powder coat removal; this is cool....
09-23-21, 04:04 PM
#26
Senior Member
Join Date: Jun 2006
Posts: 20,305
Mentioned: 130 Post(s)
Tagged: 0 Thread(s)
Quoted: 3464 Post(s)
Liked 2,827 Times
in
1,995 Posts
I wouldn't hold PC in such a high light. Yes, it's hard. Yes, it's durable. But it's merely a coating over the metal, and it doesn't bond with the metal as fiercely as top-coated self-etching paint, so if (a) not finished thickly enough, and/or (b) not topcoated and/or (c) not finished properly at the edges like the BB shell face, seat tube edges, head tube openings, and even the tubing vent holes, OR you chip at one of those locations while installing things, water can easily get underneath the coat and rot things from the inside out without you knowing until CRUNCH, your thing falls in half under you. It's not like paint, which will send up warning bubbles when compromised.
This isn't me hating on PC, it's just a sad reality of the product. I've seen it happen countless times in the offroad vehicle world with tubed vehicle frames, tubular roof racks, step bars, and even A-arms /control arms. We've seen it here on C&V forum at least once or twice since I've been here too ...
If you really care about your frame and it's been PC'ed, make sure you install framesaver in the tubes and, if you can, topcoat with a good 2K clearcoat (Disclaimer: Wear proper breathing apparatus w/2K paint, it's no joke).
This isn't me hating on PC, it's just a sad reality of the product. I've seen it happen countless times in the offroad vehicle world with tubed vehicle frames, tubular roof racks, step bars, and even A-arms /control arms. We've seen it here on C&V forum at least once or twice since I've been here too ...
If you really care about your frame and it's been PC'ed, make sure you install framesaver in the tubes and, if you can, topcoat with a good 2K clearcoat (Disclaimer: Wear proper breathing apparatus w/2K paint, it's no joke).
09-23-21, 04:24 PM
#27
Senior Member
Join Date: Apr 2011
Location: Maryland, USA
Posts: 2,424
Bikes: Drysdale/Gitane/Zeus/Masi/Falcon/Palo Alto/Raleigh/Legnano
Mentioned: 34 Post(s)
Tagged: 0 Thread(s)
Quoted: 977 Post(s)
Liked 626 Times
in
400 Posts
I wouldn't hold PC in such a high light. Yes, it's hard. Yes, it's durable. But it's merely a coating over the metal, and it doesn't bond with the metal as fiercely as top-coated self-etching paint, so if (a) not finished thickly enough, and/or (b) not topcoated and/or (c) not finished properly at the edges like the BB shell face, seat tube edges, head tube openings, and even the tubing vent holes, OR you chip at one of those locations while installing things, water can easily get underneath the coat and rot things from the inside out without you knowing until CRUNCH, your thing falls in half under you. It's not like paint, which will send up warning bubbles when compromised. If you really care about your frame and it's been PC'ed, make sure you install framesaver in the tubes and, if you can, topcoat with a good 2K clearcoat (Disclaimer: Wear proper breathing apparatus w/2K paint, it's no joke).
__________________
Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
Larry:1958 Drysdale, 1961 Gitane Gran Sport, 1974 Zeus track, 1988 Masi Gran Corsa, 1974 Falcon, 1980 Palo Alto, 1973 Raleigh Gran Sport, 1974 Legnano. Susan: 1976 Windsor Profesional.
09-23-21, 07:20 PM
#28
PM me your cotters
Join Date: Jun 2015
Location: ATL
Posts: 3,241
Mentioned: 80 Post(s)
Tagged: 0 Thread(s)
Quoted: 1137 Post(s)
Liked 588 Times
in
420 Posts
No, but Tacoland is! Tacoland, it's a panacea, Tacoland, they're always glad to see ya!
As long as the frame wasn't overly rusty before, it's inner-coated, and whoever did the work knows what they're doing, understands how to finish edges, you should be fine.
It's a running joke in some circles how PC tends to hold its cast form so well, "you'd never know there wasn't any steel inside!" There are certain situations that cause this, mostly all due to application and finishing.
Most critical thing about PC is exactly what repechage said - it's not a panacea. It isn't the end-all be-all coating. It's a cheap, quick, durable coating that will last a long time. But it's also so hard, you'll get little to no warning if something is wrong.
It's a running joke in some circles how PC tends to hold its cast form so well, "you'd never know there wasn't any steel inside!" There are certain situations that cause this, mostly all due to application and finishing.
Most critical thing about PC is exactly what repechage said - it's not a panacea. It isn't the end-all be-all coating. It's a cheap, quick, durable coating that will last a long time. But it's also so hard, you'll get little to no warning if something is wrong.
__________________
███████████████
███████████████
09-23-21, 08:21 PM
#29
(rhymes with spook)
Thread Starter
Join Date: Aug 2009
Location: Winslow, AR
Posts: 2,788
Bikes: '83 univega gran turismo x2, '85 schwinn super le tour,'89 miyata triple cross, '91 GT tequesta, '90 yokota grizzly peak, '94 GT backwoods, '95'ish scott tampico, '98 bonty privateer, '93 mongoose crossway 625, '98 parkpre ariel, 2k'ish giant fcr3
Mentioned: 26 Post(s)
Tagged: 0 Thread(s)
Quoted: 919 Post(s)
Liked 745 Times
in
546 Posts
the dead milkmen!!! hell yeah!! 
Likes For thook:
09-23-21, 10:10 PM
#30
Senior Member
Join Date: Jun 2006
Posts: 20,305
Mentioned: 130 Post(s)
Tagged: 0 Thread(s)
Quoted: 3464 Post(s)
Liked 2,827 Times
in
1,995 Posts
Where powdercoat can get in trouble is-
when the time from cleaning ( blasting usually ) allows any oxidation. It will be trapped, 2 or three layer jobs help close up the pinholes in the coat.
the other problem is with the physics of the process, the powder becomes a liquid, at areas that have any 90 degree edge, it will pull the coating thinner- in the semi liquid state.
so, lug shorelines, any cable braze ons, the edge of a through frame cable fitting, bottom bracket face ( fixed cup - think of where the edge is exposed ) all are potential invitations for under the coat corrosion- every frame I have that was one or two stage powder coated has exhibited hidden corrosion exposed when chemically stripped. This can happen to wet coated ( painted ) frames too but less often.
as written elsewhere in this thread, paraphrasing, PC does not bind to the metal, it encapsulates it - that would be how I would describe it.
when the time from cleaning ( blasting usually ) allows any oxidation. It will be trapped, 2 or three layer jobs help close up the pinholes in the coat.
the other problem is with the physics of the process, the powder becomes a liquid, at areas that have any 90 degree edge, it will pull the coating thinner- in the semi liquid state.
so, lug shorelines, any cable braze ons, the edge of a through frame cable fitting, bottom bracket face ( fixed cup - think of where the edge is exposed ) all are potential invitations for under the coat corrosion- every frame I have that was one or two stage powder coated has exhibited hidden corrosion exposed when chemically stripped. This can happen to wet coated ( painted ) frames too but less often.
as written elsewhere in this thread, paraphrasing, PC does not bind to the metal, it encapsulates it - that would be how I would describe it.
Likes For repechage:
09-23-21, 10:58 PM
#31
Senior Member
Join Date: Apr 2010
Location: Elevation 666m Edmonton Canada
Posts: 2,475
Bikes: 2013 Custom SA5w / Rohloff Tourster
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1233 Post(s)
Liked 318 Times
in
245 Posts
I've heard the stories about the metal underneath rusting. Several builders refuse to use it. But maybe my custom tour bike was done better, with 2 coats and maybe it was clear coated. It spent 5 months in wet Vietnam and China. Nothing rusted, except where the fork broke and was welded 3 times. LOL
There's been a few tiny chips come on my frame. After a couple years nothing happened.
Right away, I had to change my DIY stem that was PC on the top. It took 10x longer to sand and scrape than paint. I just don't see how it isn't bonded very well.
The steel bike I bought this year gets a chip or scratch almost every time I use it. And it's said to be a very good paint job.
And I've seen 4 yo Linus bikes look like they're 30 years old. LOL.
There's been a few tiny chips come on my frame. After a couple years nothing happened.
Right away, I had to change my DIY stem that was PC on the top. It took 10x longer to sand and scrape than paint. I just don't see how it isn't bonded very well.
The steel bike I bought this year gets a chip or scratch almost every time I use it. And it's said to be a very good paint job.
And I've seen 4 yo Linus bikes look like they're 30 years old. LOL.
Last edited by GamblerGORD53; 09-23-21 at 11:16 PM.
09-24-21, 06:52 AM
#32
Senior Member
There exists powder coat with a rust preventing zinc base coat. Nobody uses it for some reason though. The cool thing to do now is ED coating. Not entirely sure what the process is, but all Surly frames come that way now. It's some sort of black coating, even inside the frame.
Likes For wesmamyke:
09-24-21, 07:36 AM
#33
Senior Member
Not sure I want anything to do with anything called "ED". (smile)
Seriously, here's a brief (and rather marketing-oriented, IMO) web page that somewhat explains the process.
https://handsomecycles.com/blogs/cul...n-for-bicycles
This process is a form of "electrophoretic deposition" (the acronym EPD is also sometimes used). Wikipedia's article on the subject contains more details.
https://en.wikipedia.org/wiki/Electr...tic_deposition
Seriously, here's a brief (and rather marketing-oriented, IMO) web page that somewhat explains the process.
https://handsomecycles.com/blogs/cul...n-for-bicycles
This process is a form of "electrophoretic deposition" (the acronym EPD is also sometimes used). Wikipedia's article on the subject contains more details.
https://en.wikipedia.org/wiki/Electr...tic_deposition
Likes For Hondo6:
09-25-21, 03:38 PM
#34
Senior Member
Join Date: Apr 2010
Location: Elevation 666m Edmonton Canada
Posts: 2,475
Bikes: 2013 Custom SA5w / Rohloff Tourster
Mentioned: 7 Post(s)
Tagged: 0 Thread(s)
Quoted: 1233 Post(s)
Liked 318 Times
in
245 Posts
That reminds me. My bike got the zinc undercoat. Nothing to worry about then.
Some of my frame is stainless anyway.
Some of my frame is stainless anyway.
