Tweek

I'm watching American Chopper right now, and they said you can't powder coat a cro-moly frame, because of heat issues, does that mean it's not possible to powder coat a cro-moly bicycle frame as well?

Don Cook

Steel (some call it cro-moly) is routinely powder coated. Less than 1% of the material weight is made from chromiuim and molybdenum. All of the AISI 4000 series steels contain chromium and molybdenum and they can be powder coated. It could be that in the TV programs motorcycle application, there were other issues where they didn't want to powder coat the frame because the heat might damage something else.

Check these out: https://www.matls.com/search/SearchSu...&catid=352#nfm
and
https://www.engr.ku.edu/~rhale/ae510/steel/sld001.htm

KrisPistofferson

I just found a guy in town who'll sanblast and powdercoat a frame and fork for about a hundred bucks. That's pretty good, right? Sorry if I'm hijacking, but I didn't want to start a whole new thread just to ask this question.

roadrasher

I had my Columbus cro-mo Cramerotti tourer blasted and powdercoated this winter $125 CDN all in.
'Rasher

Retro Grouch 

That didn't make any sense to me either. I mean they welded those tubes! How could a powder coating oven do more harm to the tubes than welding heat? There must be something going on here that I don't understand.

suntreader

They sure do a lot of grinding on that show... which also generates more heat than a powdercoating oven.

twahl

Sounds to me like Paulie misunderstood something, or maybe they are brazing parts to the frame, and the lower temperature of those joints could be a problem. The oven can be set to whatever heat, but for proper adhesion, the temperature needs to be consistant on the parts being coated.

I dunno, but my brother-in-law does powder for a living, and his entire bike is coated. As an aside, he said that typical to do a frame and forks is about $100.

suntreader

That's a phenomenal price... IF he does quality work.

Otherwise, it may fall into the "if it sounds too good to be true" category.

khackney

I saw that too and went "Whaaatt"?

I had my Nishiki coated and haven't had any problems at all. The only thing I could think was that the type of CrMo they were using was heat treated and they were worried about losing strength. 200 hp puts a little more stress on things than 400 watts of human muscle as well.

chris_pnoy

I thought it was just because of the fact that they were using it in fast motorcycle drag racing...

Mentor58

I have some small expertise on this, as another activity that I actively persue is Drag Racing. Both the NHRA and IHRA have absolutely NO problem with 7000HP Top Fuel dragsters having the frames powder coated. Most of the racers I know running dragsters or altered have the frames powercoated rather than painted, simply because it tends to be more durable than paint. There is NO way that the temps involved in powder coating would ruin welds or CrMo steel.

FWIW

Steve w

boycey

Could a lugged steel frame be powder coated, or would the heat required compromise the strength of the brazes?

Dudette

What is powder coating?

khackney

Go here for some examples and information...Spectrum

Don Cook

A lugged and brazed steel frame can be powder coated. When I did a restoration on an older Italian lugged frame, we chose to have it powder coated rather than liquid painted.