Framebuilders - Sanblasted Frame Powder Coated Clear
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Sorry if this is the wrong forum. It seemed to make the most sense to post it here.
I'm going to have a frame stripped and then have the raw steel clear powder coated. The powder coater will sand blast and then powder coat the frame. I'm wondering if the sand blaster will remove the sheen of the raw steel and leave it looking matte in quality.
I want to achieve this look if possible. I realize that this frame was never painted.
So, should I use a chemical stripper or go ahead with the sand blaster? Thanks for any insight!
04-07-09, 09:10 PM
the sandblaster will leave the tubing with a matte finish. Also, make sure your snadblaster is very careful with his work, because the tubing is very thin and the pressure used to blast can be very high.
04-08-09, 12:58 AM
That frame looks like a wet paint. I say that because the slight oxidization of the tubing underneath would not have worked with a powder coat.
Many frames I build my powder coater does a clear coat over bare metal. They come out nice and glossy. But I will admit, I am not sure if my powder coater does something to smooth the steel after the blast and before he coats it... but I don't think he does. Maybe I should as him!
04-08-09, 02:20 AM
I never did figure out why people find that Rivendell bike attractive, or why Riv wouldn't have more pride than to allow that bike to be seen by the public.
General consensus is that it can be done. Get the PC done quickly after sandblasting because it will rust. It will not look like the rivendell bike. You will probably find defects that you didn't notice before.
Thanks everyone for the replys. This bike is going to be my around town ride and I'm going for a rough, yet classy look. Any defects in the steel are fine by me.
So, do you think that I would be better off using a chemical stripper or is the sandblasting process necessary before the frame is powder coated?
04-08-09, 08:18 AM
chemical stripping is probably better, but there is usually some paint left on that has to be mechanically removed. If this isn't a super light bike, my inclination would be to let the builder sandblast.
04-08-09, 12:35 PM
+1 on sandblast. If you don't sandblast, any little unclean spot that you don't even see will come up in the powder coat. A blasted frame with clear is down right beautiful (assuming good metal work).
I guess I'll be going with the sand blast. Sounds like the safest method to avoid oxidation. I appreciate everyone's response.
Your frame will not look like the Riv Bombadil frame you showed. I had asked them about it, and they told me that to get that look it has to be freshly welded then clearcoated. Once it's painted, you can't go back to how it looked after it was welded, no matter what paint removal method used. True or not, I don't know, but I think it's true because sandblasting surely removes all the little details you see on a freshly welded frame. That's why they're painted, most people don't want that look.
It's likely too late for the OP though. I guess he'll find out yeas or no for sure.
Thanks for the reply. It's not too late. I'll most likely use a chemical stripper or sand blaster and then polish the steel to give it a nice sheen. Thanks.
You're welcome. I think it however you do strip it it will certainly look unique. I've been wondering what to do to find a unique finish myself. I ran across a forum where this person was talking about rubbing a bare frame with varios oils. It's a very old method used to prevent rust from steel. Here's the pasted forum post about "alternative bike finishes":
"Over one hundred years ago some European gun makers offered a finish called slow rust browning.
I have tried to find a description of the process on the internet, but the links lead to chemical processes.
Slow rust browning requires a cool, humid room, and vigorously wiping every bit of the steel's surface with a clean, damp, lightly-oiled cloth twice a day, without fail.
One day without wiping and the steel might rust and pit.
The steel will gradually darken, perhaps first going through a straw-colored phase.
It may stop at brown or go on to a dark grey.
Once the color-change stops, the steel will have substantial resistance to rusting and pitting.
One often sees this finish unintentionally created on steel farm tools that get handled daily in cool, humid environments.
The steel turns dark grey or brown, but it doesn't rust where frequently touched by human hands.
This process takes about two weeks of patience and diligence, but it works and, with an occasional rub down with a lightly-oiled cloth, will protect the steel from everything except neglect.
For an environmentally friendly and aesthetically-pleasing oil, consider Camellia oil, made from the plant of the same name.
Camellia oil is a favorite traditional tool treatment among both samurai and woodworkers, used both for preventing corrosion and for easing chisels and knives through their work. Light and odorless, the oil is non-staining and doesn't affect glue-up. Use a light wipe on all your steel tools to keep them clean & shiny.
For that matter, a person could leave a bike frame in its raw metal state and wipe it down once or twice a week with Camellia oil, and just see what happens.
The steel shouldn't rust if regularly and carefully wiped down with Camellia oil."
Now, he doesn't say he did it..... but I'm pretty sure it would work. What exact color it turns depends on the alchemy of metal and oil. If it stopped at the staw-colored phase that would be cool.
I'm looking for alternatives because the same ol' ppg or powdercoat paint is losing it's appeal. Tired of the chips and touch ups and does the color match. It sure would be easier just to oil it with Carmelia Oil.
Now that I think of it, I have an "84 Stumpjumper that has many areas of lost paint. Did I ever fret over it? No. Over the many years, I applied various rust-prevention liquids, and often times just oil. It never rusts. Damm good steel back then. The steel that I applied the rust stuff to has turned a dark bronze. Interesting. I never thought of using something like that but it's got my creative interest. If I could find a rust prohibiter that stayed light colored when applied, that would be cool.
I don't know if I have the patience to rub an entire frame with oil once or twice a week. To cover the areas around the crank and brakes would be a pain in the ass. I might start stripping my frame today. I'll post it when I'm finished, but who knows when that might be. I have too many interests.
Id say save the brown rust layer for hand tools in the garage. If you want the frame to last, protect it somehow. Clear powdercoat (as in your pic) is great. Even a couple coats of clear poly spray for a quick and easy coating. This isn't a hammer, its thinwall tubing you bet your life on every time you ride.
04-16-09, 09:49 PM
FWIW, you can get close to the "pre-paint" finish by using a chemical stripper to remove the paint and then an acid-based toilet cleaner like Sno-Bowl to brighten the frame back up. This will remove the multi-colored hue of the heat-affected brazing zones, though. If you REALLY wanted to you could flux up the joints and use a Home Depot propane torch to heat them to a level a bit below that required to melt the filler material, thus "restoring" the colors of the heat-affected zones, but if you reach that point you may consider checking yourself into some kind of clinic. You also have to wipe the frame down with mineral spirits or something similar because the bare metal left behind by the acid will flash rust within minutes.
As for the rust browning, I collect antique rifles and can authoritatively state that such finishes do not stand up to the elements at all well. They require constant care to avoid deterioration.
04-20-09, 11:52 AM
There are lots of different media to put in a blast cabinet.You can use walnut shells to brighten the steel back up or there is engineered plastic media you can polish with.Not everything that comes out of blast cabinets has a matte finnish.
04-21-09, 05:58 AM
As a powder coater for many years I would suggest that you have your paind incinerated in a temerature controlled burnoff oven this oven heats and cools over a long time frame to avoid tempering. Once the frame is burned use isopropyl alcohol and coton rags or steel wool for a more brushed look, to clean the ash. Then a single coat of Cardinal CL - 01 will acheive a nice finish. There will be some bluish coloring like tail pipes but it looks good. - Wes
04-25-09, 10:59 PM
Rivendell uses a Powerder Coater called Etech Collision there in Walnut Creek. I talked to them about their process, and they told me they have a special process where they dip the bike frame in a product that removes any rust, oils and other contaminants from the frame. They can also just blast the frame, but the frame in the OP was clearly not blasted. I really like the look but obviously, some others do not.
I recently built a frame for my wife, and I soaked it in Oxallic acid for about 24 hours to remove all the surface rust. Then I simply painted it with aerosol clear coat. It came out looking like the raw clear powder coat frames, but the aerosol clear coat will not last long. Eventually, we will get the frame powder coated, but I wanted her to ride it a while to make sure she liked it before we spent the money.
If you want a frame to look like the Rivendell frames, I suggest contacting Etech Collision in Walnut Creek. They clearly have experience doing it. None of the coaters around here that I've contacted were willing to do the job without media blasting.
Thanks for the information. I'm not going to have the money to ship the bike both ways AND pay for the work. I'll ask my local guy if he's able to use that method.
04-26-09, 07:48 AM
Here is a frame that I didn't feel like paying for a full paint job so I just got the painter to put some bands on it and then clear-coated it with a light flake. The tubes didn't retain the initial shine but it has held up fairly well. I ride it everyday.
Will you elaborate on the method you used? I'm not exactly sure what bands are or what a light flake is? It looks awesome. Thanks for posting.
04-26-09, 08:19 AM
I just sanded the raw frame with like a 200 grit sandpaper to get it good and shiney. I wanted to see if it would maintain the shine under a clearcoat after some ageing(did I spell that right?). Anyway, he just painted two black panels on the down and top tube and then took clear coat and added some kinda small flake and clear-coated the whole frame, I am not a painter so I don't know much. The tubes did change a couple shades from the original shine but it still looks okay. When its cloudy it just looks like a raw steel frame and when its sunny the flakes show up in multiple colors. I was happy with it. He only charged me $75 but I did all the prep.
I'm glad you posted this thread! I, too, am thinking of baring the metal on my old Raleigh. The paint is chipped and battered as it's my newest project fixed gear. I'm going to put it all together tonight and see how she rides then decide what exactly i'm going to do with the paint. But I am seriously thinking of placing it in a garbage bag and applying stripper gel to it this weekend! Let us know how your project is turning out.
I'm actually just now getting ready to have the frame clear coated. I've been really busy and will get around to it shortly....after I can justify dropping 100.00 on it.
07-23-09, 06:18 PM
how'd she come out, i am also thinking of doing this!
Glad you asked as I'm not going to be doing it anymore. I moved to the ocean and it simply won't last long enough to make it worth 100.00....at least to me. I'll be doing a regular powder coat. Sorry guys!
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