Emergency Wooden Comb Surgery
Hello Harp Techs, I’m “back”!
Recently, I purchased a NOS (new old stock) Hering Professional 40 Chromatic from ebay. The delivery was rapid and my enthusiasm was high.
I removed my new Chro out of the box and launched into playing my chromatic scale patterns--UGH! When I played holes #1 and #4, very breathy dissonant notes poured out of this instrument.
This phenomena is trademark of a cracked wooden comb, allowing air to travel into the top and bottom chambers. The top and bottom reeds (within that chamber) would vibrate simultaneously.
My suspicion was confirmed when I removed the top and bottom reed plates (see photo)
Because none of my custom comb sources had available Hering replacement combs, I decided to use and epoxy based wood filler.
I protected the mouthpiece slider by laying down a strip of Scotch clear tape.
Not the most handsome repair, but successful. This chromatic harmonica is now playable.
Your Harpsmith, Kinya
Hey Kinya - welcome back!
I've found a good way to deal with cracked wooden chromatic combs is to start with the outside before you take the harp apart - if there is a visible crack in the comb in the back - 10 minute epoxy - just a dab in the middle , away from the reed plates.
The idea is to progressively stabilize the comb you are repairing a little at a time starting with the easiest part you can access...
Then you remove the mouthpiece, leave the comb, covers and reed plates attached and use a thin piece of business card cut to fit inside of the chamber - put a little epoxy on one side and then get it inside into part of the crack - let it dry, then get the other side of the crack with the same process
This is another way of keeping everything in place as you progressively fill and glue the gap. You just have to be careful
I've done this with old 280 wood comb Hohner chromatics and once I knew the comb was solid again, I could take the harp apart to fill in the rest of the gap and driill and tap the comb and reed plates for screws
I hope this makes sense - I don't have any good examples at the moment for photos...