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Posted by: r_towle Mar 15 2021, 08:37 PM

Bare metal flares, the rest of the body is painted

So the question is for bare metal.

Order options

1) epoxy primer, bondo, high fill primer, sealer, paint, clear
OR
2) bondo, high fill primer, sealer, paint, clear

What would you suggest?

And, given my lack of a paint booth, I will have a paint shop do whatever stage I need to ensure no bugs land on the paint.
I will paint and bodywork up till it must be a clean room process.

I need some advice on the steps and order.

Rich

Posted by: Literati914 Mar 15 2021, 08:53 PM

I like option #1, either way would probably be fine .. but epoxy gives piece of mind. Use the epoxy primer over the (worked down) welds too, then filler..but use a short strand fiberglass filler like "kitty Hair" (bondo has the same product too - "bondo glass" I think it's called). These products maintain a certain amount of flex that's not in regular filler (making it better for use over welds). Work that down, then put epoxy on top of it too. Follow with high build (if you feel like you need it - it's more of an all over car item imho). Sealer, paint & clear if you're using one (I prefer single stage on vintage cars, you can add some clear to them in the final coats, as an option). Good luck!


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Posted by: PanelBilly Mar 15 2021, 09:28 PM

My vote is for number 1 also. That’s what I did

Posted by: roblav1 Mar 15 2021, 09:58 PM

My recent method: grind welds, etch, dp90lf epoxy primer, aeropoxy mixed with silica, sand, more dp90lf epoxy primer, filler, sand, primer, sand, primer, sand, color.

Posted by: 914 RZ-1 Mar 15 2021, 10:06 PM

When I painted my car myself, I sanded the old paint with 400 grit, used Bondo where needed, sanded again, then used polyester primer/surfacer, then single stage paint.

I made a paint booth that fit in my garage. My thread on it is http://www.914world.com/bbs2/index.php?showtopic=331582&hl=paint:
http://www.914world.com/bbs2/index.php?showtopic=331582&hl=paint

Posted by: Bucci Mar 15 2021, 10:56 PM

I like Option 2 best.

Confirm with your paint manufacturer as they have specifications for their primers and sealers.

1. Metal bodywork and dress welds. Don’t remove too much of the weld between the flare and the body sheet metal.
2. Sand all sheet metal thoroughly looking for imperfections, hammer and dolly high and low spots. Heat shrink if necessary and repeat process.
3. All body panels should be fitted at this time and check operation/ gaps.
4. Remove dust, grease, silicone, waxes. Use “Comet abrasive powder” or your favorite abrasive. Scotch-Brite pad the sheet metal thoroughly like your scrubbing a pot.
5. Rinse on a sunny day and dry thoroughly with gas heater and air nozzle.
6. Apply acid etch liquid cleaner and working in with Scotch-bright pads, noting not to embed the plastic pad into the metal surface.
7. Apply body filler over bare rough surface, metal worked areas should have some tooth to hold the filler.
8. Remove parting dust after all body filler work is complete. It maybe necessary to wash the car again. Dry thoroughly.
9. Apply manufacture recommended etch primer. Sand as necessary to be ready for the next coat of manufacture recommended sealer primer.
10. It will take several days or several weeks for sealer primer to dry allowing it to shrink onto the metal surface, rolling the car out into the sun for paint curing.
11. This is where you can help eliminate the sanding scratches. Inevitably primer paint bridges over small scratches and then sucks down during the curing process.
12. Some of the painters I’ve spoken to like to leave the sealer primer unopened or not sanded durning curing.
13. Right before they’re ready to paint they will use a guide coat over the whole body and will sand right before the final coat of paint is applied this keeps the surface clean and free of debris getting stuck on to the freshly sanded surface.

Some of these procedures and operations will vary from person to person. I’ve only managed body shops and painted small parts. It takes an artist and somebody special to want to paint cars correctly.

Posted by: rick 918-S Mar 16 2021, 02:00 AM

Are you working on your car?

Posted by: Cairo94507 Mar 16 2021, 08:05 AM

I think option 1 is the way to go.

Posted by: rmital Mar 16 2021, 08:10 AM

seriously...…

Posted by: slowrodent Mar 16 2021, 08:12 AM

My only concern with option 1 is that the epoxy primer be sanded if it is allowed to completely cure prior to filler application. There's generally a recommended window where the filler can be applied without sanding, but after full cure, it probably should be sanded prior to ANYTHING being applied on top.

Option 1, with this stipulation, has been my approach thus far.

Posted by: roblav1 Mar 16 2021, 12:34 PM

DP40LF is 24 hours.

Posted by: mgphoto Mar 16 2021, 02:30 PM

Option 1, Southern Polyurethane epoxy primer, tough as nails, they even have live tech support download their application pdf also half the price of Deltron.

Posted by: r_towle Mar 16 2021, 06:16 PM

I’m considering it, yes

Posted by: bbrock Mar 16 2021, 06:24 PM

The DPLF spec sheet says up to 1 week without sanding. That is also the primer I used. I also went with, and vote for, option #1. I had to repair too much metal where paint had failed over body filler and trapped moisture against the steel. I think either option is fine until the paint fails, but am operating with believe that a continuous coat of epoxy next to the metal will provide that last line of defense.

Posted by: mepstein Mar 16 2021, 07:09 PM

The dtm fillers are different than the old bondo products.

One of our guys had a rule of thumb. Etch primer over old metal and epoxy over new metal.

Posted by: bkrantz Mar 16 2021, 08:08 PM

My paint shop owner (who has been doing this for decades) was absolute: bondo on bare metal, then priming.