Re: [Harp-L] XB-40 bending

[Zombor Kovacs <zrkovacs@xxxxxxxxx>]

Hi,

Yes, I have a tip. When I bought my XB-s I had to realize that the factory airtightness was poor. I sealed all my harps with silicone. I do not recommend anybody to do this (you can mess up reeds), because it was a very delicate job what I did with a syringe of silicone and a dispensing needle. But the result was close to dramatic together with some regapping and embossing. The response could not remotely be compared to factory response. What I can still recommend is regapping, some embossing and SEALING with silicone grease or a similar non curing agent. Even silicone grease or similar could get into reed gaps if you are not careful and temporarily block reed action (even for a longer time since it gets out of the gap slowly). But if somebody feels he is clever enough to do an all round sealing with the above mentioned method, he can expect some good results. I sealed the combs between the reedplates. If you don't want to actually get it bonded
 together, you should apply some release agent to the reedplate (it can be either grease or real release agent). However I warn you again that you need special equipment. Professional adhesive dispensing needles, a syringe and choose the right viscosity silicone (not too low). Seal the mouthpiece as well. 
The problem with the XB is that wall thicknesses are very low (not enough sealing surface) and not enough clamping force as bolts at the front are far from bolts at the back and there is nothing in between to press the reedplate to the comb where air escapes from one chamber to another. Of course if you could add extra bolts, that would be the best, but you have to drill holes and I am not sure if it is a good idea, so I stayed with the tricky silicone sealing. I am not saying this is the only way, it is just how I did it. 

Zombor






________________________________
 From: "burket@xxxxxxx" <burket@xxxxxxx>
To: harp-l@xxxxxxxxxx; robert@xxxxxxxxxxxxxx 
Sent: Saturday, June 16, 2012 6:07 AM
Subject: Re: [Harp-L] XB-40 bending
 

Hi Robert:

Nice to see folks still in support of the the XB 40.  I picked up a few new keys myself recently.  

I'm not sure if this will help, but:

I recently had a problem with a brand new, out of the box Low D XB40 which had a very weak and unresponsive 1 and 3 hole draw.   Phhhffftttt,   Phhhffftttt.  (sounded like that- right :)  The 2 and 4 draws and all the low blow notes were nice and tight.  Not a good way to start a relationship with a new harmonica.  

In taking it apart and checking the reeds, I noticed that the 1 and 3 draw gaps of the primary notes were set pretty high and not profiled all that flat  (   \___    ).   I worked on this a bit, but still did not have much improvement.  I then looked at the sympathetic/ bending reed gaps for those same notes and noticed that they were gapped "way" high. Almost as high as the primary reeds themselves.

All the other bending reed gaps for the other notes (except the 1 and 3 draw), were set very flat, and very tightly gapped.  I re gapped the bending reeds for the 1 and 3 draw almost to where they were closed, made a slight tuning adjustment to the low E, and the harp plays great now.  That fixed the problem for me.  I have to thank Rick Epping for pointing me in the right direction in terms of how the reed chamber, primary, and sympathetic bending note reeds interact on this amazing piece of harmonica construction.  

It makes sense that if the bending reed gap is too high, you end up leaking critical air that should be going to the primary reed.  

I'm going to take a look at my other keys and see if there are any similar problems.  If others have any other tips for maintaining and working on the XB I'd be very interested in hearing your experiences.


Good luck
Burke T.



Message: 1
Date: Thu, 14 Jun 2012 16:31:30 -0700
From: Robert Hale <robert@xxxxxxxxxxxxxx>
Subject: [Harp-L] XB-40 bending
To: harp-L list <harp-l@xxxxxxxxxx>
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I have an XB-40 in A.
What reed adjustments can I consider for making Blow 3 and 4 a little more
responsive?
Everything else is sweet.

Thanks.

Robert Hale

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