Advertise on Bikeforums.net



User Tag List

Results 1 to 15 of 15
  1. #1
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

    Powdercoat or clear finish?

    I took my frame and fork to a chrome plater to have the fork chromed and the frame chemically stripped. The fork turned out well but the steel on the frame was discoloured and scratched from a wire brush, so I went to work on it with some abrasive paper.
    Now I'm getting to the point where the bare (almost) polished steel is starting to look good. I've polished and flattened Plane irons and chisels by hand, so I know I can get a mirrored surface on it that would rival chrome. I don't think I want to go that far though. I would like the steel bits to look like steel, and the chrome to look like chrome. I also know that the more highly polished steel is, the more it shows rust.
    So I'm thinking of clear powdercoating over the bare steel. I've searched some threads on powdercoating, and several people have mentioned rust appearing under the powdercoat. I suspect poor preparation is the culprit. I believe that I can get the frame clean enough that abrasive blasting is unnecessary, unless it's to key the surface. Obviously I will have to discus this with whichever powdercoater I choose.
    Should I just spray some rattlecan auto clear on it, and see if it rusts? At least I can strip off the auto clear easier than stripping off p/coat.
    And it's a nondescript (I assume) probably Taiwanese frame. Nice enough and light enough but no museum piece.
    The serial numbers are on the bottom bracket :438283, Q9,4. Brazeons for 2 bidon carriers and shifters only, cast dropouts with screw adjusters. So should I just go straight to powdercoat, or try a clear sprayed finish first?

  2. #2
    Randomhead
    Join Date
    Aug 2008
    Location
    Happy Valley, Pennsylvania
    Posts
    12,083
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I wouldn't do it myself. I saw a bike made by Mike Appel where he had the same idea as you. He was obsessive, and polished his frame to a high shine. By the time the clear coat had cured, there was a spiderweb of rust underneath. It was beautiful, but I'm sure it eventually caused the clear coat to fall off.

    If your powdercoater leaves pinholes or thin spots, there will be rust. Primer keeps that from happening.

    Apparently there is a clear primer. Don't know anything about it.

  3. #3
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by unterhausen View Post
    I wouldn't do it myself. I saw a bike made by Mike Appel where he had the same idea as you. He was obsessive, and polished his frame to a high shine. By the time the clear coat had cured, there was a spiderweb of rust underneath. It was beautiful, but I'm sure it eventually caused the clear coat to fall off.

    If your powdercoater leaves pinholes or thin spots, there will be rust. Primer keeps that from happening.

    Apparently there is a clear primer. Don't know anything about it.
    I can't see the difference betwen a powdercoat with pigment and a powdercoat without, unless it's the primer.
    If rust will occur under clearcoat, what stops rust when the frame is painted or powdercoated with a pigmented?
    I've seen powdercoated steel that was continually immersed in salt water for a year. Not a trace of rust.

  4. #4
    Senior Member Oldpeddaller's Avatar
    Join Date
    Apr 2008
    Location
    Maidstone, Kent, England
    My Bikes
    1970 Holdsworth Mistral, Vitus 979, Colnago Primavera, Corratec Hydracarbon, Massi MegaTeam, 1935 Claud Butler Super Velo, Carrera Virtuoso, Viner, 1953 Claud Butler Silver Jubilee, 1954 Holdsworth Typhoon, 1966 Claud Butler Olympic Road, 1982 Claud
    Posts
    2,345
    Mentioned
    1 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Fidelista View Post
    I can't see the difference betwen a powdercoat with pigment and a powdercoat without, unless it's the primer.
    If rust will occur under clearcoat, what stops rust when the frame is painted or powdercoated with a pigmented?
    I've seen powdercoated steel that was continually immersed in salt water for a year. Not a trace of rust.
    Continually immersed in seawater, I'd believe it.

    But if used in a coastal atmosphere, rather than submerged without air, it'll rust - steel rusts, even stainless steel, aluminium goes crusty and crumbles, galvanising peels and brass loses its copper and goes weak. I work in a port environment and see high quality powder coated equipment cabinets flaking and bubbling from rust under the coating in around eight months from new. It's not just the salt in the air - acids from thousands of truck exhausts per day, chalk dust from the "White Cliffs" and heaven knows what from the ships funnels create an always damp corrosive miasma. A GOOD paint system, regularly checked and touched in - or fibreglass instead where possible, seems to be the only answer. Hopefully the OP doesn't live in this type of atmosphere, because his idea sounds stunning!
    Oldpeddaller - The older I get, the better I used to be !!!" ***** If at first you don't succeed - hit it with a hammer.

    [SIGPIC][/SIGPIC]

  5. #5
    Jet Jockey Banzai's Avatar
    Join Date
    Jul 2005
    Location
    Leavenworth, KS
    My Bikes
    Cannondale CAAD9 SRAM Red, Ritchey Breakaway Cross, Nashbar X-frame
    Posts
    4,009
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I wonder if there's a framesaver equivalent for aluminum, or if it's necessary?
    Good night...and good luck

  6. #6
    Randomhead
    Join Date
    Aug 2008
    Location
    Happy Valley, Pennsylvania
    Posts
    12,083
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Seems like Rivendell has done this with at least one of their frames, but they didn't even bother to clean all the carbon cruft off of the frame. Some people like it. I had to work hard not to be embarrassed for the framebuilding community. I have thought of doing this to an all stainless frame. Not too many vintage frames that can withstand this kind of scrutiny.

  7. #7
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by Oldpeddaller View Post
    Continually immersed in seawater, I'd believe it.

    But if used in a coastal atmosphere, rather than submerged without air, it'll rust - steel rusts, even stainless steel, aluminium goes crusty and crumbles, galvanising peels and brass loses its copper and goes weak. I work in a port environment and see high quality powder coated equipment cabinets flaking and bubbling from rust under the coating in around eight months from new. It's not just the salt in the air - acids from thousands of truck exhausts per day, chalk dust from the "White Cliffs" and heaven knows what from the ships funnels create an always damp corrosive miasma. A GOOD paint system, regularly checked and touched in - or fibreglass instead where possible, seems to be the only answer. Hopefully the OP doesn't live in this type of atmosphere, because his idea sounds stunning!
    Actually, I can see Sydney Harbour from my window.
    I don't plan to ever ride the bike in the rain, or leave it outside. I have other bikes for that.
    I used to be shipwright, and I worked on more than a few old wooden boats. I've seen thick stainless bolts fall apart with only a few months exposure. OTOH, the powdercoated railings at my sailing club are constantly bathed in salt spray and look like new, 8 years later. It's only a gut instinct ATM, but I can't help feeling that it comes down to preparation and as Unterhausen said...primer.
    I can say I have a new appreciation for the work necessary for chrome plating now!
    I'll be seeing the powdercoater this afternoon. I won't proceed unless I am completely

  8. #8
    Randomhead
    Join Date
    Aug 2008
    Location
    Happy Valley, Pennsylvania
    Posts
    12,083
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    nothing bad is going to happen, so go for it. My thought is that they are going to want to media blast the frame, in which case I don't see the value in doing this. If you can get them to clear coat a polished frame and it works, you'll be a hero.

  9. #9
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)

  10. #10
    Senior Member squirtdad's Avatar
    Join Date
    Jul 2006
    Location
    San Jose (Willow Glen) Ca
    My Bikes
    '89 Miyata 1400, '82 nishiski (current utilty/commuter project)
    Posts
    3,099
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    [QUOTE=Fidelista;8461054There is no need to remind me what a crap photographer I am.[/QUOTE]

    if you use the IMG options in photobucket then it will display in your post when you paste it

  11. #11
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    Quote Originally Posted by squirtdad View Post
    if you use the IMG options in photobucket then it will display in your post when you paste it
    For some reason the IMG options don't come up, just on those two pics.

  12. #12
    Senior Member squirtdad's Avatar
    Join Date
    Jul 2006
    Location
    San Jose (Willow Glen) Ca
    My Bikes
    '89 Miyata 1400, '82 nishiski (current utilty/commuter project)
    Posts
    3,099
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    as noted by unterhausen...Rivendell uses clear coat over steel on some bikes. I think it is a love it/hate it type of finish

    My assumption is that if there were potential rust issues they wouldn't use this option.

    Afaik powder coat does not use "primer" like paint does....the coat is the the coat, clear or not.....

    anyway here is a link to a pic it feels kinda of a steampunk finish

    http://www.rivbike.com/products/list...product=50-640

  13. #13
    Senior Member Grand Bois's Avatar
    Join Date
    Mar 2005
    Location
    Pinole, CA, USA
    Posts
    14,756
    Mentioned
    2 Post(s)
    Tagged
    0 Thread(s)
    There's a cleared Bombadil on the Rivendell site. It wasn't polished prior to applying the clear powdercoat, but it certainly wasn't blasted either. I like the look.

  14. #14
    Senior Member
    Join Date
    Oct 2006
    Posts
    251
    Mentioned
    0 Post(s)
    Tagged
    0 Thread(s)
    I spoke to the powdercoater today. My first question was "Is this possible" and he said yes of course. He seemed surprised that I would ask. When I asked about rust under the coating he told me that if it isn't rusted when it gets coated then it shouldn't rust on a bike frame.
    I have to do the prep, which suits me actually.
    I'll sand some more to get a fine brushed look I've been spraying WD40 on it after every sanding session. I'll deliver it with the WD40 on the frame and they will clean it off with a solvent.
    The Rivendell link was quite encouraging. Thanks for that.

  15. #15
    Senior Member squirtdad's Avatar
    Join Date
    Jul 2006
    Location
    San Jose (Willow Glen) Ca
    My Bikes
    '89 Miyata 1400, '82 nishiski (current utilty/commuter project)
    Posts
    3,099
    Mentioned
    3 Post(s)
    Tagged
    0 Thread(s)
    Waiting for pics when it it done

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •