Great forum! Love DIY!
I need some advice how to avoid getting a dull film after tumbling.
With my homemade tumbler, I've been tumbling tanks with aluminum oxide chips and usually end up with a thin, beige film that dulls the shine.
I don't believe it's rust. It seems more like a residue from the slurry that hasn't been rinsed off completely.
My rinse water, even though softened, is still quite high in iron and quite hard.
By the way, I follow a standard tumbling procedure based on Global's guidelines, including use of rust inhibitor.
http://www.gmcscuba.com/ttips.htm).
To try to solve this residue problem, I've varied the amount of degreaser, used more extensive rinsing, used de-mineralized water for the final rinse, varied the drying methods and used repeated tumbles.
Essentially, I have to do a second or third "cleansing tumble" with degreaser and well-rinsed aluminum oxide chips, followed by final rinses with demineralized water to get a good shine. I've been drying the cold tanks with compressed scuba air, taking about 5 minutes to get them thoroughly dry.
Am I being too fussy about getting that shine?
With my own tanks it doesn't bother me, but I'm occasionally doing tanks for other people.
My main goal then is to try to eliminate the need for a cleansing tumble, I'm thinking of increasing the pressure of my final rinse by using a 200 psi water fire extinguisher I've converted. I can get a high-pressure nozzle for broad spray coverage (like 270 degrees or so).
I'll try that next time I tumble, but if it doesn't work, I'm also thinking of using glass beads or cylindrical ceramic media for the "cleansing tumble" to make it more effective.
Questions- (If you know off-hand- please don't go to the trouble of searching- I'll keep looking myself)
1. What size glass beads work well? I'm assuming something about 3/16" diameter.
2. Who sells that size glass bead? (Other than Global, which is expensive.)
So far, I've only found blast media suppliers, and the largest they sell is what they call size 6, 50-70 mesh, which I assume is closer to 1/8".
3. McMaster-Carr sells angle-cut cylindrical ceramic media in different levels of abrasiveness.
Which level would be best for tank tumbling: Polishing (no abrasive), Medium or Coarse?
A buddy has ceramic media from Global and it's definitely either medium or coarse.
Anyone here know?
If you have other ideas, I'd appreciate your input. Thanks in advance.
Dave C
I need some advice how to avoid getting a dull film after tumbling.
With my homemade tumbler, I've been tumbling tanks with aluminum oxide chips and usually end up with a thin, beige film that dulls the shine.
I don't believe it's rust. It seems more like a residue from the slurry that hasn't been rinsed off completely.
My rinse water, even though softened, is still quite high in iron and quite hard.
By the way, I follow a standard tumbling procedure based on Global's guidelines, including use of rust inhibitor.
http://www.gmcscuba.com/ttips.htm).
To try to solve this residue problem, I've varied the amount of degreaser, used more extensive rinsing, used de-mineralized water for the final rinse, varied the drying methods and used repeated tumbles.
Essentially, I have to do a second or third "cleansing tumble" with degreaser and well-rinsed aluminum oxide chips, followed by final rinses with demineralized water to get a good shine. I've been drying the cold tanks with compressed scuba air, taking about 5 minutes to get them thoroughly dry.
Am I being too fussy about getting that shine?
With my own tanks it doesn't bother me, but I'm occasionally doing tanks for other people.
My main goal then is to try to eliminate the need for a cleansing tumble, I'm thinking of increasing the pressure of my final rinse by using a 200 psi water fire extinguisher I've converted. I can get a high-pressure nozzle for broad spray coverage (like 270 degrees or so).
I'll try that next time I tumble, but if it doesn't work, I'm also thinking of using glass beads or cylindrical ceramic media for the "cleansing tumble" to make it more effective.
Questions- (If you know off-hand- please don't go to the trouble of searching- I'll keep looking myself)
1. What size glass beads work well? I'm assuming something about 3/16" diameter.
2. Who sells that size glass bead? (Other than Global, which is expensive.)
So far, I've only found blast media suppliers, and the largest they sell is what they call size 6, 50-70 mesh, which I assume is closer to 1/8".
3. McMaster-Carr sells angle-cut cylindrical ceramic media in different levels of abrasiveness.
Which level would be best for tank tumbling: Polishing (no abrasive), Medium or Coarse?
A buddy has ceramic media from Global and it's definitely either medium or coarse.
Anyone here know?
If you have other ideas, I'd appreciate your input. Thanks in advance.
Dave C
