How To Paint a Bicycle

I have been painting motorcycles, cars, and bikes for something like 35+ years now.

I started off like most, with rattlecans in the garage or driveway, but I got bitten bad by the kustom kraze in the early seventies, and wanted to airbrush, and pinstripe, just like ed 'big daddy' roth, so I went out and got brushes, a paasche VL (good ol airbrush) and just completely screwed up perfectly good looking motorcycles, cars and bikes for a year or so (all my own, thank god), but eventually I learned the rattlecan way, the hard way, the easy way, the fast way, the super uber quality way, and just about everyway in between.

since most of you can probably (or already have) figured out the hard way, the rattlecan way (which looks good=not for long though), the easy way, and the fast way, I'll detail the "reasonably fast, but still high quality way" which is, by the way, a PERFECT way to paint a something metal if you hate sanding; I have never met anyone who loved to sand things down, so I'll assume most of you will be with me on this.

this assumes you have access to a compressor, a HVLP or LVLP paint gun, a respirator (dual charcoal dust/mist type), a detail gun is also helpful (tiny paint gun w/ a 3" fan pattern) and a space to paint free of any ignition sources, and with good ventilation: usually painting outside with the ground wetted down, and then the piece moved into a sealed up garage after painting works VERY well) be VERY careful about overspray settling onto neighbors property as nothing will piss off a neighbor more than finding the car dusted with paint overspray. (so you get tarps, and offer to cover the nearby cars)

here's what I do with just about every bicycle frame I paint now:

A) TEAR IT DOWN COMPLETELY: headset cups, BB and all, nothing looks more amateur than tell tale overspray on chrome or shiny bits, because they should have been removed, not masked off. if you are going to remove any braze ons, eyelets or cable stays do it now now before the next step.
This also includes brazing new ones on, if you want, the point is to get all the metal work done before the going to the blaster.

B) TAKE IT TO A BLASTER: and have them blast it: note! tell the blaster if the frame will be powdercoated or painted, because they will want to use different blasting media, for each type of coating.
this is usually something like $20-$40
I HATE chemical strippers for ONE REASON: you cannot get all the stripper off: it's impossible there will be tiny specks left in crevices, and once painted these specks will start to remove YOUR PAINT JOB! so take my advice after 50 or so bike frames, and too many motorcycle frames to count, GO TO THE BLASTER, it's easy, it's fast, you get bare metal, and no residue (just remember to blow all the leftover media out of all the tubes!)

C) CLEAN THE DANG THING! paint will not stick to oil or grease, hamburger drippings, or taco juice and that includes the oils from your hands. (taco or not)
steel can be cleaned with alcohol or mineral spirits.
for aluminum I reccommend PPG's aluminum cleaner (quart=$10@ body shop supply houses or "color shops") once cleaned DO NOT TOUCH IT WITH BARE HANDS, USE GLOVES. (NOTE: if powdercoating, now you would put it in a plastic bag, and deliver it to the powdercoater)

D) SEAL IT/FILL IT/SEAL IT AGAIN: using a decent 2 part EPOXY BASED NON SANDING SEALER. (PPG, House of Kolor, DuPont etc,...)
this is special stuff, and is just a god send if you remember acid etch primers.
this sealer is designed to go over just about any type of bare metal, sealing it off from oxygen (no oxygen=no oxidation: rust) and provides a topcoatable surface that can be directly painted over with NO SANDING NEEDED, for something like 5 days. follow the "p" sheets (instructions) available online or where you buy the paint and shoot two good coats, waiting about 15 minutes between each coat (USE A TIMER! DON'T GUESS)
in the old days, you had to scuff the etch primer after it cured or your stuff would peel off in sheets,...not anymore.
now you'll need to grind all the braze on sites so they are a tiny bit LOWER than the surrounding tube, use a file, or a angle grinder, but obviously be careful, and don't go very deep at all, you just can't have anything sticking up from the repair area. to fill the tiny grinder marks or little indentations where you removed the braze ons, you use a GOOD QUALITY filler (NEVER, EVER, EVER, EVER USE "BONDO" brand from kragen/shucks whatever, EVER!) I use "METAL2METAL" from evercoat, it has powdered aluminum in it, so it's like filling with lead, except no stunted growth or brain and nerve damage from lead fumes! (no I never used lead, nice try!) sand the filled areas down with 180 grit sand paper on a HARD block of some sort: if the block is longer than the area you are sanding, and you sand along the length of it, the area will be nice and flat when done. you should sand in a "X" pattern for round tubes, so the filler profile after shaping/sanding matches the tube profile, and you get an undetectable repair. NOTE!! only sand down the areas you are repairing. now blow on another two coats of the sealer, and after 30 minutes look at the frame, it should be all smooth, and even, with no tell tale sanding or grinder marks visible anywhere,...if you see some sanding scratches, wait another hour, and then another coat of sealer, and check it again. REMEMBER: paint will NOT hide anything (except white paint), in fact it will highlight ANY surface imperfection ESPECIALLY if you are going to use a metallic or pearlescent color coat.

E) BASECOAT: I prefer modern urethane basecoats which will chemically bond with both the substrate (the epoxy sealer) and the clear topcoat, creating a nearly solid paint layer from bare metal to surface: VERY tough and durable, and polishable YEARS after painting. the only real tips I can give you for this are: 1) use the proper temp range reducer for the painting area (thinner for urethanes) this is CRITICAL if you are applying a metallic or pearl basecoat or the tiny flakes wont settle properly and the surface looks grainy and bumpy, this is called "MOTTLING", less critical for solid colors.
(TIP: Less is actually,...LESS: only shoot enough LIGHT coats of the base to get "HIDING" (you can no longer see whats underneath) once you get hiding STOP SHOOTING. the basecoat dries in minutes so a common mistake is to just start hosing the thing down with multiple coats, DO NOT DO THIS! shoot for hiding, and even color and then stop.

F) CLEARCOATING: (USE A FREAKIN RESPIRATOR, DUH!) this is the most technical step; everything usually goes GREAT until you get to the clearcoat and it falls apart fast, so tips learned the hard way: USE A PRACTICE PANEL FIRST!!
the BIGGEST (and most common) rookie mistake is to try and "learn" how to shoot clearcoat ON the thing you are trying to paint, again DO NOT DO THIS unless you have experience shooting urethane/polyurethane clearcoats ON TUBULAR SURFACES, and thats the rub, just because you know how to lay glass on a car hood, or motorcycle tank, don't think you can just start shooting tubes and not have a learning curve.
so "ALL PAINTERS MAKE MISTAKES, BUT THE PROS MAKE THEM ON TEST/PRACTICE PANELS NOT THE PROJECT PIECE"
I would get a section of steel pipe and set it next to the frame and when you use the epoxy sealer/primer shoot the pipe at the same time, and shoot the base on the pipe as well when you basecoat, NOW you have a perfect practice panel, and if you screw it up (orange peel, or runs, it'll happen) you can just wipe it all off with thinner and start again: the epoxy can be topcoated 20 minutes after shooting, same with the basecoat. once you feel proficient THEN you shoot your beloved PX-10, grand jubilee, colnago whatever.

G)SHOOT A COAT OF CLEAR: thats ONE even pass over each surface: for tubes I shoot lengthwise once on top, once for each side, and the bottom, so four passes (with about a 50% overlap) then move to the adjacent tube. for bicycles I like FOUR COATS, BUT!!! YOU MUST WAIT AT LEAST 15 MINUTES before shooting the next coat: here's a great trick for determining when the previous coat is ready for the next: on the masking (headset, bottom bracket or anything nearby, thats NOT the bike) touch your gloved finger to the clear after shooting and pull it away: directly after shooting it will pull away clean, after 2 minutes you see "strings" when you pull away, and after about 15-20 minutes it will just be tacky, and will no longer "string", now it's ready for the next coat. (this is assuming a 70 degree painting area, colder will take longer, hotter will be faster, don't paint under 60 degrees or over 85 degrees for best results)

now keep in mind that the clearcoat has a hardener, and that hardener starts doing it's thing the moment you mix them both together, how long you can work with it is called the "pot life", so only mix enough for for two coats, and then mix another batch for coats 3 and 4, or your 3rd and 4th coats will go on gloppy and you'll get orange peel of biblical proportions.


you don't paint your bicycle frame to save money, if your trying to save money, have it powdercoated, you paint your frame because it's a very satisfying feeling to ride something you painted, when you stop, and people ask "who painted that"?, you get to say "I did" and then bask in the compliments, or simply ride feeling like you took part in more than just the selection of components and assembly of your steed.

my current bicycle wont be painted till spring, so here's a 62' dominator (almost as cool as a fixie)


peace, love and isocyanates

Reckon, Thanks for the nice post on painting. Lots of good info in there. It also helps people to understand why a quality paint job is expensive and why I would leave it to a professional. Have you done anywork on carbon frames yet? I would imagine that the prep work and actual painting would be somewhat different. Thanks again!

Scott

__________________
"A gentle answer turns away wrath, but a harsh word stirs up anger." Prov. 15-1

I currently work as a plastics fabricator, and have made carbon motorcycle fairings and other carbon fiber parts, and have painted LOTS, and LOTS of CF, and one of THE BIGGEST MYTHS ON THE INTERNET, is that if you paint carbon fiber you will destroy it, or that it takes special techniques, or exotic paints and materials. The companies that produce CF cycling parts would like you to believe this as well, so they have lots of cryptic messages in their information: use "of any non approved waxes or solvents will void any warranty" stuff like that.

NOTHING COULD BE FARTHER FROM THE TRUTH.

all that carbon fiber material is: is epoxy resins and carbon fiber cloth(matting) cured under vacuum tension, and usually at a fairly high temprature (120-190 degrees), basically it's JUST like fiberglass in construction, layering, and composition. in fact if you took exact same size panels made from fiberglass and carbon fiber and compared the difference in the cost to manufacture it would be less than a dollar, yet the CF part will fetch TEN TIMES that amount when sold,.....so again they want you to believe it's some magic space material so you wont mind forking over that kind of money....it's not, and you shouldn't have to,.....but one guy paid that much, so now they want EVERYBODY to pay that much.

I think it's more dificult to make a steel frame, than a CF frame, there are more steps in the steel framed bicycle, and the techniques are more difficult and require a VERY high skill set with years of practice time needed to become proficient.
with the correct CF lugs, just about anyone could glue up a CF frame.

now there ARE some caveats: you CANNOT strip the frame down to the bare material, before painting, and there is no need to, because plastic cant rust, so there is no need to expose the bare material before painting (to uncover any hidden rust or previous bodywork/damage). so no stripping of any kind, no blasting , no chemical strippers (which WILL weaken the CF matrix), and no heat or abrasive stripping techniques, because a) you don't need to, and b) it will screw up the CF material.

ANY bicycle frame made from CF will have a polyurethane clear coat on it, and THATS what your painting over not the CF material in it's epoxy matrix, so basically you just scuff up the clearcoat, and topcoat it just like it was sealed or primed, thats it: FIRST CLEAN THE DANG THING!, if you just start scuffing, you can grind any wax or oils present right down into the surface, and have adhesion problems later on, so clean it first with detergent and HOT water (I like dawn), and then use windex to remove any traces of organics on the surface, THEN you would scuff the frame very well with a scotch scuff pad (water and a scuffing paste make this job a snap) until it's nice and dull all over with no shiny spots anywhere (shiny=peeling paint) and then paint as usual.

easy peasy lemon squeezy

When applying the clearcoat do you lay down enough so that if there are 2 base colors you would not feel a edge between them? Or over decals , how may coats would be enough?

you guys ask really good questions,..glad I've been at this awhile

ok this is a little "trick" we custom painters use to flatten or "bury" the edges from graphics, decals, stripes, yada yada.

presuming you did NOT shoot more basecoats than needed for hiding (so you don't have much of an edge to begin with right?) you basically shoot the recommended four coats of clearcoat as described above and let cure for 24 hours, then using a hard block, and 1000 or maybe 1200 grit, you wetsand that "edge" down till it's almost flat. NOTE!! you MUST BE SUPER CAREFUL not to sand too deeply in one spot or you'll expose the basecoat, and then need to re-shoot at least that tube, but if it was a metallic paint, you'll probably have to re-shoot the entire frame to get the shade even again, SO BE CAREFUL!!.

after you've flattened the edge with the 1000-1200, take a GREY SCOTCH PAD (NOT RED!!!) and scuff up the entire frame all over to rough up the surface to accept more coats of clearcoat, then clean it again with the wax & grease remover, and then the windex, and then shoot another four coats of clear.
Because you sanded about two coats off when you flattened it with the wetsanding, this is about 6 coats total.
CAUTION!! never shoot more than 4 coats without letting it cure, and sanding between, so shoot 4, cure, wetsand, shoot 4 more, etc,...
you can repeat this about 5 times believe it or not for a whopping total of 20 or so coats.
Now this type of ridiculous clearcoating is usually done with layers of different candies and pearls and should be left to the kustom chopper/hot rod guys,....4 to 6 coats of clear is all you'll EVER need for a bicycle frame.

once cured this will be totally flat when you run your hand over it: everybody always goes "oooooooh" over this.
a true sign of a pro custom spray monkey is the totally flat surface even with multiple layers and graphics under the clear.

I think this is a worthwhile step: recommended

In the past I've heard people on this board say "don't sandblast a bike frame, it takes too much material off! Beadblast it instead". However, I recently had a flat plate of aluminum sandblasted for work, and using calipers before and after blasting there was no difference in thickness! Perhaps Reckon you might weigh in on this?

I did cover it a bit:
"B) TAKE IT TO A BLASTER: and have them blast it: note! tell the blaster if the frame will be powdercoated or painted, because they will want to use different blasting media, for each type of coating.
this is usually something like $20-$40"

they almost never use sand anymore, usualy it's some form of natural media like walnut or coco hulls, or glass or plastic beads, in addition some blasters are using dry soda now.(bicarbonate of soda)

like I said, just tell the blaster how you will be coating the frame afterwards, either paint or powdercoat (or chrome plating), as they all get different media, and use different tips and pressures in the blasting process.

you would have to use some serious pressure, and something very hard like carbide or tungsten as media to get a noticible (or as you pointed out "measurable") decrease in material thickness.

the exception is of course CARBON FIBER, you NEVER strip, or blast CF (because you don't need to), you just scuff the clear coat already on the CF, seal, and paint.

Windex? LOL

I know, weird huh?

but try this: smudge a good fingerprint on a shiny painted surface. now wipe that fingerprint down with a good wax and grease remover,..and look at the surface, clean right?
ok NOW use a clean white paper towel and wipe it down with windex (or any ammoniated glass cleaner) and look at the towel,..where did that dark stuff come from if the surface was clean??

THATS why you do a solvent wipe to remove any wax, grease or oils, and THEN use a water based cleaner to remove any traces of sugars or other water soluable organics.

in the old days I'd mix rubbing alcohol and water 50%-50% and add a splash of ammonia and use that in a spray bottle. now I just use that foamy spray window cleaner you get a kragen/shucks/pep boys yada yada.