Paint and Final Finish Hardness

H

Hedidit

Promoted Users
Greetings Forum,

I am a Newbie and have posted a few questions before. The Forum has always provided top level info and solutions for my questions.

Today's question with some added situational awareness-

Pre-condition-
I am prepping a shell of a car for final color and clear.
  1. I finished the sandblasted body with SPI Epoxy Primer.
  2. I did the hammer/dolly/filler work.
  3. I sprayed SPI Turbo 2K Primer and sanded.
  4. I sprayed 2 coats of SPI Epoxy Primer to seal the work. I did not dilute with reducer. I mixed the epoxy as the SPI Manual describes for full epoxy, not as a sealer.
Problem-
As I work with the primed and sealed doors, lids, and body, I find that they are 'soft' and any bumps or touching leaves divots or deep scratches through the 2 layers of epoxy and into the 2K Turbo. Should I be worried? I am 100% sure I mixed everything correctly.

Bottom Line Question-
When does the paint process get to the point that the final finish is resilient to parking lot dings and shopping carts? How do we make the final finish hard?

I love the SPI products that I have used so far (Epoxy Primer, 2K Turbo, Reducers, and Retarders. I fully trust the 700 cleaner and will be buying gallons). They deliver just as this Forum and Barry has described...no lies or sales-smithing. It is totally honest and that is why I am writing this.

Thanking you all for your past and new help!

Dave Tucker
Chandler, AZ
 
A few questions for you that may help the pro's access your situation.

1. Did you spray any epoxy over the hammer/dolly/filler work before spraying 2k turbo primer?

2. After spraying 2k Turbo primer, was the shell of he car placed outside in the sun, if so, for how long?

3. How long did you wait before spraying epoxy over the 2k turbo primer?
 
Although I'm not exactly sure what you mean by soft, from your description something has to be off on your end. Epoxy when it cures is never soft, as in your description. What were the air temps when you sprayed your initial coats of epoxy? Did you notice this softness after spraying the initial coats of epoxy or only after spraying the last two coats over the Turbo? What were the temps when you sprayed those last two coats?

Only possible things it could be are you mixed it wrong, (perhaps grabbed something else instead of the activator IDK) or air temps and therefore metal temps were lower than 65 which if you are in Phoenix I would imagine temps would be ideal this time of year for epoxy. I know you said you are certain but if it's staying soft that's indicative of one of those two things. Again when you sprayed the initial coats prior to body work were they soft? If not you have your answer. Not trying to be harsh or insulting but in almost every instance issues are the result of operator error not product error.

The only other thing it could possibly be would be applying the Turbo then applying epoxy over that too soon. But you said you sanded the Turbo so that doesn't seem likely.

Again did the initial coats of epoxy over metal do this as well?
 
Only other possible thing I can think of is this. Did a very long period of time go by between the first coats over the bare metal and when you sprayed the last coats over the Turbo? Meaning like a year or longer? And did you use the same batch of epoxy and activator? It would probably have to be longer than that for epoxy activator to go bad but I guess it could happen in a year. How was the activator stored? Cap tight?
 
There are no timeframe details given. I would push it out in the sun for a day or two.

I recall Barry saying it can take a few months for epoxy to fully cure inside a shop.
 
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Full cure for epoxy can be about 90 days...this is completely different than the 7 day open window. The epoxy is still not cured after the open window. The epoxy is still pretty soft before it cures and can be pretty soft within the few days following spraying.
 
From his description though it sounds really soft. Two coats, 24 hours wait, you should be able to sand with whatever grit you want and not have any issues.
 
All,

I had family issues and had to be offline for a few days. Wow, I appreciate all of the comments. This is the great part of this forum...details.

1) I sprayed 2 coats of epoxy over the hammer work. The heat was in the 110 range every day. It was 2 weeks before I scuffed the epoxy and sprayed 2K at about 85 degrees in the early morning AZ temps.
2) By 'soft' I mean that if a door or lid bumps against another door during movement from spray area to my garage, I get a divot wherever anything touched. I am carrying these one-at-a-time then leaning them against a table.
3) I used reducer per the Manual guidance both with Epoxy and 2K. There was a week of gap between each. Both usually dry past 'fingerprint' within 30 minutes. From reading this forum, I am familiar with problems from confusing activators. I get everything set up in order L-R on the workbench the day before spraying.
3) I did the epoxy over hammering in June. All other paint work has been mostly in the early morning in late August to now due to our 110+ late summer. It would be 90 by 10AM.

If the divots and dings are due to me contacting panels together, will there be more hardness after all correctly layered paint is cured and color and clear are applied. Will there be some hardness protection after clear? I am equating the contact that I might have done to the contact that might accidentally happen in a parking lot. I want to make sure that at some point the finish turns to a harder shell.

Or, would a better plan be to apply more layers of epoxy above 2K before going to color?

Thanks for this great help!

Dave Tucker
Chandler, AZ
 
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