Fixing a leak by heating the cup.
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If it were only that easy, but it is not. Pads can be leveled by heating the key cup and manipulating the pads while the glue is in its "plastic" state, but clamping is ill advised. A more accurate technique to get the pad close is what Curt Altarac calls the tap method. Once the key cup is heated you repeatedly tap the key closed several times. This can help the pad find its level position. To get the pad to eclipse the light perfectly 360° with just the lightest touch often requires a small amount of push and pull in the appropriate areas. A good way to learn the behavior of your shellac or hot glue is to put some in an empty key cup off the instrument and heat the cup with your heat source while counting and watching to see at what number it turns soft, and what number it turns liquid. There is always a "sweet spot" where the glue is malleable, but does not come out of the sides of the pad.
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Exactly. It's based on whether the pad is held in with shellac or hot glue. You'll know if you overheat the cup by burned lacquer or before that, the pad falls out.
Personally, unless I put the pad in myself, or someone I really trust to do a superior job, I would pull the pad out of there (using heat, after marking its orientation) because I have very often found pads held in by the faintest little trace of shellac. In that case there's nothing to float the pad on anyway.
I have seen this on a horn that was supposedly given a "complete overhaul" by a shop of very high reputation.
I generally use a soft pencil to mark where the key arm is, then heat the cup to remove the pad (this also gives me an idea what I've got for cement under there). Then I may clean the old stuff up as best I can and reinstall with a proper bed of shellac; or just add some more to what's in there already; or bag the whole thing and put in a new pad.
If I knew that one particular pad had a good bed of shellac I might try to level it out in the cup, especially if it's just recently been put in there.
If this pad has been in place some time, you also have to ask yourself why it appears to have shifted? It's just as likely that it hasn't shifted but rather has reached the end of its life. For example, repeated wet-dry cycles will eventually cause the thing to shrink and swell and get hard; in that case it just needs to be replaced.
Single pads are cheap; so is shellac.
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Whether you clamp, tap, push or pull, if you use a painter's heat gun, you won't burn the pad or lacquer. For example, I have an older red Milwaukee which I use with the air vent open for the coolest setting. No problem melting shellac or amber colored glue stick.
Good luck if you use a butane or other flame torch. Grumps' post will become clearer.
Good luck if you use a butane or other flame torch. Grumps' post will become clearer.
Just a caution, my 40-yr old red Milwaukee heat gun has two settings. The low one is I think 750 degrees. That's hot enough to melt solder! Milwaukee may have made more than one model heat gun so be careful
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The temp of heat gun air depends on how close to the nozzle the work is. Obviously!Just a caution, my 40-yr old red Milwaukee heat gun has two settings. The low one is I think 750 degrees. That's hot enough to melt solder! Milwaukee may have made more than one model heat gun so be careful
And if it is hot enough to destroy paint, then it is hot enough to destroy at least some lacquers. Different lacquers vary enormously in the temperature they can cope with.
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- It is rare for a sax manufacturer to use enough glue behind a pad to "float" the pad. They use glue as an adhesive, not a filler.
- I find that if I simply heat and close, then the result is a pad that seals at the "back" but barely at the "front". That is a result of the travel being greater further from the hinge axis. It is definitely not that simple if you want an accurate result.
- I find that if I simply heat and close, then the result is a pad that seals at the "back" but barely at the "front". That is a result of the travel being greater further from the hinge axis. It is definitely not that simple if you want an accurate result.
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I guess caution is appropriate for all of these heat guns. Spec on the Vortex air torch is 500c or 932f.Just a caution, my 40-yr old red Milwaukee heat gun has two settings. The low one is I think 750 degrees. That's hot enough to melt solder! Milwaukee may have made more than one model heat gun so be careful
But I have actually burned pads with a butane torch!
I would first find out why it is leaking.
Pad deteriorated, torn, distorted
Key cup not level
Tonehole not level
Pad not seted level in the first place
If it's a reasonably decent pad and without any already heavy indentations made by the tone hole chimney, then you can probbaly fix it by heating and floating (although ideally if the reason is non-level keycup or tonehole I'd go for getting those addressed, by a tech)
I think as saxocleese says, just heating and clamping is not good. It will maybe help for a day or two as you are really just compressing the felt and doing a very short term fix. I have seen some decent techs use a pin in the side of the pad to manipulate it into the correct position, but as has been mentioned, this won't be much use if there isn't enough shellac behind it in the first place.
A better method (but still a bodge) might be to put shims behind one side of the pad to help make it align in a non level keycup or to a non level tone hole.
Still better is to get a good tech to do it properly.
Pad deteriorated, torn, distorted
Key cup not level
Tonehole not level
Pad not seted level in the first place
If it's a reasonably decent pad and without any already heavy indentations made by the tone hole chimney, then you can probbaly fix it by heating and floating (although ideally if the reason is non-level keycup or tonehole I'd go for getting those addressed, by a tech)
I think as saxocleese says, just heating and clamping is not good. It will maybe help for a day or two as you are really just compressing the felt and doing a very short term fix. I have seen some decent techs use a pin in the side of the pad to manipulate it into the correct position, but as has been mentioned, this won't be much use if there isn't enough shellac behind it in the first place.
A better method (but still a bodge) might be to put shims behind one side of the pad to help make it align in a non level keycup or to a non level tone hole.
Still better is to get a good tech to do it properly.
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My tool of choice to melt shellac and heat keycups is the Blazer ES-1000 (grunt, grunt, grunt). It produces a pin point flame and only burns pads when you aim it directly at them.
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Yeah, that's what I used to burn pads on my burnished gold Conn soprano. Very close spaces.
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In those situations there is a better solution to heat the keycups safely on unlacquered keys. There is an expensive tool called the "Votaw Pad Cup Heater" that heats the key by passing electricity between two carbon jaws. I have a "poor man's version" of that tool made from a Weller soldering gun. You simply cut the end leaving two copper prongs instead of a connected heating element. The photo below shows the tool along side the Blazer. When using the soldering gun it is critical to make contact with the key cup with both tongs before pressing the trigger, and to release the trigger before removing the tongs. Otherwise the electricity may "arc" and make a permanent mark on the part.
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A butane torch has a flame temperature up to 1,430 °C (2,610 °F). This temperature is high enough to melt many common metals.
I use a Bunsen burner, which has a similar flame temperature.
Even a candle has a flame temperature above 800C, and you can burn pads with a candle.
The flame temperature or hot air temperature is only one of several important parameters involved in heating processes.
In short, it is how you USE the equipment that is important. And burning pads is one possible outcome. Some lacquers (and key "pearls" are extremely heat sensitive, and so are some adhesives that hold on corks and felts.
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I checked spec on the Milwaukee: 750 - 1000F.
So, using the heat gun carefully to melt shellac didn't burn anything on my soprano. If I were doing more, I'd get the 500 degree air torch from Music Medic.
The first guy that did pads on my mark 6 tenor burned the lacquer off the keys with a Bunsen burner. He, apparently, didn't follow Grumps' warning.
So, using the heat gun carefully to melt shellac didn't burn anything on my soprano. If I were doing more, I'd get the 500 degree air torch from Music Medic.
The first guy that did pads on my mark 6 tenor burned the lacquer off the keys with a Bunsen burner. He, apparently, didn't follow Grumps' warning.
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I'd be interested to know how you control the air flow on a tool designed to remove paint. Do you have special tips for it? I own the Music Medic air torch, but prefer the butane torch. I use it for pad work and soft soldering. I like the fact that it is completely portable with no hose or cord to worry about. The one thing that every tool requires is a bit of common sense.
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If you heat from behind so not direct on the pad, then depending on the heat and the materials the sax is made of (glues, lacquer, etc.) a lot of things can be damaged before the pad burns. The key cup acts as a very good heat shield for the pad.
As others mentioned, there is rarely (from factory) enough glue behind the pad to float it. Heating would change nothing except maybe make the pad seem like it is sealing slightly better (or sometimes worse) temporarily. Even with enough glue, either pressing or tapping that was mentioned, like gordon explained, the difference in lever length cause the pads to (most of the time) hit harder at the back when doing this.
As others mentioned, there is rarely (from factory) enough glue behind the pad to float it. Heating would change nothing except maybe make the pad seem like it is sealing slightly better (or sometimes worse) temporarily. Even with enough glue, either pressing or tapping that was mentioned, like gordon explained, the difference in lever length cause the pads to (most of the time) hit harder at the back when doing this.
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I do not use it extensively because I'm not a professional technician but I bought this
https://www.aoyue.eu/aoyue-int852a-hot-air-station-digital-smd-rework-station.html
and, in my opinion it works very well and is quite versatile
It is equipped with different nozzles to work on the various cups sizes,
very good for clarinets also (with the smaller 2 mm nozzle)
https://www.aoyue.eu/aoyue-int852a-hot-air-station-digital-smd-rework-station.html
and, in my opinion it works very well and is quite versatile
It is equipped with different nozzles to work on the various cups sizes,
very good for clarinets also (with the smaller 2 mm nozzle)
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