The 1947 - Present Chevrolet & GMC Truck Message Board Network - View Single Post - Questions about primers, prep and such, for parts

**71CHEVYSHORTBED402** · 03-25-2017, 01:10 AM

Thank you guys, here's my education. Appreciate any corrections, etc........For the record, these are just parts and there's no visible rust.

1. Final grit should be heck, I don't know. Lots of info. and variances. 80-120 grit by some accounts, and approx. 400 by others. Correct me if I'm wrong, I'm guessing 80-400ish works, depending on what it is you're painting. Considering I'm just painting parts and have no need for urethane primer, I'm back to the maroon pad. They're about 320 grit. Unless I'm mistaken, scouring/sanding is a form of etching the surface.

2. Then Clean: Use lacquer thinner, mineral spirits, acetone or wax & grease remover. You can follow that up with isopropyl alcohol to lift additional contaminants. Really, there doesn't seem to be any shortage on products used to clean surfaces. On a side note, I've read you risk fisheyes by using lacquer thinner or mineral spirits, and imagine that may apply to alcohol and/or acetone as well. As a rookie, seems wax & grease remover is a safe route, and perhaps isopropyl alcohol.

• Use a lint free towel to wipe it clean. You can even follow that up with a tack cloth. At this point you're ready for primer.

3. Epoxy Vs Self-etching: Some debate over the existence of self-etching primer. However, this is my understanding of the differences, whether they're real or not.

3A. If self-etching:
• Apply any body fillers first. Doesn't apply to me, but just saying.
• You don't have to scuff up the metal surface because of the acids for adhesion.
• If you leave it sitting around for say 1/2 hour or more, then scuff it up before the next coat in your process.

3B. If epoxy:
• This provides better resistance to the elements than self-etching primer.
• You do have to scuff up the metal surface for adhesion. As a metal prep. goes (i.e., phosphoric acid), perhaps it's best to use it only if the manufacturer paint line calls for it.
• Apply any body filler afterwards.
• You can leave it sitting for a longer period of time before having to scuff before the next coat in the process. Word is it's a (*&^^ to sand.
• Guessing here, but I believe it has some qualities to stop rust, say rust that's not visible. Not to be confused with a rust converter.

I think I'll:

1. Scour following any sanding & brushing. At this point the parts are clean. I won't bore you with the details, but I clean and tuck them away for another day. Despite the Nevada climate, that may mean I hit them with white vinegar and neutralize. Regardless, I'll be revisiting all the parts for prep. I do not have a blaster. Not yet anyway (cough). Really though, on a scale 1-10 for rust, this truck is a 1.

2. Wax and grease remover.

3. Epoxy.

4. Paint.

5. Two stage is pending. Not sure on that one yet. The frame will be Master Series stain black. Whether or not the core support etc. sees a clear coat is pending, but they'll likely be painted satin black. I sure like the looks of powder coat, but the separation etc. scares me off a bit. That and once it's scratched there are only two options, ignore it or start over.

Good videos:
https://www.youtube.com/watch?v=jvUhchmHTCM
https://www.youtube.com/watch?v=-bSE1AUKxQ0

03-25-2017, 01:10 AM	#13
71CHEVYSHORTBED402 Senior Member Join Date: Feb 2009 Location: Northern Nevada Posts: 7,129	Re: Questions about primers, prep and such, for parts Thank you guys, here's my education. Appreciate any corrections, etc........For the record, these are just parts and there's no visible rust. 1. Final grit should be heck, I don't know. Lots of info. and variances. 80-120 grit by some accounts, and approx. 400 by others. Correct me if I'm wrong, I'm guessing 80-400ish works, depending on what it is you're painting. Considering I'm just painting parts and have no need for urethane primer, I'm back to the maroon pad. They're about 320 grit. Unless I'm mistaken, scouring/sanding is a form of etching the surface. 2. Then Clean: Use lacquer thinner, mineral spirits, acetone or wax & grease remover. You can follow that up with isopropyl alcohol to lift additional contaminants. Really, there doesn't seem to be any shortage on products used to clean surfaces. On a side note, I've read you risk fisheyes by using lacquer thinner or mineral spirits, and imagine that may apply to alcohol and/or acetone as well. As a rookie, seems wax & grease remover is a safe route, and perhaps isopropyl alcohol. • Use a lint free towel to wipe it clean. You can even follow that up with a tack cloth. At this point you're ready for primer. 3. Epoxy Vs Self-etching: Some debate over the existence of self-etching primer. However, this is my understanding of the differences, whether they're real or not. 3A. If self-etching: • Apply any body fillers first. Doesn't apply to me, but just saying. • You don't have to scuff up the metal surface because of the acids for adhesion. • If you leave it sitting around for say 1/2 hour or more, then scuff it up before the next coat in your process. 3B. If epoxy: • This provides better resistance to the elements than self-etching primer. • You do have to scuff up the metal surface for adhesion. As a metal prep. goes (i.e., phosphoric acid), perhaps it's best to use it only if the manufacturer paint line calls for it. • Apply any body filler afterwards. • You can leave it sitting for a longer period of time before having to scuff before the next coat in the process. Word is it's a (&^^ to sand. • Guessing here, but I believe it has some qualities to stop rust, say rust that's not visible. Not to be confused with a rust converter. I think I'll:* 1. Scour following any sanding & brushing. At this point the parts are clean. I won't bore you with the details, but I clean and tuck them away for another day. Despite the Nevada climate, that may mean I hit them with white vinegar and neutralize. Regardless, I'll be revisiting all the parts for prep. I do not have a blaster. Not yet anyway (cough). Really though, on a scale 1-10 for rust, this truck is a 1. 2. Wax and grease remover. 3. Epoxy. 4. Paint. 5. Two stage is pending. Not sure on that one yet. The frame will be Master Series stain black. Whether or not the core support etc. sees a clear coat is pending, but they'll likely be painted satin black. I sure like the looks of powder coat, but the separation etc. scares me off a bit. That and once it's scratched there are only two options, ignore it or start over. Good videos: https://www.youtube.com/watch?v=jvUhchmHTCM https://www.youtube.com/watch?v=-bSE1AUKxQ0 __________________ Tony 71 Custom Deluxe, SWB, 2WD, 402, A/C. I developed an assm. guide "kit" for restoring it from ground up. With assys, the guide accts for 1000s details such as OEM identifications& part numbers, written in short order. 700+ images include assm, illust., charts, and points of interest. Much of the info. applies to all 67-72 GM trucks, and to a lessor degree all 67-72 GM vehicles. My build thread, and more on the guide https://67-72chevytrucks.com/vboard/...d.php?t=730025 Last edited by 71CHEVYSHORTBED402; 03-25-2017 at 01:34 AM.