<html><head></head><body><p dir="ltr">Outside of acrylic (Plexiglas) and polycarbonate (Lexan), there are three other plastics which I tend to employ often: acetal (Delrin), ultra-high molecular weight polyethylene (UHMW), and perfluoroalkoxy alkane (PFA). I use Delrin for most machined components when plastic is preferable to metal for reasons of corrosion resistance, thermal or electrical insulation, avoiding wear, etc., but I otherwise need a reasonably strong, reasonably hard dimensionally stable part that is easy to machine. UHMW I use for skids, bumpers, wear plates, spacers, stops, insulators, component mounts and other parts which do not demand tight tolerances, but still can perform well. UHMW is great for tubing mounts. PFA I use when I need chemical resistance, or for any components in breathing conduits, potable water or food safe applications, as it is easily disinfected and does not present any offgassing or toxicity risk, and behaves otherwise like
PTFE (Teflon).</p>
<p dir="ltr">Sean<br>
</p>
<br><br><div class="gmail_quote">On February 8, 2016 5:21:18 PM MST, Stephen Fordyce 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;">
<p dir="ltr">Hi Jon,<br />
Regarding banging delrin around, I can add that it's the plastic of choice for tech diving canister lights (which have 200m+ ratings), reels and general paraphernalia, and it has an excellent track record. </p>
<p dir="ltr">I have a book about DIY dive lights (it's by Steve Lindblom and is pretty cheap if you're in the states) which went into a good discussion on plastics and why delrin was right up there - properties like being impervious to water, impact resistant, pretty strong, easy to machine, good over a range of temperatures, etc.</p>
<p dir="ltr">Cheers,<br />
Steve</p>
<div class="gmail_quote">On 9 Feb 2016 4:51 am, "Jon Wallace via Personal_Submersibles" <<a href="mailto:personal_submersibles@psubs.org">personal_submersibles@psubs.org</a>> wrote:<br type="attribution" /><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><br />
Anyone know how the delron is going to hold up to being banged on assuming I swing the sub around and something hits it? Maybe a stainless body with a delron insert would be a better design from that perspective?<br />
<br />
Jon<br />
<br />
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