TheSamba.com :: View topic - Are all Epoxy Primers created equal? SPI, HOK...?

Sun Oct 05, 2014 9:41 am

I'm really considering the Southern Polyurethanes on East Coast (SPI Epoxy Primer) has anyone worked with it? What did you think?
The price is very good and the quality seems to be really good also!
Okay, a few questions...
Is it compatible with a Shimrin (House Of Kolors) Designer Pearl paint?
It is designed to be sprayed then filler applied directly over it!!? That's kinda cool...

So what steps would I take?
Buy a gallon of the SPI ep primer...
Clean my car with dawn detergent and water really well with a white bristle scrub brush....
Dry the HECK out of it.
Then apply the ep.
Wait and spray it another coat or two with ep.
Then what?
Apply my filler?
Then apply my 2k high build primer?
Any help would be much appreciated from anyone in the bodywork/paint fields!

Mon Oct 06, 2014 8:51 am

'67 Sunroof wrote: I'm really considering the Southern Polyurethanes on East Coast (SPI Epoxy Primer) has anyone worked with it? What did you think?
The price is very good and the quality seems to be really good also!
Okay, a few questions...
Is it compatible with a Shimrin (House Of Kolors) Designer Pearl paint?
It is designed to be sprayed then filler applied directly over it!!? That's kinda cool...

So what steps would I take?
Buy a gallon of the SPI ep primer...
Clean my car with dawn detergent and water really well with a white bristle scrub brush....
Dry the HECK out of it.
Then apply the ep.
Wait and spray it another coat or two with ep.
Then what?
Apply my filler?
Then apply my 2k high build primer?
Any help would be much appreciated from anyone in the bodywork/paint fields!

I believe SPI epoxy is compatible with all brands of base. I used it on my car and found it easy to work with and easy to sand as well.

The steps you take depends on what state your car is in now. Is there paint on it already? Bare metal?

From bare metal you'll clean with wax and grease remover, 2 coats epoxy, filler, another coat epoxy to seal any sand-throughs, 2k primer, sealer (or reduced epoxy), base, clear.

The best place to ask questions about SPI products is their forum http://www.spiuserforum.com/forum.php. Lots of helpful people there.

Mon Oct 06, 2014 10:57 am

No - there are different epoxy primers. You need to read tech sheets for the various primer products and understand what you are buying and if it is applicable to your project.

The terminology is all very confusing. You have Etch, Epoxy, Urethane, Acrylic, and Lacquer primers. Those products are then marketed as: high build, 2k, & sealer. Some are Direct To Metal (DTM). Some allow 'Wet on Wet" application. The term "sealer" is used in 3 different ways as best I can tell - seal the metal from corrosion, seal the substrates from the new primer, and seal the primer from the topcoat.

I have never used SPI products but they have a loyal online DIY community, which i'd take to mean that they have happy customers.

Mon Oct 06, 2014 1:58 pm

Well add another to the customer base. Bought the SPI EP today which is a 1:1 ratio so I'll have 2 gallons of the stuff!!
I shopped around and the price was cheaper than others.
I also posted many questions on their website forums. What impressed me is they had the presidents (not Obama) phone number listed on the homepage and he will answer 24/7. (Kinda nice to know)
I called him today and had a LIST of questions. He answered them to my satisfaction.
So I ordered.
I'll let you guys know what my experience will be like.
I appreciate your help. Oh yeah, they have black/grey/white/red colors available......
I ordered black. I'm thinking with the filler and a grey 2k primer it might be easier to see the high/low spots when sanding. What do you think?

Tue Oct 07, 2014 4:40 am

Product compatibility is the issue. Asking for which is better is sometimes a heated issue in shops. Most products as marklaken said are the same. Some painters & body repair techs like certain products & that is all they use. What I use & the shop I go to are 2 different things, so when I go there I bring my own products, tools as to not contaminate the shop tools. If you are doing the whole project yourself, this is a mute point.
The SPI EP sounds good looks good on paper & has a president answering your questions. All good things to have. As far as which color to spray, I like base & prime colors to be close to finished colors. Dark for dark, light for light, red for red. Spaying a guide coat over your prime will give you high & low spot visibility. you can also use a powder that is available at body shop supply places.

Tue Oct 07, 2014 4:27 pm

While I understand there can be compatibility problems.......
IMo spraying "urethane sanding primer" over "epoxy" you can't go wrong.

After that maybe better stick to one brand, and don't use any lacquer spot putty please.

Tue Oct 07, 2014 9:48 pm

The blaster guy picked it up today.. He said it will be ready next week and will spray HoldTight102 on it to prevent flash rust for like 3-4days?
My question is this:
There are 2-3 spots that are rusted. Do I spray the ep THEN do the repair? I don't think I'll have time before we have to spray it.

The rust spot that concerned me the most was the front passenger corner of the sunroof. Looking at it from behind, there is about a 2"x2" section where it is rusted very badly and I have a feeling he's gonna put a damn hole in it when he blasts it. What then? Weld in a piece I guess? Then grind, seam sealer, and epoxy prime again?
Confused there...

Tue Oct 07, 2014 10:21 pm

If there are multiple holes then probably should replace that area, but if it's just ROUGH then your ok. Pitted metal looks fine painted, at least to me! Or you can spray plenty of that high build primer on there and smooth it over.
I have just prepped and painted some areas that were so thin there were actual pin holes.........years later still good. If a rock hit at just the right spot it would fly through but it never did. Have to look very close to see the pin holes! that's not rust it's chemical etched lightweight....for racing

Light rust actually helps paint adhere. Same as etching. I would not be afraid of flash rust. Of course in humid areas I'm sure it's a lot more severe

Wed Oct 08, 2014 5:41 am

Sorry, this may be long, lots of different ways to do this. Everyone has a certain way of working, If I sandblast a whole car I will epoxy prime & put on a coat of paint (close to what the finish will be). I can the work on a spot at time, prime & spot paint as I move along. Some guys blast only the spot that they work on & prime & go the next spot. If you read some of the bigger build posts, eg. fastback build from clatter, or bobnotch build of wolfee, there are others. We all have a way of doing things that differ & you need to find the way for you. Use good products, learn from your mistakes & keep going. Ask questions & post pictures. :wink:

Wed Oct 08, 2014 11:14 am

I've shot a couple quarts of SPI 2k epoxy primer; white and black. Both layer out great with a cheap HF gun. Really impressed with the product and support -- and they ship it to my door for free. No reason for me to look elsewhere. :wink:

Wed Oct 08, 2014 9:55 pm

Yeah, the shipping was FREE!
Did you ever try their 2k epoxies or clears? They boast that their clears are some of the best out there....?
I'm having a hard time understanding the proper steps to take...
I have 2 rust areas that concern me. They say DO NOT paint over the rust!!
So:
Get the car back from media blast:
Tape off just the rust areas
Epoxy prime the whole car-twice
Then work on my rust areas???

OR
Get car back from blasting
Epoxy prime the whole car
Grind down/cut out rusted areas
Weld-in new metal
Grind
Seam seal??
Epoxy prime over patch areas??

OR
Grind
Epoxy prime
Seam seal?

The order is throwing me off..
Also, they say it is SUPER important the car is above 65 degrees for 24 hours to cure fully. At night the temps have been getting a little cool here man...(fall)
It will be in the garage but don't wanna really leave the heater on all night:(
Afraid of not being out there. Maybe I'll spend the night in the garage! Hahaha!!

Thu Oct 09, 2014 4:26 am

Okay, media blast, epoxy, filler,let cure. The 24 hours at 65 degrees will slow you down, just do not work on it for a couple of days to allow it to cure. grind off the area you want to work in, prime, seam seal, reprime, repeat. The key would be to see when you have to top coat & how to prep the surface to top coat. Some manufacturers will say to top coat within so many hours, if you go over that you will need to scuff & reprime the car. That is the reason I will prime then put a coat of paint on the whole car. Gives you a good solid base to work from, helps you see low & high spots, you will need to sand & reprime only where you worked.

Thu Oct 09, 2014 12:42 pm

Some of this depends on how fast you can work. At a minimum, media blast and epoxy primer. I would then do the 2k primer in the recoat window of the epoxy so that you don't have to sand down all that epoxy primer. Then I would do metal repairs and filler work at your leisure thru the winter. You will need to sand down to bare metal in the repair areas and make the repairs. You can temporarily protect your work areas with rustoleum to prevent corrosion. Filler on scuffed bare metal is fine (you need warm temps for filler to cure - heated garage is ideal). When temps come back, block sand the 2k primer and reapply more 2k primer and block (repeat until you are happy), then seal and topcoat (or just topcoat if you have a uniform sanded 2k primer surface).

Thu Oct 09, 2014 8:33 pm

Couldn't you guys just have said its easy?? Haha
Seriously, why not tape over the 2-3 areas of RUST concern and spray the whole car and everything else first?
THEN cut out those sections, tack weld in new metal and go from there?
Just seems like an ep coat over the rust THEN sanding/grinding it down might be redundant?
Just my opinion but you guys have WAAAY more experience than me!!
Mark-I've read that it is an easily sandable primer even after cured compared to other primers. I don't know man..?

Fri Oct 10, 2014 5:47 am

Don't paint over rust. But you won't have any rust when he's done blasting. You will have bare metal with holes or pits, you can prime over that if you don't have time to fix it before the whole car flash rusts.

Fri Oct 10, 2014 5:51 am

You can mask off the areas & go back & repair. The only reason I will coat the whole car is time. If you are going to weld & repair the spots all at once & the car will be indoors & dry (very dry) then yeah mask away. But if this is a long term project & it does start to rust all the blasting will be for not. I repair & prime as I go to keep the rust away, bare metal is just asking for rust.

Fri Oct 10, 2014 10:09 am

I treat car areas like a gun and spray wd-40 on the areas that I will give attention to in the near future. When I want to work on it , it clean it off with mineral spirits. This is commonly done with impact sockets and other tools as an example to keep them from rusting as well.

Sat Oct 11, 2014 5:55 am

Yeah, the wd-40 idea sounds great but SPI specifically says DO NOT use anything under the epoxy primer! In fact, their waterborne grease remover and cleaner is mainly alcohol, water, ammonium, and ammonium hydroxide as ingredients.
I guess we'll just epoxy the whole car first, then go back and cut out/tack weld in new metal, seam seal, then prime back over? They aren't that bad, but just didn't know how to handle them.

Sat Oct 11, 2014 10:23 am

Bare metal & no masking. EP is Very Hard to sand. If you let it harden up you are supposed to rough it up before spraying the sanding primer. Most spray sanding primer immediately after the EP, so they never have to try to hand sand EP.

Sat Oct 11, 2014 6:52 pm

Keep the wd40 and silicone based stuff out of the body shop, unless you like fisheyes :x . Good in the tool crib and gun safe though 8) .