I did a google search for the melting point of Delrin and came up with a number of 172 degrees F. So, are delrin whistles safe in a hot car in the summer? How hot do car interiors get?
I’m in Miami. I’ve heard claims of 140 degrees F.
I guess it depends on who’s in the back seat. 
I think a few years back there was a thread on whistles melting, let me see…
http://chiffboard.mati.ca/viewtopic.php?t=3827&highlight=dixon+melt
Looks to be more of a discussion of the possibility. At least there’s some interesting opinions on there. We at Chiff and Fipple always are suffering from a lack of expressed opinions.
Edited because I noticed who started the last thread. 
So I take it you didn’t risk leaving it in the car after all? 
170 F sounds low. A quick search I did seemed to indicate about 375 F for Delrin. Our whistles are probably safe. 170 F is about 340 C so maybe the F was wrong.
Mike
I got it backwards. 170 C is about 340 F or is that what I said? I don’t know, the coffee hasn’t kicked in yet.
Mike
I don’t think there is any danger of the Delrin itself melting. However, if a whistle also has metal fittings or tuning slide, repeated exposures to temperature extremes would cause expansion and contraction of the various whistle components at different rates which might loosen the fittings: Delrin is notoriously difficult to glue at best.
When it gets hot enough here in Upstate NY, I will subject one of my Delrin whistles to this test and report back here. Still, I think that a bit of caution is in order-- take the whistle out of the car with you. Besides, why would you want to go anywhere WITHOUT your whistle?
hehehe…good one…
I’ll bet it’s 170C. Delrin certainly won’t melt in boiling water.
Car interiors can get to well over 170F. I was at a meeting on manufacturing a few years ago, and there was a session on materials for the interiors of cars. All of the materials are made to withstand something like 110C. I asked someone about that, and he said they build in a margin for error of something like 20C, which means they plan on the interiors getting up to 80 or 90, or about 180F. These guys wouldn’t put money into it if the interiors didn’t really get that hot. Will it happen in Yellowknife? Nope, but it will happen in Texas, where you really CAN fry an egg on the sidewalk.
We use delrin in the oven caps at my job. I’m in PTFE extrusions by the way… Anywho the delrin in those (white) stands temps of about 750degree F. Before it starts to burn. Delrin will get soft at around 300 degrees. Some of our Mandrels are made out of delrin and when we polish them before use they can get scortched by the rubbing compound and the lathe if one is not careful.
-Cyf-
So true!!
Edited because I noticed who started the last thread. >
Man, Beth, good memory!! I have thought of that thread several times while wondering if Delrin made things more worry-free in this regard. If I hadn’t worried about the Dixon melting, I’d probably still only own that one whistle today. It was not wanting to lose my precious Dixon (bought on one of my trips to Ireland) that started me down the road of WhOA.
All in all, Delrin appears to be safe from melting in a hot car. Good points, though, Paul. Thanks everyone!
Delrin is Hexapolymer and Acetal a Copolymer, they are very similar and some whistles are actually using Acetal instead of Delrin. The melting points might be different.
Delrin gives off nasty fumes when it burns, someone told me that it was like formaldehyde.
Delrin should be case in the car, a lot of those round stick-shift knobs are made of Delrin.
Great, one more thing I need to wear a mask to work with - I might as well sleep with my respirator on :roll:
Seery flutes have been around for quite some time, and I don’t recall hearing any melted flute stories regarding those. Dixon polymer flutes are another story however…
Loren
Nah, I never smell any fumes when working with Delrin under normal circumstances… it does stink a bit if I get carried away with the drill bit while doing the preliminary boring of rod stock though.
PVC… now THAT was some nauseating stuff to work with!
Delrin aint so bad when it burns. Smells a little sweet. Plumbing PVC is pretty bad… smells like model cement (sort of) which may or may not be a bad thing 
. Isopar G fluid (used as an extrusion lubricant) smells gawd awful, and anyone who’s ever had “polymer fever” can tell you how fun 18-20 hours of dry heaving, cold sweats, uncrollable shaking, and disorientation can be. I’m not talking about a frat party either.