kjc9640

I plan to have my frame powder coated this month. I would like to plug all of the holes to keep the PC from getting into any of the threaded areas. What is the best method of doing this. I know the powder coater should do this but I have heard horror stories where the process got into the threads and was difficult to get out.
All suggestions are appreciated.

fietsbob

It gets taped after blasting, , rubber tape May survive, taping in advance,,
.. perhaps choose a top ranked service .. with bicycle focus
Spectrum has a premier reputation.

pmt

Why not just put screws/old junky parts into the threaded areas to protect them?

CCrew

Because then the powdercoat can get between the threads effectively welding the screws into the threads. Back them out and they may take part of the surrounding powdercoat with them .

Pro powdercoat shops have a selection of silicone plugs they use. They can survive the 350-400 degree oven heat. I'm with fietsbob, Spectrum has a good rep. So does CyclArt ( https://www.cyclart.com/ ) but they're more a paint shop. Color Factory in NJ, and also Joes Bicycle Painting ( https://www.joesbicyclepainting.com/ )

kjc9640

I plan to have the frame coated here in Orlando. I have looked at the web sites that have been suggested and I am just not prepared to pay that high of a price. The shop that is doing it for me does a lot of motorcycle frames and parts so hopefully the know what they are doing. They charge 150 dollars plus I will have to pay a bike shop to take the bike apart and put it back together, that will be about 130 dollars. The big thing for me is that the bike will only be out of service 4 to 5 days.

Chris_in_Miami

If you're not doing the disassemble/reassemble work yourself, you should ask the shop to blow out the frame before they put it back together.

I found quite a bit of blasting media inside my tandem's frame after it was PC'd, and it took some effort to get it all out. I wouldn't want that stuff ending up in my bottom bracket(s).

TimeTravel_0

silicone plugs. any powdercoater that regularly does bicycle frames or metal stuff that has threads & fittings should have these on hand. if not, they're amateurs and not worth your money.

kjc9640

Thanks guys, this is the type of info I am looking for.

surreal

i've had a few frames powdercoated in my day, at a few different spots. Here's the best advice i've got:

-talk to the powdercoater. make sure he seems competent.
-ask if he does bikes a lot. if he doesn't, it's no deal-breaker, but it's best if he has. Guys who do a lot of motorcycles tend to be good w/ detail work
-when you drop the frame off, point out the threaded/press-fit zones. The inside of the seat-tube is important, too. it may help to make a half-azzed attempt to mask them off; it''ll all get blasted off anyway, as someone mentioned, but it'll help remind the guy doing the job
-threaten to punch the guy square in his face if he buggers any of your threads

good luck
-rob

Jeff Wills

Brooker Enterprises does bicycle and motorcycle powder coating here in Portland: https://brookerenterprises.com/ (They've got a good little video on their site.) If they've done a motorcycle frame, a bicycle frame won't be to different. You want to make sure they don't sandblast the hell out of the frame- it's probably thinner tubing than they're used to.

If you're really worried, make sure the bike shop doing the reassembly chases all the threads before reassembling the bike. OTOH, I recently had a frame powder-coated by Brooker and they had blocked off all of the threads correctly. When I reassembled the bike it went together like it was brand-new.

sch

To emphasize what Jeff said, Bike Tech (RIP) experimented with blasting frames back in the 70s and using cutting sand media found that
it was easy to strip 0.01" metal off a frame. No biggy you think, but high end steel frames these days can have sections as thin as 0.3mm,
which translates to 0.012" thick. High end aluminum frames are not a whole lot thicker. Bead glass is safer and walnut hulls or plastic media
even better for paint stripping and superficial rust or corrosion. Even 70s era high end frames in steel were not much more than 0.032" thick,
taking off a third will noticeably weaken a tube. The blaster should be made aware of the fragility of some frames.

kjc9640

sch, I had been cautioned about sand blasting and the dangers of using it. I think that this company uses plastic but I will confirm before I hand the bike to them. The walnut hulls process is very interisting, I had not heard of that.

Thanks for the heads up...