21 replies to this topic

[wheelz]

I've read a bit about restoring corroded magnesium with glass bead blasting, but wondered if anyone had first hand experience with it. I have a few Cox frames and a bunch of wheels to clean up. A friend of mine has a blast cabinet and I can get #8 glass beads from Harbor Freight nearby, but not sure that this is the right size and want to make sure that it doesn't erode the base metal. Has anyone done this?

[TSR]

Just make sure that the pressure does not exceeds 80lbs/sq.inch

[Horsepower]

The Harbor Freight blast cabinet works pretty good for blasting magnesium.The only beef I have is my compressor is a smaller one like for powering air nailers and the little gun on the Harbor has a pretty large opening so it runs out of air fast. I tried making the muzzle smaller with some tubing but couldn't get it to work right, so I just use the factory provided one. If you have a larger compressor set at 75 lbs. it should be no problem. Yes, I have done it. Make sure you seal the parts ASAP with either the clear paint method or some Future Floor Wax.
RANDY_ Check out this article. http://electricdream...agnesium-parts/

[BWA]

Bead blasting, no mater how carefull you are deffinately makes mag parts look like they have been bead blasted. Even the finest glass bead is too coarse.

What I use instead, is ordinary houshold baking soda through my airbrush.

Yes, that's right, I use an ordinary airbrush to Soda Blast Cox Mag Parts. The finish is fantastick, being a nice even and very smooth matt finish, that removes little if any metal. The parts just look clean, and, not blasted.

One nice feature, is, that the Soda is completely enviromentaly neutral/friendly, it's safe on the lungs, and, you don't need a cabinet. As well, a small compressor works just fine.

For small quick jobs, I just blast away in my paint booth, or, even just in the workshop it makes so little mess.

Badger actually makes a small very cheap Grit Blaster that would probably work just as well, or even better than a standard airbrush.

[TSR]

Al,
Thanks for this great tip!

[Bill from NH]

Al, have you tried the baking soda on other metals? If yes, what's been your results?

[Horsepower]

I don't know about baking soda, but my bead blaster makes them come out like new, and they don't look like they are missing anything except oxidation. Maybe the baking soda deal is worth trying, although in Chicago they use baking soda to blast graffitti and they have to wear masks due to health concerns. Lots more blasting there, so maybe that's why. So how badly oxidized can the mag wheels be before the baking soda won't work? How much time does it take?

[BWA]

Haven't tried it on other metals, but, it works fast on Cox mag bits.

Yeah, big difference between blowing a bit of baking soda through an airbrush at 40-50 pounds and a 2 inch hose at 150 or more.

I've never had one oxidized bad enough that it doesn't work, and, I've had some pretty fuzzy ones. It won't put metal back, so, just like a bead blaster, if they are pitted when you start, they will be pitted when you finish, just, a lot cleaner.

[Horsepower]

Good, thanks! I have to try that on my next round of cleanup on the parts!

[Mopar Rob]

Why wouldn't you just put the baking soda in the blast cabinet? I'm not a medical professional, and I the risk of silicosis is probably minimal from the airbrush but why inhale it anyway?

[BWA]

Why wouldn't you just put the baking soda in the blast cabinet?

Well, because, I don't have one.

[Mopar Rob]

Well, because, I don't have one.

I would look into buying an Air Eraser before I would destroy an air brush needle and fluid tip. You can probably buy an air eraser for around $70-80

[BWA]

On the other hand, Badgers Grit blaster is probably less than 20 bucks. However, I have done a fair amount of blasting with my airbrush, and, so far, it's showing no signs of wear.

It is also, VERY clean.

[wheelz]

I just tried the baking soda blast with my $9 Harbor Freight airbrush. Really neat and easy to use and a pound of soda would last a month. Tried various pressures, up to 120 psi. It completely removed the nasty white and brown oxide crust on the parts, so that was a distinct improvement. There was no change to the patina of the parts, darkened areas would not lighten up even with prolonged blasting. I hope the attached pics come across.


I need something a bit more agressive, so I'm thinking of getting the finest mesh glass bead available and start by using the airbrush method, outdoors.

[slotbaker]

Has anyone tried tumbling these Cox bits?

Might be OK in fine sand, or the coarse dry medium that is used for amo shells.

[BWA]

Has anyone tried tumbling these Cox bits?

As a matter of fact, I have. In my very much jury rigged plastic tub in my biggest chuck in the lathe on full back gear.

I used some shiny black sand blast type grit, and, it worked sort of. The blasting is just so much faster.

[proptop]

I have one of those Badger abrasive blasters that looks like an air brush...model # 260-1

I made a blasting "cabinet" out of a cardboard box...it's about 18" across and 12" high and deep, it has a hole on each end for your hands, and a window in front and one on top so I can set an aquarium light on top. I got some plexiglass from Lowes (or was it Home Depot, don't recall right off hand) and just duct taped everything together.

It works quite well...and I only need between 25 and 40 p.s.i.
It comes with 12 oz. of Alum. oxide that is rather fine, but it cuts through oxidation on model airplane engine cases pretty doggone good

I like the baking soda idea...gonna haveta try that next time.

[slotbaker]

Has anyone tried tumbling these Cox bits?

As a matter of fact, I have. In my very much jury rigged plastic tub in my biggest chuck in the lathe on full back gear.

I used some shiny black sand blast type grit, and, it worked sort of. The blasting is just so much faster.

Though I'd try and answer my ?? so I tried the tumbler.

Don't waste your time.

Al's right.
It sort of does ok on the outside surfaces, but not real good on internals like Chap wheels.

Stick with the blasting option.

[wheelz]

Here's a follow up. I used glass beads in a standard sandblast gun (12.95 from Harbor Freight) and followed advice from previous postings and the article from Electric Dreams. Here is the result. Same part shown. I'm sold on this method. It was a blast!

Attached Images

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[Horsepower]

Here's a follow up. I used glass beads in a standard sandblast gun (12.95 from Harbor Freight) and followed advice from previous postings and the article from Electric Dreams. Here is the result. Same part shown. I'm sold on this method. It was a blast!

And a thing of beauty too!

[TSR]

Now do the right thing and coat the parts with 95% clear urethane and 5% candy-apple red. Then your parts will look EXACTLY like the parts Cox produced in 1965.



Of course, some Canadian friends may disagree, this is why I posted the absolute proof above...

[Horsepower]

Eh, doze hosers! Dey can't take yer werd for it, eh?