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Yes Brent, I'm definitely a fringe element builder.
I'm going through the process of buying everything
inside & outside my sub before I've
finalized the shape & material I'm
building the sub out of.
Probably comes from living upside down on the other
side of the world.
Whats your excuse?
Alan
----- Original Message -----
Sent: Thursday, September 03, 2009 5:54
PM
Subject: Re: [PSUBS-MAILIST] cast dome
cost
Looks like we are the fringe element builders, Alan.
;} The secrets out
Now instead of worrying about bubbles on the dome, I
can worry about the bubbles in the dome. If you can't see clearly, it
might not be your eyes that are the trouble, but the acrylic fabricator you
chose. ;}
Mudpuppy
" Part of being sane, is being a
little bit crazy. " ~ Janet
Long
Sent: Tuesday, September 01, 2009 4:10 AM
Subject: Re: [PSUBS-MAILIST] cast dome cost
Jay
I wonder if Greg exports really thick goldfish
bowls to NZ.?
No, I have someone making a dome for me at the
moment, out of certified GS grade cast acrylic ,
(not from the local hardware store Frank) &
intend to test it well.
The alternative ideas were just something Brent
& I were brain storming off site.
Regards Alan
----- Original Message -----
Sent: Tuesday, September 01, 2009 10:17
PM
Subject: RE: [PSUBS-MAILIST] cast dome
cost
Alan,
Have
someone build your dome ports for you. I understand that Greg Cottrell
is not making ports for the sport market anymore due to liability issues and
“fringe” element builders that are developing subs with little grasp on
reality. Our German/Dutch PSUB members have been manufacturing some
large blown domes for members I believe.
R/Jay
Resepectfully,
Jay
K. Jeffries
Andros Is.,
Bahamas
Save the
whales, collect the whole set.
From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Alan
James
Sent: Tuesday, September 01, 2009 12:24 AM
To:
personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST] cast
dome cost
Hey I could be
paying huge consultation fees for your advice
Jay.
----- Original
Message -----
Sent: Tuesday,
September 01, 2009 3:04 PM
Subject: RE:
[PSUBS-MAILIST] cast dome cost
Alan,
Do
you want the blunt answer or the tactful answer? J
R/Jay
Resepectfully,
Jay K.
Jeffries
Andros Is.,
Bahamas
Save the
whales, collect the whole set.
I was playing
round last week with the idea of roto casting a dome by joining two
thin
blown domes at
the flanges, squirting acrylic resin in through a hole in the flange &
rotating it
on the
horizontal & vertical axis similtaneously. This would invlove stopping
when the resin had set,
squirting in
more resin & starting & slowly building up to the desired
thickness.
Its a lot
easier setting a thin section than a thick. I rotated vynil
ester in a hemisphere attached to a drill
& found it
removed the bubbles caused by mixing, wich is a plus. Didn't need much
speed either.
I wasn't going
to persue this till after I had built my sub, but while we're on the
subject, has anyone got knowlege
/ thoughts
on this that will save me the bother.
-----
Original Message -----
Sent: Tuesday,
September 01, 2009 10:39 AM
Subject: RE:
[PSUBS-MAILIST] cast dome cost
Alan
& Brian,
Our
resident expert, Greg Cottrell gave an excellent presentation on this
subject at the Raystown PSUB Conference a few years ago. He has
accomplished some remarkable things with acrylics and noted that casting
a dome was not a simple matter, fraught with opportunities for
failure. He described three methods if my memory serves me right.
From his presentations it was the audience’s opinion that it
should be left to professionals when it comes to casting a dome.
Depending on the casting, the heat generated if not compensated for,
could result in an intense fire in the mold.
R/Jay
Resepectfully,
Jay K.
Jeffries
Andros Is.,
Bahamas
Save the
whales, collect the whole set.
From:
owner-personal_submersibles@psubs.org
[mailto:owner-personal_submersibles@psubs.org] On Behalf Of Alan
James
Sent: Monday, August 31, 2009 6:10 PM
To:
personal_submersibles@psubs.org
Subject: Re: [PSUBS-MAILIST]
cast dome cost
Brent & I
have been looking at this off site recently.
I spent a lot
of time looking for an unpolemerized methyl methacrylate with a
catalyst.
wich is the
raw materials they start with to make the sheets. Eventually
I found some
with a
plastics guy who has blown domes for
me.
He bought a
drum of it & said it was very hard to work with. With the domes
there is a very controlled heating process
in
pressurized ovens. Out gassing in the setting process forms bubbles that
attach to the sides of the molds
and are
hard to remove. Hugh went over to Stanley plastics & saw the
process. He said they over compensate
the
dimentions to allow for the outer faces to be taken back beyond the "
bubble layer ".
I've mucked
around with polyester casting resin for a while & large castings are
a bit of an art. They can take days to set,
& there
is a relationship between temperature & amount of catalyst. If you
get it wrong the mold cracks or the materials too
soft.
Hope someone
else comments, it would be interesting to learn
more.
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