2.2 How to paint a bike in 10 easy(?) steps
Description
This article is from the Misc Bicycles FAQs, by various authors.
2.2 How to paint a bike in 10 easy(?) steps
From: android@ccwf.cc.utexas.edu (Andy Wilks)
Date: 9 Apr 91 23:16:17 GMT
Reply-To: android@ccwf.cc.utexas.edu (Andy Wilks)
In article <4863@dirac.physics.purdue.edu>
war@maxwell.physics.purdue.edu (Warren D. Murphy) writes:
>In article <10835@uwm.edu>, zark@csd4.csd.uwm.edu (Steven M Kosloske)
writes:
>> I have an old (6 years old) Raleigh bike frame I would like to
>>strip and put together a new paint job on. The bike has a few decals
>>on it, which will have to come off with the paint. My question is,
>>what is the best/easiest way to get the frame prep'd for painting? I
>>believe that it has to be stripped to bare metal to paint, correct?
>>Would having it dipped somewhere to have it stripped all at once be a
>>good idea?
>>
>>Steve Kosloske
>Well, you might get good success with having the frame dipped, but
>I'm not sure that the solution would take the decals off. This might
>lead the shop you're having do the job to charge you extra.
>Sandblasting has always worked well for me, just be sure that a fine
>grade of sand is used.
> But, here's a summary of the general procedure.
>
>1. strip the frame of ALL components. This includes chainstay guards and
> all the headset races
>2. degrease the frame thoroughly. Get every nook & cranny using a
> toothbrush
>
>3. sandblast the frame completely. A trick that helps this is to
> rough the surface with coarse sandpaper. This will give the
> sand a start on removing the paint, and tears the decals up a
> bit which helps the sand immensely in removing them.
>
>4. degrease the frame again.
>
>5. Have the alignment checked and the frame re-aligned if necessary.
>
>6. if you had number 5 done, degrease the frame again. This should
> be the final degreasing, so if you didn't have #5 done, do
> this for #4. Use denatured alcohol as your last cleaning
> solution, then use the recommended thinner for the paint
> you'll be spraying as a final prep solution. Use a lint-free
> cloth for this, and do it in the area you'll be spraying in.
>
>7. now you're ready to spray. I would strongly recommend that you
> get some pipes, tubes, or anything cylindrical to practice on
> before you try to spray your frame.
>
> As far as the painting itself goes, I posted on this a little
>while ago, so it should still be easily accessible. Clear coat is,
>IMNSHO, an option. It protects paint and decals, but makes touch-up
>work harder.
>
The above is fairly good advice but goes a little overboard on the
degreasing!!
You might find the following more practical:
1: As above, take the bike completely apart.
2: Apply a good quality aircraft grade stripper such as Klean Strip (PPG)
don't worry about the stickers, they'll start to peel at the edges and
will scrape right off. ( USE CAREFULLY - VERY STRONG STUFF ) You might
have to do this twice. Don't use OLD stripper, a chemical reaction can
cause hydrogen embritlement in certain grades of steel. Rinse well with
water to remove strippr. Lightly brush away any remaining paint flakes
around lugs or fittings with a brass bristle brush. OR GLASS bead blast
away the remaining paint. ( there won't be much. ) Sand blasting is
pretty harsh for road grade lightweight tubing. (IMHO!!)
3: Now is the time to get that alignment or new braze-ons!!
4: This step is VERY IMPORTANT so pay attention. If it isa steel frame
use Metalprep(DX-579) to chemically prepare the surface for primer.
If it is aluminum then use Alumiprep(DX-533) or Alodine to prep the
bare metal. If you skip this step on steel, well, you will get a
mediocre adhesion ( will chip easily ) if you skip this step on
aluminum watch out!! Paint will chip and flake away in weeks. (
No, I didn't try it, But we saw samples in Paint and Final
Finish School in the Navy )
5: Now you can degrease!! Use something like 'Acryli-Clean'(DX-330)
wax and grease remover. Alchohol is OK, but it will not dissolve
some types of grease very well.
6: Now it's time to prime. I use DP-40 Epoxy Primer. Light Gray or
grey-green works best. You can use a sealer over this but this is
not %100 necessary.
7: Apply the topcoat. I use and reccomend Deltron Acrylic Polyurethane.
Acrylic lacquer is OK but not as durable unless clearcoated with a
Urethane. A good gun for painting bikes is a Binks 115. It is an
auto touch-up gun and is nice and small.
8: Apply the clearcoat. This is require for some finishes and not for
others. Most fancy stuff (pearls, neons, candy, etc...) require this.
Plain colors do not, but it will enhance the appearance (assuming
you've done a GREAT job thus far) and make the difference between
a good looking bike and a GREAT looking bike. If decal are being
replaced they can (* sometimes *) be put on before the clear
coats. This is very nice, because you can build it up to where
they are smooth to the touch.
You will have to experiment on spare tubes with spare decals to check.
Don't try w/o doing this as some decals will wrinkle melt or dissolve!!
9: Let dry for 72 hrs. Polyurethane cures by a chemical reaction so
baking is not neccesary. It only speeds up the reaction and does
not add to durability.
10: Put it back together and ride all around town so all of your friends
can say "WOW! is that a new Topolini??"
************************* SAFETY PRECAUTIONS ***************************
ALL material used for painting are poisonous and hazardous. ALWAYS wear
a respirator (NOT a dust mask) with an organic vapors catridge. NIOSH
approved. A forced air system is a must for painting cars but A touch-up
gun does not create as much overspray, o a respirator is PROBABLY OK.
Wear your respirator at all times while stripping, prepping, mixing and
painting. When you are done painting, don't remove your mask and gawk
at the lovely job you have done. Come bak later. The solvents are
evaporating and the air is very toxic right now!!
TRY VERY hard to find someone to let you paint in their booth. This is
best for the enviroment :-) and will also keep away dust and float stuff.
Follow all of the instructions on the cans. Waiting times for second coats
and topcoats ARE important for a quality finish.
Follow all of the rest of the safety precautions on the cans and in the
FREE literature the friendly(?) gentlemen at the auto-parts store will
give you. They will also help you select the right clear coats etc...
that you need to do the job right.
If you *don't* follow the instructions and die, don't send me e-mail
complaining or flaming... (Ladies and Gentlemen, these are trained
professionals, don't attempt this at home!!! (Unless you've really
got a good idea you can handle it SAFELY.)
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