The Golden Boy 

Hi helloimtimo! I think he answered it in the first line- the user wanted a red bike, paint doesn't stick to Ti, so it was powder coated to make it red- and the polishable high gloss clear shot over.

The intent for PC isn't corrosion resistance- it's adhering a color.

Reading this thread is interesting seeing the way people tiptoed around Dr. Deltron...

jackbombay

I had a Redline BMX bike as a young teen, it had a chrome fork and stays, I stripped the paint off the frame and used "Bluing compound" for shotgun barrels to blue the frame, I then kept a light coat of oil on the frame to prevent rusting, the chrome/blue steel combination was great, IMO.


Yes, I see this thread is OLD.

guy153

I made a frame recently for a friend who wanted a raw finish. I had heard about rust spiders appearing under the clear so I tried blackening it with "Phillips Professional Cold Gun Blue" from Amazon which is selenious acid. I worked that in neat from the bottle with a green scotchbrite until I had a good smooth blackening everywhere. Then after a few hours you rub some oil on. Then after several days I cleaned any surface oil off with acetone and sprayed the whole thing with automotive 2K clear.

I've no data yet on how durable this will turn out to be but it does look badass.

The gun blue ought to provide a protective layer of magnetite (it's basically artificial mill scale).

Deepcherry

I have a nickel plated steel Ritchey frame which had later been clearcoated. The rust still formed beneath the clear.
It is not recommended as clearcoat generally does not key well to steel, and the moisture trapped beneath or within the lacquer will still cause oxidation immediately.

Perhaps the best, but still fairly unreliable way to clear a bare steel frame is undoubtedly powder-coating, preceded by thorough media blasting to remove ALL oxidized metal.

Here’s the Ritchey as it was before stripping the lacquer off:

Salamandrine 

This comes up periodically. I've seen many people try to clear a bare steel frame. They always rust eventually, underneath the clear. Basically, it doesn't work.

Bluing it first would probably work, as noted a couple posts back by jackbombay . Or plate it first then clear. If you do that I'd use lacquer or something else that can be periodically stripped and reapplied easily.

Drillium Dude 

August 2018:



A little patina begins to show in December 2019:



May 2020:



June 2020:



I think the key is to be careful to maintain the finish by wiping down after every ride, particularly if you sweat a lot (like me). Not quite perfect, but definitely no "dog's ass" IMHO

(I figured this zombie thread could do with some pictures)

DD

Ferrouscious 

I was hoping that bike would show up!

herr_hest

Fairlight cycles made their faran 2.0 in raw steel until they just recently started selling it with paint on it. You can see it on the pdf on their site, i can't link it since i'm a new menber.

I seen some dudes do it back when fixies was a thing, the frames usually ended up with filiform corrosion. That is "rust spiders" beneath the top coat.

Deepcherry

After stripping the clear coat, a light brushing and regular waxing, it holds up well enough in dry weather.

P!N20

These are recent pics of a friend's Colnago that was clear coated about five years ago:









Needless to say I was pretty amazed how little corrosion there is. I believe it's a clear powder coat, FWIW.

SJX426 

I have two frames that are still bare steel. I keep them from rusting with a light coat of WD-40. No recent pictures.
2013
1983 Trek 610 60 cm (24&quot on Flickr
Now has primer on it.

2014
1994 Burley Duet in the raw on Flickr

2015
P1020903 on Flickr

J.Higgins 

I've done this a few times. It works. To my eye its not particularly attractive, but it works. What I may try next is to texturize the lugs with a 1/8" ball mill chucked into a Dremel. This will give a visual contrast between the lugs and the main tubes. Then 2k over everything, maybe a couple pinstripes and gtg.

branko_76 

What is it about clear-coating that promotes rust? If you spray a bike with clear polyeurethane, isn't it the same as spraying it with an opaque poly?

Maybe it's the preparation of the frame for a clear coat that increases the likelihood of rust. Polishing a frame to a mirror finish before applying any paint is not a good idea, the steel needs to have a "tooth" for the paint to adhere to. If a finish "floats" on top of an ultra-smooth surface, I imagine moisture can migrate more easily.

guy153

I think the primer does some "etching". Not sure exactly what that is but it's reacting with the metal somehow to stop it rusting. The problem is not the clear topcoat so much as the non-existence of a clear primer.

RggBee

Primer itself needs something to stick to. So polishing metal shiny is not a good idea. But you can polish the coat afterwards. I've never tried to paint bikes, buy I do scale modelling as a hobby, and I use a lot of metal parts. Sometimes it's a great idea to add some roughness to the surface before covering it with a primes. Especially if it's a moving part which means more stress to the coat.

Splendidtutiona

My understanding of good primers designed for steel is that they contain a lot of Zinc. Zinc is what is known as a "sacrificial anode" which means that is reacts with oxygen before the iron in the steel can. It "sequesters" the free oxygen before it can react with the iron (which, steel is mostly iron) and cause rust. This is why (along with paint adhesion) primer or a zinc coating is important.

I would be curious is you could somehow zinc coat the frame from the inside (either shoot a "cold zinc" product through all the tubes, or dip and the frame in a zinc bath remove the zinc from the outside, though not sure if this is worth it) and then powder coat clear the outside. The internal zinc being enough anode to prevent long-term rusting while the clear prevents surface rust.

I bet it's not that water is getting through the clear, but maybe some air is, and then the oxygen gets stuck, and causes the rust, would be my guess. Or there is some tiny pore in the metal, and it is getting in that way, hence the zinc coating on the inside idea. Maybe?

Also, this thread wants brains...BRAINS!!! (this forum needs a zombie smiley)

RggBee

Zinc. Yeah covering steel with zink is a very good method to prevent corrosion. However I believe that electrogalvanizing is the best way in terms of coat lifetime. Though it's impossible or really difficult for a bike frame. So yes zinc to prevent corrosion then paint to protect zinc.

JaccoW

🧟

Copy paste from Emojipedia + Or just use:

Charliekeet

Have just been thinking about this as I’m going to strip my old Cannondale to bare aluminum (the original red paint has had it), but was debating what to do with the steel fork. The fork already has some rust through chips in the paint and I may try stripping, using a rust-stopping product, sanding (but not polishing) and clear priming and seeing how that goes.

Other option is prime & paint the fork, but idk if I want a silver-aluminum frame and say, a red fork.

Johno59

If you keep it dry there is not much to worry about as the rust is very fine and looks badass. Clearcoat (a semi-permeable membrane) does not seal the underlining metal form water molecules - paint does that. There is a osmosis process going on and water is one of the molecules that gets thru the clearcoat. Like I said keep it dry and the aging effect looks good. Perhaps a coat of wax would help out

I id the clearcoat on this 1903 Sunbeam. I waxed it but don't get it wet.
.

martl

I've taken some pics at a short lived hand-built bike expo here in Germany a few years ago (09?) of such bikes. One was raw steel with leaf gold application, one was the sort that is supposed to rust over time. Some variations of the theme I guess.

herr_hest

i got some pics of my old cyclepro optima which was stripped, will post soon when i have my 10 posts....

P!N20

I'm not sure it promotes rust, rather that clear coats are porous so the steel is in contact with moisture - atmospheric or otherwise.