Skipjack 1/72

[He Who Shall Not Be Named]

If water is getting by the pump into the SD, then you have a bad pump (maybe a pin-hole in one or all of the diaphragms).

M

[greenman407]

Thanks Dave. Ill take the subdriver and put it in the bathtub and operate it and see If I can see anything.

[greenman407]

Its quite obvious to me that the factory periscopes arnt going to cut it from a durability standpoint. Fast water will almost bend them in half. So, using some brass tube and just the top portion of the factory periscopes I have constructed and installed a reasonable but more durable facsimile.

[trout]

Will that extra weight up high cause problems?

[He Who Shall Not Be Named]

Go to aluminum instead of brass. To limit the topside weight, as Tom suggested. But, also because you want those scopes to bend when you hit something with them ... AND YOU WILL!!!! Better the scopes fail than the sail get knocked off the hull!

M

[alad61]

Nice job on the scopes but actually Mark the kit ones on the whole are pretty durable. Sadly though the thin aerial atop the scope will be the first casualty That would be one that shoud be replace with aluminum wire or such.

[greenman407]

Hmmmm.............

[greenman407]

Dave, earlier we had discussed a leak in the Sub-driver. I noticed that when you slide in the equipment tray and seal up the rear bulkhead, you can hear air leaking thru the system, perhaps thru the SAS pump. I know on the non SAS ones this would be a bad thing. Is this normal with the new system or does this point to a bad pump? It cant be normal, otherwise you would not include a equalizing valve in the bulkhead. It cant be motor seals or pushrod seals or the like because If I plug up the SAS system , there are no leaks.

[alad61]

Interesting question Mark. Mine does the same but I have just assumed that was normal. As an additional question to HWSNBN. I noticed that I can clearly hear the safety float move in the Gato sas but not in my Skipjack. Is that normal? It could explain or partially explain the water ingress I get.

[He Who Shall Not Be Named]

With the SAS, the over-pressure in the cylinder (when pushing the motor-bulkhead into place, for example), will escape through the induction line through the safety-float valve.

The 'equalization valve' on the motor bulkhead is there to serve as a test-point for leak-checking the system, not to relieve the slight over-pressure created within installing the bulkheads.

M

[He Who Shall Not Be Named]

With the SAS, the over-pressure in the cylinder (when pushing the motor-bulkhead into place, for example), will escape through the induction line through the safety-float valve.

The 'equalization valve' on the motor bulkhead is there to serve as a test-point for leak-checking the system, not to relieve the slight over-pressure created within installing the bulkheads.

M

[greenman407]

Ok, thats what I was hoping. Funny! Tonight I had her in the tub and was testing things.....when all of the sudden.......BOOM! She jumped out of the water and I could see the hull flex open and then shut as she bobbed up and down in the water. I immediately knew what it was as Ive seen this before. The gas reservoir either pushed the hose off or popped the hose. Sure enough the hose had come off, I reset it on there but this time I pushed the hose much further on to the brass tube. I dont think that it will happen again.
As far as water ingress, tomorrow Im going to install another snorkel valve. If that doesnt fix it Ill probably just build a con formal tank to collect it like Manfred did. No big deal. The pump and snorkel system seems to function well, other than the little bit of water I am getting. After five complete submerge and surface sessions I had about a 1&1/2 tablespoons of water inside.

[He Who Shall Not Be Named]

Ah! ... the joy of the gas sub-system. Was the tub water warm? Betcha it was.

M

[He Who Shall Not Be Named]

Ah! ... the joy of the gas sub-system. Was the tub water warm? Betcha it was.

M

[greenman407]

I gotta new snorkle valve from Dave and I installed it this evening. Its different from the original one in that it doesnt use the soft pink foam but a more firm material thats light grey in color. I discovered where some of the water might be coming from. Where the snorkle brass tube goes into its base and tightens with a set screw, I never sealed around it on top. Might have been siphoning some thru there. Tomorrow more tales will be told.