Quote:
Originally Posted by rasilverbird
I have a rather large gash in my bumper, and I'd like to fill the '68 badge mounting holes to make it smooth like a '69. Anybody see any issues with filling large areas with the 3M product?
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I Vee'd out all the cracks that were anything more than a surface imperfection after I had the bumper completely stripped bare to raw endura. I pushed against the sides of all crack lines with a screw driver, & anything that opened up, got ground out. whiping it down with W/G cleaner helps show crack lines as it evaporates.
I filled every grind out with 3M #05895, then skim coated the entire surface to fill in the superficial lines that had no depth to them. & sanded about 90% of it back off. This ensured I wasn't going to be filling any superficial marks with primer. Then put three coat of SPI epoxy on. block sanded it. Re coated & repeated the process a couple times until every mark was gone. Spot touch ups with the SPI is fine too. Its important not to fill in any missed marks with too much primer though. You have to take the time to go back to the 3M material & get it filled in properly & flat.
I used nothing but SPI gray after the epoxy repairs. My final sanding was in 600 & I used one 40-50% percent reduced coat of SPI epoxy as my sealer & painted it.
I do not have any cracks or even a shrink mark in the surface to this day.
So, to answer you question, yes you can fill those holes in, just make sure you use the correct materials & there are no air pockets. fill the holes as deep and complete as possible. Also, grind off the edges of the emblem mount holes so the 3M filler material can be feathered to meet the endura surface. you don't; want a square edge. that could cause a problem down the road.
The reason SPI works so well is two part. #1, it has a high build, its sands easily after 24 hours & has just enough flexibility to it. All this stuff expands & contracts & over time can fail if its not done right.
I followed Paul at fasts method it worked just as he said it would. In fact I have been using SPI epoxy for a lot of things now. Suspension parts, etc. Good Stuff. I have a two complaints about spi, but its unrelated to what this thread is about.
I am a believer in letting this stuff sitting at least a few weeks before final sanding & paint if your schedule allows. Any paint product with added & transfer solvents shrink. Most of it very quickly, but the last bits can take many months before its 100% done shrinking. Just depends on how fussy your going to be & how close you want to look at it.
