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I don't have any experience with longevity, but I've heard good things and I selected Eastwood's Chassis Black for all my chassis refinishing. It is paint, so you'd have to clean and prep appropriately. Undercoating may be better suited if you can't clean all the previous undercoat off completely.
I'd put an etching/2k down first to get in all the nooks and crannies. "Rubberized" undercoating is crap and also NOT waterproof as the name implies.
Y'all are going to laugh (I did until I saw it), but Flex Seal in a spray can.... Yes, the same stuff hocked by Phil Sukoluski on the infomercials. It has a textured finish, very similar to Line X bed coating. A couple of old timers around here started doing it, and they build some nice cars. Alternatively, something in a DIY bed liner like Raptor or Lizard Skin would be my next choice.
Spray on flex coatings are good until they get a crack from age, moisture gets behind the crack is trapped and causes corrosion. Recently took a bed off of a pickup that had a spray on liner, took much of the bed off with a razor to cut the liner. Once the liner was razored there wasn't any solid metal behind it.
What to use varies with where and when the car will be driven.
Last edited by Sugar Bear; February 7th, 2022 at 09:30 AM.
If I was dealing with floor pans as clean as those appear to be, I would media blast at just adequate pressure to remove the rest of the old finish, prime with epoxy, and top coat with a 2-component stain black paint.
I've done both of my '69's with the following method:
1) Clean. Then clean again.
2) Sand or remove any surface scale.
3) Clean/degrease.
4) POR-15 semi-gloss black. I've always used a foam brush to apply. Seems to yield better results in hard to reach areas.
5) Wet sand (lightly) and clean/degrease.
6) Top coat with Eastwood chassis black (Extreme Chassis Black is newer formulation).
I did my 442 over 25 years ago and it still looks as good as the day I did it. I don't drive it on gravel roads but I suspect that may not be your plan. I swear by the durability of POR-15 but don't use it if you're not planning on applying a top coat.
My 2 cents,
Wouldnt you want to put down some zinc-rich primer that etches? Not sure if that product exists? Maybe apply two separate stages etch then zinc or visa versa then topcoat? Particularly inside the floor braces and other blind hidden areas. Eastwood makes frame paint for inner frame rails. Now is the time to salve it up in the areas you cant see. To bad you cant dip the tub in a vat of zinc then another tub of topcoat. That would seal er up.
Then apply a durable semi-gloss black of your choice over the zinc/primer. The paint will be easier to repair down the road. I've never had luck with POR15 sticking. It usually peels off in chunks after a year of regular driving.
The bed liner or similar coating is a bad idea IMO. It will create pockets that will hold the water in the areas where you cant reach to apply it. That is where the water will pool forcing its way up or down into the metal actually accelerating rust whereas if it could escape and breath it would not do that.
I had an F250 undercoated with "the tar-like substance" from the national rust-proofing chain. It had the same negative effect. As it expanded and contracted with temperature, this opened up cracks that allowed road grime in holding it to the metal. Rust actually accelerated. Never again will I go that route with a daily in the-rot belt. Granted, bed liner isn't like the tar but the idea is similar.
I've done both of my '69's with the following method:
1) Clean. Then clean again.
2) Sand or remove any surface scale.
3) Clean/degrease.
4) POR-15 semi-gloss black. I've always used a foam brush to apply. Seems to yield better results in hard to reach areas.
5) Wet sand (lightly) and clean/degrease.
6) Top coat with Eastwood chassis black (Extreme Chassis Black is newer formulation).
I did my 442 over 25 years ago and it still looks as good as the day I did it. I don't drive it on gravel roads but I suspect that may not be your plan. I swear by the durability of POR-15 but don't use it if you're not planning on applying a top coat.
This is the process( and products) I used on my Supreme way back in '91. Still looks the same today.. Only thing I can add is to cover yourself, and anything else you dont want painted. POR-15 will be on your skin for weeks if you dont wipe it off before it tacks up.
If I was dealing with floor pans as clean as those appear to be, I would media blast at just adequate pressure to remove the rest of the old finish, prime with epoxy, and top coat with a 2-component stain black paint.
Whats an example of a 2-component paint? Not familiar with paints.
Thanks!
As for POR-15...I've used it before on my Rallye frame and it's lasted exceptionally well.
But from everything I've read, it works better on seasoned metal with a light rust...meaning it doesn't stick to nice smooth bare metal as well.
I'm up for using it...just worried that this isn't the right application for rust free metal.
-peter
my 3 cents worth, after blasting i brushed summit rust bullit black shell. i used it on my nova and it holds up welll
. so i used it on my 65 cutlass, then scuffed lightly,sprayed on herculiner. looks excellent. also used herculiner on my buddys 66 belair
A light blasting will activate the surface (as my electro-plater friend would call it) making it favorable for paint adhesion. Alternatively etchants and primers containing such cut through surface contaminants and light oxides to also promote adhesion. In my limited experience I've blasted, dusted, and covered immediately with a 2-part epoxy primer like DP50. Sanded and top coated with a 2-part satin black urethane. This should be durable and look very good. Maybe not adequate for NE winters with the multiple daily road saltings, but almost nothing can survive those.
Use something to abrade (media blast) or etch the surface (Ospho or similar product) to promote adhesion for the primer. A two part urethane top coat will give you a long lasting finish. It has been many years but I have successfully used Ospho in the past.
POR stands for paint over rust. I don’t see any rust, so do not use it. It will peel off clean metal like that. DA it with 80 grit, then DP 90 epoxy it. That original Olds coating wasn’t that great and it lasted 50 years. PPG epoxy is tough as nails.
If I was dealing with floor pans as clean as those appear to be, I would media blast at just adequate pressure to remove the rest of the old finish, prime with epoxy, and top coat with a 2-component stain black paint.
I agree that would be the gold standard.
I would add as soon as the media blasting is done and the surface is prepped apply the epoxy primer ASAP
This should be done in a spray booth with the correct PPE
Two component paint has an activator/hardener and is found in commercial auto body finishes.
Commercial finishes require a healthy dose of respect spray booth and correct PPE.
Think about it; if you spray a product on that undercarriage and a year down the road it starts to fail, what do you do? You need guaranteed results. If it cost a few bucks more it's worth it.
You've got a lot of bare metal there; you need a good adhesion primer. I don't recommend putting any kind of paint over so much bare metal. Steel should be primed, and then painted.
If you spray two good wet coats of PPG's DP90-LF it will look close to a factory finish and hold up exceptionally well. Treat the metal, wipe down what's left and you'll be as close to guaranteed results as you can get.
Not disagreeing with any of the comments or particularly advocating for POR-15. I'll just say that any instance where it doesn't adhere to the metal is an example of the surface not being treated properly. I've used it on 'clean' metal and lightly pitted steal and my experience has been that it stands up extremely well when the surface is properly prepped.
The benefit is that once it dries the surface is sealed. Nothing penetrates it and that's the protective layer. A painted topcoat just makes it look good/better but does nothing to provide any additional protection for the metal. It does protect the POR from UV.
If you elect to use epoxy primer I suggest top coating with another product (such as a 2K urethane). Epoxy is presumably vulnerable to UV. Granted we're talking about the underside and something like DP90 is incredibly tough, but seems like a good measure.
When I restored my 55' super 88 I used rust oleum satin black paint on driveshaft, leaf springs etc. The rest of the undercarriage I used 3M brand undercoating. You don't need to spray it heavy though.
THAT looks really, really nice Jasen. I'll look into the syphon gun. I would love that finish.
Do you really think I'll have the space?
Maybe I can put another set of blocks under it for more clearance.
And thank you for chiming in. You know exactly what I'm striving for.
-peter
When I did mine (many years ago) it was also on a dolly, probably 2 to 2-1/2 foot clearance. Sprayed D90, the satin black top coat, and body color overspray using a Sharpe 75 siphon gun. Worked well.
Youve got plenty of room. Did this car the same way. Used a Binks siphon gun. For the coupe I bought a new rotisserie and sold it after I was done. Lost about 300 bucks on it.
Last edited by TK-65; February 12th, 2022 at 08:06 AM.
THAT looks really, really nice Jasen. I'll look into the syphon gun. I would love that finish.
Do you really think I'll have the space?
Maybe I can put another set of blocks under it for more clearance.
And thank you for chiming in. You know exactly what I'm striving for.
-peter
what is the color of your car, is it sterling mist? looks sweet.
Youve got plenty of room. Did this car the same way. Used a Binks siphon gun. For the coupe I bought a new rotisserie and sold it after I was done. Lost about 300 bucks on it.
Ok…another tool I have to learn how to use. I’m game.
As for the color…it’s supposed to be Lucerne blue. In daylight it looks pretty close.
Although the original owner told me they used ‘86 Honda blue. I doesn’t look half bad I have to say.
-peter
February 6th, 2022 | 03:16 PM
