Re: [PSUBS-MAILIST] Stern of KL-250 Coming Apart

Vance,

I'll trade you a hatch assembly drawing for a Mushroom vent drawing. ;}

I noticed I've been holding out on you as well, with these pictures of my subs stern parts coming apart.

You can really see the need for 316 SS in many of these parts. I'm replacing all the connecting parts with SS or some thing else apropriate, and I might just go with SS push pull cable control means for my new pair of sterring/braking flap rudders.

How to you like that big rust spot under the port side of the MBT's siliconed attachment area?

I'm planning on sealing the new MBT's I'm planning to fabricate to the heads with a soft rubber or urethane strip bonded onto the heads. Then just put PVA mold release on that strips outer surface, so that the Sekaflex bead I add to the FRP MBT sealing edge will not bond to the strip when I clamp it on to the head. Once the Sekaflex is curred I will remove the FRP MBT and clean of the PVA then reattach the tank. What this does for me is gives me a good sealing means, while making it easy to remove and reattach the MBT's when ever I want to, with out having to apply some sort of goop sealant every time. If I have cameras, lights, sonar, and what not under those heads, it will make it really easy to work on them and the new plate thru hulls, if I can easily remove the tanks.

The reason for the Sekaflex added to the FRP, is to deal with the voids and uneven FRP mating surface. I can see I might be able to do the above without the sealing strip, an just apply the PVA directly to the flange of the heads and use a really soft Sekaflex. This configuration would give me little lower profile, for the high speed runs. ;}

I might just replace the whole stern weldment to a aluminum tubing weldment, that is coated with polyurea. That would take some weight off the sub, that I could relocate lower down, and perhaps add some of that weight to the new double drop weight.

If I do that I would also replace the bow MBT holding weldment to a aluminum one.

I'm adding a fair bit of weight in terms of a full set new K-350 ribs to the original ones. So that might take up most that weight savings in the new MBT holding weldments. But I'm much lighter on the new thrusters, crash cage/tangle guard, and on and on. So it will be a whole new animal when finished.

If it turns out to float upside down when it's done. Then I'll just remove the hatch and use it as an ambient sub, and enter it, like you would many SportSubs. ;}

The original lower stern fairing and the rudder was changed out by Dr. LeShack to the design you see now.

http://cid-5085d10eb6afe47c.skydrive.live.com/browse.aspx/Stern%20MBT%20Coming%20Apart

Regards,
Szybowski

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