Have finished all of the chrome work for my front bumper clip. Is it recommended to coat the rear side of these parts with an oil spray or grease, as a means of rust protection, (prior to re-installing)? Or should those surfaces be left dry? Thanks. Clay/Lexi
I am going to paint my bumper interiors with a chrome paint. My bumpers have been done and packaged away for years now. I opened one up a while ago and saw some rust forming on the inside surfaces. I will clean and paint those to the best of my ability similar to what I did with my ashtrays.
I use Rustoleum satin black on the backsides of my bumpers on all of the cars I do, they will definitely rust without protection. Oil spray, grease, will be messy and won't last. "Chrome" paint is OK, but I like the hiding properties of satin or flat black.
I had my bumpers rechromed. I cleaned the backside with thinner to make sure any oils were gone and paint the rear statin finish black. I have to take a look. That was during Covid and it's a garaged car. But I don't want the inner shine hitting places it should not. And I wanted something beyond just the chrome as a coating.
Also mine is not a perfect restoration or points car.
I purchased a "frame on restored" 72 Eldorado back in the early 2000's with what was described by the CLC owner as "peeling show chrome." Indeed on some surfaces, several inches of chrome had peeled off of those very complex bumper surfaces, and the defects did not appear to have rust associated with the defects. I concluded that "show chrome" was a less expensive substitute for a durable re-chroming process, and that such a failure was to be expected. Thoughts? James
Interesting comments on this, especially as I don't recall seeing this topic in the Forum before. One would think oil spray would work, (like Krown rustproofing, but DIY), though as Geoff noted it would not last, so it would have to be re-applied. Gobs of grease would work. How often do you see rusty car parts that are also grease encrusted in an auto salvage yard? But again as Geoff pointed out, "messy" to apply. So think I am going to go with a flat black rustoleum paint.
Just learning that this bumper project and re-assembly is a ton of work. Still have to source some proper fasteners to replace those that are rotted. Had to turn my living room into a work space. Nothing beats matrimonial bliss like having a front bumper clip in your living room! Clay/Lexi
What's called "show chrome" is just a more thorough buffing of the parts during the plating process to give a deeper more lustrous shine. It's more expensive due to the additional labor cost involved.
The actual plating process copper-nickel-chrome is the same.
Mike
Neverdull! Love that stuff!
Quote from: Cadillac Jack 82 on April 09, 2025, 04:15:19 PMNeverdull! Love that stuff!
Yes, Neverdull is good and it does not seem to leave a residue. Only looking to coat or protect the inside of the chrome though, that no one sees, to keep it from rusting. Picked up some flat black Rustoleum paint today. Clay/Lexi
My preference is to have the chrome removed, and then sandblast the backside prior to straightening and polishing. That way the new plating will adhere well and protect the metal from rust. If old rust exists, it will come back, because acids used in the process aren't necessarily used for rust removal. Even doing this extra step, coating the backside is a good idea.
That makes sense. Good news is that in this case the back was media blasted, and looks plated, but with no attention to detailed work or polishing. I also had to do some welding and repair work prior to chroming. One of the brackets that hold the turn signal boxes was missing, (rotted away). So I cut a good one off of a donor bumper and mig welded that one into place. Had to patch the other one with steel as well. This inside area is still a place where moisture can collect, and I am not likely to ever get back there to clean it once installed. Shot shows one of my repairs with weld tacks holding a thick metal plate attached to better anchor one of the brackets. A little worried about blowing through the metal where there was a lot of rust and some tiny pinholes beginning. This was also a donor bumper but really straight and true, hence my choice to use it for this project. To be installed later on my car. Now that it is back from the chrome shop, I don't even recognize it as it looks so good. Holes all repaired. Clay/Lexi
Before I proceed with the Rustoleum, my son-in-law said that POR 15 is far superior. He thinks it is expoxy based, and meant to stop new rust from forming. Very tough to knick or scratch. Supposed to be way better than Rustoleum. Just don't coat any hardware that you may have to remove down the road. Anyone use POR 15 on bare metal and if so, how did you find it as a metal sealer? Did it peel? Did it stick well? Did it separate? Clay/Lexi
I sprayed a lot of POR15 recently. It wasnt bad but I am not completly happy with it. I dont think it was worth the extra effort it requires.
I sand blasted most parts completly before paint. There was some peeling. But rare. I thinkbit was specific to parts and conditions. And two of the brake drums I painted still rusted through.
Thanks Carl. Wanted to check first with someone who has used it. Clay/Lexi
Between epoxy and POR, which is urethane, I'd recommend epoxy because it is catalyzed and cures solid. POR is moisture cure. Anything that cures with moisture also has to allow the moisture to evaporate. Evaporation leaves microscopic pores in the coating which weakens the coating and potentially allows moisture and oxygen back in.
Makes sense David. Thank you for pointing that out. Perhaps that is what Carl may have experienced. The surface should also be super clean. Can you recommend an epoxy product for my purpose? Clay/Lexi
SPI epoxy. Southern Polyurethanes Inc.
For me, their epoxy is the best on the market. Much better than the big boys, and I've tried most of them. It's forgiving enough to be brushed or rolled on, and lays out nice. Which is great for bumpers. It stays flexible even in thick applications. But it primarily is designed to spray. Comes in five colors. They do mail order as well.