chroming the rear triangle of an already painted/finished bike?
w.a. manning
bicycle that's already nicely painted and finished. of course the
perfect solution would be to have the whole frame chromed, but i got
it refinished a few years ago and was able to source the proper
decals...and i'm loathe to go thru all of that again.
i'm thinking that with thorough masking of the frame and careful work
by the chromer, i can minimize any potential damage to the existing
finish. but someone told me that getting any masking tape into the
various solutions will contaminate them. but i had this guy chrome the
fork, and he masked off part of it in that process.
is this do-able? any "gotchas" that i need to consider?
i intend to paint a contrasting color where the chrome and existing
paint meet so it looks clean.
http://brown-snout.com/cycling/bikes/ciocc_mockba80/to_be_chromed.jpg
fixit
chrome on paint? forget it. :)
--
fixit
Phil Brown
>by the chromer, i can minimize any potential damage to the existing
>finish. but someone told me that getting any masking tape into the
>various solutions will contaminate them. but i had this guy chrome the
>fork, and he masked off part of it in that process.
Sorry, it won't work. It's not the plating-although any acid splashed on the
paint and it's toast, and you can mask area not to be chromed, it's the
polishing. If you really want it chromed you'll have to repaint.
Phil Brown
Zog The Undeniable
> Sorry, it won't work. It's not the plating-although any acid splashed on the
> paint and it's toast, and you can mask area not to be chromed, it's the
> polishing. If you really want it chromed you'll have to repaint.
I suppose someone ought to mention that chroming is usally a bad idea.
Polishing involves removing metal, then there are nasty acids and the
chroming process itself. On thin vintage tubing that might already have
rusted internally, this could shorten its life considerably. I wouldn't
be as worried about chroming thick parts like dropouts and fork-ends.
David L. Johnson
> i'm debating having the rear triangle chromed on a vintage steel bicycle
> that's already nicely painted and finished. of course the perfect solution
> would be to have the whole frame chromed, but i got it refinished a few
> years ago and was able to source the proper decals...and i'm loathe to go
> thru all of that again.
>
> i'm thinking that with thorough masking of the frame and careful work by
> the chromer, i can minimize any potential damage to the existing finish.
I'd recommend against it. I tried to get my old track bike chromed about
4 years ago, but no one I talked to wanted the business. Too much chance,
I was told, of contaiminating the baths with extra solution carried in the
tubes. So, I got the frame powder coated, and the fork chromed.
4 years later, the powder coat is still nearly perfect, but rust has
appeared in several places (external, guys, external) on the fork. It
could just be a poor chrome job, or it could be that old, previously
painted and rusted steel can't be cleaned up enough to prevent this.
I also have a bunch of old parts with chrome bits (such as the original
Campy pedals, and the toeclips) that have quite a bit of rust now as well.
I wonder how powder coat compares to chrome in general, in terms of rust
prevention.
--
David L. Johnson
__o | Arguing with an engineer is like mud wrestling with a pig... You
_`\(,_ | soon find out the pig likes it!
(_)/ (_) |
Donald Gillies
>i'm debating having the rear triangle chromed on a vintage steel
>bicycle that's already nicely painted and finished. of course the
>perfect solution would be to have the whole frame chromed, but i got
>it refinished a few years ago and was able to source the proper
>decals...and i'm loathe to go thru all of that again.
I think that rechroming is possible but it's high risk. First, you
will have to mask and seal all 11 bicycle tubes very carefully. Then,
the paint will need to be chemically stripped, and the rear triangle
polished with 2000 grit sandpaper and/or rubbing compound. You can do
this and i recommend you do it yourself to avoid unexpected "gotchas"
elsewhere on the frame.
Then you need to take it to a chromer who understands bicycle frames.
Very few of them really understand them. If they do not, then they
could leave acids inside the frame, which will eat your rear triangle.
They will need to make electrical contact with the frame, probably in
the bottom bracket or seat lug area, so make sure that there is
recently sanded bare metal in this area for the electrical
connectors. Another good place will be with temporarily installed
dropout adjusters (www.loosescrews.com) that will be thrown away when
the chroming is done.
Then, go ahead and get it chromed.
After chroming the frame will again need to be polished on a buffing
wheel to remove salt deposits and this is one place where again it
will pay to have the rest of the frame protected by thick bubble wrap
or something equivalent to prevent damage.
It goes without saying that you should get the entire process
"cleared" with the chrome shop before stripping the rear triangle.
I recently had some forks stripped & rechromed & completely polished,
and it was about 2 hrs of labor, or about $115 per fork, with $50/hr
labor charge for the polishing guy. I think that to do the rear
triangle it will probably cost you a little more, maybe $120 - $200
since the polishing may be more difficult.
- Don Gillies
San Diego, CA
Donald Gillies
very porous, and the nickel & chrome layers are usually applied to
areas that see a lot of road abrasives (forks, rear triangles, etc.)
It stands to reason that any chromed part will develop many pinholes
in the chrome from grit. These pinholes should be kept filled with a
good quality paste wax to slow the rusting process.
zulutime
hydrogen embrittlement
jim beam
i used to work in a chrome plating factory. what you want is do-able,
but if you'd come to our shop, we wouldn't have touched it. we'd do new
frames for bikes & wheelchairs, but trying to preserve an existing paint
job is just too much brain damage. especially if it doesn't turn out as
the customer had hoped.
regarding the work required, as stated by others, you need to strip and
polish the parts you want plated, mask the painted areas you want
preserved, then process the frame in a number of chemical baths before,
during & after plating. again, as stated, there are problems with bike
frames because they retain chemicals where drain homes allow the
processing solutions into the tubes, and these rust badly over time. i
sawed up a broken chrome frame this weekend and the rear stays had
substantial internal corrosion.
honestly, you're better off sticking with paint. it's better for the
frame, and much more maintainable for you.
w.a. manning
> ...snip...
> honestly, you're better off sticking with paint. it's better for the
> frame, and much more maintainable for you.
but the chrome is so purty!
well, it's basically a done-deal...i've already marked up the paint
with a sharpie and begun the masking process...will let everyone know
how it turns out!
Weisse Luft
My suggestion would be electroless nickel. There is also selective
plating processes, you just need to shop around. You will need to do
some buffing after the plating.
--
Weisse Luft
Donald Gillies
Another alternative is to buy a few brush-plating sets and try to do
some "brush plating" on your own. With some practice, you might be
able to do 5 square inches per evening. In maybe 2 or 3 weeks, you'd
be done.
Frank
Hydrogen embrittlement
===================
Five words:
Can be prevented by baking.
Ron
===================
Fifteen words:
Not an issue at all if you just leave the beautiful frame like it is.
Frank
Johan Bornman
wrote:
I fail to see what road abrasives you talk about. Yes, the road is
abrasive, but the bike hardly ever comes into contact with it. When it
does, the handlebar tape, saddle and pedals feel it, not the rear
triangle or fork. You further talk about grit that causes pinholes. I
think you confuse space travel with bicycle riding. I never come
across any high-speed grit that flies fast enough to damage my bike's
paint and aluminium frame, yet alone penetrate hard chrome causing the
pinholes you mention.
Finally, should porosity be an issue, I'm sure even a poor quality
wax, paste or any other form or smearable solid will do the trick.
Johan Bornman