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Hi Frank, The sub has been painted a couple of times, and so I'm not sure what exactly they did. I think the original paint is still there, since it doesn't look like the sub has ever been sanded or sand blasted. All the little weld splatter is still there, of which would of been very easy for them to sand off. From the looks of it, I would guess they only did stick welding on the sub, and did it very quickly. There is some voids next to some of the weld beads that look like they used to much power for those welds, and then didn't make another bead to clean it up. I plan to TIG those voids up. I have some pictures in regards to this I'll post in a bit. I've sanded some test areas, and there is a pretty good gray primer at the base that is still protecting most of the exterior. I don't see any of that primer on the interior, so I think they skipped that coat in there. Most the rust on the sub is from it being left outside for the last 10 plus years, and allowing water to get in thru a open hatch and not draining it. I cleaned up the mud, loose paint, and water about a year before I acquired the sub and drilled a .25" hole at the bottom of each ribbed section, so it would at least drain, and not deteriorate as fast as it was if it stayed there longer. The worst rust pitting is were the lead slabs were attached,since they didn't put any spacers between the lead and the painted metal. That area couldn't breath and dry out easily. So I might need to replace the main steel vertical panels on both skids, as well as the lower horizontal strip, with SS. Regards, Szybowski From: ShellyDalg@aol.com Date: Thu, 22 Jan 2009 14:58:27 -0500 Subject: Re: [PSUBS-MAILIST] Side Thruster Removal on K-250 #118 To: personal_submersibles@psubs.org Hi Brent. Good pics. What type of paint was used on George's subs? I see
where the rust has gotten pretty bad in some spots, and I wonder if it's caused
by simple lack of maintenance, or not enough protection in the first place.
Heavy zinc paint stands up well if maintained properly. Where two components are
bolted together, there are several solutions to prevent rust. Delrin disks,
bushings inside the bolt holes, judicious painting of all exposed parts,
stainless, anodes, and lots of other ideas/methods are easy solutions.
I designed my sub so I can dis-assemble it quickly and easily for
maintenance/repair. I should be able to strip it down to the bare hull and
re-assemble it in a day, with minimal tools. That way I will be able to get it
clean after dives, and touch-up any paint that needs it, without having to sit
in the shop for a week. I like the idea of putting plastic/nylon bushings in the
bolt holes. Stainless bolts and nylon/stainless washers, so the potential for
rust is lessened. There are some places where I'll be using brass bolts with
stainless nuts, and some places where I'll use lead bolts with stainless nuts. I
have some parts that need to be very strong, and others that are designed to
break-away if needed. Brass fasteners are good in some spots because they may
need to be drilled out for removal. Here's a quick sketch of one place where
it's needed.
Because the fairing covers the mounting tab, I'll be welding a stainless
nut onto the bottom of the tab. The brass bolt head can be cut/ground off if
need be to remove the fairing. The nylon bushing keeps the different metals from
corroding together, and once the brass bolt head is gone, the bushing and
fairing can be lifted off. Then some vise grips will pull out the brass bolt, or
if needed, drill out the bolt because it's soft. This of course will only be
necessary if I don't maintain that particular connection and allow it to get
crusty.
Spare bushings, washers, brass bolts, etc are just a few things to carry
along in the field for repairs/maintenance. I want to be able to repair this
thing with a minimum of tools when I'm out some where remote. Frank
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