I was not able to find any existing Threads that covered the subject of using undercoating vs paint on the frame of a truck. I have spent a lot of time cleaning the rust and dirt off the frame of my 54 F250 and although not many will see it in the future, I want it to last. First off is there a spray cleaner that I can use prior to painting that will clean off the residual dust, dirt,etc or do I need to wipe it all down with a cleaner, and what cleaners do others suggest. I have used brake cleaner on small parts in the past with good results, was hoping to use a spray to get into small spaces, springs, etc. Second I was going to use gloss black paint on the rear end, springs, wheels, etc. but use a spray on undercoating on the frame. I have read a few responses on other sites stating the undercoating tends to flake off and then hold moisture under it, and has to be redone. The frame is somewhat rough, may have even had a light undercoating on it before, so thought that might cover better. Granted I am going to use spray cans to do this, so don't expect show quality results, but once the box is put back on, I don't want to have to redo it later. Suggestions on what has worked well for others is appreciated. Hope to do this over the weekend if I get that far.

 

I used this on my frame. Rust-Oleum Professional 1-gal. Flat Black Protective Enamel-K7776402 at The Home Depot

 

The biggest problem I have with undercoating is it stays a little tacky. Even the rubberized stuff collects enough dust and dirt that it never looks clean to me.

I have also had a problem with it flaking off, but I don't think the frame was cleaned properly. For what it's worth.

 

Under coating is not paint. Some of the rustiest vehicles I've seen and owned have been undercoated.

Just paint your frame.

 

I used Rustoleum on my frame. I put 2 coats of primer and 2 coats of black. That was 2 or 3 years ago, but it hasn't been out of the garage much. It's still looking pretty good. I have used the frame as a workbench some so I do have a few scratches, but I have just painted over those some.

Others swear by POR-15.

 

Rustoleum is fine, rattle cans are a bad idea. Expensive and just do not put down enough paint. I would use foam brushes if unable to use a regular spray gun.

 

I like to use tractor implement paint like they sell at Tractor Supply, etc. Valspar and Majic make such a paint and they sell a hardener that goes along with it. Get it, clean the frame good and brush it on. Don't waste your time with spray cans, brush it on for good coverage.

 

There isn't any spray that will adequately clean you surfaces prior to paint. Use a good detergent with a scotch-brite pad/strong cloth to degrease and rinse thoroughly before painting to the completely dry surface. The time you spend prepping the surface will be repaid with a better result.

Another option for the paint is POR15 (Paint Over Rust). This stuff is a bit pricey - with instructions that need to be followed - and has a pre-paint treatment available that can be misted on. Once on, this stuff is very tough and durable with a decent finish.

DW

 

Took the advice, took back the spray undercoat and spay cans. Going with the Rustoleum and brushing it on. Finished cleaning off the rust today, cleaned the frame with Laquer thinner, (suggested by a Body Shop friend) and started painting. Looks pretty good, what little I got started. Hopefully a second coat will look even better.

 

2 coats looks good on mine. First coat you can see some of the brush strokes pretty clearly. The second coat really smooths it out.

 

This is what i used and am really pleased with it. When I get enough
scratches I can touch them up with a brush.I used Massey Ferguson red that matches the Corvette torch red body color pretty well.