Epoxy primer question

[70 sublime]

I have a project car I am thinking about getting sand blasted by a local guy
Last time I had one done he just used regular red primer
He does a lot of sand blasting (not a lot of car stuff) and just gets his primer in 5 galon pails

So two questions

Is it easy to mix it to spray if I supplied it to him  ?
(Just the paint and thinner or reducer or is there hardener also ?)

If the car is completly sealed with epoxy and I do some body work to fill some dents can I use regular primer over top of it before the final colour goes on the car ?

[b5blue]

  I used Eastwood's epoxy primer and cheap Harbor Freight HVLP guns. Thinned about 10% with Lacquer Thinner you can get to lay down nice. I treated rust flash/spots or pits with OSPHO, keeping it wet and removing before it drys after it burns the rust off. A good scuffing with a scrubby and cleaning before spray.
  Eastwood Rust Encapsulator can be gotten with a 24" spray tube "wand". The tube can reach into seams and areas you could never get to any other way and if you clean it you can reuse it with more cans of the same stuff without paying the extra. I even adapted the wand to fit a spray bottle and pumped OSPHO inside frame rails and other areas blasting can't reach.
  Plan on coating right away as the steel will flash rust very soon!       

[Pete in NH]

Hi,

Epoxy primer is a two part system that includes a hardener. Usually it's a 50/50 mix ratio and reducer can be used to thin it out a little if need be. I'm pretty sure the Eastwood epoxy is relabeled Kirker and you can likely get a better price on the Kirker.  Do an internet search on Kirker automotive paint. You will find applications information on the Kirker site.

Sandblasting makes a very good surface to apply the epoxy primer over. Each primer manufacturer has a slightly different surface prep and cleaning routine and it's best to follow their suggestions. You can apply your body filler directly over the epoxy primer. The primer manufacturer will give you a time frame suggestion for their product before you would have to scuff it up to get adhesion.

You can then apply more epoxy as a sealer coat  before your color coat but you would more likely use a 2K primer surfacer and block sand to get things flat and smooth before sealing and applying color.

[b5blue]

I'm pretty sure your right about the Kirker thing. I actually got a better deal from Eastwood as the activator was included free if you bought the epoxy at that time in a sale they had going on.

[Dreamcar]

If you don't mind spending a little more, get SPI epoxy!!!!! It's a little more then Nason or Eastwood (but cheaper than Dupont name brand), but they have a distributor near Toronto who is their Canadian rep. I reasearched the hell out of epoxies before buying mine and SPI always came back at the top of the list. With shippping to Ottawa and taxes, a gallon kit (with activator) cost me about $230.00

SPI's president/ceo/big cheese will actually answer most of your questions by email within 24 hours. I've read tones of tech sheets, and their's leaves almost no guess work on what to do or how to do it. And, if you have a question, they are very easy to get a hold of. Finally, there's the SPI user forum which the company rep will also participates in.

I used Nason brand on my other project before this one...It was ok, but the recoat window is only about 24 hours vs the 7 days with SPI (I would still not let it go 7 days though before recoating).  Having seen the red primer you're talking about and what happens when moisture gets to it, definitely go with quality epoxy and you'll have no issues even if the car sits for while.

Like most epoxies, if it cures past its recoat window, you should scuff (as per the tech sheet) and apply another coat to reactivate the recoat window, then apply your next primer within that recoat window (i.e. primer surfacer for blocking).

[70 sublime]

It is starting to get very technical to use epoxy primer

After you mix it all up and ready to spray how long do you have to use it before it turns ?
The red primer we always used around home we just made up a bunch and put it in a jug with a lid and could use the left overs with just a shake of the jug a week later

Next question would be how much would I need to paint everything ?

body inside and out (not underside)
hood
fenders
doors
trunk lid

[Dreamcar]

It is starting to get very technical to use epoxy primer

After you mix it all up and ready to spray how long do you have to use it before it turns ?
The red primer we always used around home we just made up a bunch and put it in a jug with a lid and could use the left overs with just a shake of the jug a week later

Next question would be how much would I need to paint everything ?

body inside and out (not underside)
hood
fenders
doors
trunk lid

Using any type of primer (etch, epoxy, surfacer, sealer, etc) correctly as recommended by the manufacturer requires knowing what it is and reviewing the tech sheet. Thus, they are all "technical". Plus, if you're going to keep the car and want to have the "red primer"  sprayed , then I would find out what it is so you can figure out how fillers, other primers, and topcoat will react in the long term before you paint it. For example, if the red stuff is etch primer, then putting filler over it will be very risky as the acid may eat the filler over time.

That red primer was covered by grey primer on the other Charger I had...drops of water got on the trunk lid over the winter and rust started showing up. Rust also started showing after the rainy drive home on trailer!. It didn't bother me much because I was going to strip every panel anyway. So, the corrosion protection was not that great. Epoxy will be much better in the long run.

How long you have to use the mixed epoxy depends on the brand you buy as they are all different...this is where the tech sheets help because all that info is there, including how to prep the metal before you put it on.

I'd say that a gallon kit (which ends up being two sprayable gallons) should cover the entire car (two coats), but the manufacturer, if their customer service is good, should be able to tell you that.   

[Pete in NH]

I'll second all of Dreamcar's comments. Automotive finishes are much more technical today than when our cars were built 40 years ago. However, they are also so much better in terms of long life and durability. Like Dreamcar, I have also done a lot of research on epoxy primers for an up coming project and I have to say SPI is the hands down winner. I have never seen a negative comment about them. The technical support seems to be excellent and the users forum is one of the most professional I've ever seen on the internet.

Epoxy primers are really the only primers that are truly waterproof. That red primer you spoke of is very likely a lacquer based primer that really should  not be used under any of today's modern paint systems.

[b5blue]

Here are some examples for you....
  http://www.kirkerautomotive.com/PDFS/ENDURO%20PRIMEtech.pdf

  http://www.kirkerautomotive.com/images/PDF/ULTRAGLO.pdf

  I'm no painter so on a real tight budget and not needing much more than to repair and protect the car from further rotting I went the cheapo route. (My Charger is a daily beater not show.) If you study these links you'll see where your heading into more or less. A big issue for me was getting dry air to shoot and getting rid of the crap left from sandblasting, that stuff just keeps coming out of every nook and cranny after blasting. (I just did spots on my car here and there but it gets everywhere!)
  So much depends on intent of finished car and how much money you have to spend, it's so much work and the devil is in the details.     By the way this is a crappy time to start unless you live where it's cool and dry this time of year. If you look at the temps and humidity % this stuff is rated for windows for dry time/cure/pot life are 70 degrees at 50% humidity so anything higher REDUCES all the stated times. (What I would have given for a climate controlled stall/booth for 2 months!)
  I'm going to butt out of this as so many here helped me through my ordeal they have much more sound experience then I could share! Good Luck!   

[70 sublime]

I stopped by the sandblaster guy this evening

He said he has used epoxy before so I guess that problem is solved

As for the heat and humidity I am shooting for a winter project so I will wait till it is nicer out to get it done