Assembling Doubles

[sunshower]

I picked up some highland bands but they have no instructions and I'm not mechanically inclined enough to figure out the right placement of the bolt kit bits. I have a couple of capped screws, lock nuts, standard nuts, lock washers and flat washers. I could put the washers and a nut on the front, as one video suggests, but I'm not sure where the lock nut would go.

Google and youtube are generally helpful but not specifically for this. Any help in what goes where would be appreciated. Thanks.

 

[Wookie]

Put lock nut on the stud until the plastic ring is just engaged. Put a flat washer on it. Slide it through the band, and put a regular nut on the other side to lock down the stud and keep it from spinning. Place the band on the ground and place the rigged but not tight cylinders on top of the band and slide the band to the sholder of the cylinder. Place another nut and flat washer over the stud and tighten, not too much (yet). Rig the other band the same way and place the cylinders on the band and slide the second set up so the studs are 11" apart. Snug up the second band. Adjust the manifold so that the cylinders are set at the same width as the bands without binding. Tighten the top band. You should be able to rotate the isolator valve through about a turn so you can set it the way you like. Tighten the top band. Make sure the isolator still turns freely. Tighten the isolator lock nuts. The last thing on the studs is a lock washer, flat washer, and the wingnut.

 

[doctormike]

First hit on google. Shows where the lock washer goes.

 

[sunshower]

Thanks guys. I've watched that video. It's using all thread rods; mine have a hex head; that's why I'm uncertain about where to put the lock nut.

 

[Wookie]

You would use the lock nut (in that case) to tighten the bands together.

 

[cool_hardware52]

If you'd like to avoid damaging your manifold I'd recommend watching this video.

It's *much* easier to cross thread fine brass threads on the isolation bar than the corse threads on the tank valves.


Tobin

 

[Scared Silly]

You would use the lock nut (in that case) to tighten the bands together.

Highland bolt kits come with both a lock nut and std. nuts. So you have a choice. I prefer to use the std. nuts with a locking washer rather than lock nuts. Mostly because lock nuts IMHO are better suited for permanent usage. At some point you will need to disassemble for inspection/re-qualifying.

Tobin, great video - I never thought about adding the second nut on the opposite side of the band so not to need two wrenches when tightening the bands.

 

[KevinNM]

The written instructions from DGX are good too.
Assembling Double Cylinders | Dive Gear Express®

 

[sunshower]

I got it. Just going to get some thumbwheels to replace the wing nuts and be done with it. Thanks again for the input.

 

[divezonescuba]

If you don't like the derlin plastic thumbwheels, you can get 316 stainless thumbwheels for about $17 a piece on amazon. I think that they are more durable than the plastic thumbwheels in that they cannot strip and do not need any washers as well. They have holes on the edges in case you want to insert a Phillips screw driver and really want to torque them down. Even though they are 316 stainless, it is still a good idea to maintain them.

On the subject of threaded rod versus bolts, I have found out that in reality, there are some variations between tank band manufacturer where the flat part goes between the tanks. If the spacing is wider between the two flat parts that the bolts go thru, you will need a longer bolt. This caught me by surprise the first time I encountered it, because I thought everything was standardized.

On a recent trip, I encountered three out of three different setups. I now bring my own set of 6 inch bolts, nylock nuts, hex nuts, washers, and thumbwheels.

If you use a 6 inch threaded bolt, you will always have the extra threads in case you have a problem with there not being enough bolt for your bladder and plate. If you have excess thread, you can thread the nylock nut further down on the back side.

I use a plastic plate that is much thicker than a stainless one and frequently have this issue when renting tanks from other places.