Frame Painting

[Ssalmon]

I have a frame and fork that I am thinking about painting, does anybody have any experience with painting their own bike? I have an air compressor but I am not sure where to start, any pointers?

[Gsinill]

Assuming you are not talking rattle can job:

I am in the process of doing this right now on 2 frames/forks for the first time as well.

Did some spray painting on cars years ago, so I know the basics but most of the info below is based on my own research and what I haven't done myself (didn't get beyond base coat yet) is purely me passing on what I found out via Google etc...
I hope others chime in in case I have it wrong or for additional input.


Strip paint: best find a good blaster in your area; should cost about $30 but definitely worth compared to the mess/effort using paint stripper; some folks argue that sand blasting is too aggressive removing too much material, but every RS frame is sandblasted by JB before painting (at least in the past)
Assuming there are no dents or major scratches: apply 2K epoxy primer; I bought DuPont at a local paint supply and all I can say this stuff is pure magic, no comparison to what has been around 20 years ago. Runs (if any, like I said that stuff is easy to apply) or slightly rough surface are not that big of an issue since it is really easy to sand. Don't think that is DuPont specific but simply general improvement when it comes to paint products
Wet sand (320ish grid) until smooth - not rocket science, just needs to be done thoroughly and if you hit metal you'll need to apply another layer of primer
I was thinking about using DuPont 2K for the base coat as well but after some research I found that a lot of the frame painters seem to use waterborne paint, same stuff as for airbrushing projects. I settled on Auto-Air Colors and just did some testing last weekend: used an airbrushing gun from HarborFreight and it worked great. Big advantage of that paint: if you screw up, use some mineral spirits or alcohol on a rag and wipe it off. Really easy..
In addition it's much cheaper since you can buy it in really small amounts (4oz.). Requires some trial and error on hitting the right tone if you want to blend.
Apply decals (I am actually toying with cutting my own vinyl stencils and paint vs. adhesive decals on one of the frames).
Clear coat: Best is 2K urethane which seems to be the only really durable option. Apparently the most tricky part and that stuff is nasty and hazardous nit just breezing it in but also on any exposed soft tissue since it contains isocyanides.
Apply first layers over the decals, wet sand so the decal edges are smooth and apply additional layers of clear.
Polish and wax


I didn't get to the clear coat yet, but so far so good - lots of effort but even more fun. The only part that sucks is cleaning up after painting (guns etc.)

I used a HF touch up gun for the primer which worked great and I am planning to get a high-quality spray gun for the clear.
So far I did all of it outside and no problems so far but again, clear coat will show how this goes.

One more thing, you said you have a compressor but at least for primer and clear you will need something decent with appropriate CFM.

I am happy to share more details, PM me with your email and I'll send you some additional info.

Enjoy,
GS

[Gsinill]

One more thing:

You have to be careful with the pantographed areas like seat stays and make sure you don't lay down the primer too thick since it will level them.
On the other hand, the primer I used actually seems to shrink a little when it cures.
In other words, even if the pantos look blurred when the primer is still wet, they might actually come out crisp once it dried...

BTW, I bought a beater frame locally on eBay for $25 that I used for test runs.

[nicrump]

I didn't get to the clear coat yet, but so far so good - lots of effort but even more fun. The only part that sucks is cleaning up after painting (guns etc.)

Enjoy,
GS

just know that most base coats have an open time less than 24hr. this means get that 1st coat of clear on there usually within a few hours if you want a durable finish.

[saf-t]

Clear coat: Best is 2K urethane which seems to be the only really durable option. Apparently the most tricky part and that stuff is nasty and hazardous nit just breezing it in but also on any exposed soft tissue since it contains isocyanides.

Isocyanates are potent respiratory sensitizers- one of the better known cases of work-related asthma. Dermal contact alone can cause respiratory as well as skin sensitization, so if it were me, I'd leave that part to someone who does it all the time rather than doing it myself........

[numbskull]

Don't you have to heat set these paints? How are you doing that?

[Admiral Ackbar]

i painted probably half a dozen with just aerosol cans, prep well, hit em with enough clear and its plenty durable and looks just a good as factory paint.

[mike p]

I rattle canned an old frame that I really didn't care that much about. I really took my time and did lots of prep work and it really came out nice! I ended up using that frame a lot because I was proud of how it came out. A lot of my buddy's asked about it and some even asked me if I could paint bikes there's. I say go for it, it's a great experience.

Mike

[Gsinill]

just know that most base coats have an open time less than 24hr. this means get that 1st coat of clear on there usually within a few hours if you want a durable finish.

True for the 2K base coats but not for Auto-Air Colors; here's what's in their guide:

"There are no time windows when painting with Auto-Air Colors and Wicked Colors.
Additional coats of paint and the top-coat clear may be applied at any time after the underlying coat has air dried.
Scuffing is not required. Colors or top-coat may be applied direct to paint any time after it has air dried."

This is another huge advantage of the water-based paint when doing this on the side.
I wouldn't want to rush any of the steps (laying down the base, applying the decals, potentially masking, 2nd color etc.) in the process.

You brought up a good point though: both DuPont and Auto-Air Colors have really good technical guides that describe everything you need to know, from air pressure to tip size, drying times, temperature impact etc.
For the DuPont stuff, the guy at the paint store printed them for me but they can also be downloaded from the internet, same for AAC.

[Gsinill]

Don't you have to heat set these paints? How are you doing that?

From the Auto-Air Colors tech guide:

5. Use air movement to assist curing, not heat. Wind from a fan works excellent to decrease drying times, especially when paint is applied lightly without excessive material. Avoid force drying with heat as this may create a latex-like film which easily peels up.
6. For best drying times, set air blowers and fans to 200 feet per minute (FPM).
7. Auto Air Colors and Wicked Colors air dry to a cured film suitable for direct taping and top-coating with a catalyzed, ure-thane clear. Use of heat as a final cure after paint has thoroughly air dried is only essential when painting textiles or other substrates which will be washed.

[sand fungus]

I also experimented with painting a while back and ended up with water droplets in the paint which caused a fish eye effect may (I was not using water based paint) so if you are in a area of high humidity think about adding a air dryer or frequently drain the air tank.

Other than that I was very happy with the result and durability of the finish.

Good luck and have fun.

[druptight]

I've built 2 frames that I then painted myself. Did the first one with rattle can paint from the local auto store (engine enamel), then used high quality 2k urethane clear in a can (sold by Eastwood). This proved to be a huge pain, if you follow the directions on the base coat rattle cans they need FOREVER to dry, then I didn't get good adhesion between base coats and the primer, so some stickers that had to be put on temporarily for charity rides proceeded to just rip the color off the bike right down to the primer.

So for #2, I went with high quality House of Kolor urethane paints pre mixed and reduced and put into spray cans by coastairbrush. Spent about $100 on paint and 2 years later it's holding up very well. Then cleared it with the same 2k clear noted above. I think you can get close to a compressor level job with these high quality spray cans if you have the right environment and take your time. I did all my spraying in a makeshift paint room that was very dusty and dirty, and didn't spend any time wet sanding to fix any issues that arose - and it still looks pretty good.

It's extremely time consuming, requires LOTS of patience, and FOR ME the painting is honestly harder and infinitely more frustrating than the frame building. #1 is due for a repaint and I'm not really contemplating doing it myself. That being said, the finished product is very rewarding, I've just not found it to be nearly as durable/beautiful as the professionally done jobs. But with the proper prep, TLC, and precautions I think it could be.

[ultraman6970]

THe problem druptight got is pretty much typical, the problem is that all the rattle can lacquer that is sold in the stores takes like a week or 2 to dry and like 6 months to cure, is more than clear that wont work in a bicycle but will work in a plastic chair and in a piece off wood. Those paints dry by air and temperature. you can't use them in a bike period. the other problem is that are not porous paints, is like a plastic so depending of the clear you put over it you risk bubbles because the lacquer will fight its way up (gasses), just sucks.

With Polyurethane paints basically react chemically and start drying right away, will take a bit to cure (days or weeks) but at least you can be ready to use the bike next day if all the conditions are right.

Pretty much rattle can laquer like rustoleum or any other crap you find in a store like advance autoparts is a NO NO, and dont even dare to paint over or under with polyurethane.

Water base paints are ok IMO, tamiya has a lot of colors too and those are water base, even you can thin them with rubbing alcohol, then apply 2k urethane clear and ready to go.

I think druptight figure it out why good repaint jobs are so expensive, too much work for something as simple as a bicycle.

[abalone]

What about the paint curing/hardening process after the painting to make the paint more durable? Don't the pro painters oven bake the frames after painting? I'm not sure how an amateur DIYer painting his own frame can do that.

[Gsinill]

What about the paint curing/hardening process after the painting to make the paint more durable? Don't the pro painters oven bake the frames after painting? I'm not sure how an amateur DIYer painting his own frame can do that.

Don't know whether all the painter heat cure.
The guide for the DuPont clear does not say that it is required.
It actually states 2 different sets of times for Air Dry and Force Dry, including the time "To Deliver".

I actually plan on putting the finished frame up in the attic of my garage for a week before I build it up.
Assuming there will be a few more days above 70, it gets probably around 120 up there.

[nicrump]

force dry is not needed with 2k PUs. in hotter summer months here i can usually sand and buff out nibs in about 36 hours and i typically let a frame hang the rafters for 2 weeks before building it or up packing and shipping so it will be a bit tougher.

in my experience force drying(at least over 120f) is a risk of die back and blushing or excessive shrinkage. ymmv

[abalone]

Don't know whether all the painter heat cure.
The guide for the DuPont clear does not say that it is required.
It actually states 2 different sets of times for Air Dry and Force Dry, including the time "To Deliver".

I actually plan on putting the finished frame up in the attic of my garage for a week before I build it up.
Assuming there will be a few more days above 70, it gets probably around 120 up there.


Don't the pro painters cure the painted frames in large heated oven-like rooms with temps reaching over 400 deg Fahrenheit?

[Gsinill]

Don't the pro painters cure the painted frames in large heated oven-like rooms with temps reaching over 400 deg Fahrenheit?

Well again dunno, but I am not sure I would like to have my car "baked" at 400F in case of a repair involving a paint job.

Same clear coat body shops are using...

[nicrump]

Don't the pro painters cure the painted frames in large heated oven-like rooms with temps reaching over 400 deg Fahrenheit?

that would be powder coat curing. which is an entirely different process than wet painting. not even similar chemistry involved.

[Ssalmon]

This is all great advice! Is there a required temperature for painting? I'm thinking about painting it during the winter and letting the frame cure and dry in my basement over the winter.

[Gsinill]

This is all great advice! Is there a required temperature for painting? I'm thinking about painting it during the winter and letting the frame cure and dry in my basement over the winter.

Between 70 - 80F seems to be ideal.
2K apparently does not dry/cure under 50.