Vintage Double Hose

Just picked up a circa 1967 USD tank backpack in pretty good condition for about original cost (based on VDH catalog database). I've got a comment and a question.

Compared to my first tank pack (circa 1975), this is like a Hummer vs. a Corvair ("Unsafe at any speed -- The sporty Corvair"). But I see that a double tank version was made as well. I just almost can't believe that the sheet metal handle with two rivets could hold up toting around ~70 lbs. of twin 72's and a ScubaPro MK-7 "honker" (circa 1971). Especially the torgue resulting from picking them up from a vertical position. Fortunately, this one is in great shape mechanically, with the exception of a missing butterfly nut.

I suppose that VDH members have seen these in every state of repair. So how DID the handle hold up? And how about the tank band -- it is so thin as compared to my 1975 "oldie but a goodie." I wonder how it did in salt water if not cared for? The u-bolt with the butterfly nuts seems rather light gauge as well.

The "chrome-plated quick release brass snaps" (1967 catalog) on my shoulder straps are covered in verdigris while the other hardware is flawless. So I'm guessing at least the marine stainless parts are top quality.

I still have the one I bought way back then, never any issues with a single tank.

There are a couple of issues that we ran into with these paks during the 70's, but with a little care you can avoid those problems.

Many of the paks were cracked from over-tightening the band to the point that the cam mechanism would put way too much stress on the plastic pak, then they would crack where the metal components attached. Just tighten to the point that the tank is securely held and not too much effort required to fold the cam lever into position.

The other cause that we found for damage was caused by laying the tank down on the contoured pak. That was particularly harmful when on the deck of a bouncing small boat, and believe it or not I actually saw people sit upon their tank while it was propped up on the contoured plastic pak. I recommend laying the tank down flat with the pak facing upward when not in use.

Dacor's similar pak was made of aluminum instead of plastic, and was virtually indestructible. I still have one of them, and folks usually remark how comfy it is when I let them use it on our vintage outings.

Thanks to you both. With this information in mind, I feel like I made a good purchase. Although there may also be a Dacor in my future if I can locate one cheap.

Both of those sources of damage sound highly likely. Who would think that that thin, brittle plastic could hold up to a boat trip or human load in that position? Either way, 'praemonitus, praemunitus' -- forewarned, forearmed. I love this board!

Now I just need to try it out with a steel 72 and my DAAM. Cheers.

Isn't that the same thing as the Voit Snugpack? With just a little different hardware.

I never had any issues with the metal button snaps, mine works fine. The plastic pack can crack if you beat it around or as my recent one, fell over one time too many.

The handle on the Voit pack was through bolted, worked fine.

Nem

I wondered if maybe the Voit wasn't a little different in that area. A bolt would certainly resist bending much better than a pair of rivets. But I will keep mine original unless I see evidence of damage.

As I mentioned, the USD pack I have is missing one of the butterfly nuts. I am likewise curious if there was a SS plate that backed-up these nuts -- I can't tell from any of the literature of the day. Mine has none, which will make the plastic around the holes rather susceptible to stress cracking if overtightened. I considering looking around for a plate that I could install there. I would rest easier.

cdharris wrote:I wondered if maybe the Voit wasn't a little different in that area. A bolt would certainly resist bending much better than a pair of rivets. But I will keep mine original unless I see evidence of damage.

As I mentioned, the USD pack I have is missing one of the butterfly nuts. I am likewise curious if there was a SS plate that backed-up these nuts -- I can't tell from any of the literature of the day. Mine has none, which will make the plastic around the holes rather susceptible to stress cracking if overtightened. I considering looking around for a plate that I could install there. I would rest easier.

I am pretty sure there is supposed to be a plate there, my Voit packs have plates. Should be easy enough to fabricate two thin stainless plates.

Nem

cdharris wrote:....As I mentioned, the USD pack I have is missing one of the butterfly nuts. I am likewise curious if there was a SS plate that backed-up these nuts -- I can't tell from any of the literature of the day. Mine has none, which will make the plastic around the holes rather susceptible to stress cracking if overtightened. I considering looking around for a plate that I could install there. I would rest easier.

The missing plate is absolutely needed to spread the load over a larger area of the plastic. I don't feel like a washer is a viable alternative. One plate is needed on each side. If you are handy with tools and shaping materials you could probably make one that fits the recessed area of the plastic molding. I can make a template by tracing around one of mine if you need it.

A good hardware store should be able to provide a wing-nut in stainless steel that will fit. I think those are 10-32 threads, but you should take your other one in to match up.

If the plates are the same as on the Voit pack I have an extra set and a band too. For free, just for you, if you want them.

The plates are three inches long, hole centers approximately 2.25 and the plates are .75 inches wide.

Nem

Fortunately, screws on the other side have a backing plate that I can use as a template. I thought about the washer approach, but figured there was a good reason USD didn't use washers. So, that leaves me wondering where I can lay my hands on a piece of marine stainless of about the right dimensions.

I will get the wingnut at my local West Marine store to ensure it is marine SS. I figured I would also browse their sailing fittings to see if there was something close enough to the plate, or that I could trim down to size. I know it will cost me a pretty penny (being West Marine and a sailboat fitting), but then again, I'm not crazy enough to think that vintage scuba is a poor man's hobby. OK, maybe I was originally, but that was before I discovered eBay.

In a related (sort of) question: if I am only going to use one size tank (steel 72), is it possible to use a nylock nut on that (as long as I'm not going into salt water), rather than a butterfly? In other words, is it adjustable only for the sake of versatility, or is it necessary for getting the pack on and off the tank? I'm just wondering if that would work since it would guarantee that I am putting minimal (and consistent) stress on the plastic by ensuring that the nut is situated consistently. (Bet you're starting to wonder if I sort my socks and shirts by color, huh?)

Nemrod wrote:If the plates are the same as on the Voit pack I have an extra set and a band too. For free, just for you, if you want them.

The plates are three inches long, hole centers approximately 2.25 and the plates are .75 inches wide.

Nem

Wow THANKS Nemrod! Those appear to be the same dimensions: 3 x .75 x 2-1/8 (screw centers). That is a mighty kind offer!!! It would save me a lot of time and trouble as I would have to drive into Nashville just for that.

So how do you want to handle this? PM me if that works for you. I need to send you a check for postage at least. And I'd be more than happy to put a little extra in for the parts.

I'm just really happy to think that I can dive it this spring. All I'll need to do (thanks to you) is remove the verdigris from the snaps. Right now they will hardly snap and might actually pull through the nylon if I'm not careful.

Thanks again!

Please dont take this as an insult as it's not meant that way at all.

The Kam EZ is pretty easy to come by. You should have no problem getting a stack of them if you ask around. When I get them I scrap the plastic and webbing, keep the buckle and put the band and hardware in my scrap metal pile for my neighbor. Put an ad on craigs list. Look at the marine swap meets or scrap yard and I will bet you can find plenty for free or darn close to it. Happy Hunting!

Bryan wrote:Please dont take this as an insult as it's not meant that way at all.

The Kam EZ is pretty easy to come by. You should have no problem getting a stack of them if you ask around. When I get them I scrap the plastic and webbing, keep the buckle and put the band and hardware in my scrap metal pile for my neighbor. Put an ad on craigs list. Look at the marine swap meets or scrap yard and I will bet you can find plenty for free or darn close to it. Happy Hunting!

Insult? Not for a moment. Rather, I think this falls under the category of "familiarity breeds contempt."

A good analogy is me and fossils. I'm a geologist. It takes a pretty special fossil for me to do more than glance at one, much less pick it up and pack it home. Whereas most people think they are all collectors items.

For me, this backpack is a labor of love and a real find. I bought what I bought for the Conshelf XI. So this EZ cam is more-or-less a freebie, and a challenge to bring back to life. Besides this one is coming together with little or no effort, and will -- unlike a lot of stuff I wind up with -- actually be a servicable rig for years to come. Not to mention that I wouldn't have a clue how to locate a marine swap meet in middle Tennessee.

As they say, to each his own. But I appreciate the advice and will keep my eyes open. Heck, maybe I can become an EZ Cam aficionado.

You can use the nylon lock nuts in place of wing nuts with no problem. Most Lowes home improvement stores have a fair selection of SS nuts that are OK for your application. They may have the wing nuts in SS if you want them instead. Another option is to use 1 or better yet 2 regular SS nuts with a drop of blue locktite. You could use red LT but I seen no need for that strength. As a last resort you could use brass, in any event, do not use regular steel if the BP is going to get wet, saltwater or not.
By the way, DIY nickel plated brass snap kits are also available if the snaps on the shoulder are defective, I have replaced a bunch of them....or just replace them with a second weight belt buckle.

I agree the aluminum backpacks are simply the best. I have all Sportsways, but I know Dacor made them also. I throw mine all over the place, literally THROW them and have had no issues whatsoever. I find these style backpacks to be very comfortable and really can't figure out why not many use them. I had a voit cycolac that broke on the first dive. And the smaller plastic ones seem do break where all the strap hardware attaches. US divers made a more durable one, but I still prefer the old aluminums.