<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><div></div><div>All,</div><div>as we are talking about testing this for General Psubs use I'll elaborate</div><div>on something I mentioned earlier.</div><div>In the product specifications below it mentions that in the setting of this product</div><div>the temperature is critical, & that temperatures below 75 degrees F will make a</div><div>denser product. One would assume that temperatures above 75 F would make</div><div>a less dense & hence weaker product. </div><div>With 2 part chemical reactions there is generally a heat produced & this is </div><div>exponentially greater the thicker the pour. I used to use casting resins for art</div><div>& they would get very hot on thick casts.</div><div>If this were the case then filling any large voids in one pour may cause the</div><div>centre of the material to be a lot weaker than the outside.</div><div>To check this we could ask the rep about thick pours, do a thick pour & cut it</div><div>in cross section to see if it is less dense in the middle or stick a heat probe in</div><div>the middle of the pour to check for an increased temperature.</div><div><ul><li><font style="background-color: rgba(255, 255, 255, 0);">All expansion rates and times given are temperature critical. Temperatures below 75 degrees F will lower the expansion rate therefore requiring more foam. Ideal working temperature is 75 to 80 degrees F or above.</font></li><li><font style="background-color: rgba(255, 255, 255, 0);">Accurate measuring of these products is extremely critical.</font></li></ul><div>Alan</div></div><div><br></div><div><ul><li><font style="background-color: rgba(255, 255, 255, 0);">All expansion rates and times given are temperature critical. Temperatures below 75 degrees F will lower the expansion rate therefore requiring more foam. Ideal working temperature is 75 to 80 degrees F or above.</font></li><li><font style="background-color: rgba(255, 255, 255, 0);">Accurate measuring of these products is extremely critical.</font></li></ul>On 28/06/2019, at 11:04 PM, Jon Wallace via Personal_Submersibles <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br><br></div><blockquote type="cite"><div><div class="ydpda9d2138yahoo-style-wrap" style="font-family: times new roman, new york, times, serif; font-size: 16px;"><div></div>
<div>Not my forte, but given the hardness of this product when cured is there really an expectation that it is going to deform in a visually measurable way and spring back into shape from a depth test? Seems like it's more likely to either structurally fail or not with obvious non-elastic results such as cracks, cavities, etc, hence the weight test to see if it absorbs water. I'm thinking the dunk test from the sailboat is a good first start.</div><div><br></div><div>The cost of this product seems to be on par with trawler floats from a pound to pound buoyancy perspective but it has the advantage of allowing custom shaping. I'm interested in the results.</div><div><br></div><div>Should we invest in a small amount of this product and put it to some more rigorous pressure testing?</div></div></div></blockquote><blockquote type="cite"><div><span>_______________________________________________</span><br><span>Personal_Submersibles mailing list</span><br><span><a href="mailto:Personal_Submersibles@psubs.org">Personal_Submersibles@psubs.org</a></span><br><span><a href="http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles">http://www.psubs.org/mailman/listinfo.cgi/personal_submersibles</a></span><br></div></blockquote></body></html>