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Technical & Reference Section => Tech and Restoration => Topic started by: aditup2004 on November 04, 2005, 02:36 PM

Title: Powder coating chromoly. DON'T DO IT, apparently.
Post by: aditup2004 on November 04, 2005, 02:36 PM
I have just been watching American Chopper, on which they are building a drag bike, with a chromoly frame (they normally use high carbon steel). In the part when it comes to going to the powder coaters/painters, they pointed out that all the components have to be painted, opposed to powder coating, as the heating process of powder coating, has a SERIOUS detremental affect to the strength of the frame. WHOOPS. Is this right? If so, nearly all my builds are gonna snap! Glad I've sold em. :-\ :-\ :-\ :-\ Only joking! ;) Any shed any light on this subject? Cheers, Ad
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: greentoad on November 04, 2005, 04:15 PM
Hmmm    :o

There could be something in this -

http://forums.svttexas.com/showthread.php't=6869

This really all needs reading -

http://my.execpc.com/~davewrit/Powder.html

Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: oberonspacefruit on November 04, 2005, 04:16 PM
whoops.
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: Bob_Acid on November 04, 2005, 06:43 PM
it's something to do with the heat at which powder is appied having an effect on the heat treatment of the tubing. If it were that much of a problem we'd have been seeing frames cracking and breaking all over the place as neally all restoration bikes these days seem to be powdered.

Not to worry though we'll all be dead from bird flu in a few weeks anyway so it won't matter.
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: oberonspacefruit on November 04, 2005, 06:52 PM
heh heh. ive been rubbing dead birds in my eyes all week. im tired of life
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: OrgasmDonor on November 06, 2005, 01:43 PM
not too sure dudes could be wrong, but i reckon the stress goin through a dragster is a smidgeon more than what goes through your chainstays (mightymini's chainstays are the exeption), gotta keep things in perspective dudes.

Ad, Stop scarin people dude, thats the last time i buy owt off you !!!!!!!!!!! ;D
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: aditup2004 on November 06, 2005, 04:05 PM
You never by owt anyway, always have to give things to you, Tight git ;D ;D ;D ;D Ad
SCARE, SCARE, SCARE  ;D
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: Sanmarcopizza on November 07, 2005, 08:58 AM
Lets face, I would have thought that the multitude of companies out there who powder coat their frames would know whether it was going to be detrimental, and if so would just paint them. You have quality manufacturers of low quantity hand built frames, such as Curtis & Pashley in the UK who have been in the bike building industry for 20 years+ and they powder coat rather than paint.
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: graeme on November 07, 2005, 02:40 PM
Thinking about it, powder is baked at what, bout 180 deg if i remember right, anyhow, how hot does metal get whem you weld it? Loads hotter than baking temp.
So the frame would already be seriously weakened at the joins, and a few inch at least away from every join.
Dont bikes snap near joins?
This is all just typed as i think.
If bikes snap near the joins, it could be more evidence this is true.
Or, the fact that all chro-mo bikes survive after welding, means that the heat of power coating will have little effect.
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: TwoBobRob on November 07, 2005, 10:54 PM
I wouldn't worry about it.  People have been powder coating MX bike frames for donkeys years, and you don't hear of any problems there... :)
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: retrorider.u.k on November 08, 2005, 09:17 AM
a complete load of tosh ! hope you dont own a TVR then anyone.. :D
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: theRuler on November 08, 2005, 09:21 AM
yeh go powder coat your old chromo frame
then force a set of 1 1/8" forks in it

joking aside, do bike manufacturers spray or powder?
my old redline mx2 was sprayed. well i think it was - i just shouted BOO and the paint fell off
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: missfitsat101 on November 23, 2005, 01:29 AM
i dont think any bmx's should be powder coated  they should all be painted ::) ;)
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: sam hudson on November 23, 2005, 10:57 AM
Controversial but i agree...sort of.Only because its hard to find a really good coater that you can trust...i know a few exist ..not near me tho.Powder coating is as hard as nails if its done properly,but its pants if its not.At least with spraying you get a relativley good job even if the sprayer isnt all that good..and paint isnt as hard to get off if the monkey has ballsed it up.
Can you tell i have had a bad powder experience.
Loads swear by it tho and they cant all be wrong
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: theRuler on November 23, 2005, 11:04 AM
rattle cans in the backyard ghetto style!!!
choke the neighbours with fumes.


lol one time me and my mate sprayed his diamond back silver streak with green spray paint IN HIS BEDROOM
that smelt bad. just sprayed straight onto the chrome. it looked good (ish)
Title: Re: Powder coating chromoly. DON'T DO IT, apparently.
Post by: gmac on November 23, 2005, 01:22 PM
My RD350LC has a powder coated frame, and so do almost all restored old bikes these days. Paint gets baked on at similar temps to powder coat anyway, and that doesn't affect any structural integrety.

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