scuba tank for pcp questions…

just say'in steel tanks are heavy you would not want to carry very far without a cart of some making. Like i just mentioned a bit ago , Fire men tanks are around and used $$ are much less . and you might be able to find a fire station that will fill it for $$ or free . ASK here to get what to look for and what NOT to look for .

450BM said:

Background first…. I’m not new to pcp but I am a novice. I’ve had a Benjamin Marauder .177 for about 6 years with a hand pump. Love shooting it, hate filling it so it hasn’t been shot that much. Decided to buy the FX Impact .25 last month that I’ve been dreaming about but also purchased a small electric pump too. Love the gun, love the pump but know I’ll shoot even more if I get a scuba like tank. The electric pump works well but it’s still 6-9 minutes to fill the Impact, about 3 for the Marauder. So…

I’m not cheap but I’m conservative and don’t want to spend extra just to have the latest and greatest. (yeah, I know, I just bought an FX Impact… )
A carbon fiber bottle would be awesome but they’re $500+ for the smaller ones. New aluminum scuba tanks (I think it’s 80 cubic feet) can be bought for less than $250 and pcp valves for around $60. Weight isn’t a big issue for me. I’ll be shooting mostly at home so the tank doesn’t have to be that portable. And, the electric pump will also run off a 12 volt truck battery so I could just take that with me if I’m shooting away from home.

Are there reasons I should invest in the carbon fiber tank that I’m not thinking of? Have others went the scuba tank route and regretted it? Any and all input will be greatly appreciated.

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450BM,

The carbon fiber tanks are 4500psi. Is the Scuba tank a 3000psi. You get a lot more fills from the 4500psi tank than you will a 3000psi tank.

Best regards,



Lewis B.
Satellite

450BM said:

I think I’m finding out why they are cheaper, working pressures are much lower than carbon fiber tanks.

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LOL, yes see my initial reply. You will be much happier with a 4500psi tank. If you go scuba you will need a cascade setup.

I recommend you go for a 4,500 PSI CF tank of some sort. IMO a small compressor like what you have paired with a small CF tank (100 cu inch or so) will give you the option for a good day's shooting away from home. You should be able to find a small 4,500 PSI CF tank set up with a valve and hose for $350 or so.


The aluminum scuba tank you mention will be good for only 3,000 PSI. The FX Impact has a nominal fill of 3,625 PSI.

badger5th said:

I recommend you go for a 4,500 PSI CF tank of some sort. IMO a small compressor like what you have paired with a small CF tank (100 cu inch or so) will give you the option for a good day's shooting away from home. You should be able to find a small 4,500 PSI CF tank set up with a valve and hose for $350 or so.

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The aluminum scuba tank you mention will be good for only 3,000 PSI. The FX Impact has a nominal fill of 3,625 PSI.

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Wow I didn't know the FX Impact has a 3,625psi working pressure. Impressive. I have been out of the Air Gunning world for a bit.

Won't be happy with a scuba set up can't even get to a full charge.

You definitely want SCBA, not SCUBA. If you don't care about weight there is still the pressure. You could fully fill your Marauder once but could never fill your Impact with a SCUBA tank. There are three ways to buy one.

First option is a new SCBA tank. Small ones are a little cheaper but this is the most expensive option. The tanks only have a 15 year life and they need retested every 5 years. But if you go this route you can get the tank filled commercially.

Next option is kind of the in-between option. If you look on ebay you can find used SCBA firemens tanks still within their 15 year life. Price varies with how well within the 15 years they are. The price seems to vary a bit over time.

Cheapest option is what I did. I bought an expired SCBA tanks for less than $100 and I fill it with my Yong Heng. It may fail - start leaking - at some point but if it does I will just get another. I guess there is some chance it will fail more violently but I doubt it and am willing to take the risk. The YH costs about $300 but you would probably spend another $100 for extras. Still it can be cheaper than a new large SCBA tank. My 45 minute Scott tank holds 66 cubic feet of air.
I hand pumped my Marauder pistol and it was not too bad. Then I got an Avenger and got the YH. Later I added the tank. Filling from a tank is definitely the quietest, quickest and therefore nicest way to fill your PCPs. A YH would fill your guns in about 10% of the time your little pump takes. But it's noisy and not nearly as portable as a tank (or your little pump).

450BM said:

Yeah, didn’t refresh my page before I responded…. Could probably get away with a 3000 psi tank shooting the Marauder but not with the .25 cal Impact! I don’t know what you mean by cascade setup, would that be shooting with the scuba tank attached to the gun?

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Cascade is using multiple tanks to use as volume and keeping the last inline at higher pressures so you get to the 3000psi number. Better off with a Carbon Fiber tank.

450BM said:

I’m not opposed to a smaller tank. If I could get 3-5 fills from it, that would be LOTS of shooting.

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I just did a quick calc using AoA online fill calculator (Great resource!)


Based on the data for an FX Impact a 100 cu.inch CF bottle would only give you two fills (2,000 psi up to 3,635 psi). Well... for only $150 more you can get a full size 88 cu.ft. CF tank good for 13 fills. I doubt your small compressor would survive long trying to fill one.

I can’t really comment on what would be best for you but here is my situation.

I have one carbon tank with. 4,500 fill, two steel tanks with a 3,300 fill and two aluminum tanks with 3k fills. So one carbon and 4x scuba.

I have a dive shop about 10 minutes away but he charges for fills, not much, and won’t fill the carbon bottle over 3,500. He says it isn’t worth the strain on his compressor.

My local airgun shop is 45 min away and fills for free. But gas is $6 plus tole fees. And is walking into a gun shop ever really free.

I only use the carbon bottle for going to field target matches. It is so much lighter and easy to take with.

The scuba tanks are heavy but I only bought one new.l so I’m not into them for much money. There is the cost of testing every two years. I shoot daily and have a range of guns with fill pressures from 2k up to 3.5k. As a tank drops down in pressure I will use it to fill a rifle and then finish the fill with a tank that is still closer to full. Makes them last a lot longer. I am usually good on air for a few months like this.

Not tank related but if you are mostly a backyard shooter consider tuning the marauder for a lower power. For example I have a BSA goldstar tuned to 12ftlb. This gets me 120 shots from 3,000 psi. Even on a short fill from a low tank I can get 50 shots. I had a marauder I put a Huma in and set it around 14ftlb. I’m not sure how many shots it got but it was a bunch.

Not sure if this was helpful but I hope so.

450BM said:

I’m seeing “expired” carbon fiber tanks on ebay for $75 bucks. These were used by fire departments and are listed as having X number of minutes of air, like 45. Anybody have experience with these? My search was for 4500 psi tanks.

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Here's the deal with those.. If they are expired then no dive shop, airgun/paintball store, fire department will refill them. You can fill them yourself with your own compressor at your own risk. There may also be DOT issues with transportation of a pressurized expired tank (not sure on that but "heard about it once"). Is it SAFE to use such a tank? Probably, most likely yes... But you don't know the history of the tank with whatever FD they came from. Remember YOU would have to fill any expired tank, no one else will do it commercially. A 45 minute tank is about a nominal 77 cu foot tank.

wildcj5 said:

I have a dive shop about 10 minutes away but he charges for fills, not much, and won’t fill the carbon bottle over 3,500. He says it isn’t worth the strain on his compressor.

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I have a similar situation here, although my 4500 psi tank is only for paintball. The dive shop will only fill to 3600, maybe 3800 if I tip.

try other fire stations in your area and ask of they are getting rid of any tanks,
also ask if they will continue to fill them for you.

been getting my fills from fire stations for years and years

450BM said:

Would my little compressor be able to fill a larger tank? I know I’d have to run it for 10-15 minutes and then rest it. I bought a 4 year warranty for it and I’m not opposed to thoroughly testing the compressor and the warranty.

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If it is one of the small air cooled units then Yes, but almost certainly at the cost of dramatically reduced life expectancy. Another important thing is to never start/stop it under load. If you can bleed the compressor high pressure stage/hose you will be able to start the compressor at no load which will help. Also may be a good idea to only fill to 4,200-4,300 PSI to remove the worst load from it.

Based on your fill time data in your original post (3 minutes to fill M-Rod) your unit works out to about 80cc fill per minute to 3,000 PSI. A standard SCBA tank is nominal 7 to 9 liters. To fill one of those from the same start pressure would be minimum 80-90 minutes; BUT that is only a fill to 3,000 PSI. It could almost double going to 4,500 PSI (3 hours?). With 10-15 minute run and same cool down period, a tank fill could take half a day.

Many here on the boards use the Yong Heng compressors. For a "cheap small unit" they are powerful at 1,900 watts and are water cooled. Many users report they can fill a 88 cu foot tank in under a half hour. Many also report 2-3 years good service and going strong. Numerous YH threads here on the forums.