How often do you have to send your tank for a tumble?

[Bob DBF]

But, a bit of flash rust is nothing to worry about and can easily be brushed out with a light wire brush on a long stick. Tumbling is a bit more aggressive.

Which is what my LDS said on the last viz, he saw the rust and checked it with a whip and it was gone. Worked out well for me, just cost the viz and he showed me what he was looking for during the viz. LDSs may vary.



Bob
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I may be old, but I'm not dead yet.

 

[drbill]

I've had two HP120 tanks over the last 15 years. Both failed. The first due to over-expansion from hot fills on land (it was used almost entirely for shore-based diving). The other due to significant rust on a VIP that couldn't be tumbled out. It was used almost entirely on dive boats. Had I taken the second tank in for VIPs m,ore frequently than once a year, they could have tumbled them clean again. I fully trust my dive shop. Sine this time I have been diving neutral buoyancy Al 80 tanks exclusively although I may need another HP120 for some deeper diving in the future.

 

[dytis-sm]

How do you know your tanks need to be tumbled? Is it the dive shop telling you? Is this the same shop that fills your tanks?

The humidity in the air has no effect on the inside of the tanks, unless the shop's compressor is not filtering out all the water. This does happen occasionally. All it takes is one wet fill and your tanks will get some rust.

But, a bit of flash rust is nothing to worry about and can easily be brushed out with a light wire brush on a long stick. Tumbling is a bit more aggressive.

This is the same shop I get 70% of my air fills. I do use another shop for Nitrox fills and rarely (3-4 times a year) I get fills on a couple of boats. The shop claims that I probably got a wet fill on a boat. What struck me is that this is the second tank that I bring for VIP at this store and have to tumble it and I questioned it because this is a tank that was bought new a year ago (Faber 117cf)... To be frank I did not try to debate and take it elsewhere as I tend to trust those guys but wonder as the frequency was surprising.

Somebody told me that this is common on HP tanks...Why would that be?

 

[AfterDark]

I've had 2 tanks tumbled in 44 years. One of the tanks I bought for $10.00 knowing it had rust inside. Still using it, just passed it's 3th VIP since the tumble. Another tank got water inside because I sucked the air out of the tank 4ft from the surface entangled in line I was suppose to be setting for a beach area. I doffed the tank and surfaced. The tank surfaced upside next to me! That tank failed hydro a few years ago due to expansion and not returning. B!tch tried to kill me but I out lived it!