouldn't be able to see it. I'm more comfortable with primer and frame paint, where you can see if you need to get after it.

It's an encapsulator, not a convertor... and I agree with you about rust forming underneath it. If the rust is really deep for sure it will come back to bubble the POR treatment. Encapsulators are great for clean virgin steel... but imo not so great for deep rusted parts. Heavy medium sand blasted, wire wheel/flap wheel then rust convertor, then primer and paint.
 

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