I have a Seery delrin flute that feels slippery, for lack of a better description. Or at least its not as grippy as my wood flute. Based on pics i have seen, a delrin flute like a Gary Sommers has more of a matte finish and perhaps has more grip to it? Does anyone have experience with the different feels of delrin flutes? Hope that makes sense 
A lot of makers deliberately roughen the surface of their Delrin flutes to increase friction. Iāve experimented with the same
approach on some Delrin flutes Iāve made. In my experience this helps a bit, but I find that all of the Delrin flutes I have played
are much more slippery in the hand than any wooden flute Iāve played, regardless of how it was finished.
On days when my hands are particularly dry, this lack of friction makes it noticeably more difficult for me to play a Delrin flute
than a wooden one. I think part of the problem is that I end up having more tension in my hands to make up for the lack of friction.
Perhaps another minor factor is the weight.
I also find that there is less friction between lip and flute on a Delrin flute, making it difficult to maintain a good embouchure. Any
amount of lip balm or face cream will greatly exacerbate this problem. If I switch immediately to a wooden flute the problem is
greatly reduced.
For these reasons, and the fact that Delrin is plastic and therefore not biodegradable (i.e. it will remain in the environment
pretty much forever!), I am no longer a fan of Delrin as a material for flute making. Because of this, and despite much discussion in
these forums to the contrary, I would say that Delrin is not a sustainable material for flute making. But that is probably best discussed
in a separate thread.
One may be able to solve the problem this way. Paste rectangles of moleskin on the delrin flute.
They stick quite nicely. Put one where the flute rests on the left hand, one where my rt pinky rests on the flute, and one where the rt thumb goes. Then, roughen the moleskin by putting superglue or some other glue on the moleskin (the outside of it), so that there is a firm grip. I do this with all my flutes, wooden or delrin. Works well.
Even firmer if the superglue is fresh. 
Delrin - I like it rough.
Jon C. Does this on his Delrin flutes. Texture is like a wood flute, easy to grip, not shiny, & visually not easily distinguishable from wood.
Rats! No wonder I havenāt been able to put down the flute in six months.
What is moleskin? Not a term I know here in Australia.
Itās a thin piece of soft fabric like a synthetic wool with an adhesive backing. Used to reduce friction with bunions or other friction-related skin ailments. Sold in every pharmacy and grocery store.
One other thing the OP might try, is a very light rub of cork grease on the outside of the flute. I do that on my wooden flute every so often, just for normal maintenance to avoid rapid moisture transfer. It was recommended in the Windward flute FAQ for my previous flute and it made sense. I notice there is a tiny bit more āstictionā of my right thumb and left index finger knuckle after a wax treatment. Iām talking about the lightest possible coat here, nothing heavy. A Delrin flute wouldnāt need the concern about moisture, but it might help with keeping the hold on the flute more stable.
I think there are different grades of delrin or delrin-like products, and that might account for a difference in feel.
I have played and owned a lot of delrin, ebonite and wooden flutes (boxwood, rosewood, blackwood and cocus)ā¦I have found them all equally slippery until you play them long enough to be accustomed to them. Seriously, I have owned flutes from at least 15 makers from 1850 to the presentā¦even a wooden flute with a German silver covered head joint. Until I spent the time with each to truly be used to playing them, I found all slippery. I play indoors and outdoors in temps from 40 farenheit to 105 farenheit (where I sweat like a madman).
I think itās all about what you are used to playing and prefer playing.
YMMV,
Eric
There are. For instance, there is a Delrin variety with Teflon. Might be great to machine as a bearing, not so grippy to hold.
Heh heh, young people these days, I donāt knowā¦
Back in the late sixties, early seventies, before weād reinvented Irish music (Antipodean perspective at work here), many of us played Australian Bush Music. To look the least bit the part, this meant colourful shirts and moleskin pants, as per this famous Tom Roberts paintingā¦
Moleskins werenāt made of hollowed-out moles, but were a heavy cotton with a soft pile. Very comfortable workwear. Still available. We referred to them as āmoliesā.
Iām not too worried about the flute itself not being biodegradable, and remaining in the environment pretty much forever - that sounds like a sound investment (urgh, pun alert!).
Itās the waste that bothers me, the stuff we bore and ream out of the middle and turn off the outside. Even that shouldnāt be a problem - it should be very easily recycled into some less demanding product, like garden pots or the like. But, as weāve seen recently in Australia, a lot of our kerbside collected recyclables have been being exported to nearby developing countries for processing and ending up in landfill, instead of us doing the decent thing and developing a responsible recycling industry here. Grrrr.
The ideal would be for us to be casting our poly flutes, so there is little or no waste, but that involves a level of manufacturing infrastructure that we couldnāt probably justify. Maybe 3D printing offers a more responsible approach?
Perhaps after the tongue-lashing young Greta Thunberg gave world leaders at the UN today, we might see some stirrings of guilt and remorse, hopefully starting to shift our planet out of its death plunge into the sun, and into a safer orbitā¦
Itās possible to 3D print Acetal now (also called POM). I am starting to look into this for flutes. Proper industrial 3D printers are capable of high spatial resolution. Things have moved on quickly from the ones used to make pink plastic novelty chess pieces. 3D metal printing is also a reality, and that means you can print keys. Now thereās a thought. Material heavily loaded with carbon fibre so that it is almost pure carbon fibre is also available in printing spools. I am thinking carbon fibre keys also a possibility.
[By the way, I think the moleskin referred to here is not actually the material for Aussie pants, is it?]
Indeed there are dozens if not hundreds of Delrin materials with specific and distinct engineering properties. The Delrins with 20% PTFE (Teflon) are specifically for very low friction bearing applications and quite expensive. I canāt see why any flute maker would order that. No advantage for flute acoustics.
I have a McNeela Delrin 6 key flute. Itās mirror polished, looks great, and I have never experienced slipping holding it. Must be just me. But I play Boehm flute as well and the idea of the grip there is to have a three point lever that holds the flute against you composed of embouchure, left hand finger and right hand thumb acting as a torque couple. Seems to me the wooden flute grip is more or less the same. In the other axis, I never have trouble with flutes rolling. Everybody is different!
For Boehm flutes you can get āFlute Gelsā that non-destructively stick on the body which not only stop pain in the left hand but provide a firm sticky grip as well.
I donāt have problems with delrin being slippery, and I love the total lack of fussiness you get with delrin. Waterproof, wonāt crack, wonāt oxidize, doesnāt need to be oiled or really maintained at all. Itās like a good hammer. But the two delrin flutes I have both exhibit kind of a damped quality and are mulch less fun to play. Could just be the flutes and not the material.
I can see the annoyance of dealing with delrin shavings, and itās true I suppose that a delrin flute will end up in the ocean or in landfill sooner or later. So back to deforesting Brazil and fussing about cracks? Or looking for non exotic hardwoods that machine well? Black locust is a common N. American hardwood. I made some bodhran sticks out of it and it turned really well. Not a very attractive grain thoughā¦
I have an Ellis flute in ebonite that I just love, but I donāt take it out in the sun, because ebonite is vulnerable to UV light. I have an Ellis flute made of walnut, lined with Marine epoxy thatās awesome, and it makes me wonder again why maple or other more common temperate climate woods canāt be used.
It turns out perfection is not possible.
I played an ebonite flute for close to 4 years and played it outside frequently, and it did not discolor. I think modern ebonite has less of a problem with UV discoloration.
are you sure itās Delrin? i know they advertise one of their flutes as Delrinā¢, but itās absolutely identical to the M&E polymer flute, which is not Delrin. someone else recently mentioned that McNeela is claiming to sell Cocuswood flutes for a price at which it clearly canāt be Cocuswood, so iām not sure how much iād trust their claims of the materials used.
Forbes and Yola Christie of Windward Flutes have been offering the option of āTorrifiedā (heat treated) Canadian birds-eye and fiddle-back Maple in addition to tropical hardwoods for their flutes. Itās an interesting alternative to using petroleum products to stabilize a softer wood species. It looks very nice, a darker brown than untreated maple. They say it smells like pancakes.
I have a delrin flute made by Rob Forbes, and Iāve played delrin flutes made by Dave Copley belonging to others, and none of these are in any way slippery. They have a matt finish but it is very smooth. The material just doesnāt seem to be slippery. Are you sure your flute is made of delrin?
Yes I saw that on their website. Iāve made a couple guitar necks with āroasted mapleā and to me it smells like burned wood. But there may be a difference between āTorrefiedā and āroastedā wood. The words get thrown around kind of casually. Pretty sure ātorreficationā takes place in a vacuum, but I think roasting can take place in your oven