Chasing/ Facing Following Powder Coating

Having just had my frame powder coated I am having real difficulty reinstalling the BB. The shell seems to have deformed slightly - I assume as a result of the oven heat. Has anyone else experienced this? Is it a common problem following coating and if so should frames not be chased and faced as standard by the people who do the coating (since a bike is coated with the intention of rebuilding it)? Also does anyone have an idea of how much this service normally costs? (A tapping/ facing tool seems to cost over £400)

Much appreciate any help/ advice.

S

Powdercoat oven is about 200 deg C I think, so it is really unlikely to have deformed a metal frame (alloy or steel).

All the frames I had powdercoated were masked so the BB face didn't get any coating.

Thick areas of powder would not be a sign of incredibly competent powdercoat personell.

the oven heat should not affect it

sometimes some of the sand/bead blasting material works it's way into the the bb threads and needs clearing out

^This.

I dunno what its like in London but up here the people that do powdercoating are not the people that understand bicycles. Or want to spend hundreds of pounds on tools to do a job they probably don't realise needs done.

Having watched a lot of car, motorbike, boat etc etc restoration programs on telly I'd say that having to recut threads after powdercoating is the norm.

Sounds to me like the frame wasn't masked properly during the powder and oven process.
We specialise in masking products for exactly that purpose to avoid retapping threads and reworking material after finishing. http://www.afac.co.uk.

Where did you get the work done? Perhaps we should contact them.

Yeah, sounds likely that there's just a bit of crud or some powdercoat in the threads - I'd chase and face the BB shell as a matter of course after having the frame refinished, but then I've got the tools ...

Happy enough to do it if (a) the frame's British threads and (b) you can get the frame SE-ish

Chase and face the shell, probably just paint, - (saw something alike recently when chasing etc). Get a LBS or ^ to do it for you as the tools cost a killing.

Thanks all for the advice and offers of help. It was coated at Armourtex and I think they did a very fine job of coating and masking. There were no signs of coat on the inside. The reason I thought it might be deformed through possible uneven heat expansion and contraction, was because there's now a gap between the fixed cup (which is in) and the shell on the underside whereas its flush on the topside. The faces are clean. The adjustable cup is being even more stubborn after a few turns - so much so that the pins on my tool broke. My local bike shop say they can chase, face and install the BB for £20 which seems very reasonable. Will be interesting to see if they also think it's deformed. Thanks once again for your help.
S

My local bike shop say they can chase, face and install the BB for £20 which seems very reasonable.

It is.

Or is it?

#jeez

I always chase the thread after a frame has been powder coated. In regard to facing the shell, this is only necessary if you are running an external bottom bracket. If your frame is steel, and you face the shell and run it with a non-external bottom bracket, it will leave and exposed area where rust can start forming, which could potentially be problematic with powder coating as rust grows under the surface. I always touch up any chips in my frame with nail polish! A good phosphate primer will also help prevent rust spreading.