repairing/priming sandblasted body panels

[bkvail]

We are getting the individual parts of our 36 Diamond T sandblasted to bare steel to get rid of a strange paint/sealer that was used on it (and rust of course). We plan to prime/paint it ourselves. I took an auto-body course in the 80's, but I remember very little from the course! Anyhow, doing research today as we just got back one part from the sandblasters (the cowl/firewall/dash section) - it had some cracks in the metal that needed welded, so Brian welded them yesterday. Then, there is a small section on both sides that has rot that we need to piece in some sheetmetal.
My question - should I primer it right away? I was planning on using epoxy primer. We still need to do the rot repairs - and probably some small amounts of body filler where there was lead filler in seams. I am just worried about priming it, then having to do welding. I think that body filler can be used over the epoxy primer, right? If we don't plan to paint the parts right away, I think that I will need to reapply the epoxy primer, then high build primer, then paint when the time comes? I don't think we'll be getting around to painting it until next spring at the earliest, but we want to get rid of the rust between the parts that need assembling so we can do things like build a floor, etc.

 

[bob w]

There's far more experienced bodymen/painters on RRR than me. But since no one has responded, I will. Usually when I have parts sandblasted I have them shot with an epoxy primer. I sand it off if I need to weld. On occasions when I don't have the parts primed by the sandblaster I mask an inch around the area to be welded and apply epoxy primer to the rest of the bare metal. I still use plain old lacquer primer at times but realize it doesn't hold out moisture. And I've applied Bondo to bare metal and over primer. Seems okay either way.

I might have the wrong attitude but I don't worry about bodywork lasting for 50 years. It only needs to last as long as I do. And I'm old.

 

[bkvail]

thanks, I am ordering epoxy primer from Southern Poly Inc (along with their wax/grease remover). I might have to resand before priming, but we just don't have all our ducks in a row, guess we got ahead of ourselves! I'm not seeing any rust come back on the cowl we had blasted so far luckily........

 

[Old Dude]

I do it the old school way:
Things to remember: Primer is porous, it sucks moisture. Bondo on bare metal, after you use a torch to flash the moisture off the metal. You can actually see it run away from the flame. I use a product called "Ospho" it's some great stuff. You can actually let it set outside in the rain for a few weeks and it won't rust. A good sealer is a light coat of lacquer paint. It sands easy when you get ready to work the panel. I've never had bondo crack and fall off using this method. Then again, I only use bondo to fill grind and file marks. A good spot putty like eagle claw for sanding scratches. A heavy fill primer works quite well also. Water sand with 600 and then shoot the paint.

 

[bkvail]

ospho is a rust treatment, and I am going to be using an epoxy primer (epoxy primer is not porous like regular primer according to what I've read), and the epoxy primer I am going to use cannot be used with rust treatment unfortunately

I think the ospho might be similar to a product we've used for years ''rust seal'' an SEM product. It goes on white, but turns black where there was rust. Fantastic stuff. Can't use it under the epoxy primer though or I would.......

 

[sgtpontiac]

I think you've got the right ideas....

ospho is a rust treatment, and I am going to be using an epoxy primer (epoxy primer is not porous like regular primer according to what I've read), and the epoxy primer I am going to use cannot be used with rust treatment unfortunately

I think the ospho might be similar to a product we've used for years ''rust seal'' an SEM product. It goes on white, but turns black where there was rust. Fantastic stuff. Can't use it under the epoxy primer though or I would.......

on how you want to proceed.....depends on how much pre prime work you / us want to do and the cost factors involved....do it right it lasts a very long time....do it on the cheap and not so much.... most of us probably use the field expediant method on things and the cheapest way out barring doing it flat out wrong..... you need to do it the way you feel is the best from your perspective...i've used a number of rust solution chemicals before, but haven't used epoxy primer....the things I've done worked out fine.....new blood, new times, new products and abundant funds will sometimes dictate new thinking..... have fun....

 

[bkvail]

on how you want to proceed.....depends on how much pre prime work you / us want to do and the cost factors involved....do it right it lasts a very long time....do it on the cheap and not so much.... most of us probably use the field expediant method on things and the cheapest way out barring doing it flat out wrong..... you need to do it the way you feel is the best from your perspective...i've used a number of rust solution chemicals before, but haven't used epoxy primer....the things I've done worked out fine.....new blood, new times, new products and abundant funds will sometimes dictate new thinking..... have fun....

abundant funds, we do not have.... but since we aren't going to be able to do body work right away, we almost have to spend the money on the epoxy primer (since it's not porous like regular primer). I wish we had a real shop to keep the truck in to work on it over the winter, but unfortunately we don't..... it's getting worked on on our patio, LOL. Anyhow, I did TONS of reading and research since my original post. I very much appreciate the advice though!

I think that this winter, I am going to try my hand at pinstriping........ practice over the winter, then decide when we paint in the spring if I can do it well enough to do some pinstriping ::crossing fingers::

 

[sgtpontiac]

Good luck......

hope you can find an inside storage area....working out in the cold under the car port / patio is a bummer....been there done that....don't want to be there again.....can remember as a kid pulling transmissions with the car strattled across the ditch in front of the house...lol...was a 58 chevy impala 348 with a Turbo glide trans....reverse was at the bottom of the selector...learned my lesson about power slams into low gear..LOL...hope you can find a dry if not warm place to work on it...

 

[bkvail]

hope you can find an inside storage area....working out in the cold under the car port / patio is a bummer....been there done that....don't want to be there again.....can remember as a kid pulling transmissions with the car strattled across the ditch in front of the house...lol...was a 58 chevy impala 348 with a Turbo glide trans....reverse was at the bottom of the selector...learned my lesson about power slams into low gear..LOL...hope you can find a dry if not warm place to work on it...

unfortunately, we just don't have one....... we have a garage, but it has a HORRID floor (and boat in one side, vintage camper that the roof leaks on in the other) - that and it has horrid lighting and it's too far from the tool storage. It pretty much has to be the carport...... I only wish we would have talked the builders into making a garage door in our daylight basement when they poured the cement 16 years ago. Nice area for a woodshop, not so great for working on cars.......

 

[klink]

I would spray it with epoxy primer. Body filler can be used over it too... the primer you'll have to sand away for metal work will still be worth the effort.

Having epoxy or urethane under the body filler is a good move, if the paint ever chips, moisture will most likely never come into contact with bare metal and cause rust.

 

[rainbow lungs]

Make sure it is a direct to metal primer. SOme epoxy primers require an etching primer first, if they are not direct tometal.

Lungs

 

[bkvail]

Make sure it is a direct to metal primer. SOme epoxy primers require an etching primer first, if they are not direct tometal.

Lungs

we used Southern Poly epoxy primer on the bare metal (after we washed with grease/wax remover and then rubbed down with red scotchbrite pad)