Frame Prep/Paint

[Mark Pierce]

Hello all. Newbie here with a question.

I have a '79 L-82 that I'm doing a body-on resto. I'm working on the suspension/drivetrain first and have removed the entire rear suspension and gas tank.

The frame is in good shape with no rot and only surface rust. I'm going to remove all the rust I can with a little elbow grease. I've been contemplating then coating the frame with a rust inhibitor/convertor such as POR-15 or equivalent and then painting.

My question is have any of you had any experience with this or similar products? What were the results like? Any recommendations or tips I should know? Thanks in advance.

[Lenn #40977]

Re: Frame Prep/Paint

I don't have any personal experience, but I recently read a magazine article on this issue and they said that the Rust Encaptulator was better than the POR-15. Worth checking into, I guess.

[Clare Carpenter]

Re: Frame Prep/Paint

Here's a link for a frame-on resto on a '70, done by NCRS member Juliet#32595. Quite impressive actually. Lots of photos and details shown, along with descriptions of the process. She used John Deere Blitz Black to finish it. I've seen that paint recommended here several times.

http://www.corvetteforum.net/c3/juliet/rearsusp.htm

POR-15 is very glossy and is not UV resistant. You will need to topcoat it with their Chassis Black if you want a realistic finish, other paints won't stick and are not compatable. This has to be done while POR-15 still uncured for best results. You can brush it and it flows fairly well, if you spray it you MUST use a respirator as the fumes are DEADLY. If you get it on your skin, you'll wear it off. It doesn't come off with solvents. I think it would be better suited for a frame off situation.

[Mark Pierce]

Re: Frame Prep/Paint

Thanks for the response, and especially the link. That's pretty much how my restoration will/is go(ing).

Apparently Juliet did not prep the frame with a primer or rust inhibitor prior to painting, or if she did, I must've missed it. I'm more inclined to use the POR-15 or equivalent to coat the frame prior to painting to as to eliminate any potential rust problem in the future.

Thanks again!

[Chuck R.]

Re: Try the archives Mark

There has been a ton of banter over rust encapsulators espcially POR-15

The tech board archives can easily assist you there.

I went a different route and used "Zero-Rust" purchased through my good friends at JC Whitney.

I coated only the interior frame cavities by taping off as many gaps and opening as I could, pouring the inhibiter in a section at a time and then rolling the bare frame around and around and tipping it from end to end to make sure I covered every square internal inch. I then drained off the excess and moved on to another section

Yes it was messy, but it was controllible and I'm 99.99% confident the rust won't EVER get me from the inside now! At least in my lifetime

I then pressure washed, wire brushed, primed and coated the exterior frame surfaces with John Deere medium gloss black. It came out (in my estimation anyway) great!

The frame has been setting in the garage exposed to the worst of North East temperatures and moisture levels for over six months now and it hasn't even offered to rust back through!

Personal preferences and thresholds of pain Mark.

You will numerous options.

Chuck

[Chuck S.]

Re: Frame Prep/Paint

Mark, my opinion is that POR-15 on the outside of the frame is overkill unless you have deep, scaling rust...well, the exception to the "overkill" thinking may be if you live in Canada. I wouldn't like it on the outside of the frame because it is high-build (won't look original) and it is permanently there once you put it on. All the king's men and all the king's jackhammers can't get it off.

If you are going to use POR-15 anywhere, then use it INSIDE the frame; that's where the real damage gets done, particularly at rear wheel kick-ups. But, then getting good effective coverage inside the frame will be impossible unless you do a body off resto (not recommended).

I would wire wheel it to remove surface rust as well as I could, then top coat it. There are other things you could try like using a cheap portable sand blaster to bead blast the worst areas, or applying chemical cleaner and conversion coatings like those sold by PPG (acid based, wear protective gear, BE VERY CAREFUL), or using self-etching primer. You are limited only by your strength and your penchant for hard work.

[Mark Pierce]

Re: Frame Prep/Paint

Chuck,

I appreciate your response. I happened upon an individual on another board who had used POR-15 and had posted some pictures. And, just as you said, it had a "high build" look to it that, IMO didn't look all that great.

No serious rot or anything on my frame. In fact my frame looks in better condition than Juliet's in the link provided earlier. So it's looking like elbow grease and top coat is the probably the best way to go for the outside frame. Thanks for your response. It's greatly appreciated.

[Mark Pierce]

Re: Try the archives Mark

Thankfully, I'm in Texas so I don't have as bad of environmental factors to deal with like you would.

I'm thinking perhaps my original idea of using POR-15 might be a bit too much, given the other comments I've seen. Can't say I'm dissappointed though!

[Dave F.]

Re: Frame Prep/Paint

We bead-blasted mine, and used a self-etching primer. Also shot POR-15 inside the frame through every opening and in every direction possible. Didn't want the next owner (40 years from now?) to suffer what we went through.

[Ed D.]

Re: Frame Prep/Paint

Mark ... I painted my frame (body on) with POR15 . I started to spray (what a mess) and changed over to a brush. I am not that excited about the finish. I did use a another paint to topcoat with and had no problem doing so. It sticks to everything !! You can clean up and get it off with carb/choke cleaner!! ..Ed

[Dick W.]

Re: Frame Prep/Paint

Mark, clean the frame with a wire brush, a grease remover, use a phospate wash, prime with a rust inhibiting primer, then use something like PPG DDL 9300 (I believe the number is right, a semi gloss lacquer). You will be pleased with the finish. You can buy the asphalt base paint from Quanta and use it also

[Juliet P.]

Re: Frame Prep/Paint

Clare, Thanks for the kind words and posting the link to my website.

Mark, No, you didn't miss anything. I didn't use POR15 or any other rust inhibitor for that matter. I didn't prime it either. I wire brushed all I could reach on the frame down to bare shiny metal. I only used wire brushes (the thinner wire ones) so that I didn't take off welding splatter. Then after cleaning it really well I just put on a few fresh coats of Blitz black. If I ever do see some rust starting up, (after screaming) I'll wire brush and paint again. So far, so good.

As for getting into the nooks and crannies - spraying it is easy. The spray goes into the nooks just fine if you spray from various angles. The nozzles on the blitz black put out a really nice flat spray which is easy to control & predict (unlike the cheaper krylon rattle cans). Spray goes everywhere that isn't masked. I tended to spray in one direction in slightly overlapping strips. Then I'd put on a second coat in the perpendicular direction (where the area being painted was large enough). On the thinner parts of the frame I'd just paint it a second time about 1/2 hour later. Masking everything took about twice as long as the painting. And of course cleaning & prepping the metal was a real chore. There were a few places that I didn't get clean enough so it started to fish-eye. So I cleaned off the paint with lacquer thinner and then rubbing alcohol and tried again (and again in some cases). If you wipe it right away it comes off easy. But then you need to let the edges dry so you can later feather the wiped area into the dry not-wiped area. Otherwise you'll get a ridge - of course on rough textures (wheel wells) that wouldn't show up, but on the smooth parts of the frame it did.

Even with all the masking there were some spots I had to go in with lacquer thinner & Q-tips afterwards to clean up some - mostly around the edges of the body mounts and brackets and stuff. If you break a Q-tip in half, and wet the paper stem in lacquer thinner, it works great on bolt edges and rivets and other little things. You get a lot of paint removal control. And if you slice the edge with a razor blade you can get really fine pencil edged control. You need to get the Q-tip brand though - many of the other cheaper ones have plastic handles and the fuzz part on the cheap ones also comes off too easy - plus the Q-tip ones are cotton and they seem more absorbent. I'd put about 1/4" of lacquer at a time in an empty cat food can w/ a cat food plastic can lid just cracked open (otherwise it evaporates too fast) and took boxs of Q-tips and spent lots of quality time with on the creeper under the car. If you have some patience and take the time to mask everything but where you want the paint, it works just fine.

~Juliet




1970 Corvette Registry

[Richard D.]

Re: Frame Prep/Paint

Hi Mark.

I used a paint called "Chassis Saver" by a company called Magnet Paint. They have a web site, and are located in Long Island.

It is (they claim) a direct equivalent to POR15, which was what I was gonna use.

I used it, and applied only one coat (I brush coated it on after wire brushing the surface rust and scale off (my chassis was in fairly good condition, but had surface rust and scale that looked bad), then I spray painted over that one coat with GM Chassis black paint. It went on easily with the brush, was not "thick", and covered well in the one coat I did. They did say you could do multiple coats, but I did not feel that was necessary after the first one set up, and I was going to overcoat it anyway with the GM Chassis paint.

I used it because of it's rust inhibitive properties.

It was exactly the same color as the GM chassis black by the way, so overspraying it did not cause any discernable color differences to my eye.

I'm not going for judging, but I wanted a clean looking underside for my car.

If you want a couple before and after shots, let me know and I will email you a couple.

How it will hold up? I can't say as I just did it over the recent Christmas break, but since I won't be driving my car in any bad weather, it should probably last forever, which for that matter, the GM chassis black would also probably have been just fine on it's own, but you know how it is, you just feel better by going the extra mile and hopefully not having to do the same job twice.

Regards,

Rich

[Mike S.]

Re: Frame Prep/Paint

Mark -

Eastwood makes the excellent rust converting primer "Rust Encapsulator" that Lenn mentioned. I used it on my frame, and I'd use it again. Unlike the POR, it can be removed from your skin just like any other paint, and it doesn't have the toxic vapor issues.

[Rick S.]

Re: Frame Prep/Paint

Mark, I agree with Mike S. I hand stripped the underside of my 67 and used the Eastwood products last year and have received many compliments. Rick