Spraying an old frame

Discussion in 'Cycling Equipment' started by Yonni, Oct 20, 2010.

  1. Yonni

    Yonni New Member

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    I've got an old steel frame that could do with a lick of paint. Getting a pro job done would cost at least twice what the frame cost me so I'm thinking of using aerosol cans and doing it myself from scratch.

    Any tips on preparation, stripping, sanding, technoque and places to get good primer paints & lacquer etc.? I now the basics of good spraying technique and how to make a spray booth but I've never stripped & prepped a frame before.

    Thanks.
     
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  2. BHOFM

    BHOFM Active Member

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    Find, rent, steal, borrow a sand blaster. Blast the frame. Five or six coats of good primer as per directions on can. Let it sit for a week
    or so. Sand with 400g wet paper. Check for blems and re prime. Two coats. three on the blems. Resand with 400g and then 600g.

    Apply five or six coats of paint as per directions on can.

    Some electric conduit, duct tape and plastic drop cloth will make a booth, any small fan with a dryer duct will do
    for ventilation.

    You need good lighting and plenty of fresh air. And most important, the proper temperature..

    Depending on the color you may want to do a clear coat over the color coat.

    All in all, a lot of work and some cost.

    To do a good job, you will spend more time and money than the frame is worth in all likely hood...
     
  3. adambialy

    adambialy New Member

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    Hi
    Really not a rocket science. On steel frame you'll need good paint remover:
    http://www.google.co.uk/products?hl=en&biw=1920&bih=823&q=paint+remover&um=1&ie=UTF-8&ei=0sK-TOX7JdO6jAfwnaiFAg&sa=X&oi=product_result_group&ct=title&resnum=3&ved=0CEIQrQQwAg or sand it down, I prefer sanding (that stuff might help http://www.google.co.uk/products?q=rubber+sanding+disc+for+drill&hl=en&aq=f but you need to be careful), sand paper 100 and 200, good primer for steel, paint and optionally lacquer as a top coat (the stuff for cars is quite hard after drying).
    also some tape to protect frame holes, old spoke to hang it during painting, and methylated spirit/clean rag to degrease and clean after sanding.
     
  4. Froze

    Froze Well-Known Member

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    You should first test paint on a piece of round pipe roughly the size of the frame tubing. Why do I suggest that? Because round tube shapes are far more difficult to spray then flat surfaces due to runoff resulting in drips. So once you figure how the correct speed and lightness of coat that results in no drips then your ready to go. This will mean you will have to do 5 or 6 maybe 7 coats to get a good solid color down.

    I recommend the clear coat, especially if you want the paint to last, in fact I would recommend 2 clear coats because the second coat will make the paint look wetter.

    You do have to color sand the paint between paint coats and color sand the clear coat between coats or the paint and/or clear coat will peel later.

    What brand and model is the bike? It may be worth having it pro done if the bike has any old school value to it. Problem is most pro sites on the web that are famous for doing bikes are ranging from $600 up. I wonder about two things though. Could a community college teaching students painting cars be willing to paint a bike frame for the cost of supplies? and if a student did take it on I would tip him nicely if it meant your expectations. The second thought is, could a car repainter do it for less then those online places? The amount of paint needed to paint a bike frame is minor compared to typical car with about 3 quarts, vs a bike with at the most 1 quart and that would be multiple coats. A quart of paint cost around $125 plus a another $125 for clear coat. Maybe an auto repainter may have enough clear coat left over after doing a car they could use on your bike? Really the biggest cost in painting the bike is prep work.

    Also if your going to go that far you could also buy decals at: http://www.velocals.com/servlet/StoreFront and have those applied before the clear coat, if you do want decals you have to have the clear coat. If you don't care about the decals you could forgo the clear coat since you would have so many layers of paint any fading after years of use could easily be buffed out.

    Also if you paint the bike the same color then the amount of paint and prep work is less.
     
  5. BHOFM

    BHOFM Active Member

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    I would also check into having it powder coated. This is cheaper than having it painted.
     
  6. Yonni

    Yonni New Member

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    A courier told me over the weekend about a local guy who will powder coat a frame for £30 ($47) but he uses an acid bath to strip the paint rather than a sand blaster. When I had my old pine doors dipped in an acid bath to strip the paint the hinges (which they told me to leave on) corroded like mad.
     
  7. Froze

    Froze Well-Known Member

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    Why in the world would they tell you to leave on the hinges knowing they were going to tip them in acid? That's just plain weird.
     
  8. Yonni

    Yonni New Member

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    Well, they were covered in old gloss paint and he said it would clean them up!
     
  9. Bigbananabike

    Bigbananabike Member

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    [SIZE= medium]I’ve resprayed a reasonable number of frames now. [/SIZE]
    [SIZE= medium]I take mine to a sandblaster I know who does a good job and only charges me $20 – to blast and prime the frame. [/SIZE]
    [SIZE= medium]I then spray an undercoat and a guidecoat on the frames and put filler on if needed. [/SIZE]
    [SIZE= medium]I sand the frames with 320 grit wet and dry paper and leave them to dry. [/SIZE]
    [SIZE= medium]I usually check the sanding job a day or so later to see if I can improve on them. [/SIZE]
    [SIZE= medium]Why 320 – doing them wet it’s a smoother job and on a frame if I used say 600 or 800 grit they’d take forever and having previously sanded some with 600 I know that with a bike frame there is no visible difference in the finish once the job is done. [/SIZE]
    [SIZE= medium]I then wipe them down with thinners (or Prepsol). [/SIZE]
    [SIZE= medium]Spraying – I do the forks separately. [/SIZE]
    [SIZE= medium]I mask off half the frame as frames are really tricky to do – so many areas to get into.[/SIZE]
    [SIZE= medium]Spraying – (half at a time) – I do the colour (basecoat) coat, apply decals if any and then about 4 coats of twopack clear coat. [/SIZE]
    [SIZE= medium]I allow that to dry for a few days (no rush although it could only be two day), unmask, mask the parts painted, thinners on the previously masked side and spray it. [/SIZE]
    [SIZE= medium]Where do I spray them? [/SIZE]
    [SIZE= medium]I hang the frame from my carport on a day with little wind and that is warm and dry. [/SIZE]
    [SIZE= medium]The forks – I just hold them in my hand and have a place ready to put them when done. [/SIZE]
    [SIZE= medium]Remember if you get a bug or dust on your sprayed paint (or even a run) leave it to dry and sand (now use 600grit) it off. [/SIZE]

    [SIZE= medium]BBB/img/vbsmilies/smilies/smile.gif[/SIZE]
     
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  10. Yonni

    Yonni New Member

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    Some great advice so far so how about a slightly different question:

    What about touching up the odd scrape here and there? Is it better to respray the whole frame or can you get an acceptable result just respraying the scratched bits?
     
  11. BHOFM

    BHOFM Active Member

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    As small as a bicycle frame is, it is about as much trouble to touch it up as it is to repaint.

    Really, sand blasting and prime, paint is the best way, and you will be much happier with it.

    If it is worth doing, do it right. And then it is done!

    After blasting it needs to primed right away, then you can take your time to do the rest.

    Spray cans will work, spray gun is better, two part paints are best but $$.
     
  12. Bigbananabike

    Bigbananabike Member

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    As the last two posters have said - stripping a frame and painting it properly is much better and then you'll have colourmatched touchup paint for the future too.
    If you do just touch it up - get a professional to make up the colourmatched paint for you. It's worth the time and extra $.

    Powdercoating? It can be good but there are some really crappy/img/vbsmilies/smilies/mad.gif powdercoating finishes out there that are worse than two pot paints.

    BBB/img/vbsmilies/smilies/smile.gif
     
  13. BHOFM

    BHOFM Active Member

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    OK,, I have never done a bicycle before, several motorcycles but not a bicycle.

    I am helping a friend redo an old IronMan, about twenty years old and has been
    sitting for over ten years in a garage.

    I took me less than an hour to strip the forks with a common electric sander. A
    bit of chemical stripper on the welds and a wire brush and it was bare clean metal.
    Only down side is it is a bit dusty, so cover things and use a mask. I used 120
    grit paper and it lasted fine and cut quickly.

    Three coats of primer, waited 24 hours, light sanding, three coats of dark blue
    Toyota paint, Duplicolor spray can, four coats of Duplicolor clear and it looks
    just like it did when it left the factory. A near perfect color match.

    The frame is clearcoated aluminum and in good enough shape we are
    going to leave it as is. That way we save doing the decals.

    New pedals, brakes, cables, all the bearings cleaned and packed, new
    rear axle and bearings, the original was bent and wore the bearings
    badly.

    It was stored in the dark so the tires seem to be fine, new rim tape and
    tubes and a lot of cleaning a polishing and it is starting to look like new.

    Total cost of rebuild is just under $60 with all free labor!

    Here is a thread with pics.

    http://www.cyclingforums.com/forum/thread/481463/redo-on-an-old-ironman-mountain-bike#post_3979981
     
  14. mnop99

    mnop99 New Member

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    Great advice. I think colour matching bikes is so difficult so I would definitely advise leaving it to the professionals! /img/vbsmilies/smilies/tongue.gif
     
  15. Bigbananabike

    Bigbananabike Member

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    Often a small can of touch up paint can be mixed up by a carpainters suppliers. They can usually be done in a spray can too but usually the colour isn't so good and a spray can isn't so practical.
     
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