<html><head></head><body><p dir="ltr">Cliff, I'm on conference in Austin for August 2-7. If by any chance you and your boat are going to be home at that time or the following weekend, I could probably manage a side trip to Devine to have a chat if you're available?</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On May 22, 2015 10:19:33 AM MDT, Cliff Redus 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;">
<div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:12px"><div><span></span></div><div></div><div id="yui_3_16_0_1_1432310706800_2411">Sean, good to hear from you. I am waiting to get on a plane to Barcelona so this will be brief.</div><div id="yui_3_16_0_1_1432310706800_2479"><br /></div><div id="yui_3_16_0_1_1432310706800_2487" dir="ltr">From what I understand of the photos, you design the hydrodynamic<br />fairing and then create virtual slices of the completed design, which<br />you fabricate out of expanded polystyrene. I presume the slice<br />thickness just depends on the available thickness of polystyrene board</div><div id="yui_3_16_0_1_1432310706800_2488" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2489" dir="ltr">Yes, I used 4'x8' x4" sheets.</div><div id="yui_3_16_0_1_1432310706800_2499" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2512"
dir="ltr">and/or how much work you want to do in shaping? I notice that you have<br />these sections joined with wire ties in the photos... am I correct in<br />assuming that this was a temporary measure, and that you moved to<br />adhesives etc. prior to the body filler?</div><div id="yui_3_16_0_1_1432310706800_2513" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2514" dir="ltr">Yes, used a special spray on adhesive that joined the sections. I used a CNC flat bed cutter that a local furniture fabrication company had to cut the section profiles based on a Autodcad drawing of the sections. Bailing wire was used to temporary hold the sections until the adhesive set.</div><div id="yui_3_16_0_1_1432310706800_2551" dir="ltr"><br /><br />Once you've carved the EPS down to shape, you cover in a layer of body<br />filler which you can further refine and sand to a smooth finish, which<br />you then painted. Is the paint necessary? Or can you just
apply a mold<br />release at that point?</div><div id="yui_3_16_0_1_1432310706800_2552" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2577" dir="ltr">Paint is probably not necessary but I wanted to make sure the mold release worked correctly.<br /><br />After that, it would appear that you added flanges to define the mold<br />split lines. Were these centered on the split line, or did you move<br />them slightly before laying up each half? </div><div id="yui_3_16_0_1_1432310706800_2578" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2587" dir="ltr">Slightly off-center so that face was on centerline plane,</div><div id="yui_3_16_0_1_1432310706800_2588" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2590" dir="ltr">Furthermore, was it necessary<br />to split left and right, or do you think you could have done the mold as<br />only two parts?</div><div id="yui_3_16_0_1_1432310706800_2591" dir="ltr"><br /></div><div
id="yui_3_16_0_1_1432310706800_2616" dir="ltr">Not sure I could have removed the female mold from the plug mold without splitting down the middle. Also it made it easier to do FRP layup on the haves.<br /><br />Do you just use a mold release on the plug and then start fiberglassing,<br />or do you apply a gelcoat first?</div><div id="yui_3_16_0_1_1432310706800_2624" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2626" dir="ltr">I used a mold release on the plug first.<br /><br />Did you lay up the whole mold at once and then cut at the flange, or did<br />you do a section at a time?</div><div id="yui_3_16_0_1_1432310706800_2627" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2636" dir="ltr">Section at a time.<br /><br />Once the female mold was finished, I presume you did some further<br />finishing / smoothing to the inside surface?</div><div id="yui_3_16_0_1_1432310706800_2637" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2653"
dir="ltr">Yes, even though I sprayed a gel coat the surface was not clean enough so used normal auto paint procedure to paint the FRP shell.<br /><br />Then a mold release / gel coat / glass to create the shell?</div><div id="yui_3_16_0_1_1432310706800_2654" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2656" dir="ltr">Yes<br /><br />Once the shell was done and trimmed, how did you join the pieces<br />together and smooth the seam before casting your syntactic in?</div><div id="yui_3_16_0_1_1432310706800_2678" dir="ltr"><br /></div><div id="yui_3_16_0_1_1432310706800_2679" dir="ltr">Assembled on the pressure hull and used normal FRP layup techniques to join sections. This normally included grinding down the joints and doing a layup. <br /></div><div id="yui_3_16_0_1_1432310706800_2701"><br />Om my next boat I am looking at generating a polystyrene plug mold <br />cut on a 3-d CNC machine. I would then apply tin foil to plug and lay the final FRP shell
on this. This will give better dimensional shape and should be quicker.</div><div id="yui_3_16_0_1_1432310706800_2702"><br /></div><div id="yui_3_16_0_1_1432310706800_2703">Got to run.<br /><br /></div><div id="yui_3_16_0_1_1432310706800_2404"><br />Cliff Redus<br />Redus Engineering<br />USA mobile: 830-931-1280<br />cliffordredus@sbcglobal.com </div><br /> <div id="yui_3_16_0_1_1432310706800_2456" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12px;"> <div id="yui_3_16_0_1_1432310706800_2455" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 16px;"> <div id="yui_3_16_0_1_1432310706800_2454" dir="ltr"> <hr size="1" id="yui_3_16_0_1_1432310706800_2453" /> <font id="yui_3_16_0_1_1432310706800_2457" face="Arial" size="2"> <b><span style="font-weight: bold;">From:</span></b> Sean T. Stevenson via Personal_Submersibles
<personal_submersibles@psubs.org><br /> <b><span style="font-weight: bold;">To:</span></b> Personal Submersibles General Discussion <personal_submersibles@psubs.org> <br /> <b><span style="font-weight: bold;">Sent:</span></b> Friday, May 22, 2015 10:28 AM<br /> <b id="yui_3_16_0_1_1432310706800_2459"><span id="yui_3_16_0_1_1432310706800_2458" style="font-weight: bold;">Subject:</span></b> [PSUBS-MAILIST] R300 FRP work<br /> </font> </div> <div class="y_msg_container" id="yui_3_16_0_1_1432310706800_2460"><br />Cliff - I have once again been studying your photos of the R300 build,<br />and I was hoping you might be able to elaborate a bit on the process you<br />used to construct the FRP fairing. There are a couple of details that I<br />am still fuzzy on...<br /><br />From what I understand of the photos, you design the hydrodynamic<br />fairing and then create virtual slices of the completed design, which<br />you fabricate out of expanded polystyrene. I
presume the slice<br />thickness just depends on the available thickness of polystyrene board<br />and/or how much work you want to do in shaping? I notice that you have<br />these sections joined with wire ties in the photos... am I correct in<br />assuming that this was a temporary measure, and that you moved to<br />adhesives etc. prior to the body filler?<br /><br />Once you've carved the EPS down to shape, you cover in a layer of body<br />filler which you can further refine and sand to a smooth finish, which<br />you then painted. Is the paint necessary? Or can you just apply a mold<br />release at that point?<br /><br />After that, it would appear that you added flanges to define the mold<br />split lines. Were these centered on the split line, or did you move<br />them slightly before laying up each half? Furthermore, was it necessary<br />to split left and right, or do you think you could have done the mold as<br />only two parts?<br /><br />Do
you just use a mold release on the plug and then start fiberglassing,<br />or do you apply a gelcoat first?<br /><br />Did you lay up the whole mold at once and then cut at the flange, or did<br />you do a section at a time?<br /><br />Once the female mold was finished, I presume you did some further<br />finishing / smoothing to the inside surface?<br /><br />Then a mold release / gel coat / glass to create the shell?<br /><br />Once the shell was done and trimmed, how did you join the pieces<br />together and smooth the seam before casting your syntactic in?<br /><br />Thanks in advance.<br /><br />Sean<br />_______________________________________________<br />Personal_Submersibles mailing list<br /><a id="yui_3_16_0_1_1432310706800_2462" href="mailto:Personal_Submersibles@psubs.org" ymailto="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a><br /><a id="yui_3_16_0_1_1432310706800_2461" href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles"
target="_blank">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /><br /><br /></div> </div> </div> </div><p style="margin-top: 2.5em; margin-bottom: 1em; border-bottom: 1px solid #000"></p><pre class="k9mail"><hr /><br />Personal_Submersibles mailing list<br />Personal_Submersibles@psubs.org<br /><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a><br /></pre></blockquote></div></body></html>