Leaky CX-12

Hi Alex, great to hear from you. You made a good decision to invest into a CX12 Chromatic harmonica.

I love the Hohner CX12 it is one of my favorite Chromatic workhorses--it never lets me down!

The CX12 was built for easy maintenance access; in fact, after a gig or practice I pull the slider out and spray it with Roche' and Thomas Mouthpiece santitizer. Before I return the slider into the housing tracks, I give it a final spritz then clean dry with a micropore cloth. I NEVER have an issue with sticking sliders with the CX12 harmonicas.

I have found that if I remove the reed plate/comb assembly, then did not align the four black index posts (molded onto the back of the comb) squarly into the four divots located on the inside (near the opening) of the housing--then there will be leakage between the front of the comb and slider. I also noticed this will prevent the torsion bar from properly locking in place, preventing the necessary downward pressure onto the slider and mouthpiece ;o(

I don't believe you have a windsaver issue. Lets work the numbers:

1. depress the latch on the slider button and pull it out of the housing (shell) tracks
2. turn the harmonica over so that the back torsion bar-with HOHNER-printed on it is now facing you. You'll notice two 3/16" index holes drilled through this bar (flat plate). Apply downward pressure to one of the two index holes, then slide the torsion bar to one side. The tabs on the opposite end of the torsion bar will pop out of the two slots located on the sides of the housing
3. turn the harmonica right side up and lightly tap the back of the housing opening against your open palm, then the entire reed plate/comb assembly will snap away from the housing and drop into your open palm
4. examine the now open housing and see if there is any debris lodged into the bottom slider track. Also examine the face of the comb for complete smoothness
5. OK, now lets put your CX12 "LEGO" model back together
6. rest the mouthpiece side of the housing on top your workspace (the Hohner Made in Germany CX12 label facing left forward)
7. pickup by pinching the reed plate/comb assembly with your index finger and thumb (long reeds to your left), insert it into the open housing, mindful to lineup the approach of the four index posts with the divots of the inside housing 
8. applying slight pressure to the back of the comb and you will hear a satisfying "click". This means the Space Station has sucessfully docked with the Mother Ship ;o)
9. return the black torsion bar, equally spaced--otherwise the torsion bar will not latch properly and pop off
10. finally return the slider (keep the spring straight and it should click lock into place. Depress the slider a few times to ensure everything is true.

If this does not work, let me know.

Your Harpsmith, Kinya

Hi Alex,

1. if your sliding mechanism is working well, I wouldn't recommend you sand the face of the comb or the slider; as it would increase the tolerances and invite leakage.
2. I don't believe you have a windsaver issue, however, if you want to give it a try, installing windsavers to slots #11 and #12 is relatively easy to do, especially if you use the glue-free windsaver from Don Makowski: https://www.bluesharmonica.com/sometimes_sequel_better_premier
3. As for sizing the reed plate slots and/or gapping the reeds, I don't believe you will notice a decernable difference in the upper octave of your CX12. It's will be difficult work with very little to show for it. 

Do you know anyone with a CX12, that will allow you to do a A/B comparison?

Do you typically play in the upper octave? If not, I would not stress over this issue.

In general, working on chromatic harmonica reeds requires a surgeon like touch and patience, but doable--I haven't lost a patient yet;o). When your ready to practice on an old chromatic harmonica, let me know and I will post photos and instructions here on the forum.

Your Harpsmith, Kinya

OK Alex. I'm glad you have a friend at your local Harmonica Morturary. The SWAN will make an excellent cadaver to learn chromatic maintenance fundamentals. Keep an eye out on this Forum and I will publish a "how to" photo article.

Your Harpsmith, Kinya