|
Well, for example you may
have to remove a viewport if you want to have the hull sandblasted, weld on
it, or paint, or remove it for repair if it gets scratched. With
the silicone I did indeed get rust in the pocket. But even if that
hadn't been the case, I would have needed to pull the dome when I decided
to get the hatch ring powder coated. You hope these things won't come
up every day, but if you can avoid all the hassle by using an o-ring seal, go
for it. Un-bedding a viewport is really a pain, even if all psubbers
necessarily have a high pain threshold when it comes to maintenance jobs. If you
see a psub that's getting a "touch up", chances are it looks like a
bomb went off in it.
Alec The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it.
From: owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of
ShellyDalg@aol.com
Sent: Thursday, February 28, 2008 2:17 PM To: personal_submersibles@psubs.org Subject: Re: [PSUBS-MAILIST] FEA of a Basic Flat Acrylic Viewport Hi Alec. I would guess that removing and re-using a lens sealed in
urethane would be difficult, if not impossible. The Sikaflex 295 is what I was
considering too. Now, for maintenance, if the lens is sealed in, is it necessary
to remove it ? What maintenance task is necessary that would require removing a
lens other than replacing a lens because it was damaged or reached it's maximum
life cycles ? If a dome or disc is damaged, well, then you won't be using it
again anyway. I'm trying to imagine a scenario where I'd need to pull one out
and re-use it. Coming up with nothing. Repainting wouldn't need a removal unless
there was rust or corrosion in the pocket. Pulling the lens to put something
through the hole ? The hatch would be the logical choice for that.
How often the lens needs replacement would depend on how many cycles it's
been through, and how well it's protected from UV and scratches. Although a lens
is a considerable investment, it's relatively small compared to the overall cost
of the sub, and after all, the windows are the main reason for building a sub in
the first place.
My main window is going to be exposed to wave action when surface
traveling. I hope to be able to motor along relatively quickly with the
''outboard'' option. To prevent collision with small floating debris while
running on the surface, I was thinking of a removable cover for the main window.
I saved the disc I cut out of the hull for the main window so I could use it as
a cover. Haven't really spent much time on the design, but thought I could just
add an angle iron ring with latches that can be released easily
to the cover disc, and then put the cover in the support boat when readying for
a dive. It could possibly be attached to the hull for storage while diving too,
as long as it was in a location that didn't get hung up on something.
I had some discussions earlier here about a bow shaped plexi cover that
would stay in place, but bubbles get on the inside and would interfere with the
view. A removable cover seemed like the next best option.
Anyway, Have you had to replace any of your plexi besides the instance
where the seal was bad?
Frank D. Delicious ideas to please the pickiest eaters. Watch the video on AOL Living. |