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> >