The bed floor of my 65 F250 has some peeling paint. It only has the original paint under it and I would suspect inadequate prep at the time of the 2nd paint job to be the cause of the peeling. Seems likely because that ribbed bed ain't exactly easy to sand on.

But I've got me one of those cheapo bucket type sandblasters and enough compressor to run it. Seems to work OK, but I'm a bit nervous about what's left after sandblasting. From the Building Supply I've tried 60# and 100# Silica Sand and that seems to leave too rough of a surface. Rips the paint right off but leaves it all gray lookin' and it feels like sandpaper.

I heard walnut shells are a better way to go so I got me some large grain from McMaster-Carr, but, short of designing some sort of vibation fixture to keep 'em loose, they wouldn't go thru the bucket!

Tried the small grain today and while they'll flow they sure don't seem to be getting much done. I get some action where the peeling is but most of the 2nd coat's still there lookin' nasty right back at me. Unless I sit right on it the original paint ain't getting bothered at all.

So now I'm thinkin' medium grain, but I'm startin' to wonder if I shouldn't just get me some Silica Sand and blow this thing away!

What do you guys use and where do you get it?

Thanx.

 

I feel your pain...I have gone through two bed restores and
it is difficult. First one I tried my own sanddblaster
but that was like kissing your sister..not the
real deal so I has it pro done and O.K.
but spendy. Second one was aircraft stripper with
every concievable abrasive tool known to man.
Best tool was a dremle with various grinders and
brushes. I hit it with a good two part urethane
primer surfacer and just fine for a work truck.

My next bed I am going to try a tool I have seen
bridge painters use. Don't know the name but
they are a hand full of wires coming out of
a air tool basically designed to "descale"
prior to painting. I think welders use them
also.

Hope this helps!

 

Maybe that rough surface the blaster is leaving is rust pits and you're just cleaning them out? I'm not sure what a bucket blaster is, but I use a pressure blaster and the only places I have the kind of pits you mention are the places that have "surface" rust. The cab floor looked okay until I blasted and what was left after blasting away the rust was holes, not pits.

If someone had your truck before you and painted over a rust problem, then that's all they did - painted over the problem. Now you're seeing the effects. That rough surface is fixable. Covering rust with paint is NOT.

If your "bucket blaster" is anything like a syphone feed blaster, it shouldn't be causing any pitting from blasting alone. Even the pressure feed blasters (more powerful) will not pit the metal. It'll warp it if you concentrate your blasting to one spot for too long, but from my experience, will not pit it out. I've even used a professional blasters in the past on our race trailer rails and never had a problem with pitting except where rust had already found its way.

Blast it to clean metal, treat it and fix it. If the pits aren't too bad, a few coats of a good high-build primer and lots of muscle will hide the pits.

 

The finish from a sand blaster will be rough, similar to 100-200-grit sandpaper. If this is what you’re referring to, then that is the perfect finish for primer to bite into. If you were expecting 'shinny', you will be disappointed. Wire wheel stripping will leave a shiny finish that actually closes the pores in the metal, making it more difficult for primers to hold.

 

Thank you for your responses. I can't thank you enough for your responses!

It is a siphon feed type blaster. Just a bucket with a hose on the bottom and a gun, but it'll do some work with that Silica Sand. As a matter of fact it works so good I was afraid to use it! Thought it might be one of them regret later deals.

If I can get me some weather tomorrow I'll bet it's rough gray lookin' metal by tomorrow night.

Thanx again.

 

go ahead and blast it. i know what you mean about the sand blaster leaving the metal kind of rought. take some either 220grit paper or some fine scotch pad, and just go over it quickly. it will smooth out the metal and make it shine.