Bicycle Mechanics - Powder coating - which type, how thick, stripping?

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Charles Wahl
07-17-07, 12:22 PM
I have a frame + fork that I'd like to have refinished, in NYC. There are a few coaters locally, one (Carter in Brooklyn) claims to have experience doing bicycles. The person I spoke with said that they'd use polyester TGIC (triglycidyl isocyanurate) powder rather than Urethane. From what I've gleaned online, these are the only two types recommended for exterior exposure. I've done Google and forum searches, but nobody mentions what type powder is used for bikes. Urethane generally goes on with a lower mil thickness (1.5 to 3.0) than TGIC (1.5 to 20), I think. Urethane may be a bit harder, but TGIC may have better coverage of sharp arrises (edges). Gloss is easier to achieve with Urethane, apparently. But the colors that seem to be available for TGIC are much brighter and more varied. Is that the stuff to use?

For anyone interested, here is one link to a page with some explanatory/characteristic information on the right hand side:
http://www.caswellplating.com/powder/

Carter also said they don't prep, and could recommend a blasting place to do that. My frame is double-butted chro-moly. I'm happy to strip the existing paint using Peel-Away (caustic) if it reduces the possibility of structural damage due to over-blasting. Is that the thing to do, or should I find a single-source place that will do both prep and paint?

Cost quoted was $120 for painting, and about $50 for blasting. Is that about right?

Thanks for any help,
CW

Dr.Deltron
07-17-07, 12:35 PM
Cost quoted was $120 for painting, and about $50 for blasting. Is that about right?
Yes. The guy I use charges $160 for both and it's a beautiful job.
The best media for blasting is #60 mesh sand. It's about $8 for 100 lbs, compared to $100 for 50 lbs of Walnut shells. ($50 for the shells/$50 for shipping)
Takes about 50-60 lbs for a frame/fork.
Only problem I've encountered is that the blasters around here aren't allowed to USE #60 mesh.
But for lil ol' me, they make an exception. (and I take the empty bags with me when I leave)

Oops, forgot to add that I can't spaek to the different powders used in coating. I'm a painter!
ieandro
07-17-07, 08:29 PM
I would think a single source place would be best since it can go straight from blasting to pwder to prevent contaminationof a raw frame since you mention Carters does not do any frame prep.


Good luck and post any after photos as I am interested in powdercoating myself.

SugarPILL
07-17-07, 08:50 PM
can you apply decals over powder... and is it possible to clear over the decals on powder??

and lastly, can lugs be masked off? Or is it all or nothing?
Dr.Deltron
07-17-07, 09:11 PM
can you apply decals over powder. (YES) .. and is it possible to clear over the decals on powder?? (YES)

and lastly, can lugs be masked off? (YES)Or is it all or nothing?(NO)

There are many variations to that theme as well.
Your "basic"...
Powdercoat some color X.
Clean with wax & grease remover. DO NOT SAND!
apply decals and spray automotive clear.

OR

PC color X.
Clean.
Mask lugs and spray automotive basecoat color.
Remove mask.
Apply decals.
Clear with automotive clear.

Durable AND beautiful! :D