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Brian I have had good luck with mold release. The stuff they use in
a fiberglass mold.
You basically just wax the surface.
I have not done any long term with it, but not much of
anything will stick to it.
Dean
In a message dated 7/16/2009 10:26:23 A.M. Central Daylight Time,
ojaivalleybeefarm@dslextreme.com writes:
I am
going to be needing a type of rubber to form a gasket between the two halves
of my ferro-cement ballast-supersturcture. I have a flat surface that
goes all the way around, all of the ferro-cement will be coated with
epoxy, so I will need a type of rubber that will not stick to the epoxy
coating. Since I will most likely be taking this thing apart and putting
it back together many times I don't want to have to be scraping material off
every time I need to lift the top half off. I was thinking of
just using regular silicone out of a tube ( a lot of tubes !)
. There will be bolts all the way around every 6" or so where the clam
shell mates up. Since this is a soft ballast area there will not be too
much pressure difference at the area where the clam shell mates up so I'm
hoping that I don't have any problems. I made the mating area very wide
( 6" or so) so that I would have a better chance of sealing the
area. Having the an air leak in that area would mean I
would not be able to bring the sub up to it's maximum buoyancy and would
severely limit my freeboard. I was thinking of maybe putting a
light coating of vasoline on the surface before I applied the silicone so it
would not stick.
Brian
Yeah, understood.
The point to RTV for George was that it serves both as gasket and sealant,
ie., quick and dirty, and it works. Not fun later, as I said, but it's great
stuff. I was thinking of cutting thin red rubber gaskets (1/8" thickness)
then using a thin coating of RTV on both sides. That would give me the soft
barrier and less vulcanized goo down the road. Wish me
luck
Vance
-----Original Message-----
From:
Recon1st@aol.com
To: personal_submersibles@psubs.org
Sent: Wed, Jul
15, 2009 9:05 pm
Subject: Re: [PSUBS-MAILIST] sikaflex suggestion
That is what I have heard about RTV. So I am assuming then you
would use
Sikaflex. It sounds right but there about 400 different
versions. Hard on a poor old
boy like me.
Dean
In a message dated 7/15/2009 7:39:06 P.M. Central Daylight Time, vbra676539@aol.com writes: I
haven't looked into it. Mine were bedded in RTV, which
sealed effectively, but were not what I'd call great fun to get out
again for paint, etc. Sikaflex doesn't cure the same way, and never takes
a set. RTV is, of course, the acronym for room temperature vulcanizing,
and they ain't kidding. It bonds and sets up something fierce. The other
problem with it is that RTV can't be repaired. It won't bond chemically to
itself once the original application kicks. Meaning that if you have a
leaker, you get to try out the car jack again to break the port loose (and
hope that the RTV is the ONLY thing that breaks). In either case, you have
to start scraping and go back to square one. What a pain. Trust me,
there will never be another submarine in my garage with goop sealed ports.
Never.
Vance
-----Original Message-----
From: Recon1st@aol.com
To: personal_submersibles@psubs.org
Sent:
Wed, Jul 15, 2009 8:20 pm
Subject: [PSUBS-MAILIST] sikaflex
suggestion
I have been looking at sikaflex for my viewports and did not
realize the number
of types.
Any suggestions on which one to use?
Dean
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