Re: Hull Material ??

["D. Blake" <dblake@bright.net>]

If I understand your question, fairing the inside would be performed with a
easily removable appliance consisting of plywood bulkheads evenly spaced on
a horizontal axis covered with a durable plastic film wth plaster and a
chicken wire reinforcement.
Once cured, a steel mesh matrix reinforcing the cement would be spaced
midway between the surface of the appliance and the expected external
surface.  Once the surface cement  has been faired and cured, the
wood/plastic/chicken wire/plaster appliance could be removed by whatever
means with careful attention to not disturbing the less fragile reinforced
cement hull.  Bust it out with a sledge hammer by cracky if you don't intend
on reusing the forms.
Think of it as working from the inside out.  Once the general shape of the
hull is achieved minus the desired thickness of the hull, all that is left
is constructing a strong skeleton matrix to reinforce the cement.  Use
finishing nails and small washers to accurately locate the skeleton halfway
between the internal appliance surface and the planned external surface.
I have done a little reading on ferrocement boat construction--albeit a few
years ago--and I remain excited.  I remember seeing a picture of a small
rowboat constructed in the 19th century from cement still moored to the bank
of a river in France.  Talk about longevity...
Big Dave
-----Original Message-----
From: Marsee Skidmore <heyred@email.msn.com>
To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
Date: Tuesday, October 26, 1999 12:11 AM
Subject: Re: Hull Material ??


>I am also under the impression that ferrocement has a poor reputation in
>yachting circles, and not all of it deserved. I'm not aware of any inherent
>weaknesses as a hull material, but there is a wide variety in quality of
>workmanship. It's hard enough to fair the hull on a blowboat, when you've
>got ready access to both sides. How would you manage the same with a psub,
>when access to the inside is restricted? :-o Joe
>-----Original Message-----
>From: Karl Fuller <fullerk@voyager.co.nz>
>To: personal_submersibles@psubs.org <personal_submersibles@psubs.org>
>Date: Saturday, October 23, 1999 2:34 AM
>Subject: Re: Hull Material ??
>
>
>>Hi Dan,
>>I agree, ferro must be a possibility  and it should work in theory but it
>>could be hard to get certified. I guess that like in yacht hulls it has a
>>poor reputation and for a sub hull you can't afford to experiment.
>Certainly
>>it has merits in the way of cost and hull forms that could be made.
>>
>>Good luck,
>>Karl
>>
>>----- Original Message -----
>>From: Dan J. Rice <dan.j.rice@sherwin.com>
>>To: <personal_submersibles@psubs.org>
>>Sent: 21 October 1999 19:54
>>Subject: Hull Material ??
>>
>>
>>>
>>>
>>> Is Ferro Cement a possibility? What reinforcement? What sealants?
>>> I know it has been used for power boat hulls. The weight would seem to
be
>>a plus
>>> for subs, as well as ease of construction and cheaper price.
>>> Design would be more flexible than steel, and it would seem to be a good
>>choice
>>> for compression strength.
>>> Anyone tried it?
>>>
>>> Dan
>>>
>>>
>>>
>>
>>
>
>
>