JonnyHK 

I'm thinking of repainting a frame, but just going with a clear coat.

I would be nice to see a lot of bare brushed steel. Industrial, yet practical?

Any pitfalls? Any tricks to get a good result?

I'm thinking of stripping the frame myself and then giving it to the local car paint shop to use automotive clear coat on it.

Thulsadoom

Make sure you use a clear coat that is formulated for that sort of application. Not just any clear will work. If you get it on there good, it will look very cool!

SingleSpeeDemon

Back in the 1980's I remember reading an article about this approach and at that time the concensus was that clear finishes of the day were somewhat permeable to air and moisture (albeit slightly) and would not provide protection against oxidation.

I am not familiar with the chemistry of today's coatings, but there are obviously products on the market that will work for you; Don Walker had a bare steel track bike and InterBike and even Masi has a production fixed gear that comes in a "raw" finish.

BengeBoy 

The Rivendell site was featuring a new bike model (the Bombadil) that had this finish on it as an option. I think it's still live on their site.

Nessism

Clear powdercoat might hold up for a while, but rust will form under the clear with most clear paints because they are not formulated to seal over bare metal.

JonnyHK 

Thanks guys.

I'll put some research into the automotive clear coats and see what works.

If I have to pick a colour to get a proper seal underneath, then so be it!

NoReg

It's not as though paint is impermeable, it's just better, and probably more UV resistant if you are planing on leaving it chained up in direct sunlight.

A friend of mine just bought a fillet brazed Brompton in clear coat. So some manufacturers are risking it.

Nessism

I’m pretty sure you won’t find an automotive clear paint that sanctions its use over bare steel; clear is applied over built up base coats, typically including a primer layer over the base steel and then a color coat of some sort. You can give it a try but don’t expect stellar durability.

I definitely think you will have best results with clear power coat.

geronimemo

you could use a sealer then apply the clear coat over it

geronimemo

p.s. tell them it has to be a clear sealer some of the sealers have actual color in them

Nessism

A sealer is not a primer. You need a primer for the bare metal or corrosion will come through.

JonnyHK 

The need for primer gave me an idea.

How does this sound...

Get the guys to paint the frame with a primer in grey. Then put some graphics/text on top (using computer cut stencils) in a slightly darker shade of grey. The effect will be the same as many modern military aircraft that have the low-vis grey paint scheme with the national markings also in grey. Then a couple of clear coats on top.

The whole military/battleship theme continues if I call the bike "dread-0" (old naval joke).

Local body shop uses DuPont products and has a steady stream of mercs, bmws and a couple of ferraris for repair - presume they know what they are doing.

duane041

Very true. I sell PPG products, and the only thing close is DAU75 clearcoat, a straight acrylic urethane clear. But PPG only recommends its use over aluminum, not steel. It would probably work for awhile, but you will get corrosion eventually.

JonnyHK 

I've got a Cannondale CAAD9 R5 which is bare al with a clear coat (partly where I got the idea of doing this steel frame in clear only from). Any idea what Cannondale use?

kingennio

CAAD9 is alu so rust is less of an issue

a7knight

I have a steel bicycle that I have wanted to do the same thing with. While I understand the bike won't be as durable as one with a solid coat of paint, I'd still like to try. After polishing up the metal, do you think a clear primer, followed by a clear coat or two, followed by a clear sealer would be sufficient in terms of both aesthetics and protection?

SingleSpeeDemon

how about clear powdercoat as an option?

a7knight

A clear powder coat would definitely be a better option - a lot more professional. For me though, as a diy project, powder coating is a bit over both my budget and skill level. My game plan consists more of purchasing the cheapest supplies I can find at any hardware store. If I conclude that this method is an effective one and start this project, coming up with a professional result will obviously take a lot of elbow grease and luck.

NoReg

One quite interesting material is CA/crazy glue, specifically the Hot Stuff thin. It's applied with a hard balled up cotton rag like French polish, and makes a tough clear finish. Never used it on a shape that complex or extensive, but I would give a little section a try.

modestmouse

https://www.por15.com/prodinfo.asp?grp=GPC&dept=6

POR 15 makes fantastic product. It's insanely hard stuff, I think this would do the trick. They also have another clear system that is a single part clear that's supposed to be great as well. I'm going to be painting my Bob Jackson project with it.