Home fill station for dummies?

[stuartv]

I was just reading the thread about what is the best booster to buy for home use.

I have a bigger picture question. Is there a resource I can read to really get me up to speed on how best to setup a home fill station for myself?

It seems Vance Harlow's "The Oxygen Hacker's Companion" would be the book to read, but that appears to be unavailable.


I mainly want to be able to fill my own CCR cylinders (O2 and Trimix). But, I might also end up filling BO bottles or even twinsets of trimix.

I'm already a gas blender and do my own fills at my local shop. But, I'm moving and will no longer have a convenient local shop.

I had been thinking I could just get some T-cylinders of O2 and He and a booster, and get some doubles filled with air periodically at the local dive shop. I have a good shop compressor that will push up to 150psi for drive gas.

I figured that setup might be slow, but would allow me to get the job done.

But, I have read some other stuff that makes me wonder if I would be better off to get an actual scuba compressor and setup a continuous mix setup. Then I wouldn't have to depend on a dive shop at all, and I could run the O2 and He cylinders all the way down to empty before swapping them out. And, I guess, only need one of each, instead of 2 or 3 of each as banks. And maybe that would also let save me from needing to buy a booster? Or possibly I would need a less expensive booster?

I couldn't find a thread that already explains this. Can anyone point me at some worthwhile reading material to help me figure this out?

 

[tbone1004]

aren't you moving to Charlotte? Just make friends with the local VFD and get free air and pp blend at home. It depends on how much you gas you really need. If you're filling a set of doubles twice a month or more, then buy a compressor. If you're not, bribe the local VFD with pulled pork and pies.

 

[kensuf]

How are you planning on doing the air-top up when filling mix? If you do not plan on buying a compressor, you might want to have a long talk with whatever shop you plan on doing the air top-up with before you start showing up with bottles partially filled with mix.

For years I used to blend in my garage. I found 3 O2 T cylinders and 3 helium cylinders worked well enough to fill just about anything without a booster. A low and high bank would have been fine if I had a booster. I also remember it was a pain in the butt when I had to run to the welding supply company to rotate bottles out and I'm really glad I have local options with the dive shops in my area.

 

[NAM001]

I was just reading the thread about what is the best booster to buy for home use.

I have a bigger picture question. Is there a resource I can read to really get me up to speed on how best to setup a home fill station for myself?

It seems Vance Harlow's "The Oxygen Hacker's Companion" would be the book to read, but that appears to be unavailable.


I mainly want to be able to fill my own CCR cylinders (O2 and Trimix). But, I might also end up filling BO bottles or even twinsets of trimix.

I'm already a gas blender and do my own fills at my local shop. But, I'm moving and will no longer have a convenient local shop.

I had been thinking I could just get some T-cylinders of O2 and He and a booster, and get some doubles filled with air periodically at the local dive shop. I have a good shop compressor that will push up to 150psi for drive gas.

I figured that setup might be slow, but would allow me to get the job done.

But, I have read some other stuff that makes me wonder if I would be better off to get an actual scuba compressor and setup a continuous mix setup. Then I wouldn't have to depend on a dive shop at all, and I could run the O2 and He cylinders all the way down to empty before swapping them out. And, I guess, only need one of each, instead of 2 or 3 of each as banks. And maybe that would also let save me from needing to buy a booster? Or possibly I would need a less expensive booster?

I couldn't find a thread that already explains this. Can anyone point me at some worthwhile reading material to help me figure this out?

STEWART I PP blend at home and use a home fill unit for O2 to boot. Home fill units are relative cheap compared to a compressor 1K or less. the only issues that could arise is MAYBE the argon aspect if you are going to use trimix deep. PM me if this is what you are interested in doing. Ill give you any info I have on my rig.

Keith

 

[tbone1004]

STEWART I PP blend at home and use a home fill unit for O2 to boot. Home fill units are relative cheap compared to a compressor 1K or less. the only issues that could arise is MAYBE the argon aspect if you are going to use trimix deep. PM me if this is what you are interested in doing. Ill give you any info I have on my rig.

Keith

argon not an issue with open circuit because you're still comparable to EAN32. The issue with argon is when using it to fill CCR bottles and for that you just need to dil flush every once in a while.
@stuartv If you want to see a homefill set up in person, when you go to Jocassee next just let me know and I'll show you the one I use.

 

[NAM001]

argon not an issue with open circuit because you're still comparable to EAN32. The issue with argon is when using it to fill CCR bottles and for that you just need to dil flush every once in a while.
@stuartv If you want to see a homefill set up in person, when you go to Jocassee next just let me know and I'll show you the one I use.

I wish I knew more about RB's but I dont. I agree fully with the open circuit and argon. any normal mix you will double the argon % which in the rec world is not an issue. What info I have read says argon is 4 time narcotic as N2 or O2. Again at that point that tidbit is trivia of sorts because of the depths of rec diving. I would think that for RB you fill with O2 and other mixes the higher argon % probably should not be an issue in such gasses as deco 70% and more. Ive been using my homefill to source O2 for going on 20 years now. Since the LDS closures of years ago my closest fill station is 30-90 miles from home. It works fantastic for local diving and is much cheaper than the cost of transportation and NiTROX fills. At the time my homefill unit and O2 compressor for it was 500$. I have close to that many tank fills off it. I have about 1000 cuft O2 in the back room to PP blend with. O2 bottles are easy to come across as many are rejected for filling because of bottle leases. Many bottles are perhaps from dubious sources perhaps or bought in a garage or estate sale somewhere. Either way those bottles are hoard to get filled unless the filler leases the bottle to you and the bottle has their mark on it.

 

[rddvet]

I have a booster and a compressor. I started with a compressor only and added a booster later. Since moving to CCR and geting a booster I rarely run my compressor. Really it gets run to either top off my tanks with boosted helium and oxygen in them or to fill OC tanks rarely. I could honestly sell my compressor, and just get a couple al80s or a couple sets of doubles filled with air and 32% at an LDS and boost that as my top off gas. If I was only going to get one thing it would be a very good booster. But honestly I like being completely independent, so I am keeping my compressor.

 

[stuartv]

First, a very fine SB'er has sent me a PDF of the VH book (3rd edition). Now I have some reading to do.

Meanwhile...

@tbone1004 Yes, I am moving to Charlotte. But, I think it will probably be easier for me to get air fills at a scuba shop than put that much effort into my relationship with my local VFD.

@kensuf My thought was to get some twinsets filled with air and then use a booster to do the air top-ups with a twinset for the source gas. Of course, in that case, maybe I would get the twinsets filled with EAN32 and just stick to Standard Gases for my dil. I normally keep my dil bottles all filled with 18/45 anyway.

@KWS I deduce that your home fill unit is something I know nothing about and that it must produce argon as a byproduct? Got a link to the kind of unit you're talking about? Regardless, I do want to be able to produce trimix for deeper diving.

A further thought I have had is (please correct me if I'm wrong) that I will need a booster, no matter what. I want to be able to fill my O2 cylinders to 3500psi (as I do now, when filling at my LDS). It occurred to me that it is probably not a good idea to attempt to do that using a Continuous Mix compressor setup. I suspect that scuba compressors are probably not safe to feed pure O2 into the intake side. So, I would need a booster to do that, regardless of what else I do.

I am curious about the (other) limitations of a continuous mix compressor setup. Like, can you easily produce TX10/70 from one? What about even more hypoxic mixes? I will get started reading the Vance Harlow book and see what I can learn from that.

Thank you all for the info so far!

 

[stuartv]

I have a booster and a compressor. I started with a compressor only and added a booster later. Since moving to CCR and geting a booster I rarely run my compressor. Really it gets run to either top off my tanks with boosted helium and oxygen in them or to fill OC tanks rarely. I could honestly sell my compressor, and just get a couple al80s or a couple sets of doubles filled with air and 32% at an LDS and boost that as my top off gas. If I was only going to get one thing it would be a very good booster. But honestly I like being completely independent, so I am keeping my compressor.

Yes! That setup is pretty much exactly what I was thinking might work for me.

But, then I read some stuff about continuous mix compressor setups and started wondering if it would be better to just go down that path from the start and then maybe I wouldn't need to buy a booster.

But, I think I'll need a booster, regardless. So, I'm thinking I could start with just a booster and do things like you described. Then MAYBE add a compressor later, if it really seems like it would make a big difference to me - which it probably wouldn't.

The one reason I thought a compressor might really be nice is that I could just have one bottle of He and mix it on the intake side, so I could use the whole bottle and not have to return it with some amount (100psi? 200psi?) left in it. I would still probably need 2 or 3 cylinders of O2, for boosting into my O2 cylinders. But, I would still also be able to use the lowest O2 cylinder to feed into a continuous mix setup and also be able to really use the whole cylinder before returning it.

 

[rddvet]

Yes! That setup is pretty much exactly what I was thinking might work for me.

But, then I read some stuff about continuous mix compressor setups and started wondering if it would be better to just go down that path from the start and then maybe I wouldn't need to buy a booster.

But, I think I'll need a booster, regardless. So, I'm thinking I could start with just a booster and do things like you described. Then MAYBE add a compressor later, if it really seems like it would make a big difference to me - which it probably wouldn't.

The one reason I thought a compressor might really be nice is that I could just have one bottle of He and mix it on the intake side, so I could use the whole bottle and not have to return it with some amount (100psi? 200psi?) left in it. I would still probably need 2 or 3 cylinders of O2, for boosting into my O2 cylinders. But, I would still also be able to use the lowest O2 cylinder to feed into a continuous mix setup and also be able to really use the whole cylinder before returning it.

Continuous mixing of eanx is easy. Tmx is a little harder. You need to be careful that you don't overheat your compressor, though I never had that issue. I modified my stick to be a trimix stick and I also had a second hand Trihunter trimix stick. Both were good, but to be honest I prefer pp blending with my booster. I found when continuously blending trimix it had to be watched much more closely than eanx. And you can also lose helium through the compressor. So if it looks like you're pumping 21/35 at the inlet, the outlet may be lower if you're losing some helium. One thing I would consider is 2 or 3 separate bank bottles to fill with your preferred mix. You can set them up so that you can boost into them to fill them, then change whips over to be able to boost that gas into your BOs. I currently don't have any bank tanks, but I'm clearing out some space to get two. One for 30/30 (since it's my most common mix and not as easy to blend as a standard gas is) and one for 21/35 my second most common mix. That way I don't have to pp blend into my bailuots when they get low (since I use them as dil as well). I can just top off from the bank bottles. If I was diving a more hypoxic mix I would make one tank 30/30 and one 10/70. You can then top off that 10/70 to make all your normal mixes like 18/45 and 21/35. But at the end of the day, if you get a good booster, some bank tanks to put mixes for bailout and OC into, a bottle of He, and a bottle of O2, plus a couple tanks to dedicate to be filled with 21% or 32% to use as a top off, you'll be good. I do love my compressor though.