<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<HTML><HEAD>
<META content="text/html; charset=ISO-8859-1" http-equiv=Content-Type>
<META name=GENERATOR content="MSHTML 11.00.9600.17107"></HEAD>
<BODY id=role_body style="FONT-SIZE: 10pt; FONT-FAMILY: Arial; COLOR: #000000"
bottomMargin=7 leftMargin=7 rightMargin=7 topMargin=7><FONT id=role_document
color=#000000 size=2 face=Arial>
<DIV>Hank,</DIV>
<DIV>Here's a chart for a starting point: </DIV>
<DIV><A
href="http://www.diabgroup.com/~/media/Files/Products/Core-material-pdf/BMTI%20Selection%20Guide%20-%20October%202013.pdf">http://www.diabgroup.com/~/media/Files/Products/Core-material-pdf/BMTI%20Selection%20Guide%20-%20October%202013.pdf</A></DIV>
<DIV>Cliff used it somewhat in the R-300. I don't have hands-on
experience. This search will give you a bunch of other links:</DIV>
<DIV><A
href="http://search.aol.com/aol/search?enabled_terms=&s_it=wscreen-smallbusiness-w&q=density+of+syntactic+foam">http://search.aol.com/aol/search?enabled_terms=&s_it=wscreen-smallbusiness-w&q=density+of+syntactic+foam</A></DIV>
<DIV>Jim</DIV>
<DIV> </DIV>
<DIV>
<DIV>In a message dated 5/17/2014 6:17:39 P.M. Central Daylight Time,
personal_submersibles@psubs.org writes:</DIV>
<BLOCKQUOTE
style="PADDING-LEFT: 5px; MARGIN-LEFT: 5px; BORDER-LEFT: blue 2px solid"><FONT
style="BACKGROUND-COLOR: transparent" color=#000000 size=2
face=Arial>Jim,<BR>What kind of numbers are we talking here. How much volume
of foam per lb of
buoyancy.<BR>Hank<BR>--------------------------------------------<BR>On Sat,
5/17/14, via Personal_Submersibles <personal_submersibles@psubs.org>
wrote:<BR><BR>Subject: Re: [PSUBS-MAILIST] Gamma needs a diet<BR>To:
personal_submersibles@psubs.org<BR>Received: Saturday, May 17, 2014, 7:11
PM<BR><BR><BR><BR> <BR> <BR><BR>Hank,<BR>Greatest net buoyancy on
your syntactic foam is<BR>achieved by mixing larger <BR>spheres with smaller
spheres so the smaller ones fit in the<BR>gaps between the <BR>larger
ones.<BR>Jim<BR> <BR><BR>In a message dated 5/17/2014 6:04:36 P.M.
Central<BR>Daylight Time, <BR>personal_submersibles@psubs.org
writes:<BR>Sean,<BR>Very interesting, I just googled glass microspheres and
<BR> this is very <BR>
doable.<BR>Hank<BR>--------------------------------------------<BR>On Sat,
<BR> 5/17/14, Sean T. Stevenson via Personal_Submersibles
<BR> <personal_submersibles@psubs.org>
wrote:<BR><BR>Subject: Re: <BR> [PSUBS-MAILIST] Gamma needs a
diet<BR>To: "Personal Submersibles General <BR> Discussion"
<personal_submersibles@psubs.org><BR>Received: Saturday, May
<BR> 17, 2014, 6:34 PM<BR><BR>Hollow<BR>glass microspheres in a
(typically) epoxy <BR> matrix. The<BR>spheres are so small,
they're more like a powder (for a<BR>deep <BR> / dense foam.
Shallower foams will incorporate larger<BR>spheres). Mix the <BR>
composite with the highest possible volume<BR>fraction of glass to
<BR> resin.<BR>Sean<BR><BR><BR><BR><BR>On May 17, 2014<BR>4:09:46
PM MDT, hank <BR> pronk via
Personal_Submersibles<BR><personal_submersibles@psubs.org>
<BR> wrote:<BR>How is syntactic foam made.<BR> I once
experimented with <BR> 3/4inch plastic water line (pex<BR>pipe),
the stuff we plumb houses with now. <BR> I heated the end<BR>of a
piece and it melted shut nicely. So I planned <BR> to
make<BR>a bunch of pipes with both ends melted shut then slide a<BR>bundle
<BR> of them inside a pvc pipe. Then fill the void
with<BR>poly urethane <BR> molding resin. It would be cheap
and pretty<BR>tough. Perhaps an <BR> experiment is in order,
unless there is a<BR>better idea out <BR> there.<BR>Hank<BR><BR>On
Fri,<BR>5/16/14, Sean T. Stevenson via <BR>
Personal_Submersibles<BR><personal_submersibles@psubs.org>
<BR> wrote:<BR><BR><BR>Subject: Re: [PSUBS-MAILIST] Gamma needs a
diet<BR> <BR> To:<BR>"Personal Submersibles General
<BR>
Discussion"<BR><personal_submersibles@psubs.org><BR>
<BR> Received:<BR>Friday, May 16, 2014, 7:12 PM<BR>
<BR> <BR> There's<BR>always the not-so-easy but<BR>
very elegant solution <BR> of<BR>syntactic<BR> foam filled
hydrodynamic fairings. <BR> Go<BR>bigger than you<BR>
need to<BR><BR>accommodate future expansion, <BR> and compensate
in the<BR>meantime<BR> with keel<BR> weight.Â
<BR> Would improve<BR>stability, too.<BR> <BR>
Sean<BR> <BR> <BR> <BR> On<BR>2014-05-15 18:51,
hank pronk via <BR> Personal_Submersibles<BR><BR>wrote:<BR>
Alan,<BR> That would work <BR> but<BR>I want to keep the sub
clean on the<BR><BR>outside. Gamma is <BR> very slippery
the way it is. I<BR> am confident I can shed the <BR>
weight. I have been<BR><BR>weighing all the bits and it looks
<BR> doable. I am also<BR> looking at a winter
project for <BR> Gamma. I would like<BR>to<BR> have
the arm, and valve and a <BR> couple
of<BR>positioning <BR> thrusters on a common chassis,
<BR> like<BR>the DW's. I could<BR> reduce the weight
of the<BR>lead <BR> drop weight because the entire<BR>
assembly would be<BR>the drop <BR> weight. That also
solves<BR> the weight<BR>problem from the <BR>
batteries. I would use the<BR> <BR>original drop weight screw to
<BR> drop the new assembly.<BR> Hank<BR><BR> On
Thu,<BR>5/15/14, Alan <BR> James via
Personal_Submersibles<BR> <BR>
<personal_submersibles@psubs.org><BR> wrote:<BR><BR>Â
<BR> Subject: Re:<BR>[PSUBS-MAILIST] Gamma needs a diet<BR>Â
To:<BR>"Personal <BR> Submersibles General Discussion"<BR>
<BR> <personal_submersibles@psubs.org><BR>Â Received:
Thursday, May <BR> 15,<BR>2014, 8:17 PM<BR>Â <BR>Â
Hank,a<BR>Â <BR> simple<BR>solution would be to just have
a<BR>Â number of floats<BR>like <BR> Alec's
Snoopy.He<BR>Â has them in a tube, but<BR>if the floats <BR>
had<BR> attachment ho!<BR> les<BR>Â you <BR>
couldtether<BR>Â <BR>them & clip them on or off.Alan<BR>Â
<BR> <BR>Â <BR>Â Â Â
<BR>Â Â Â From: hank <BR> pronk via<BR>Â
<BR>
Personal_Submersibles<BR>Â <BR><personal_submersibles@psubs.org><BR>Â Â Â To:<BR>Â <BR>personal_submersibles@psubs.org<BR>
<BR> <BR>Â Â Â Sent: Friday,<BR>Â May 16,
2014 12:04 <BR> PM<BR>Â Â Â Subject:<BR>Â
[PSUBS-MAILIST] Gamma needs a <BR>
diet<BR>Â <BR>Â Â Â <BR>Â Gamma or the pilot needs
<BR> to go to<BR>Jenny<BR> Craig. My
new<BR>Â <BR>AGM batteries <BR> weigh 73 lbs each and Gamma
has a<BR> 60 to 65 lb<BR>Â <BR>weight <BR> budget, per
battery. That means Gamma<BR> needs to <BR>
shed<BR> <BR>some lbs before I can take a passenger. I<BR>
<BR> can switch<BR>Â <BR>to aluminum scuba tanks, not sure
the <BR> weight<BR> saving<BR> <BR>there. I can
make an aluminum <BR> rudder and a<BR> few
other<BR>Â <BR>parts also.<BR>Â <BR>
Hank<BR><BR>Â <BR>Personal_Submersibles mailing <BR>
list<BR>Â <BR>Personal_Submersibles@psubs.org<BR>Â!<BR>
<BR>
<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR>Â
<BR> <BR>Â <BR><BR>Â Â Â
<BR>Â <BR>-----Inline Attachment <BR> Follows-----<BR>Â
<BR><BR>Â Personal_Submersibles mailing <BR>
list<BR>Â <BR>Personal_Submersibles@psubs.org<BR>Â <BR>
<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR>Â
<BR> <BR><BR><BR> Personal_Submersibles<BR>mailing
list<BR> <BR> Personal_Submersibles@psubs.org<BR>
<BR>
<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR>
<BR> <BR><BR> Personal_Submersibles mailing list<BR>
<BR> Personal_Submersibles@psubs.org<BR> <BR>
<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR>
<BR> !<BR> <BR><BR><BR>Personal_Submersibles mailing
<BR>
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR><BR>-----Inline
<BR> Attachment <BR>
Follows-----<BR><BR>_______________________________________________<BR>Personal_Submersibles
<BR> mailing <BR>
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR><BR><BR>_______________________________________________<BR>Personal_Submersibles
<BR> mailing <BR>
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR>-----Inline
Attachment
Follows-----<BR><BR>_______________________________________________<BR>Personal_Submersibles
mailing
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles<BR><BR><BR>_______________________________________________<BR>Personal_Submersibles
mailing
list<BR>Personal_Submersibles@psubs.org<BR>http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</FONT></BLOCKQUOTE></DIV></FONT></BODY></HTML>