I'm about to blast and paint my 40 - Question (9 Viewers)

[ksaun]

Hi all,

I have had the tub off for a length of time now, I want to get everything blasted and most of it painted before winter rolls around. Scheduled to blast on Sept. 11th, I'll only have ~3 free days to prep before the day comes.

As you can see I have some body work left to do... I cut out some parts of the rockers on both sides. I've cut out portions of each rear quarter panel and have determined that I'm due for a rear sill replacement. PO jacked up the rear fender wheel cutouts. I have a fender that requires some persuasion to true up. In a perfect world (a world I procrastinate less) I would have all this work done prior to blasting, I know. I don't foresee myself getting things done ahead of time.

Last detail, I'm having a mobile blaster come out to blast all the pieces you see above in my lot. We will likely have to go with dustless blasting (with water) and the blaster highly recommends to prep and get some paint on asap. I know / have heard that epoxy primer is one of the only applications where it is okay apply bondo top of. I have a gallon of PPG omni epoxy primer that I was planning on using for this project, it was expensive and I'd like to make sure I don't screw up.

My question; Since I have all this body work to do in the coming weeks, should I use a cheap primer just to keep the rust off while I do body work? Or just go ahead and apply the epoxy, and be okay with cutting out some areas. Should I cancel and have all the metal work buttoned up? Appreciate any advice.

 

[Jdc1]

I’d run epoxy and not waste time. Do your body work and then recoat as you finish areas.

 

[igotta40]

Guys at the Tasco paint shop assured me that if I use epoxy primer I have a window of about 24 hours to get paint on or else the epoxy primer must be sanded. They further advised that stuff is a bitch to sand. YMMV.

 

[Jdc1]

Guys at the Tasco paint shop assured me that if I use epoxy primer I have a window of about 24 hours to get paint on or else the epoxy primer must be sanded. They further advised that stuff is a bitch to sand. YMMV.

Any primer is going to have to be sanded between steps, epoxy primer gives the best adhesion and base to build off of.

 

[Wasatch Jay]

To expand a bit on Jdc1's reply, you really want your primer to have the best adhesion possible to the metal. As such, why would you want to put some cheap and easy primer underneath the epoxy primer, potentially sacrificing its bond to the steel?

Yes, you will have to sand the epoxy primer after a delay, but it's likely you would apply a sandable primer on top of the epoxy before spraying the color. You could potentially spray that within the epoxy primer's window, and that would make for easier sanding while having the advantage of the epoxy primer on steel.

 

[anothernz45]

X2 on Wasatch Jays post, do the best job possible with the blast/prime stage - that's your rust preventer. After blasting you'll find plenty of new areas that will need attention anyway buy at least you're welding to clean metal instead of old rust.

 

[aztoyman]

I also agree with getting it in epoxy. But.....MAKE SURE you read the tech sheet. SOME products are sensitive to certain blasting media. I think baking soda is one of them. Also some epoxy brands requires Ospho or phosphoric acid preps to be properly neutralized prior to applying their product.

Good luck with your project!!

 

[ksaun]

Guys at the Tasco paint shop assured me that if I use epoxy primer I have a window of about 24 hours to get paint on or else the epoxy primer must be sanded. They further advised that stuff is a bitch to sand. YMMV.

Good point, thanks for the reminder.

 

[ksaun]

Thanks to everyone for the advice, I think I’ve got a clearer idea of what the process will look like and feel confident that the epoxy is the right choice.

 

[aztoyman]

The guy blasting will get further along if you make sure to knock off heavy stuff like seam sealer or undercoat.

 

[pb4ugo]

I used the Omni system too and followed the instructions sheets. What Wasatch said. This was my 1st time doing something like this. I was told and read I had 72 hrs after doing the epoxy primer sealer to top coat it, with 2k primer or color with no sanding. I was told that sanding the epoxy sealer primer was a pita to sand also, so I made a plan. Most of my parts and panels didn't need body work and were sand blasted, so they all got epoxy sealer, then either color, or high build sandable primer then color. I was painting the frt end parts.