painting tanks

[imwright1985]

if you do cap the threaded area well you dont want to mess those up, anyway you look at it you need a vis if tank is empty or outa vis date

 

[Jimmer]

Ok, awesome.

One more question, both tanks are still in hydro but have been out of vis for 3 years, should I go ahead and drain the tanks and remove the valve before blasting?

What I did with mine was drain the pressure from it, then leave in a old crappy valve to seal it during blasting. Check with your LDS, they may have an old useless valve kicking around you could borrow.

 

[deadly_risk]

As point of comparison to anyone searching this thread, all the abrasive blasters in my area want at least $75 for two AL80s. Scratched paint sure is pretty.

 

[halocline]

You can probably just take the paint off with paint stripper, then lightly sand if necessary. It's not rocket science, you'd be paying for the convenience of the media blasting.

 

[spectrum]

I did mine with paint stripper and a plastic putty knife. I think I did 2 in less than an hour. The plastic putty knife quickly forms a radius to match the cylinder and work real well.

There was a thread a while back that considered mill, brushed and shot blast. As I recall shot blast in a small way provided the greatest chance of corrosion due to the increased surface area of the finish.

IMO just get the paint off of them with the cheapest quickest method so you can effectively rinse them and let them begin to develop an new patina.

Pete

 

[oxyhacker]

Problem with this, from a dive shop's point of view, is that there is no way to be sure that a low temp process was actually used, and done properly. So many shops will just refuse to fill any tank which has been powder coated, and I can't really blame them. It's lot safer when dealing with alu tanks to just completely avoid processes which heat the tank rather than quibbling about how much heat is OK. And then there is always the chance that the guy at the powercoating shop my get bored waiting and crank the heat up a bit figuring you are being unecessarily picky.

I had our local powder coating shop do 2 AL tanks for us 4 weeks ago. They used a low bake powder coating, the cure time was longer & more expensive due to the 140 degree temp. We'll see how the coating lasts... Cost was about $50 tank.

 

[DA Aquamaster]

Problem with this, from a dive shop's point of view, is that there is no way to be sure that a low temp process was actually used, and done properly. So many shops will just refuse to fill any tank which has been powder coated, and I can't really blame them. It's lot safer when dealing with alu tanks to just completely avoid processes which heat the tank rather than quibbling about how much heat is OK. And then there is always the chance that the guy at the powercoating shop my get bored waiting and crank the heat up a bit figuring you are being unecessarily picky.

At a minimum, expect the shop to ask you to get a new hydro test to confirm the tank can still pass. The same goes for most professional paint processes that might have involved a heat curing process.

Consequently if you go the professional paint or powder coat route, do it prior to a hydro test. The fresh test date in the new paint will do a lot to convince a shop to fill the tank.

 

[deadly_risk]

Some pictures, first how the tanks came to me, then stickers removed, and lastly clean stripped tanks

Thanks for the advice guys!

(Ah, and done for $20)