I need some schooling from the all-knowing beeb. I have a set of older Marchesini magnesium wheels that I want to have powdercoated. I've heard differing opinions regarding prep (everything from "sandblasting will ruin the wheels" to "chemical stripping will ruin the wheels"). If it matters, they are currently painted. What is the best procedure?
Why not just paint them? They will be lighter painted than powder coated and isn't that the whole point of using magnesium?
i have had some powdercoated. Painting will not last nearly as long, it's just not durable. is it heavier than paint? seriously.. how much heavier could it possibly be.. LOL. they came powder coated from the factory, so just do it again. $99-125 a wheel is typical. YOU MUST pull your bearings PROPERLY if you plan to reuse them. Just pounding them out by the center collar can ruin them. I would tape over the surface where the rotors or rotor carrier adapters mate up so you don't have any chance of unevenness.
Yup, also be sure to tape over the surface the bearing sits in, tape the whole area over completely is even better. I made that mistake once and the powdercoater oversprayed and covered the surface where the bearing sits in a thing layer of PC that I had to clean out.
That's the dilemma... two different shops, two different techniques. One says sandblast, one says chemical strip.
Seriously you would only save a few grams, but to some every gram counts and they spend big bux on magnesium stuff. I have had some aluminum wheels powder coated and was very disappointed in the fact that a even a somewhat clean rag puts micro scratches all over them just by wiping them off. Maybe the PC i got wasn't the best, I dunno. The PC will not chip like paint but it will show small scratches very easily.
ask for references.. just like any service/product you are interested in, get some input from some past jobs. I'm sure each shop can provide a few numbers. as someone posted above, bad pc job.. OR.. what are you wiping your wheel with?? And a few grams is gonna make a difference? (if in fact paint is any lighter).. no way. i again point to the fact the wheels COME powder coated and NOT painted, as a reason to re-powder coat wheels. Aside from the fact paint will simply not last, nor hold up to the brake clean/wipe tire changes will inflict on your wheels. powder coat is the only way to go for race wheels.
I can recommend a good powdercoated in St. Charles, MO if it helps you at all. It's HP Coatings. http://www.hp-powdercoatings.com/ I've used them for several projects in the past, always happy with the results.
Well, here's the verdict. "Sand-blast guy" talked to his metalugist friend and concluded that chemical stripping is definitely the way to go. After calling the references, the shop who originally said "chemical strip" is getting the work. Thank you for the help!
Alan - Who are you talking with? I have a suggestion on someone who does good work from what I've seen. I plan on having him do stuff on the SV soon
Make sure that if the stripper and the place doing the coating are NOT the same, that they are told the pieces need to be out gassed.
DO NOT STRIP/BLAST the bearing areas. You can never get the finish the same as original... and the powder could add enough thickness you will damage the finish trying to get the bearings back in.
Brian, Mark Lewelen at Springfield Powdercoating. Used to run Buells with Thunder & Lightning Team back in the day. He was doing "you-know-who's" brother's R6 wheels when I was there. Same place is doing all the work. Bearing areas will be sealed off and the wheels will be outgassed at 400* prior to coating. Thanks, again!
Make sure that they are using a chemical that is safe for Magnesium The strippers that are "Organic Solvent" type are OK, the water based or "Hydroxide" type will dissolve the wheels. We suggest painting the wheels with a zinc rich primer, and an automotive quality top coat.
A local Pc shop I went to about pc'ing a set of marchesinis said no go because they chemical strip and it would eat the magnesium. Wonder if they're just using a different chemical stripper.
