Getting paint to stick to the frame

[GNVAIR]

In the summer of 2000 I carefully prepped, primed and painted my GN's frame. I cleaned all the grease/dirt off with brake clean. Then went over any surface rust areas with a wire wheel attachment on an angle grinder. I went over the now bare frame areas with denatured alcohol to make sure I removed all the grease/oil. Then I used the etch primer sold in the over sized spray can. I painted it with Rustoleum satin black. The problem is now the painted areas are popping off in sheets and the frame is starting to rust again.
I want to reprep and paint the frame again while I have the engine out of it. What I am planning to do is to remove all of the sheet metal as wheel as the radiator support, suspension pieces and steering box so I can get everything. I am planning to sand blast the front frame rails. But I dont want to do this twice.
What primer and paint should I use?

 

[GNS-FLY]

paint problem

Hi If i were you I would buy a sandblaster and blast the frame. Then go to a auto paint shop in your area and buy some self etching acid primer any brand will do. Then buy a nice quality single stage paint like ppg,dupont,sikkens,akzo nobel, house of color or and other well known paint. Don't use spray bombs. They are nice for "moms" bird house or for your local gangbanger graffity artist. Granite it's cheap but than again it looks like it also. Also you don't need to spend big money on alchohol to clean grease up. You can by laquer thinner or wash thinner from you local paint shop for about 18 dollars for five gallons plus you will need it any way to clean your spray gun up. Good luck!

 

[tom h]

Even with "self etching" primer, perhaps what's needed is a separate metal etch step to create a thin zinc phosphate layer on the steel and enhance paint adhesion (just prior to primer spraying).

Eg,
PPG's DX 520 (Metal Conditioner), or
POR "METAL-READY".

When I've applied POR15 black primer to etched metal prepared with either of these 2 solutions, the POR has stuck tenaciously ... I can even tap it with a ball peen hammer and the paint doesn't chip.

 

[turbofish38]

I used an epoxy with a black tint. I dont have the brand handy(PPG?),and it was really expensive $175 a gallon. I degreased in the fashion you did followed by a complete sand blast. Wiped all the dust off with laquer thinner and applied the epoxy straight up with no self etching sealers or primer. It stands up to a lot of abuse but will still scratch off if you try real hard,i.e. forcing suspension parts on. It is impervious to gasoline and brake fluids which is what I love about it. Direct sunlight will fade it from a semi-gloss to flat but wiping it with a rag soaked with ATF will bring it back if you wipe it off so it is not oily to the touch. I would have prefered to have the frame chemically dipped to save on time but my local striper wants almost $800 to do a frame. I also did every piece of suspension and the steel inner fenders and rad support this way too. I also was a little more complete than what you want to do by pulling the body off and detailing the bottom of the tub by stripping it and painting it the same color as the body. Just like the day it rolled off the assembly line. I guesstimate I have about 100 hours of labor just in the frame,suspension and floor of the car.

 

[GNVAIR]

I am actually doing this as a temporary measure to preserve it and make it presentable until I build my new garage next year.
I am planning to pull the body and powder coat the frame once I have room to do so. For now I just want to blast and paint to stop the rust. I unfortunately am not blessed with a garage to store the car and New Jersey climate is quite damp. The rest of the car is very rust free, but the from rails seemed to get worse once I pressure washed the oil off of them.

 

[st1nger]

frame restore

Currently restoring my car from ground up sand blasted my frame lifted body and blast entire underbody or tub wheel wells then stripped body with a/c stripper after blasting frame I used acid etch (phosphate acid) to clean and treat frame them spayed etching primer after cued for 12 hrs spayed urathane primer sealer cured for 12 hrs sprayed urathane black on frame the frame looks great car has been in and out of weather for the last year looks like I painted it last week except for dust which just will wash off you can put clear over the black and will shine like new money the deal is blast. Clean with etch. prime.seal ,paint

I've thought about powder coating my frame how ever I was talking to the tech at delphi here in phx they tested powder coating for gm and it did not hold up once it chipped water would get under the powder coat and does a lot of hidden damage before you notice it

 

[urhstry]

I am currently in the middle of a frame restoration and I powdercoated my frame... as well as everything else. Powdercoating CAN come off once something can get under it however for a frame, most of the corrosion comes from the inside of the frame rails. I had rock block shot through the frame rails and putclear coat on the ends to make sure. If you don't leave your TR outside in bad weather, I doubt you'll be alive long enough to watch your frame rot out. I can send pics to anyone who wants them. Just my .02

 

[Yedi]

epoxy it

I am in the auto body business and paint cars all the time. One thing I can tell ya is to use Epoxy. Dont waste your time with Etch primers, especially on a frame. Most "etch" primers dont hardly have any acid in them to even do anything, Epoxy on the other hand will seal the metal and is very durable, it just needs a top coat to prevent it from chalking/deterioting from Sun light.

Another great produce to try is Eastwooods Rust encapsulator. I put a 3" body lift on my Tahoe and the frame was a little more exposed, so I sanded it down and put Rust encapsulator on it and it is still on there. Unbelievable stuff, it is lacquer based so it sprays out nice and dries fast, and doesnt need a top coat like epoxy. just my 2 cents.

 

[GNVAIR]

I tried that Eastwood rust encapsulator on 2 of my cars. I prepped the metal per their instructions and within several months the stuff started popping off. This was the black color.
Needless to say I wasnt impressed. Now the POR 15 I had much better luck with, but the stuff they are selling now is no where near as durable as the stuff we got from them 15+ years ago

 

[Drop Top]

Go to your local automotive paint store and buy a gallon of industrail type of paint that is made for machinery. It goes on easy and dosent need primer. It holds up for along time and comes in many differant colors. It will run about $25.00 a gallon. I have used this type of paint on many differant projects over the years and it will hold up to alot of abuse. It should hold you over entill you get your shop built and want a better job. I grew up on a farm and painted many pieces of equipment this way. Including tractors to frames to steel buldings.

 

[John Larkin]

GM Chassis Black is OEM frame paint from the 60s. It's scammer like tar and kind of never hardens. It will mash if you put a jack under it. But if it's just the front rails, nothing will be touching them so it would work. I believe DuPont sells it. You could probably roll it on but it is meant to be sprayed.

 

[tom h]

Originally posted by John Larkin
GM Chassis Black is OEM frame paint from the 60s. It's scammer like tar and kind of never hardens. ...

I've never been able to find it!

If anyone had a specific part# and Mfr, many of us would be grateful!

 

[John Larkin]

It's been 13 years since I used any but I think this is the stuff:

http://www.performancecoatings.dupont.com/dpc/en/us/html/prodinfo/nason/422-05.pdf

 

[tom h]

Thanks, I'll check it out!

 

[turbofish38]

Originally posted by tom h
I've never been able to find it!

If anyone had a specific part# and Mfr, many of us would be grateful!

Part number is 1050104 for the gallon can but this stuff has been discontinued for the last 2 or 3 years.

Check out this months Muscle Car Enthusiast magazine. They have a article about frame painting and substitutes for frame black.

 

[Drop Top]

The stuff that I have used with some good results is called Shaflac make shure you use the hardner with it. You can get it in glossy, simi or flat. It is designed to use over bare metal so you need no primer. Of course if your looking for a show type of a frame there are much better products to use. But the cost is much more. Just depends on how far you want to go.

 

[87buick3825]

Maybe look in Hemmings (Old Cars) .

RD