Clear Powder Coat Over Raw Steel

[veryredbike]

I remember some posts a while back about rust forming under clear powder coat, but was curious about what it looked like. Anyone have some pictures lying around?

Basically, I'm making a lugged frame that I think would look nice clear coated and built up with lots of shiny silver. I don't mind if it starts to look tarnished (might actually be cool), but would like to know what I'm getting myself into.

Thanks!
Jim Burakoff

[Rody]

Here ya go...

This an about any other fabrication/finish related question buried in years worth of posts, feel free to wander around.

Groovy Cycleworks 330-988-0537: Raw finishes and a seasons worth of racing...

rody

[veryredbike]

Awesome! Thanks!

[EricKeller]

I am usually a hater when it comes to raw finishes, but I liked the idea of gun blue under powder. Spent some time researching it, and it looks like work so I gave up on the idea.
Machinist at work suggested using the old Pennsylvania trick of peeing on it. Apparently the old timers do that to firearms that get scratched.

[BShow]

Here ya go...

This an about any other fabrication/finish related question buried in years worth of posts, feel free to wander around.

Groovy Cycleworks 330-988-0537: Raw finishes and a seasons worth of racing...

rody

Rody,
I really enjoy reading your posts like this, both here and on your blog. It's a great resource to have. It seems that you've explored so many angles with all types of metal frames and it's awesome that you openly share so much of it.

I'm curious... Is there a clear Cerakote that would work for a raw look on a steel frame?

[Will Neide]

I feel pretty strongly against powdering clear over raw, whether stainless or steel. I cleared over some stainless on my own CX bike to see what would happen. Know what happened? It's a CX bike. It got scratched, crashed, beat up. Covered in mud, snow, sweat, crap, etc. All those scratches formed some mild rust, regardless of the fact that it's stainless. For steel, I wouldn't do it all, unless for demonstration purposes. I don't do it for stainless either, and I only did it on mine "just because." It was fun to watch the process unfold under the clear coat. I figure if you want to go raw on your own peronsal bike, then just go raw. Rub that thing down with some oil/wax/whatever and enjoy the work that goes into maintaining it.

[JimFrain]

Brompton describes their Lacquer finish here:

https://brompton.zendesk.com/entries...acquer-finish-

In the fourth paragraph they describe a phospher coating before the clear goes on. Which it seems is actually Clear Powder Coat. I would look around at some Brompton forums to see how their holding up.


-J

[Gattonero]

Brompton describes their Lacquer finish here:

https://brompton.zendesk.com/entries...acquer-finish-

In the fourth paragraph they describe a phospher coating before the clear goes on. Which it seems is actually Clear Powder Coat. I would look around at some Brompton forums to see how their holding up.


-J

Brompton has actually changed the way they do powder-coating for the "Raw" frames.
The very first ones, were actually transparent and you could see everything trough, in fact the blue hue from the HAZ was pretty evident. But wasn't very resistant, so it was replaced with a sort of transparent/opaque primer and a clear coat after. It is still a "see trough" but with a degree of opacity.
It works well, and stays there for years. Keep in mind that Brompton are very often thrashed to the ground by their users: those bikes works so well, that is not a rare sight of one having had the tyres pumped as the only maintenance done in the last 12 months...

[edoz]

Rody,

I'm curious... Is there a clear Cerakote that would work for a raw look on a steel frame?

Roger at Shawnee Trail Performance Coatings claims to have the prep figured out for clear Cerakote over raw steel. I have not taken him up on the option, though.

[Rody]

There is a clear Cerakote, however, it is of different composition than the ceramic normally used. I will typically use the ceramic that is heat cured or baked, the clear is an air cure product.

NIC is adament that if you desire proper adhesion, the base must be blasted and chemically cleaned before application.

I have played with numerous prep processes to use the clear over raw bases and one of two things occur; you lose the natural heat radiation and coloring of the raw material or the ceramic eventually begins to delaminate.

End result for me...I will not use the product as a clear over bare metal to achieve an aesthetic...just not worth the compromise of durability.

[Nierman]

The guy that made my frame (I've mentioned before, but I won't mess with names here since he's currently not making frames anymore) did clear over an oxidized patina. Not sure of his process, but I've done some cor-ten sculpture that I spritzed with muratic acid to speed up the ox process in order to meet a presentation deadline and this looks very similar. Despite my fondness for it, a proper strip and powder is on order during next winter down time. I trust Rody & Garro.