Discovered SPI too late.


New Member
I would like to start off with a big thank you to everybody on this forum, everybody seems to be so willing to help each other out and the way you conduct yourselves even if you disagree is very professional and much appreciated. is the story. I am trying to rebuild an old suburban to pull the bass boat and car trailer. Always wanted to try to paint a car / truck so I thought I would start on the inside first since nobody would see it anyway. Couple of guys at work who paint cars on the side are willing to help when it comes to the outside. Went to local store and talked to them about what I would need to do in order to apply some type of primer and then Lizard Skin. Truck has minimal rust in right front footwell. Bought a spray can of self etch primer and some seam sealer. Washed out the floor with Dawn and water, sanded out the surface rust, sprayed the self etch then applied the seam sealer. Then the guys at work told me about SPI (what they use) and this forum. You can imagine how I now feel (whoops).

Now I have the SPI epoxy, activator, W&G remover and some reducer. Ready to start over. Took truck to car wash and pressure washed the inside, then cleaned with Dawn and water, then wiped down with W&G remover. I have tried to remove all the self etch by sanding the entire area where it was used to bare metal, now I am concerned about areas where I cant get it all out, like where the sheet metal is lapped and spot welded, corners and crevices etc...what else should I do before applying the epoxy? What will happen to the epoxy if some self etch is present? Should I spray something else? If so, then what and does SPI have it? For the remainder of the inside can I scuff with 180 and spray the epoxy or dose it have to be bare metal with 80 grit?

Thanking you in advance for any and all advise.


Combo Man
Well it depends on how nice you want it, but it sounds like as an older tow rig, it might not really be that critical. If you have to have it right, you need to sandblast any areas that can't be sanded, but if it were mine, I'd probably just clean it up and shoot it. The epoxy could possibly lift or not adhere well where the self-etch went down, though.

SPI does not have anything to go on top of rattle can etch primer.


New Member
Thanks for the reply, and the options. Just starting this and it will be a slow process. I am about 90 - 95% positive i have gotten it all out, just getting skittish I guess. I will let you guys know what I decide to do and how it turns out.

Thanks again
Youd be suprised at just what the epoxy will adhere to vs what it wont.
Im starting to get the feeling that as long as you make a best effort it seems to adhere to almost anything, LOL... Like crashtech said, Id just go for it as well with what you already done. If you see it starting to "wrinkle", then its not agreeing with your self etch. Dont spray it too heavy at first.


Mopar Nut
I sprayed my Coronet with an undercoating gun and Aircraft Stripper then power washed it (several times) before starting the cleaning process to paint it with the epoxy primer.


evil painter
Partly as an experiment approx 7 years ago, I sprayed all rattlecan stuff on some custom steel ground effects I made & added on my already black clearcoated personal vehicle, intending to eventually strip & paint with real paint anyways. Partly did this just for the benefit of those who don't have the shop , tools & skills to do real paint. A light coat of etch primer followed by rust oleum spray automotive primer, then dupli-color ceramic engine paint.
With good color sanding & buffing skills it was hard to first detect from real black bc/cc. Looked fine for a few years while being covered up at home every day. Then was forced to daily drive & park in sun for several months while getting another sprinter van engine took record time. It started showing deterioration signs & recently is starting to peel to the metal in spots , even though it hasn't been in any sun since feburary . This is primer failure 101.
I think if it never saw more than a little minor sunlight as intended, it may still look near perfect now. But it shows that even someone with skills can't make poor product hold out to the elements.
Now in your case Rob, if you've sanded off everything that shows, it should be good. BUT, what worries me from what you mentioned, as far as long term perfection is lap joints. Any coating inside the joints is better than nothing, but if by lap joints you mean you lapped metal on a repair that should have been a butt joint, then that repair could be a cause for concern later. At the least a lap joint can cause ghost shadowing in the paint after age & even going from not showing to showing in hot sun, then going back away later in the same day.
Of course I can't see what the quality of your repair work is from my chair here, but figured I should mention it. Better to know now than later if needed. Every day is practice for the next.


New Member
Thanks for all the replies. I think I could be over concerned about the self etch. The lap joints and spot weld dimples, I am referring to are the factory seams and welds in the floor boards, no repairs. Truck had a small area of surface rust (mostly paint flaking) in the right front floorboard, maybe a 12" x 12" area that I had initially sanded and sprayed the self etch primer on. I have since scraped all the factory applied seam sealer then sanded all the self etch primer off to bare metal. I guess reading all these post about washing, W & G remover, wipe with alcohol then start the sanding process to bare metal, clean again got me a little worried about having it surgically clean. Seems to me that most of you guys are doing top notch show quality work and I am just trying to get my floors sealed for protection purposes and to practice spraying for the body.

Generally I am leery of forums and opinions, but after prowling this site for quite sometime and seeing the professionalism displayed here, I decide to join and started ordering SPI products, hence why I am trying to remove and correct my initial bad decisions. You guys are awesome and I really appreciate the guidance. Note to self: whenever I get ready to start on the outside I will be searching this site and asking the question on the front side before any fatal mistakes are made, hopefully.

Thanks again,


New Member
Update and more questions.
My old single stage compressor laid down and set me back some. Ordered a Saylor Bealle from a local distributor, figured the 60 gallon would be fine for my needs, still had to rewire the shop for it though. So it was early December by the time I was able to spray the SPI Epoxy on the floor boards of the suburban, temps were in the low 60's outside, shop was heated to about 80* with a salamander type heater, turned it off, sprayed the epoxy and then moved the truck to the basement garage for a couple weeks to cure, which is heated to around 70 or so degrees. While in the basement I applied the seam sealer. The truck was then moved back to the shop, where it stayed all winter. So far everything seems to be fine and am just waiting for the temps to come up so I can apply the Lizard Skin.
Over the coarse of the winter I've gotten the body ready to come off the frame, started cleaning and sanding the firewall and per Shines advice started removing the paint with a heat gun and scraper, which worked amazingly well.
My questions are...
1) If I am going to have adhesion problems with the epoxy due to low temps during application, when will it show up?
2) It will take me quite some time to get the body ready to shoot with epoxy due to the amount of time I can spend on it and waiting on the temps to come up. I now have several areas of bare metal and more to come. How should I protect the bare metal from rusting until I can spray the epoxy? Thanks in advance for any input and advice.



Paint Fanatic
Staff member
Sounds like you are fine, don't worry about the rust and when ready to epoxy, most shops will knock it off with an 80 grit DA and get the places like drip rail with a red or gray scuff pad and flash rust will fall right off as its not like rust and has no scale or body to it.
On the areas you already shot, if the concern is temperature affecting the bond, I'd say if it managed to cure in a reasonable time, it's probably fine. Seems like that's the big thing about low temp, it won't allow the epoxy to cure at all


New Member
OK fellas, getting closer to being ready to spray the under side of the truck. So far i have mostly scuffed the existing coating with several bare metal areas as well. Still have some seam sealer to remove and more sanding to finish. I was originally thinking about spraying one coat of epoxy and then something like UPOL Raptor or something else but was reading a reply to a post somewhere on here about that very thing. I believe the reply was by Crashtech (forgive me if wrong). He recommended just applying three coats of epoxy and calling it good. I think I would rather go that route if y'all think it is a good idea and would provide long lasting protection, plus I would like the gray color better than the black raptor liner. If, per your recommendation I shoot three coats of epoxy; do I just apply three coats mixed per directions as epoxy or reduced as sealer or a combination of the two? Please forgive the rookie questions and thank you all very much for your patience and advise.



New Member
Update: Finally got the under side cleaned, sanded, wiped down and sprayed the first coat of epoxy tonight. I mixed some black and gray epoxy to get a little darker gray than the straight gray. So far so good, covered very nice, no pin holes, no craters, no problems. Planning to spray second coat tomorrow, next day apply seam sealer and let that cure for a couple of days then apply third and final coat of epoxy.

Thanks for all the help.