# Best media for blasting a frame to repaint?



## wv_bob (Sep 12, 2005)

I'm thinking about refinishing my Phoenix to put it back in use. (Paint failed, no way to save it). I have a blast cabinet and am not afraid to use it, but wanted to check first to see if anyone had experiences blasting frames and the best blast media to use. I don't want to start in with overly aggressive media or too much air pressure and screw things up. So I wondered if any of you could recommend a good media to use that is safe for bike frames? The answer may be "anything, doesn't matter" but I'd rather ask now than be sad later. FWIW, there's no rust to be removed, just paint and decals. FWIW, the frame will be repurposed as a singlespeed, probably with an ENO hub, maybe with an Trickstuff - Exzentriker. Definitely don't want to use a Singleator though. Leaning toward the ENO just because I can run my UN-71 BB instead of a modern looking external BB setup.


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## hollister (Sep 16, 2005)

Baking soda


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## wv_bob (Sep 12, 2005)

AFAIK soda takes a special blast setup up - a pressure pot. My blast cab is a suction unit so it's a no-go. I'm happy to be wrong about that though.


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## paetersen (Jul 28, 2007)

Baking soda needs either an agitator or a dryer, I use it with a gravity feed system and it works ok.


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## wv_bob (Sep 12, 2005)

OK, I don't have those either, so soda is out

Maybe I just need to start in with some glass bead and see what happens?


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## girlonbike (Apr 24, 2008)

rody commented in this thread:

http://forums.mtbr.com/frame-building/media-blast-before-powdercoat-432710.html


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## wv_bob (Sep 12, 2005)

Great thanks, al oxide seems to be the stuff according to that

Google says the PC company used in Rody's writeup is still in business too. May give them a call tomorrow and see if they do one-frame lots.


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## wv_bob (Sep 12, 2005)

I went media shopping yesterday and the best I could do was glass bead. They only had alu ox in small expensive quantities. I'm probably going to hold off on any blasting until I have a paint or coat plan so I can keep going once I get started.

Tractor Supply was my source for abrasive material so while I was there I checked out tractor and implement paint. After reading up on it, this may be the way to go. Less than half the cost of automotive materials.

Tractor, Truck, & Implement - Majic Paints

I'll probably just shoot a single coat of red or white, but I was bored so here is JD Green, Kubota Orange, and Gloss White:


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## colker1 (Jan 6, 2004)

Paint it Black>


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## wv_bob (Sep 12, 2005)

^ I might do that too.

I found that glass beads aren't the ideal media. It took about an hour to get about 1/3 of if cleaned up. OTOH it's not like I'm doing this to save money. I'm doing it because I don't like letting things I own get too far out of my sight. Have the same problem with bodymen as evidenced by my poor old disassembled road runner.


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## wv_bob (Sep 12, 2005)

I ran into a minor problem so I had to come up with a workaround. The frame fits in the cabinet, but just barely. With the door closed I can't get to the ends of the frame (headtube, dropouts), and because of the slope of the window and tight fit, I can't get to the extreme ends of the middle of it either (end of seat tube and bottom of bottom bracket).


So to get around that problem, I cut a piece of cardboard to fill inside the door, so when finished it traps the media inside the cabinet and won't leak badly. Then I taped a trash bag into that cardboard piece, so once the cardboard is inside the cabinet, the blast area is sealed with the door open. 



After taping the cardboard/bag assembly into the cabinet, I found the very bottom of the garbage bag and cut it open so now it's a tube, and I can use a spring clip to close the end.



The end result is I can put work into the cabinet through the bottom of the garbage bag, and the bag area gives me the extra room to move the frame around more.

With this setup I've finished the headtube the top of the seat tube and half the bottom bracket. I'll be able to finish the rest once I turn the frame around (on break now, it's hot out there).


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## wv_bob (Sep 12, 2005)

After finishing up the blasting, I found that if there are vent holes places that will be covered with tape for blasting - like the ones at the hooded drops on my Phoenix, you should wire brush those places bare before taping and starting to blast. You need to do it in that order so you can handle the frame and tool with greasy work gloves on. If you do it afterward you have to wear nitrile gloves, which are no protection against a wire brush spiinning on a die grinder. At least there was no questioning when quitting time had arrived, and, no blood on the frame.


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## wv_bob (Sep 12, 2005)

Found out today that I should shoot it with an epoxy primer to seal the metal. Also found out that the only place that sells it on Sunday only sells in gallon quantities. Back to the drawing board, hoping I can buy just a quart during the work week.

It needs more blasting, but no reason to do that until just before I'm ready to start painting.


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## wv_bob (Sep 12, 2005)

FWIW I was able to find some leftover epoxy primer - now to practice my spray technique


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## girlonbike (Apr 24, 2008)

That guy's not going to live long if he does that frequently.


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## wv_bob (Sep 12, 2005)

seems like he's in Checnya or somewhere like that so he might not anyway.


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## wv_bob (Sep 12, 2005)

Hey! it's finally in primer. The last coat and a half of primer didn't lay down as good as it should have due to (water in the air, dirt from whatever, lack of skill, pick one or all. So, I have to wait 2-3 days then wet sand before proceeding. Not a surprise though.

Since I was going to go black and the free epoxy is black, I'm going to change my plans and use an alternate color because spraying black over black seems like a good way to miss spots.










No it is not sitting right atop the vise grips.


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## wv_bob (Sep 12, 2005)

It's got the first coat of Massey red on it now. Pretty close to the original WTB red, but the photo doesn't look that way


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## THE ARS (Sep 14, 2011)

Looking good, boss.


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## GMF (Jan 10, 2004)

Nice - i'm digging it!


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## wv_bob (Sep 12, 2005)

Thanks. About two more color coats and I'll be finished but the paint mfr calls for 24 hours between coats so it's going to take a while. Not sure if I'm going to bother with clear or not. Depends on how tough the red is when I'm finished. 

I'm hoping that epoxy primer will seal it so the problem of rusting under the paint doesn't come back. When I'd sand the stuff between coats it kind of made the metal look like it had been blued like a gun.


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## Cayenne_Pepa (Dec 18, 2007)

Is that the 1994 frame, with the Ritchey tubing?


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## girlonbike (Apr 24, 2008)

Good for you, Bob. Thanks for keeping us posted. You came this far, may as well suck it up and put the clear on...


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## wv_bob (Sep 12, 2005)

It's a 96 with the TT tubing.






Thanks GOB. You're right, no reason to stop short now.

I looked at it this morning and the paint laid down great. Depending on how much material I lose sanding, it may only need two coats, and the less I point the spray gun at it, the less chance I'll botch it.

It's turning out so nice I may even break down and buy the proper decals.


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