<html><head></head><body><p dir="ltr">Hollow glass microspheres in a (typically) epoxy matrix. The spheres are so small, they're more like a powder (for a deep / dense foam. Shallower foams will incorporate larger spheres). Mix the composite with the highest possible volume fraction of glass to resin.</p>
<p dir="ltr">Sean<br>
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<br><br><div class="gmail_quote">On May 17, 2014 4:09:46 PM MDT, hank pronk via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<blockquote class="gmail_quote" style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px solid rgb(204, 204, 204); padding-left: 1ex;">
<pre class="k9mail">How is syntactic foam made. I once experimented with 3/4inch plastic water line (pex pipe), the stuff we plumb houses with now. I heated the end of a piece and it melted shut nicely. So I planned to make a bunch of pipes with both ends melted shut then slide a bundle of them inside a pvc pipe. Then fill the void with poly urethane molding resin. It would be cheap and pretty tough. Perhaps an experiment is in order, unless there is a better idea out there.<br />Hank<br /><hr /><br />On Fri, 5/16/14, Sean T. Stevenson via Personal_Submersibles <personal_submersibles@psubs.org> wrote:<br /><br /> Subject: Re: [PSUBS-MAILIST] Gamma needs a diet<br /> To: "Personal Submersibles General Discussion" <personal_submersibles@psubs.org><br /> Received: Friday, May 16, 2014, 7:12 PM<br /> <br /> There's always the not-so-easy but<br /> very elegant solution of syntactic<br /> foam filled hydrodynamic fairings. Go bigger than you<br /> need to<br />
accommodate future expansion, and compensate in the meantime<br /> with keel<br /> weight. Would improve stability, too.<br /> <br /> Sean<br /> <br /> <br /> On 2014-05-15 18:51, hank pronk via Personal_Submersibles<br /> wrote:<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> Alan,<br /> That would work but I want to keep the sub clean on the<br /></blockquote> outside. Gamma is very slippery the way it is. I<br /> am confident I can shed the weight. I have been<br /> weighing all the bits and it looks doable. I am also<br /> looking at a winter project for Gamma. I would like to<br /> have the arm, and valve and a couple of positioning <br /> thrusters on a common chassis, like the DW's. I could<br /> reduce the weight of the lead drop weight because the entire<br /> assembly would be the drop weight. That also solves<br /> the weight problem from the batteries. I would use the<br />
original drop weight screw to drop the new assembly.<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> Hank<br /><hr /><br /> On Thu, 5/15/14, Alan James via Personal_Submersibles<br /></blockquote> <personal_submersibles@psubs.org><br /> wrote:<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"><br /> Subject: Re: [PSUBS-MAILIST] Gamma needs a diet<br /> To: "Personal Submersibles General Discussion"<br /></blockquote> <personal_submersibles@psubs.org><br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> Received: Thursday, May 15, 2014, 8:17 PM<br /> <br /> Hank,a<br /> simple solution would be to just have a<br /> number of floats like Alec's Snoopy.He<br /> has them in a tube, but if the floats had<br /></blockquote> attachment holes<br
/><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> you couldtether<br /> them & clip them on or off.Alan<br /> <br /> <br /> From: hank pronk via<br /> Personal_Submersibles<br /> <personal_submersibles@psubs.org><br /> To:<br /> personal_submersibles@psubs.org<br /></blockquote> <br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> Sent: Friday,<br /> May 16, 2014 12:04 PM<br /> Subject:<br /> [PSUBS-MAILIST] Gamma needs a diet<br /> <br /> Gamma or the pilot needs to go to Jenny<br /></blockquote> Craig. My new<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> AGM batteries weigh 73 lbs each and Gamma has a<br /></blockquote> 60 to 65 lb<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex
0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> weight budget, per battery. That means Gamma<br /></blockquote> needs to shed<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> some lbs before I can take a passenger. I<br /></blockquote> can switch<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> to aluminum scuba tanks, not sure the weight<br /></blockquote> saving<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> there. I can make an aluminum rudder and a<br /></blockquote> few other<br /><blockquote class="gmail_quote" style="margin: 0pt 0pt 1ex 0.8ex; border-left: 1px solid #729fcf; padding-left: 1ex;"> parts also.<br /> Hank<br /><hr /><br /> Personal_Submersibles mailing list<br /> Personal_Submersibles@psubs.org<br /> <a
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