Hey all,

So, I’m making progress with cutting out rusted pieces and fitting my new or used panels up to be welded. I’ve realized that before I weld in these new pieces I have good opportunities to blast and protect some hidden areas of the car.

I have an epoxy primer, activator and reducer by Matrix that I bought locally to try out. I guess I’m a little confused about the difference between “Primer” and “Primer-Sealer”. I’ve done some research and can’t seem to wrap my head around it. The tech sheet basically has you not add the reducer to make it a primer-sealer.

So, since these areas will not be painted (unless someone says they should be), can I just shoot the “primer-sealer” (no reducer) on the metal to keep it protected ( after the typical metal prep work of course) and then forget about them for the rest of the life of the car?

Edit/Note: I would mask off areas to actually be welded and apply weld thru primer that I have.

Also, I planned on prepping all of my body metal (tech sheet says 180-220 grit) then spraying this same epoxy primer, as a “primer” (with reducer), then filler, then high build primer, base, clear... Is that the proper use of the “primer”?

Thanks in advance.
-Tom

Sounds backwards to me. The epoxy I use mixes 1:1 with hardener for primer usage and then 1:1:1 with reducer to use as a sealer. You will need to read your tech sheet on that product.
You can also brush on epoxy primer in those hard to reach hidden areas.

According to the screenshot I attached, it’s showing to add 1/2 part reducer for “primer”. The “primer sealer” only gets a 4:1 epoxy to activator mix.

I’d rather just spray to seal while I’ve got everything apart and do it as right as possible. Brush on is an alternative though.

I’d still like to know if my thought process is correct....

Thanks

Not trying to be mean but I would get a better quality epoxy. Something that mixes 1:1 rather than 4:1.
********** or Tamco would be my suggestions as they are quality products at affordable prices.

Restorations require a lot of work and going with low budget/quality materials just doesn't make sense to me.

Hope this helps

Primer-A type of paint which has little color content but which helps the bonding process between metal and color coats.

Primer/Sealer: An undercoat (primer) which improves adhesion of the topcoat and/or seals the surface so that the paint isn't absorbed. Paint is usually applied to the sealer without the need for sanding as long as it is applied within the time window prescribed by the sealer/paint manufacturer.

That is miss print. Most epoxy is 1to1 for sandable primer, but your epoxy is 4-1 as primer. Then 4-1-.5 or 4-1-1 to make a primer sealer/sealer. Good luck.

Thanks for all the input.

Apparently I somehow ended up with a 2006 rev of the tech sheet. I went back to their site and there is a 2014 rev which does state 4:1:2 as a sealer, so the first one was incorrect.

What is the advantage of a 1:1 primer? I’m not reading anything bad online about Matrix products and it’s very convenient that an auto body supplier down the road carries it. I’d just like to understand why I should make the switch, that’s all.

I’ve also been reading that I can shoot clear over the epoxy primer for these hidden areas, any thoughts? I figure I could just use black primer sealer and clear over it. I don’t see any point in actually laying down paint in these areas.

Thanks again, this is all very helpful!

4:1 = 5 qts
1:1 = 2 gallons

Not sure what your paying for the Matrix but plan on buying almost twice as much to complete the job.

my epoxy mix is 4:1 in Valspar and 3:1 in PPG
what is you reason for saying that a 1:1 mix is quality over a 4:1 or a 3:1 mix ratio ?

matrix is a more budget line but im sure the epoxy will be fine

they fail in color match.

tdz16 wrote:.........
I’ve also been reading that I can shoot clear over the epoxy primer for these hidden areas, any thoughts? I figure I could just use black primer sealer and clear over it. I don’t see any point in actually laying down paint in these areas.........

You can, but there's very little gained. The epoxy primer alone is more corrosion protection than the rest of the vehicle has.