What makes a Conshelf 30 different?

[Green Frog]

Mention of the Conshelf 30 shows up from time to time, but in spite of several serious searches here and via Google, I can’t find a definitive answer. What was it really? It appears that AL found a batch of unused Con XIV seconds and just made a new purge button sticker and hung them on some general C 22 or 23 firsts and sent them out. Those I have seen don’t have the external poppet adjust of the Conshelf 14. Can anyone solve this problem for me?
TIA ~ ~ Froggie

 

[happy-diver]

Ultimate Conshelf Model Guide - Vintage Double Hose

vintagedoublehose.com

 

[Kupu]

The Conshelf 30 article from July 1984 SDM magazine might be of interest.

 

[Green Frog]

happy-diver, I read that thread from first to last, with particular attention to Bryan’s illustrated post of the Conshelf variants. The C30 never gets described well.
Kupo, I couldn’t open the attachment you sent so I’m sending. PM with my e-mail address to ask you to send it directly.

 

[eelpout]

Black 2nd stage cap on a Chrome plated back body.

 

[Kupu]

Kupo, I couldn’t open the attachment you sent so I’m sending. PM with my e-mail address to ask you to send it directly.

email sent. It looks like the article I attached in this thread is getting views, but I can reload it as JPG if the PDF version is not working.

 

[Green Frog]

Kupo, thanks. The article you sent gave me just what I was looking for. I switched to my older iPad and it came through fine on NOOK!

Anyway, it appears the second stage of the C XIV and C 30 are essentially the same except for the black powder coated box top and perhaps a slightly larger exhaust T on the C 30. The big ldifference is in the first stage which seems to have been borrowed from the Royal Aqualung. This does enable a variety of hose configurations and the use of a primary LP hose with larger ID, which may be an improvement, but it didn’t seem to show up in the test In the article.

I get the idea that maybe AL wanted to appeal to the “old school” types who wanted the metal 1085 box for the second stage, but a “new, improved” 1st
stage, so they would have the next new, improved toy. Apparently it wasn’t too successful sales-wise as many people have never even heard of them and they don’t appear on “comprehensive” lists people do of the Conshelf series. I’ve never seen one in the water, and only a very few scattered mentions or pictures.



PS I have been assembling a pair of regs using the standard C XIV type 1085 second stages and the later C 22 firsts that have the addition LP port (4 total) to make hose arrangement simpler. I’ve found the combination I’ll stick with. now my studies have become purely academic, so knowing about the C 30 will finish another “chapter”. Thanks again, Kupo.

 

[Green Frog]

Well, thanks to the article provided by Kupu and some serious, in depth in depth rereading of Ron’s thread, and everything else I could find, I’ve finally got a handle on the Conshelf 30. With what was said about that extra bulky, heavy first stage, I probably won’t be chasing down a complete C 30, but if a C 30 second stage shows up, I wouldn’t turn it down at the right price!

As a side note I discovered that some of the late Conshelf 1st stages had one or more larger LP ports so a larger ID supply hose could go to the primary second, supposedly for better response and easier breathing. Does anyone have any first hand experience with this?

The search for wisdom and knowledge goes on!

 

[scrane]

I think it's been established that the 1/2" ports were more for marketing than practical benefit. Most people now just buy a 1/2 > 3/8 adaptor to use with a standard LP hose.

 

[Green Frog]

Thanks, @scrane. I was doubtful that it would be worth my effort to seek out the oddball 1st stage with 1/2” port and then the unusual large ID supply hose. In the Skin Diver review article provided by @Kupu, the author didn’t express any great appreciation for that feature.

BTW, I just picked up the remnants of an orphan 1085 box from a C 30 very cheaply. It will need a complete overhaul and the black powder coat is pretty scuffed up, so I’m thinking of getting the box top recoated in yellow to make a better 1085 octo. This will give me the perfect chance to do the beta test that I promised @James79 I would do of his 3D printed exhaust T. I’ve got all the parts laying around for any level of rebuild I want, and I’ll be the only kid on my block with a dedicated C 30 octo. Something to do now while waiting for Spring!

Thanks again to all who have helped (enabled?) me as I’ve chased this particular rabbit. Special thanks to @Kupu who went the extra mile so I could read that one obscure product review that really helped me unlock the trick box of the C 30 and to @James79 who has provided advice and parts since my very first inquiries about Conshelf regs nearly a year ago

As the Grateful Dead used to sing, “… What a long strange road it’s been.”