SPI 2k primer over epoxy

[cllong1]

Hey guys its been while since i been on here and finally got my 65 mustang strip down to bare metal and been doing filler work and re- epoxy over burn through spots. I got a couple of questions now that I am ready to move to 2K Primer Yes, its been more than well over 7 days since epoxy was sprayed like over a year.
1. What is the correct way to transition from Spi expoxy to Spi 2k regular primer?
2. If re-coat is needed what grit do i sand before epoxy , I think 180 is to rough its takes off to much material and exposes a lot of bare metal?
3.What grit 320 or 400 do I sand epoxy before spraying 2kPrimer?
4. If 2 coats of 2k are sprayed, what is a good general grit to prep 2k primer for paint?
The reason why I am asking is I see these steps a lot on the forum, I am basically asking for my own knowledge and understanding trying to understand the adhesion part to this and don't want any adhesion issues the closer I get to paint. I just need the correct way and I got it from there.
Thanks

 

[RenewAP]

320 or red scotchbrite is how I do it. Always has worked fine.

 

['68 Coronet R/T]

From the Tech Manual:

Prepping the Surface: When prepping for epoxy always sand with 80 grit DA paper for bare metal, sand with 180-320 for paint or primer.
Metal must be clean of all rust, oils, and any films. Never clean metal with lacquer thinner, acetone or reducers of any kind. Clean surface with SPI 700-1 Waterborne Wax and Grease Remover and let sit for 45-60 minutes before applying epoxy.
If you have any questions on how to prep any type of substrate, please call our tech line before beginning.

You can download a copy of the SPI Technical Manual here: https://www.southernpolyurethanes.com/_files/ugd/8ced3e_fc36f99350a2405e906f53c896c5e4e1.pdf

 

[cllong1]

Thanks 68 Coronet glad to see all the guys are still here helping out.

 

[Toolin]

Prepping the Surface: When prepping for epoxy always sand with 80 grit DA paper for bare metal, sand with 180-320 for paint or primer.

Thanks 68 for the refresher. My old brain needs to be reminded from time to time. I often have doubts about grit sizes.

 

[MJM]

Thanks 68 for the refresher. My old brain needs to be reminded from time to time. I often have doubts about grit sizes.

You're not alone brother. I ask for refreshers when I'm at a new point in the painting process. Don't want to rely on a memory that could fail me. It may be a little taxing on the seasoned pro's but, I hope they understand.

 

[MJM]

Since the car has sat for a year in epoxy primer, wouldn't best practices be to sand the car with 180, then spray unreduced epoxy, then spray 2k within the 7 day epoxy window for best adhesion. I think it was shine who said, nothing adheres to epoxy better, than epoxy

 

[cllong1]

I asked the question about adhesion principle but nobody answered, 68 Coronet gave the info from the tech manual so I printed those off. I have periodically sanded with each section 180 while working around on different panels as I worked. I have basically scuffed most of it with 180 and have shot at least two coats of epoxy as i have been doing panel work in sections. I'll follow the tech manual to get it right I'm just about ready to put primer on it. I work full time so the car has been in my garage and can get it as work and money allows. To me SPI has been a great product so I'm doing both white epoxy and using grey 2k regular primer using SPI products. I don't think they do the base color I want. I'm going with Acapulco blue so if Barry can do it. Please let me know.
Reading is Fundamental so I guess I'll be able to quote the manual by the time I'm finished

 

[MJM]

So are you saying that you'll be spraying 2k primer over freshly sprayed epoxy within the 7 day window?

 

[cllong1]

Yes