On Tuesday 15 March 2011 09:36:14 you wrote:
>
James,
> I think the acrylic forward main ballast tank is an idea
worth trying.
> It is something I have thought of doing to my K-350.
As far as
> durability goes I do not think acrylic would be too much
worse then
> fiberglass. I encountered a situation while recovering my
350 one day
> where the seas picked up pretty good. The load line on
the crane was
> just slack enough for my sub to come up under the
stern of the boat. The
> boat being heavily built out of steel did not
even flinch the fiberglass
> MBT shattered like an egg shell. Luckily
no one was in the sub.This is a
> good reason to have a way of
securely dogging the hatch from the
> outside. The MBTs I have were
built by George Kittredge so I assumed
> they were made as well as
they could have been.
> The most expensive part of making an acrylic
MBT is the "form" you will
> need. If it was me I would form the MBT
in one piece. Use the K-350
> drawing that gives you the best top
looking down view of the forward
> MBT, scale up the
dimensions and cut the outline on a piece of 6mm
> steel plate.
For a one off maybe you could get away with using a thick
> piece of
plywood. You will probably have to start with 10mm acrylic
> because
of the thinning that takes place at the apex of the finished
> object.
When you are done you will have a thick outer perimeter where it
>
really counts.
> Greg Cottrell is the expert in this field maybe he
will get involved in
> this discussion. I hope I have not given you
any bad advice as far as
> the fabrication aspects.
> Dan
Lance
>
> On 3/15/2011 5:57 AM, James Frankland wrote:
>
> Hi Dan\Glen.
> > i think saddle tanks would have been the best
way to do things.
> > Similar to Nemo sub. But ive already
made the through hulls for the
> > standard tanks and i dont want
to start cutting into my hull again, im
> > done with all that now
so im just going with what i have.
> > Im investigating if its
going to be financially viable to have a clear
> > forward tank
made. I cant do it myself so i'll have to get a company
> >
in the UK to do it. I'm thinking It could be made in sections
and
> > glued together to make it easier to fabricate.
Stachiw's book shows
> > an acrylic sphere that was made in
sections, glued together and tested
> > to destruction. It
did not fail at the glued joints.
> > The one thing im concerned
about is that the entire tank may be too
> > brittle and crack if
crashed. At least glass fibre has a bit of give
> > in
it.
> > Anyway, im waiting for some companies to get back to me
with some
> > prices. Will probably be too expensive.
>
> Regards
> > James
> >
> > On 15 March 2011
06:18, Glen Brown <
gbrown091@gmail.com>
>