Sea Hornet Air Commando Regulators

[whaylonsmithers]

Fantastic video. I hope there's some more out there.

Does your source know if those drawings are stashed away somewhere? I'd love to scan one and insert it into the PDF second stage repair manual. I've got something thats workable, probably posted by you, but the source document was obviously in poor condition and it's dicky to work from.

 

[Fibonacci]

I did receive a couple of CD's of Sea Hornet archive material but I don't recall seeing the mini-poster amongst them. I will double check.
Closer examination reveals the artwork in the video to be hand drawn, so maybe it was a master for scanning and print production? It obviously had a seal of approval!
Sea Hornet manually drafted all their earlier regulators, 2D CAD was only just making an appearance for the Command Air line. The video also documents early CNC machine tools for volume production of some components, all done in Sydney.

 

[Fibonacci]

Another batch of Command Air regulators saved from land fill... pretty much every LDS here will now claim they cannot be serviced when the truth is any decent tech can replace the standard AS568 o-rings they use, clean adjust and get them back in action.

The HP seats can be refaced easily, and the iconic clear window often gets scratched up but can be refinished by masking off and careful wet sanding with progressively finer grades of wet and dry paper (finish with 2000 grit) used with an eraser backing and soapy water.
I've found the finer grade Autosol Acrylic polish to be excellent when used after a first pass with regular Austosol... pretty much optically clear, and works on HP gauge faces too.

Although the clear window is clipped in, the legs are now very fragile and usually one will snap off if you try to remove it.
One early blue label reg had the original latex rubber exhaust valve (for faster 'snap back') which deteriorated rapidly in service, hence the clear viewing window to monitor condition.
Best to remove the residual goo from the valve seat area with a Q-Tip and orange oil label remover.
On later production they were changed to silicone rubber, but the window was retained.

One tip, the notch in the chromed 'LP valve piston' can be fiddly to line up with the square air tube holes when replacing the demand lever, if you screw in the LP seat to its stop that will hold the piston at pretty much the right spot when engaging the legs of the demand lever. Back it off a few turns afterwards before installing the diaphragm.

Second tip... if the face cover is stuck in place use the rubber coated ends of a suitably sized pair of pliers reversed into the slots... easy!

MK 1 DIN has the 3 pin style adjustable IP, this satin finish one was in excellent condition.. apart from crispy original rubber hoses!
IP stable at specified 10 BAR.
One very rare Command Air Nitrox as a bonus...

 

[Kupu]

Nice save, it would be a shame for those to get tossed in a garbage heap!
If you ever find yourself having more of the Sea Hornet branded Command Airs than you want, I am interested to add one to my collection. Thanks for the tip on cleaning the second stage window, I have a couple that would look better after that beauty treatment.

 

[axxel57]

Another batch of Command Air regulators saved from land fill... pretty much every LDS here will now claim they cannot be serviced when the truth is any decent tech can replace the standard AS568 o-rings they use, clean adjust and get them back in action.

The HP seats can be refaced easily, and the iconic clear window often gets scratched up but can be refinished by masking off and careful wet sanding with progressively finer grades of wet and dry paper (finish with 2000 grit) used with an eraser backing and soapy water.
I've found the finer grade Autosol Acrylic polish to be excellent when used after a first pass with regular Austosol... pretty much optically clear, and works on HP gauge faces too.

Although the clear window is clipped in, the legs are now very fragile and usually one will snap off if you try to remove it.
One early blue label reg had the original latex rubber exhaust valve (for faster 'snap back') which deteriorated rapidly in service, hence the clear viewing window to monitor condition.
Best to remove the residual goo from the valve seat area with a Q-Tip and orange oil label remover.
On later production they were changed to silicone rubber, but the window was retained.

One tip, the notch in the chromed 'LP valve piston' can be fiddly to line up with the square air tube holes when replacing the demand lever, if you screw in the LP seat to its stop that will hold the piston at pretty much the right spot when engaging the legs of the demand lever. Back it off a few turns afterwards before installing the diaphragm.

Second tip... if the face cover is stuck in place use the rubber coated ends of a suitably sized pair of pliers reversed into the slots... easy!

MK 1 DIN has the 3 pin style adjustable IP, this satin finish one was in excellent condition.. apart from crispy original rubber hoses!
IP stable at specified 10 BAR.
One very rare Command Air Nitrox as a bonus...

Funny!
Just serviced a Pro Sub Command Air in December for a customer without realizing what it really was.
I know I was somehow irritated, because I thought I had seen that reg before, but without manuals or schematics the bell didn't ring.
I know only Pro Sub regs which are mostly substandard in terms of components, design and performance, so I didn't care much.
I don't find the data right now, must be on my old computer, but I remember that I was a bit surprised about the good performance of the 2nd.
Unfortunately I didn't make as many pics as I usually do, but I will try to trade the reg for my collection, the customer will not find anybody else to touch that reg here anyway next time it has to be serviced.

 

[Fibonacci]

Funny!
Just serviced a Pro Sub Command Air in December for a customer without realizing what it really was.
I know I was somehow irritated, because I thought I had seen that reg before, but without manuals or schematics the bell didn't ring.

After being advised ProSub bought all the remaining Command Air spare parts from Sea Hornet, I contacted them to ask about a couple of 'rare spares' particulary demand levers and LP orifices. They did still have stocks about two years ago, so maybe worth contacting them if you get stuck.
The demand levers are a strange one, on the lower spec Explorers they are 316 Stainless like most other regulators.
On the Command Airs they are chrome plated Phosphor Bronze as a polished chromed surface sliding on the Delrin rub plate has a slightly lower coefficient of friction than stainless.
Whether this difference is actually able to be effectively measured in WOB is open to question, a bit like originally specifying latex rubber for the exhaust valve! Good in theory... and I guess they were designed to reliably crack at 0.5"
What actually happens is the tips of the demand levers can trap residual salt water against the Delrin rub plate and cause pitting or flaking of the chrome over time. Quite common to find on poorly rinsed regs stored in humid climates.
This can simply be polished off a 316 stainless demand lever, but on a Command Air it will expose the bare metal which will rapidly corrode unless replated with Nickel. I've done this a couple of times and it works, but a fiddly time consuming process.

 

[Fibonacci]

Here's the corresponding ProSub parts lists FYI...
And a pic showing the RAN B-Commander upgrade parts

 

[clark01]

Another batch of Command Air regulators saved from land fill... pretty much every LDS here will now claim they cannot be serviced when the truth is any decent tech can replace the standard AS568 o-rings they use, clean adjust and get them back in action.

The HP seats can be refaced easily, and the iconic clear window often gets scratched up but can be refinished by masking off and careful wet sanding with progressively finer grades of wet and dry paper (finish with 2000 grit) used with an eraser backing and soapy water.
I've found the finer grade Autosol Acrylic polish to be excellent when used after a first pass with regular Austosol... pretty much optically clear, and works on HP gauge faces too.

Although the clear window is clipped in, the legs are now very fragile and usually one will snap off if you try to remove it.
One early blue label reg had the original latex rubber exhaust valve (for faster 'snap back') which deteriorated rapidly in service, hence the clear viewing window to monitor condition.
Best to remove the residual goo from the valve seat area with a Q-Tip and orange oil label remover.
On later production they were changed to silicone rubber, but the window was retained.

One tip, the notch in the chromed 'LP valve piston' can be fiddly to line up with the square air tube holes when replacing the demand lever, if you screw in the LP seat to its stop that will hold the piston at pretty much the right spot when engaging the legs of the demand lever. Back it off a few turns afterwards before installing the diaphragm.

Second tip... if the face cover is stuck in place use the rubber coated ends of a suitably sized pair of pliers reversed into the slots... easy!

MK 1 DIN has the 3 pin style adjustable IP, this satin finish one was in excellent condition.. apart from crispy original rubber hoses!
IP stable at specified 10 BAR.
One very rare Command Air Nitrox as a bonus...

Hi Fibonacci,

I have a bunch of Command Air regs, including one of the gold ones. Do you know if there's a list of the o-ring sizes for the 1st stage somewhere?

Alternatively, can you recommend a decent AS568 kit? I can get the reg apart, but it appears there's a variety of o-ring thicknesses. I can't find a kit that covers the right mixture of diameters and thickness.

Thanks!
-Clark

 

[Fibonacci]

Hi Clark

Hi Fibonacci,

I have a bunch of Command Air regs, including one of the gold ones. Do you know if there's a list of the o-ring sizes for the 1st stage somewhere?

Alternatively, can you recommend a decent AS568 kit? I can get the reg apart, but it appears there's a variety of o-ring thicknesses. I can't find a kit that covers the right mixture of diameters and thickness.

Thanks!
-Clark

Sorry for the delay in getting back to you, was away interstate over the Easter break.

There are no modern Sea Hornet service kits available to my knowledge, and the newest of any NOS kits would be 20+ years old.
Better to use fresh new production o-rings.

According to my records to service a MK 1 first stage (swivel head) you need the following AS568 o-rings:
-010 90 Duro
-011 90 Duro x 2
-012 90 Duro x 2

-011 70 Duro x 4
-016 70 Duro
-018 70 Duro
-020 70 Duro
-024 70 Duro

-112 70 or 90 Duro for dust cap

 

[clark01]

Thanks very much Fibonacci!

Do you happen to know a good source for o-rings? Looking at the usual industrial supplies, I can't find a general kit (with a range of sizes) that covers everything.

Companies like RS sell them individualls, but minimum order quantities of 50 o rings in one size!

-C

Hi Clark

Sorry for the delay in getting back to you, was away interstate over the Easter break.

There are no modern Sea Hornet service kits available to my knowledge, and the newest of any NOS kits would be 20+ years old.
Better to use fresh new production o-rings.

According to my records to service a MK 1 first stage (swivel head) you need the following AS568 o-rings:
-010 90 Duro
-011 90 Duro x 2
-012 90 Duro x 2

-011 70 Duro x 4
-016 70 Duro
-018 70 Duro
-020 70 Duro
-024 70 Duro

-112 70 or 90 Duro for dust cap