SPI Epoxy adhesion problems

B

Brennan Carey

Hi

I am having a hard time with this SPI Epoxy primer and dont know whats going on..

I have replaced some new panels on my 67 Mustang and removed the E coat with paint stripper. I have then treated with Evoporust. Then neturalised with water sanded with P80 and then degreased with Benzine followed by a water based wax and grease remover.

Mixed Epoxy 1:1 waited 30 mins, weather warm, yet the Epoxy just peels off...! If I take my air line and blow the edge it just flakes off in lines.. crazy!

Dont know whats going on here , I have been so careful and I dont understand how this stuff can be so difficult to adhere it really feels like hit and miss.

Any help advise pls ?

 
the evaporust is the problem. should have cleaned bare steel with w&g remover and epoxied.
 
shine said:
the evaporust is the problem. should have cleaned bare steel with w&g remover and epoxied.
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Why would evaporust cause a problem ? surely this epoxy cant be so difficult to work with.. ? Anyway if it is the evaporust and I have degreased as I have said how do I resolve? I will take panel back to metal again and then what ?
 
Leaves a film behind that causes adhesion problems.
I scrub new panels with soap and water using a red Scotchbrite pad to dull the surface. Depending on the quality of the reproduction panels the E-coat can be a weak spot itself and this will be evident when you run the DA with 80 grit over the panel. Once DA has completed its job, a simple wipe down with 710 Wax and Grease remover (making sure to spray it on and wipe it off with a clean towel before it dries) is all the prep you need. Benzine, Acetone, Lacquer Thinner etc. shouldn't be used on any panel being prepped for paint IMHO.
 
Brennan Carey said:
I see.. thks... so how do I get rid of the evaporust film that I now have all over my car ? (as wax and grease remover clearly did not do the job)
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80 grit on your DA/orbital sander. Sand every panel entirely that you used the evaporust on. Remove every trace of it. Meaning get the metal "clean" with the 80 grit scratches. You want to see nothing but fresh 80 grit scratches where you DA. Then blow it off, use a quality waterbased wax and grease remover.(this is important don't skip this step or do it out of order.) Use SPI 710. Make sure you are wearing latex/nitrile gloves while you are cleaning to avoid any oils from your skin contaminating things. Spray it on the panels and wipe it off. You may have to do this step 2 or more times, until you are no longer seeing any residue on your wipes. Use a quality automotive grade wipe if possible. Then go back over with a solvent based automotive grade wax and grease remover like SPI 700 or PPG DX330. Apply/soak with one wipe have a clean wipe to the go over where you wiped and "dry" it. Then you are ready to proceed to epoxy.
 
Chris_Hamilton said:
80 grit on your DA/orbital sander. Sand every panel entirely that you used the evaporust on. Remove every trace of it. Meaning get the metal "clean" with the 80 grit scratches. You want to see nothing but fresh 80 grit scratches where you DA. Then blow it off, use a quality waterbased wax and grease remover.(this is important don't skip this step or do it out of order.) Use SPI 710. Make sure you are wearing latex/nitrile gloves while you are cleaning to avoid any oils from your skin contaminating things. Spray it on the panels and wipe it off. You may have to do this step 2 or more times, until you are no longer seeing any residue on your wipes. Use a quality automotive grade wipe if possible. Then go back over with a solvent based automotive grade wax and grease remover like SPI 700 or PPG DX330. Apply/soak with one wipe have a clean wipe to the go over where you wiped and "dry" it. Then you are ready to proceed to epoxy.
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Chris, I think you got the SPI part numbers mixed.

Use 700-1 water/alcohol based first.

Then use 710-1 Solvent based W&G remover as the final step.
 
We're having the same problem with cars we mechanically strip. Blasted cars have zero issues. All I have for cleaner is limco w&g remover. I flood the panels and wipe dry until the towels are no longer dirty.
IMG_20161012_095131033.jpg
 
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El_Duderino said:
We're having the same problem with cars we mechanically strip. Blasted cars have zero issues. All I'm given for cleaner is limco w&g remover. I flood the panels and wipe dry until the towels are no longer dirty. View attachment 4211
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Years back Barry found out some adhesion problems with people using 5star W&G remover , so it wouldn't surprise me if it was related to that.

I'd like to think Limco is not bottom of the barrel quality wise, but you never know.

When dealing with bare metal and the foundation of your paintwork it's peace of mind to use the better grade cleaners or stick to SPI.
 
No problems here but i dont use anything to clean my metal other then W&G removers(water based or solvent eather one is fine) before i wipe i go with a red scuff brite to clean any oxidation on the surface this is just me then i go with the W&G rwmover and spray my epoxy and done,,the first time i spray this like 1-2 days after was dry i try to scratch the epoxy with a screw driver and the thing was holding really really good.

here is a good video on how this thing works when you fallow instructions.

https://www.google.com/url?sa=t&sou...xQAzLftGh4wp2w5Zg&sig2=AkxKK7wUim7VUil-eLyENg
 
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i agree with 68. i have been using spi epoxy for 15 years. i can say i have easily sprayed 300 or more gallons of the stuff. not once has it let go like that unless there was something contaminating the metal.
 
That doesn't look like a well prepped 80 grit da'd panel. Looks shiney and almost rust color.

Possibly too many internet forum concoctions in your metal prep. You didn't happen to throw in a fantastic Automatic Transmission fluid wipe down did you?
 
Do you have a picture of the back side of one of the sheets that fell off? My guess is that would show you a smut film that would tell you why it fell off.
 
how thick is the epoxy ? 1 coat or 2? thin fresh epoxy can be attacked by polyester filler or poly primer.
 
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