David Lay

Also, here is one source for manufactured individual reeds https://www.harmonikas.cz/en/uvod-english/. If you search the name on concertina.net, you can find discussions by others about their experiences buying these reeds. https://www.harmonikas.cz/en/product/dix-concertina-original-2/

Here is a website with details of Henrik Muller's journey into making his own. http://concertinamatters.se/page2/page2.html I have found his information and Alex Holden's to be most helpful (both of which have so far convinced me to stick to basic repairs). Both are members of concertina.net.

Dave Elliot's repair book explains that a reed tongue at-rest position can cause the symptom you are experiencing (gap too great). Perhaps it's this simple.

I have read here that air leaks can cause reeds to sound weak or not at all. Searching for the cause of this with this concertina, I believe I found the problem. After I seat the reed shoe in the dovetail slot, if I push down on its ends, it rocks. The reed shoe is flat, so the dovetail slot bottom is not. If I seat the inside end, I measure up to a .030" gap at the heel, though .007 is more typical. I expect the wood has changed shape since milled. I have not decided yet what might be the best repair solution. Suggestions are welcome!

I have always taken comfort in having a concertina shop available in Sunderland, MA should I need help. Someone here mentioned that Bob Snope may stop, though I have not had this confirmed. I think I know who the new instrument makers are on this continent, but not the experts/shops who will help with repairs. Please identify our options for getting help on any maker's concertina for a "tune-up" in North America.

This is the spray shellac I see most often. It says it is a 3 pound cut, so a bit heavy. https://www.amazon.com/Rust-Oleum-Zinsser-408-Bulls-Shellac/dp/B0009X8HWG/ref=mp_s_a_1_2?crid=KNHM9DLG159V&keywords=shellac+spray&qid=1679529912&sprefix=shellac+spray%2Caps%2C158&sr=8-2

I agree that the pores are too small. This chart shows that even a B6 has a wavelength of about 6".

I have designed theaters and auditoriums (auditoria?). The acoustitians always had us apply dense but soft material to walls from which undesirable reflections could bounce. The soft material (usually fiberglass board) cut reflections both at the surface and by attenuating any pass-through reflections that made it to the back-up wall. Lower frequencies always caused problems for adjacent spaces rather than for an audience. A heavy separating wall (mass) was the only way to mitigate that. Soft materials will definitely change the sound of a concertina wherever they are placed inside. Wood choices will also change the sound with their different densities. That mahogany might have resulted in a different sound in-part because mahogany typically has open pores. The pores possibly provide small chambers into which higher frequency waves enter and die rather than reflect. I suspect that the effect is subtle, however. (Based upon this principle, concrete masonry blocks are available with openings and internal chambers to be used for sound attenuation.)

Stephen. Saw your prior post about humidifiers, so can see that you are dealing with it. However, beware room humidification at 50% when it's very cold. Moisture can damage your home at that level if it migrates into walls and condenses there or on cold surfaces. That is the reason I prefer the case humidifiers. As an architect, I have seen condensation damage too often.

Monitor them, of course, but also monitor the humidity of your instrument's case. If you live in an area where it gets very cold, moisture levels in the air can get very low. Try to hold near 50% relative humidity at room temperatures. There are guitar case humidity control packs available for this. Wood objects are particularly vulnerable if they are moved from a place with a temperate climate to a place with a cold or arid climate. All wood moves as it absorbs or gives up moisture. If the movement is restrained, it will likely lead to cracking. Plywood is more dimensionally stable and less affected. Also, wood moves more in the direction perpendicular to the grain than in the longitudinal direction.

There's this post that might be of help:

Thank you. I calculated 50g/200ml = 2.08 lb./gal(US).

Interesting. I interpret that the name methylated is derived from spiking ethanol with methanol to make it dangerous to drink. Seems a bit mean when they could use something that makes you sick rather than blind. As I mentioned, other denaturing agents include propanol, and I just learned, methyl-isobutyl-ketone (MIBK). I can buy "off-road"/heating kerosene that is dyed to make it clear that the road tax was not paid in the price. (I am sure there are cheaters who put it in their diesel trucks.). I bought 190 proof denatured ethanol labeled as hand sanitizer - no dye.

Thanks to all for your great input! SteveS: When you say "1/16 cut", I interpret you are diluting your shellac with 16x more ethanol. What is you starting concentration? ...or have I missed your meaning entirely? DDF: What is "meths/alcohol"? I might guess you are using methanol. My web search result showed articles about methamphetamine 😐.

I have searched, but cannot find where others have made recommendations for applying shellac by the "French Polish" process, though I remember reading some. I tried the typical instructions found on-line and by an author, Tage Frid, using a 2# cut, a pad, and sometimes a bit of oil, but my result was bad. More recently, I went with what another author, James Krenov, advised using what is a 1# cut or even more dilute, and no oil. (Lots of coats, but then one web source recommended 30 coats with the 2# cut). I like the result. Frid wrote that for traditional FP, filled pores is usual. I left my mahogany with open pores and it is not glossy like I would expect from traditional FP. I used orange flakes in "190 proof denatured ethanol". (Ethanol will distill to 95% ethanol/water easily. Getting that last 5% out is difficult, and once a container of it is open it will absorb water from the air and be 95% quite quickly, making it 190 proof.) The labeled ingredients of my alcohol are ethanol and water, so I have no idea what makes it "denatured". Zinsser shellac from my hardware store gives a wide range for how much shellac is in their product, so it might be 2# or 4#. It lists up to 10% propanol as an ingredient, but nothing more scary. Propanol (rubbing alcohol) is a common denaturing agent. Shellac is said to go bad if not fresh but Zinsser does not have an expiration date on the can (??). Krenov thought the canned product an OK option provided it is diluted and strained. To be safe, I used flakes and as pure an ethanol product I could buy, freshly mixed. So, if I filled the pores and went to 30 coats or so of my 1# cut, would I get a glossy french polish? Also, the use of oil seems counter-intuitive. It seems it would polute the finish since alcohol and oil are miscible. What can be said about this part of the process?