Suggestions for upgrading Double AL-80's

[rob.mwpropane]

@Marie13 and @rob.mwpropane, I own a set of Faber 85s, Worthington 85s (Ok, those are really Kim's) and Faber HP 100s. The HP100s and the Worthington 85s may as well be the same tanks. Trim and buoyancy are almost identical. As individual tanks, they are both about -1 empty. The Faber 85s are lighter, individually, they are about +2 empty. I don't have trouble diving any of them. I don't really notice any difference in trim across the tanks, but I could very well be used to them and just automatically compensate.

That's my experience. Edit: you said Faber, lol.. I guess they're all close enough who cares

One thing I noticed is some people post the Worthington's as 7" and some post 7.25". They are identical to my 7.25" PST's in every way except they are just a hair longer. Here are mine lined up with an angle on a concrete floor. Black are PST HP100's, galvanized are Worthington LP85's.

 

[RyanT]

They dive slightly differently. The white ones tend to get butt light at low pressures

I should probably clarify, in my comparison of Faber LP85s to the HP100s and Worthington 85s, I was referring to the white ones. I don't really notice them getting butt light, but again, it may just be me not noticing.

 

[RyanT]

They are identical to my 7.25" PST's in every way except they are just a hair longer.

Yep, the Worthington are 7.25"

 

[tbone1004]

Wait a minute.. @LandonL , my 85s better not be diving without me. LOL!

I had left everything assembled until yesterday when I came back up from Miami. They were definitely your 85's that went diving without you

 

[Alaskan Scuba Dude]

Take two AL80s with you as deco stages for some extra bottom time.

 

[RyanT]

I had left everything assembled until yesterday when I came back up from Miami. They were definitely your 85's that went diving without you

Alright, I'll accept you diving them. But I DID NOT approve them attending an impromptu dance party in parking lot!

 

[rob.mwpropane]

Alright, I'll accept you diving them. But I DID NOT approve them attending an impromptu dance party in parking lot!

You just need to put on a request for the video.. you're entitled to that much I would think!

 

[boriss]

Good day everyone!

After my last tech dive I want a little more back gas than the AL 80's I trained with and use. I bought som AL 100's as an upgrade but those things are MONSTERS and just too big.

So what are suggestions and why?

- Occasional Tec diver
- Wetsuit/warmer water
- TEC depth avg 130-150

Thanks in advance!

You're actually not going to get that much more gas going for LP85 instead of AL80's unless you get them overfilled. That's not usually a problem down here, but depends on the shop (it'll be a problem in the Keys for sure). At rated pressure the AL80's will typically hold ~77.5cu.ft. (~155cu.ft for doubles) and the Faber LP85's will hold 81cu.ft (162 for the pair).

If you want to be sure, get HP100's. That's what I'm diving, but keep in mind they're heavy suckers and mine typically get filled to almost 4k hot and cool off to: 3500-3700psi. I've had them underfilled before, but still plenty of gas for my dives

However, I'll reiterate something that was stated earlier in the thread as this setup will make you pretty negatively buoyant, especially at the start of the dive. If you're diving a wetsuit, make sure you use a dual bladder wing for backup/redundancy, it'll be extremely hard to kick up all that weight with your fins, in case of failure.

Lastly, my single-tank setup uses a 5lb SS plate (to which I have to add 2-8 lbs, depending on tank and gear config, to stay neutral at the end of the dive) while in the doubles I use a CF backplate to help manage the weight of those HP100's.

Here are some calculations I did last year prior to buying the Faber HP100's:

Hope this helps