I have discovered an air leak under the bass regulator plate (that holds the regulator onto the mainstock). Although the plate is lined with thin leather, the maker apparently put some sort of sealant around the hole in the mainstock where the air enters the regulator, and it has apparently dried up. The leather does not seem to be sufficient to give a good seal by itself. Can anyone give me more information about what material is typically used to seal around this hole in the mainstock? I have been thinking of using a plumber’s rubber “O” ring, but even if that works, I would still like to use something to make the “O” ring adhere to the mainstock before I put the plate over it.
By the way, I have posed the same question on the NPU site, but am having all kinds of problems logging on, so help from anyone here would be most appreciated.
The safest, most conservative course is to contact your maker and find out what he used.
In the real world, this doesn’t always seem to be possible.
An excellent sealant which will adhere to metal, leather, and wood, and yet be reversable would be the same sort of pad shellac used by instrument repairmen. It can be purchased as a thick liquid goo, which may be the more appropriate form, rather than as flake shellac which must be melted. Try Ebay. A half ounce tube isn’t that dear. Or Google 'Tampa Dave’a repairman’s supplier.
This is more tricky than you might think, in my experience.
Typically, there is a gasket between the reg bracket and the drone stock, sealed either side.
I had many iterations to get things right before I eventually sealed things up tight.
The key was to use a gasket, in my case thin leather, of the correct thickness. The gasket has to butt flat to the flange and the drone stock, otherwise no matter what sealant used, air will eventualy work its way passed, and the leak reappear. To thick a piece of leather, and only the edges of the flange make direct contact with the other surfaces. To thin, and only the middle section will contact.
When I was happy that my gasket was of the right thickness, I then used silcon bathroon sealer on both surfaces and screwed the bracket back down. I made sure the silicon in the 2 mm area around the air hole in the drone stock was proud by about a mm, as a just in case, to ensure a good seal, but not obstruct air flow. Both bracket and drone stock surfaces were cleaned to remove all possible grease etc.
I use a rubber gasket…I use rubber from a bicycle Inner Tube (the fat 26" kind) and cut it to size. It didn’t require any sealant. I use smaller diameter inner tube sections as gaskets on all stocks on my Uilleann pipes, and I do the same for the chanter stock on my Highland Pipes. I’ve used this method for 15 years with great success.
I too had this issue. I had no idea I was having it until Finbar MacLaughlin pointed it out. the repair made a huge difference to the performance fo the reg and the overal air consumption (of course).
I can’t remember how he repaired it, but in typical Finbar style, it took about 7.3 seconds to do!
Thanks everyone for your suggestions. They all sound good. I am trying to find my supply of blue tac right now, and I tried to find a supplier of the liquid form of pad shellac, but so far no luck. As for the gasket suggestions, the leather that is between the bracket and the mainstock apparently is there for that purpose, but it doesn’t seem to do the job. Perhaps the mainstock has become out of round, but it is more likely that the maker used some sort of liquid gasket material to give a better seal than the leather gasket would give by itself. The material was some sort of black goo, but it is no longer pliable and doesn’t keep the hole in the mainstock sealed. Brazenkane, if you are in touch with Finbar MacLaughlin or if you remember what he did for your pipes, I would appreciate you passing it on. The only suggestion I am not sure about is the silicone sealant, which may not be reversible, and may not be good for the leather gasket. I will keep that idea for use in case the other suggestions don’t work.
I think that pad shellac would be too brittle/hard for this application - if you use the liquid stuff it will shrink as the solvent evaporates.
If the existing gasket is “black goo”, then there’s a good chance that it’s heat-sensitive and may become pliable with very gentle warming (i.e. your hands or a light bulb for a few minutes - careful not to bake your reeds
I’ve been known to use blu-tack here too. But even blu-tac does dry out eventually.
The type of sticky window decoration pictured below ,is made from some kind of silicone. Its super squishy and sticks like sh!t to a blanket. We have some of them at home for a good few years as part of our christmas window decorations and they are still soft and actually feel wet to the touch ,but are not wet. They are about 3mm thick and would be good if you cut a circle with a hole in the middle and used as a gasket.
