[PSUBS-MAILIST] Penetrators/corrosion.

[<james@guernseysubmarine.com>]

Hi Dan/Alec/Frank and all who replied to my email about the electrical penetrators.

Ive got lots of info to plough through now, so just to day thanks for the advice.

another thing ive been thinking about...

Im just ordering the pipes for the battery pods and VBT.  When i assemble the VBT, there is going to be an area of the inside around the last weld joint that i cannot paint before assembly.  I will be using my sub in the sea and the salt water will corrode that area in no time.  The steel is going to be A106.  Any ideas on corrosion prevention on the inside of this tank?  I thought i could pour in a liquid paint, roll the tank around and then pour it out?  Its still not great, but i cant see how else i can do it.  Any suggestions?

Thanks
James


----- Original Message -----
From: Kyle [mailto:edlunddds@comcast.net]
To: personal_submersibles@psubs.org
Sent: Wed, 11 Jun 2008 23:46:11 -0500
Subject: [PSUBS-MAILIST] Dome adhesive

I had my K-250 dome annealed by Greg Cottrell and also had the retaining ring (hatch) powder coated.  He suggested I use Sikaflex-295 UV as the sealant/adhesive between the dome and ring and the following instructions were from an email to me that he said I could share.

"The 3 items should be 226 cleaner (window and seat), then 209 primer (window and seat), then 295UV adhesive (a big fat bead in the corner of the seat). It's a good idea to use a few small 1/16 rubber shims between the window and seat so the adhesive doesn't all squeeze out. I usually mask off the window with two half circles of vinyl mask (from the local sign shop) to keep adhesive off the viewing area. You can wipe off the excess around the window while it is soft and pull the vinyl off later. Some guys let the excess harden and then cut it off later with a knife- this is a bad idea because it scores the acrylic and can cause it to break under pressure. Scratches/ cuts on the inside are not good."
The Items he is referring to are all Sika products.  The process went smoothly I used small pieces of 1/16 inch o-rings as my shims.
Kyle