SPI Epoxy primer questions/observations
 

I'm curious if the degree of gloss of their black epoxy primer is similar to the factory look for firewall, underside and inner fenders.

Also, how fanatical should I be about rust removal? Guy named Logan answered the phone there and says their products lock it down tight and rust is stopped. I was going to soda blast the pockmarks on the inner floor pans, he says not to even worry about it, just scratch it with 80 grit and shoot.

They don't want any residues left from Ospho or soda, so either don't even bother, or do lots of washing with Purple Power or Simple Green to neutralize before the primer is applied.

My first restorations were lead filler, Nitro-Stan spot putty and 40 coats of hand-rubbed nitrocellulose lacquer. I guess this old fart brain of mine is stuck on doing too much work...

Here are some examples of SPI black epoxy on a motorcycle fuel tank and steering shaft. Not sure of your preferred level of gloss.

On my firewall I used R-M SC804 which is a premixed satin black single stage urethane. Expensive but I love the results and have used it on ram air pans, air cleaner lid, rad support as well.

Your firewall and air cleaner lid look great but seem to be different gloss levels. Does your satin black single stage gloss level depend on various reducer and/or catalyst speeds? I use SPI black epoxy on a lot of parts as finish coat and although it is meant to be used 1:1 with activator I can vary gloss level by adding different reducers (very slow - fast, etc) or even 1:1:1 as a sealer which also can change gloss level.

Just used some Kemperle Brand ...Direct to Metal...Hot Rod Black . It has an activator and is excellent. About a 1/3 of the cost of SEM.

To my eye, the SPI epoxy primer looks far too glossy for a firewall.

I primed my firewall with DP90 and then top-coated it with Eastwood Rust Encapsulator from a rattle can. The result is more appropriate for a firewall in my view, and can be touched up easily if ever needed in the future.https://uploads.tapatalk-cdn.com/202...7da704c8d8.jpghttps://uploads.tapatalk-cdn.com/202...a8d8ca30d3.jpg

Muslcah ... you wouldn't have a part number for that would you? Thanks.

Thanks for the feedback, gents.

So the SPI is too glossy, but I'd still consider it if they offer a flattening agent. I like the idea of doing cowl to tail with one product.

The RM is beautiful, near-perfect in tone and finish. Won't rule it out.

And please forgive if I sound critical; the DP90 color doesn't look right to me, but I'm guessing its the lighting. It looks like a medium grey on my screen.

MUSLCAH, was that SEM mention a typo, were you comparing the Kemperle to cost of the SPI?

SPI matte black lets you vary the gloss by changing the activator ratio.

SPI epoxy gloss can be modified by adding reducer.

Price of DP90 epoxy is insanely high imho.

Don

Perhaps you're looking at photos of DP90 elsewhere and not in this thread, since as I mentioned, I primed my firewall with DP90 and then top-coated it with Rust Encapsulator. So in my photos, you cannot actually see any DP90 because it has been covered up.

If you are referring to what my firewall looks like with the Rust Encapsulator, I can assure you it's either your monitor and/or the lighting. My firewall is black, and not grey.

Is the dress blue and black or white and gold? 😉

Lol, there is a years long debate in my house surrounding whether my spouse's jacket is dark blue or black.

Can get you a pic of it tomorrow...when I get to the shop

Nope ..to the cost of SEM ....but yes the topic was SPI

I think the variation is mostly due to camera angles and lighting.

I have only used the SC804 with UR50 reducer and DH42 hardener based on the P-sheet I had, which is the fastest reducer and hardener from what I understand. The instructions do not specify changing gloss levels by changing hardener or reducer speeds.

As someone else mentioned SPI also makes a matte black single stage and their instructions do include guidelines for modifying gloss level with different mix ratios.

Here yah go....think it was 33.00 for that quart set up. Goes on ok....but the next morning it looked the balls.

Logan sounds like he's selling POR-15. I didn't realize SPI was intended to be applied over rust.

Ya I wouldn’t be applying SPI epoxy, or anything else for that matter, over rust. I think Logan misspoke or maybe you misunderstood him. Certainly I’ve never heard SPI making that claim anywhere else...

Give Barry a call on the tech line.

Don

Well, I was plainly asking him about the rust in the interior floorplans. Scaly rust was removed by sandblasting in the past, and as I went over it with 180 grit 5" sanding discs and a cup style wire wheel, there was still some pockmarks with rust in them. That was the rust he said not to worry about. He hollered over to Barry about it.

I had just got back from buying a soda blaster at HF and was asking him about that, and how to decontaminate that residue, he suggested that amount of rust shouldn't be a problem. But if I do the soda blast, wash after with Simple Green or Purple Powet.

He wasn't too keen on treating it with Ospho either, that they don't want their product over anything acidic.

He said just sand with 80 grit, clean and shoot. Even that is hard for me to grasp, as older products would reveal even 320 grit scratches, but he says 2 coats fills in the 80 grit prep.

But I'll get Barry on the phone and ask again. My old school brain is struggling a bit with this new way.

To be fair to your old school brain, I don't think there really is much of a "new way" when it comes to preparing for paint. Although epoxy primers do have some rust inhibiting qualities, you still want the metal to be totally free of surface rust.