[gwh]

I'm considering taking my frame, with everything removed (possibly even riveted pieces) to local Aztec hot dip galvanizing plant. Their process uses several huge tanks. First, it does ALL the prep work: cleaning, paint removal, grease removal. Then rust removal in acid bath. After acid bath, goes to neutralizing tank and then rinse. Final step the whole frame gets dipped in a huge tank of molten Zinc (and a couple other additives). It gets into every nook & cranny, including boxed sections, which must have holes drilled in them if air-tight.

Based on structural steel I've had them do, I'm guessing total cost of frame will be around $300, based on weight. Usual turn-around time is a few days. Then frame can be top-coated with whatever paint is desired, although painting would not be necessary for corrosion prevention.

If anyone has used this process, or sees any problems I'm overlooking, please submit your comments & suggestions. Thanks.

Guy

[roger1]

I blasted my frame clean with an inexpensive HF blaster and then used 2 coats of SPI epoxy primer.
First coat in gray and the second coat in black (makes it easier to get spray it on evenly on the second coat).
With SPI epoxy no topcoat is necessary and it's a nice semi-gloss finish.

Frame blasting 3/4 complete:


After first coat:


After 2nd coat:


Frame, springs, A-arms and calipers are all done in black SPI epoxy:

[gwh]

Beautiful work, Roger! Hope you have time to answer a few questions for a neophyte:

1. Size of compressor to use with the HF blaster? I'm trying to decide what size compressor to buy. As with everything else, it's $$ vs. minimum needed to get job done. If I use a HF pressure blaster like yours, based on your experience, what size compressor would you recommend?

2. What blasting media? I notice you have a tarp under your work area. Is this so you can collect & re-use the blasting media?

3. Size of hose and tip?

4. What have you done/plan to do as far as treating hidden, boxed-in parts of the frame against rust?

5. Any thoughts on pros & cons of hot dip galvanizing, as discussed in my earlier post?

Any other advice & suggestions would be most appreciated.

Thanks,
Guy

[roger1]

Originally Posted by gwh

Beautiful work, Roger! Hope you have time to answer a few questions for a neophyte:

Thank you!

Originally Posted by gwh

1. Size of compressor to use with the HF blaster? I'm trying to decide what size compressor to buy. As with everything else, it's $$ vs. minimum needed to get job done. If I use a HF pressure blaster like yours, based on your experience, what size compressor would you recommend?

As big as you can get. The more capacity you have, the bigger the nozzle you can run. I used an 18 cfm @ 90 psi, 80 gallon and it was plenty for the nozzle I used.

Originally Posted by gwh

2. What blasting media? I notice you have a tarp under your work area. Is this so you can collect & re-use the blasting media?

I used the small sized (40/80) Black Diamond media from Tractor Supply @ $8 per bag. It's coal slag and I think it's the same as another one called Black Beauty. Last time I was at TS, they didn't have the 40/80 but had 30/60 and it worked OK. Don't know about the 20/40 though.

Originally Posted by gwh

3. Size of hose and tip?

As I remember, I was using a 1/8" nozzle. The hose is 1/2" and came with the HF blaster. The air supply hose is just a standard 3/8 hose. I seemed to have enough air even when the nozzle got worn some and got larger. I modified the dead man. I took the handle and stopper off the dead man an put a 1/2" ball valve right in front of it. It takes a while to get the hang using these blasters. They will plug up and I devised a process of how to get it going again quickly. It was trial and error and since there are 3 valves, it took some time to figure that out. The most important thing is to screen your media (reclaiming and fresh out of the bag) and keep it clean and dry.

Originally Posted by gwh

4. What have you done/plan to do as far as treating hidden, boxed-in parts of the frame against rust?

Nothing. Just made sure any crud was blown out. My frame is very solid and is 57 years old. And, it's going to get much better overall care for the next 57 years!

Originally Posted by gwh

5. Any thoughts on pros & cons of hot dip galvanizing, as discussed in my earlier post?

I don't know anything about that. Sounds like overkill to me.

Originally Posted by gwh

Any other advice & suggestions would be most appreciated.

To me, epoxy makes the most sense. It's a better product than something like POR. It can be touched up easier than powder coating and looks just as good.

[gwh]

Roger

The additional info on refinishing frame is a great help. I think I'm going to follow your method & materials. Thanks much!

Guy

[Rod and Custom]

hmmm...

The problem with coating bare steel with primer is, most primers are not waterproof. They're made to be painted. That usually means they're porous, so that topcoats can get a grip. If you put enough of a porous material on though, it takes a long time for moisture to make it to the steel. On a '57 Chevy I recently stripped to bare metal, the original factory baked enamel paint had allowed moisture to penetrate and start rusting the steel. Of course, that had taken over 50 years.

The other problem is the seams. Powder coating, spraying, rolling all have the problem of filling in the seams. House painters use caulk to fill them. We have drip check and seam sealers. And then there's the whole inside of enclosed frame rails. What about them?

Here is my suggestion. Blast the frame as clean as possible. Prime with a good epoxy or urethane primer. Seal the seams with a minimal amount of material. Spray with a good two part urethane topcoat. Then, after that has cured... coat the insides of the rails with something like 3M's Rust Fighter 1. Or something in a paraffin base that has rust inhibitors.

Blasting completely clean stops existing rust. Primer gets into the pores created by the blast media. Sealing the seams stops moisture flow between the layers of metal at the joints. The topcoat should be waterproof if mixed and applied properly. And the inner surfaces will get a coating that seals against moisture. That inner coating can be re-applied periodically. Paraffin will disappear in time.

This is extreme. It will require a lot of labor, but the material costs may be within the $600.00 budget.

Just my random thoughts.

[roger1]

Originally Posted by Rod and Custom

hmmm...
The problem with coating bare steel with primer is, most primers are not waterproof....

That's why epoxy primer is superior to all the older primers. Not only is epoxy primer completely waterproof, it is very chemical resistant as well. It is also very durable. Maybe not quite as hard as powdercoat but one heck of a lot easier to touch up if necessary.

Most epoxies are not UV protected however. But that is not an issue with a frame and suspension.
SPI makes their epoxy in tintable white, gray and black. They started making their black UV resistant about a year ago.

[moroza]

Got sidetracked by mechanical work on the beast, haven't done much with paint. Was about to order a gallon kit of SPI primer, then I picked up - for free - approximately 7 gallons total of Ben Moore industrial epoxy. I have no idea how old it is. Should I use it?

Originally Posted by gwh

Based on structural steel I've had them do, I'm guessing total cost of frame will be around $300, based on weight. Usual turn-around time is a few days. Then frame can be top-coated with whatever paint is desired, although painting would not be necessary for corrosion prevention.

Wow, $300? I was expecting something 5 times that. You've inspired me to contact some galvanizers out here (Bay area) and get some prices. For anywhere near $300... forget all this work stripping and painting and then still worrying about the inside. The materials alone are at least half that.

[roger1]

Originally Posted by moroza

Got sidetracked by mechanical work on the beast, haven't done much with paint. Was about to order a gallon kit of SPI primer, then I picked up - for free - approximately 7 gallons total of Ben Moore industrial epoxy. I have no idea how old it is. Should I use it?

You can test it but it may very well be good. Epoxy has a very long shelf life.
See if you can find a P sheet for the product to make sure it is designed for what you want it for.

[Chevymon]

Originally Posted by roger1

make sure it is designed for what you want it for.

That may well be the problem with it.

[jpd37]

If you are planning on driving the car a lot, don't fuss with making it perfect. Brush or spray a good chassis paint over an epoxy primer and move on. Be sure to rotate the chassis in ALL directions and air blast it as you go to be sure all the junk is gone. If you are making a show car, then prep it like it was the body. But frankly, what good is the car if you are afraid to drive it and dirty up the chassis? Most likely you will only be driving it on dry days anyway! So, don't sweat the stuff you see very little of. Make it nice and clean and move on.