[einstein]

Originally Posted by ZeGermanHam

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.

Yeah. I'll proceed with the soda blasting and other de-rusting procedures.

I'm still considering dunking the lower part of the body in a tank of livestock feed molasses about a foot deep. Got plenty of space under the lean-to to just dig a trench and line it.

[dhutton]

Originally Posted by einstein

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.

Well that’s a little more detail. A few pits after blasting probably isn’t a big deal on an internal floor pan.

Don

[dataway]

Anyone else have any suggestions for easy sanding epoxy primers?

[400 4spd.]

einstein, maybe I'm misunderstanding your plan regarding the soda blaster, but soda will remove paint and maybe filler, but will not touch rust.

['ol Pinion head]

Originally Posted by mrennie

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.

Before we roll to another page...



The level of gloss in Michael's pic of the top of his cowl looks dead on, & IMHO, it's not something one gets & retains w/o top coating w a correct mixed paint.

On the air cleaner assembly's I disagree to a dull semigloss as the original finish, as I've had a TON of low mile original aircleaners as well as NOS Pontiac aircleaners. The degree of gloss on an original late '60's though early 80's Pontiac air cleaner is going to very shiny, around 90% gloss. You will see yourself in the reflection, but that image will not be as clean as in the refection from a total gloss black finsih. That original finish, I believe, was provided by a cheap lacquer that of course faded with time.

[Greg Reid]

Back when I did my firewall, I used Rustoleum gloss black in the quart can. Reduced it with acetone and sprayed it. It has a sheen but nowhere near what I would call a true gloss. More of a satin finish which is exactly what I wanted... I really don't like the look of dead flat paint underhood.
Here is about the only pic I have that shows it. Ignore the AC delete box...totally different finish there.

[dataway]

Greg, did you shoot that over bare metal? I've mixed the Rustoleum gloss with their flat and then reduced to get various different gloss levels.

I'm having some second thoughts about epoxy on areas like the firewall ... I mean I'm having to sand blast off 50 year old basic alkyd enamel, same as Rusoleum .... so obviously it holds up pretty good.

[Big Bear]

This the son's Charger. Sand blasted, epoxy primed and top coated with two part urethane in one day. It's a finish that will take a gas or brake fluid spill without destroying it and will look good in 20 years.

[MUSLCAH]

Originally Posted by dataway

Anyone else have any suggestions for easy sanding epoxy primers?

No such Animal ....... epoxy is NOT a primer surfacer.

[ZeGermanHam]

Originally Posted by dataway

I'm having some second thoughts about epoxy on areas like the firewall ... I mean I'm having to sand blast off 50 year old basic alkyd enamel, same as Rusoleum .... so obviously it holds up pretty good.

I think it would be somewhat dependent on the particular car/project. If you've got a sandblasted floor pan and firewall as is the case with OP, you should just epoxy prime the floor pan and firewall in one fell swoop. No reason not to, since you will have already measured, mixed, and filled the spray gun. But if you're working on just the firewall and there's already a base of some sort down, I think a rattle can solution would probably work just fine.

[mrennie]

Originally Posted by MUSLCAH

No such Animal ....... epoxy is NOT a primer surfacer.

Very true...however, as far as "easy" sanding, in my experience SPI epoxy is wayyy easier to sand compared to every other epoxy I have tried. Plus it is glossy and acts like a self guide coat which is quite useful for blocking with 180 grit.


It really is a nice product.

[dhutton]

SPI epoxy sands easily and it is used by some as a build primer. The easiest sanding epoxy out there imho...

A lot of misinformation in this thread imho....

The SPI forum is an excellent resource.

Don

[roger1]

SPI epoxy will dull some more after it gets cured for a few days.
I don't think it's too glossy for what you want.
That photo that was posted looks to me like it was less than 24 hours after it was sprayed.

[Greg Reid]

Originally Posted by dataway

Greg, did you shoot that over bare metal? I've mixed the Rustoleum gloss with their flat and then reduced to get various different gloss levels.

No, the front clip was off and engine out so I just cleaned and sprayed over the existing finish. Sprayed the suspension, frame and crossmember with the same stuff. It's held up well over the years. Inner fenders, radiator and support I did with a different paint and at a higher gloss level. I guess I did it all around 2007.

[roger1]

Here's my firewall this morning.
I sprayed it with SPI epoxy about 6 weeks ago.

[roger1]

Here is my firewall and underbody less than 24 hours after being sprayed. Definitely more glossy than it is now.



The prep you are doing will be fine for SPI epoxy with 80 grit scratches. All the surface rust doesn't have to be removed. Remove the orange colored loose rust but that deeper hard dark rust down in the pits doesn't hurt anything. SPI epoxy will encapsulate just as well POR-15. Probably better. I am not a fan of POR-15.. SPI epoxy has a many more advantages.

[dataway]

So .... are people using a primer surfacer over epoxy primer? If so ... why use the epoxy primer instead of going straight to a primer surfacer? I'm talking bare metal here, I can see it if you were trying to seal off any prior finishes.

Seems like SOP here is epoxy primer, body filler, seal with reduced epoxy primer, top coat or if there is a long wait .. scuff then top coat.

[dhutton]

Originally Posted by dataway

So .... are people using a primer surfacer over epoxy primer? If so ... why use the epoxy primer instead of going straight to a primer surfacer? I'm talking bare metal here, I can see it if you were trying to seal off any prior finishes.

Seems like SOP here is epoxy primer, body filler, seal with reduced epoxy primer, top coat or if there is a long wait .. scuff then top coat.

Adhesion is the reason. Nothing has better adhesion to bare metal than a quality epoxy primer. 2k urethane has poor adhesion to bare metal and it is poor practice to spray it on bare metal. Especially in quality restoration work.

Don

[roger1]

Originally Posted by dataway

Anyone else have any suggestions for easy sanding epoxy primers?

Here's a very good thread on the subject of SPI primer, polyester primer and urethane primer. I use the procedure JimC mentions in the second post.

http://www.spiuserforum.com/index.ph...r-primer.5616/

Although SPI epoxy can be used like a primer/surfacer I find it to be a slower and harder process and most people use it in conjunction with 2K urethane primers. I like using the step of polyester primer in the areas where I've done bodywork that needs more of a build for blocking.
Also, I always spray a single ~30% reduced coat of epoxy an hour before spraying color whether it be a basecoat or single-stage. It both seals and provides better adhesion.

[MUSLCAH]

Originally Posted by dataway

So .... are people using a primer surfacer over epoxy primer? If so ... why use the epoxy primer instead of going straight to a primer surfacer? I'm talking bare metal here, I can see it if you were trying to seal off any prior finishes.

Seems like SOP here is epoxy primer, body filler, seal with reduced epoxy primer, top coat or if there is a long wait .. scuff then top coat.

There is a lot of mis -Information here