I’ve done the blue tac tweak on several whistles and the results have been positive. But I find it hard to get a smooth surface on the blue tac in place. I think that would be more beneficial than a surface that is uneven or has cracks.
Anyone have a suggestion for smoothing out the surface of the blue tac plug. Or is there a better material to use for this tweak?
I’ve used the flat end of a chopstick or an unsharpened pencil and get acceptable results. I don’t think the blue tack needs to be perfect - it’s really just changing the airflow in the plenum.
Jerry Freeman uses some magic filler on his tweaked whistles if you really want it to be done right.
Mike
You could use a FormCard (starch-based plastic that melts in hot water) and smooth it as it cools, but it will stick to other plastics. It would be more difficult to remove than Blu Tack if it went wrong.
I’ve used it to repair a crack in a plastic whistle head, and to adapt some good ear buds I had about 10 years back that wouldn’t go inside my tiny ear openings. I made an extra bit that fitted into my outer ear contour and held them in place.
There are other plastics that soften in hotter water, which usually come as pellets. Never used them myself, but both they and FormCards are cheap enough to play around with if you fancy it. The only other option I can think of apart from filler is air-drying clay, which I’ve used to make a whistle thumb hook. It dries very hard and smooth (you could polish the surface before it dried with something wet), but would fall out of a whistle head, probably quite quickly. You’d then have to glue it into place.
If you’ve tested it with blu-tack and found that it improves a whistle, you could then take the blu-tack out, clean the place where it was, optionally sand it if you want a guaranteed permanent fix, then fill it up with liquid craft resin (epoxy) and leave it for a day to solidify fully. You could do that with a whistle without removing the head just by dripping it in through the window with the whistle nearly horizontal, then tip it back to run it into the void you want to fill, and do that repeatedly to test that you’ve added just the right amount, then leave it vertical to set with a perfect surface.
It’s expensive stuff to buy if you’re only going to use a few drops of it, but the stuff’s useful for a host of household repairs. Ask around though as you may have a friend who uses it for craft purposes and who will be happy to help out - a lot of people are using resin these days, and also silicone rubber solution for making moulds - it enables you to produce things out of what is essentially plastic but at a much lower cost than 3D printing and with a fully smooth surface.
Thanks for the suggestions.
Alaskamike, yea, I may be overthinking this. Or it’s just the perfectionist in me. Sometimes you can do too much.
David Cooper and Moof, I appreciate the suggestions. I thought about wax but feared the warm wax would soften the plastic. I had not thought about resin. And the FormCard sounds interesting for a number of possible applications. I’ll do some experimenting before I subject a whistle to anything.
There’s another gel that dries to a solid, and generally dries to the same size as it was when wet; it goes by various names, it’s
the gel sold in tubes you use to patch shoes. The brand I get around here is “Shoe Goo”, and I’ve also seen “Goop”. See image attached.
Once put in place, it levels out with the consistently of something slightly more liquid than toothpaste or like thickened molasses. Used to tweek a hole in
the mouthpiece of a whistle, held upright for at least 24 hours, it would form a smooth flat surface at exactly the level you poured
it in, so you’d have to be careful. When dry it can be carefully sliced by an exacto-knife or razor, so if there was any excess in
the whistle mouthpiece, you could easily slice it off and get the smooth surface you wanted.
I’ve used it on many shoes. It bonds parts together while still remaining bendable enough that on business, running or hiking shoes,
it still holds while having flexibility. It will endure for years on a shoe, so a lifetime on a whistle. In a mouthpiece, because there
would be no more forces working on it, it would hold it’s shape and position and no amount of saliva, hot/cold, cleaning liquids, etc., would
bother it. The color of the final product is a semi-transparent medium brown, but that’s on a shoe sole, so in a whistle it would
probably remain more transparent, it’s liquid “color”. It starts out transparent and dries basically to the exact same volume you apply;
it doesn’t noticeably shrink at the time of drying or over time/years.
NOTE: I can see this as a perfect answer if you know what
you’re doing and aren’t typically going back to practice tweeking, ripping out the product, trying it again, don’t know what you’re doing, etc.
It’s a very simple job description, but when you fill in a hole with something this good, I would not expect it to be easily removed, since
it would be the consistency of something like the black rubber on the bottom of running shoes. You could carefully cut it out with a knife tip,
but it’s not going to fall out.
One tube costs about $8 and would probably fill at least 15 or 20 whistle mouthpieces, from what I’ve seen of that high D-style plastic whistle design.
If you use it, expect to put the whistle mouthpiece outside or out in a garage for a couple days, as there is some odor while it dries, typical of any
chemical compound while it dries in the open air. Since a whistle mouthpiece would require such a small amount, the related amount of drying time
and odor would be small, but give it 2 days. I’d think it would do a perfect job of it.
But be very careful when placing the blu-tack. I made my favorite whistle non-functional when I changed out the blu-tack, apparently was not gentle enough when tamping down the new blu-tack, and broke that tiny piece of plastic that separates that void from the rest of the windway. Lesson learned.
It’s very easy to over-think this problem. I have worked with Shoe Goo and resin epoxies on other applications, and they can be very difficult to work with in tight spaces. They are both very viscous and almost impossible to clean off from unintended surfaces. If you get any on the blade or windway, your whistle head is ruined.
Blue tac may not be perfect, but it can be smoothed in any number of ways, and it is easily removed if you put too much in, get it on the blade, or simply decide you don’t like it.
That triggers another thought: Black tack.
It’s like Blu Tack, only stickier. It was used a lot in the theatre I worked at for positioning small mics, securing lightweight cables to keep them out of sight, etc. I use it for a similar purpose in my car, keeping the surplus cable for the dash cam tacked down.
The big advantage is that it never dries out, which means it’s much less likely to fall out of a whistle head. It can be removed if it doesn’t work, though; easiest done using another bit of the same stuff on a pencil or something, as it sticks to itself very well and leaves the surface clean. It’s not quite as easy to smooth as Blu Tack, but you could probably get a good result with a bit of trial and error, specially if you chilled the smoothing implement in the fridge first (heat tends to make it stickier).
Searched online for a retailer, and it seems it’s also used in building model railways! 
Also available from the usual global marketplaces.
The epoxy I use is almost as runny as water and you can easily wipe it off any surface it shouldn’t be on (other than fabrics). But if you’re dripping it through the window of a whistle without disconnecting the head, you wouldn’t want any to go round the corner and under the blade, and you won’t want any in the windway either, so it is risky if you aren’t skilled at using it.
I agree. While I think a viscous material like Shoe Goo would be a great solution, FOR SURE, the mouthpiece would have to be removable and probably held in a vice or held in place upright between two books or something, for a couple days so the material could dry and produce a perfectly flat surface where it was wanted. No way could you expect to pour some viscous liquid like that through a whistle window and expect to avoid the blade or windway; it would be one hell of a difficult mess to deal with after!
Has anyone tried hot glue? Seems like it would be easy to use (from a glue gun).
What is the benefit of using these materials in the first place? I’ve never really understood it. What actually makes a whistle better by having part of it filled a bit more?
I tried a Jerry Freeman tweaked Feadog once, and I found it…about like my normal Feadog, except maybe a bit quieter. I’m wondering what the advantages are.
YMMV - generally it only affects whistles like Gens, Waltons or Clares that are hollow beneath the windway. Filling in the hollow cavity to present a vertical surface below the edge of the windway strengthens the second octave and cleans up the sound. The hollow is a necessity of the injection-molding process when forming the head in a single mold. More expensive whistle heads do not have this hollow space because they are made from two or three pieces rather than a single-piece injection molded. The debate is endless about how much difference it really makes for an experienced player or for a particular brand… I am simply commenting on why some players fill in the hollow space.
-AW
The debate is endless about how much difference it really makes…
This divergence of opinion can only be resolved on a try-it-for-yourself basis. Blu-Tack — or more generically “poster putty” — has become the benchmark material for easy application, adjustment, and removal. It is also nontoxic and requires no cautionary measures in the workspace, which is not the case with several of the alternative substances mentioned in this thread. The acoustic effect of Blu-Tack’s surface properties can be tested by affixing a small piece of something with different properties to the exposed surface of the filled area.
Well, having suggested epoxy, I thought I ought to try it myself, so I just had a go at it on a Bb generation whistle using Craft Resin (food-safe, non-toxic epoxy). I ran it drop by drop down a narrow steel rod (2mm diameter narrowing to a rounded spike at each end - 22cm long, and while I’ve no idea where it came from, it’s one of my most used tools), so the drops went in through the window without touching the sides, then I occasionally tilted the whistle it to measure the depth when running it into the cavity to be filled. Being transparent, it’s hard to see the surface without touching it with a pin. Anyway, it’s now full and standing vertically to set for 8 hours, so it should be ready to play tomorrow. Really easy process, but will be less easy on each subsequent whistle as I go up through C, D, Eb, F and G. Assuming that it really makes a useful difference to the quality of notes, I’ll do it to them all and let you know how it goes.
Okay - it’s set now and it’s an invisible modification until you drop a ball bearing down the tube and watch it sit level with the window instead of disappearing into the cavity. I don’t hear any improvement in note quality, tuning, or anything else, although I can’t compare it with how it used to sound other than by testing it against my C whistle. It certainly hasn’t made it worse though, so I’ll go ahead and put resin into the C next, then compare the two again. (These are old Generation whistles.)
I have successfully used Polymer clay (Fimo, Sculpey…) from a hobby shop or art supply store for filling the cavity in the past. I would definitely avoid baking it to set the clay, and haven’t seemed to need to with my whistles, but also see that it now is available in an “air-dry” form as well. I also recommend you first make your whistle head removable (as noted in other posts on tweaking whistles) as that makes the filling and tamping process easier.
That’s the C whistle’s cavity filled with Craft Resin too, but again I can’t hear any difference. The modification is invisible as the surface of the epoxy is as smooth as glass.
There are other modifications I’d like to try out though, so how hot can you go with the water for heating the glue in the head to remove it without risking warping the plastic?
I’ve always used beeswax.
The problem with that is that if the whistle gets too hot it will turn into liquid and run wherever gravity takes it.
So I don’t leave those whistles in a hot car.
About the face of the “block” you’re creating, I’ve noticed that my old Clarke has it at an angle, and I do the wax at a slight angle too.
About what it does, for my trusty old Generations and Feadogs it raises the pitch of the 2nd octave a bit, and very slightly reduces the whistle’s volume and brightness.