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How Airtight is Enough?
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MindTheGap
1255 posts
Mar 08, 2016
4:01 AM
Picking up one point in Superbee's writings on the Crossover, where he says that if there are 'leaks' most of it is through the non-sounding reed slot...

People talk about leaky/airtight combs/reed plates as something to work on. So how close does the fit have to be in practice? I see these new East Top harps even have a gasket.

From a physics point of view, I know that 'airtight' is relative, and when you have flows involved it's NOT about having a hermetic seal. It's about having enough resistance to the flow.

For instance, in electrical generators (big ones I mean) they have a hydrogen atmosphere to reduce drag, and that is kept in using a 'Labyrinth Seal' which doesn't having any touching parts, but simply gives a long and narrow path that makes it hard work for the gas to escape. And so you can maintain the pressure inside.

What I'm saying is that, beyond a certain point, there's nothing to be gained by having a better and better seal between comb and reed plate.

That's the theory - what's it like in practice?

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Last Edited by MindTheGap on Mar 08, 2016 4:01 AM
Killa_Hertz
706 posts
Mar 08, 2016
5:25 AM
I think the more airtight the better.

Where it gets outweighed is ... what is it going to take/cost to get there?

Do you have any super airtight harps MTG?
Flatsanded with a custom comb goes a LONG way.


One of my harps is SO airtight that it just screams. If you play it with normal breath, its so loud and the tone is so rich. Its incredible. Also much easier to play , especially for long periods of time. I make sure to keep it well tuned and the octaves beat free so it always sounds good. It takes alot of work to get a harp to play that well tho. The volume is actually too much sometimes.
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"Trust Those Who Seek The Truth. Doubt Those Who Say They Have Found It."

Last Edited by Killa_Hertz on Mar 08, 2016 5:35 AM
MindTheGap
1257 posts
Mar 08, 2016
5:47 AM
No I don't. Early on I did try flat sanding a reed plate and noticed nothing, apart from it took a little while for the metallic taste to subside, even after extensive cleaning :) My guess is that I had to wait for the fresh metal to oxidise slightly.

It's possible of course that I didn't do it right. But it wasn't better, or worse. So it's also possible it wasn't wrong in the first place.

What you say does make me think about getting a customised one, at least one, again. I have actually played a custom, and while it was more responsive, it wasn't a step change.

You'll have to stop writing all these enthusiastic posts - it's going to cost me money!

All interesting stuff though.

Last Edited by MindTheGap on Mar 08, 2016 5:51 AM
MindTheGap
1258 posts
Mar 08, 2016
8:20 AM
Update. I did a quick experiment on a Harpmaster and LO. Took the covers off and taped over some reeds, put the covers back on.

Result: appears to be as tight as the proverbial. I can't get any air in or out even with much, much larger pressures than I'd ever use playing.

I note that it did need the covers to be on, to pinch down the reed plates properly. Or I could pinch with my thumb and forefinger. Without that, there was a bit of leakage.

What do you think? Do you assess reedplate-to-comb airtightness directly like that, or just go on overall response?

Last Edited by MindTheGap on Mar 08, 2016 8:52 AM
Killa_Hertz
707 posts
Mar 08, 2016
9:37 AM
Damn captcha. Try this again. It went something like .....

My main focus area is the comb and plate mating. But i check it with the harp correctly and fully assembled.

I get everything as flat as i can and put it back together. N see what the results were. N if they were not perfect, it ll have to wait till next time, because it takes up some time to get everything flat, shape the reeds, tune the harp. But with all that done you should see a pretty dramatic improvement either way. But you ll have to soon take it apart to finish the tuning and shaping once it has had a chance to settle. So you can always give it another go with the sanding n see if got can refine it a bit.

I find recessed harps to be pretty airtight overall. The best thing for them (i would think) would be light embossing. And some proper reed shaping also. Surely both would maximise air efficiency. I have yet to buy a custom comb for a recessed harp. They are a lil pricey. I don't do much to my recessed harps other than reed shaping. I've never flat sanded one either. Not much point with a stock recessed comb.

But that's my thoughts anyways.
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"Trust Those Who Seek The Truth. Doubt Those Who Say They Have Found It."
MindTheGap
1259 posts
Mar 08, 2016
12:14 PM
Thanks. I wasn't quite sure from that whether you do the flattening part first, then reassemble and see what that does, then do the reed work?

I mean, do you have a sense of how much of the improvement is from comb/reed tightness and how much is from the reed work?
Killa_Hertz
710 posts
Mar 08, 2016
2:55 PM
I mean, do you have a sense of how much of the improvement is from comb/reed tightness and how much is from the reed work?

Yes. Because i dont emboss. So almost all of the airtightness is from the flatenning of the comb and plates. But reed shaping will/can(depending on how bad the harp was to start with) greatly increase the ease of playing and the efficiency of your air. So it kinda goes hand in hand with what you want to accomplish.

Ok heres the way it normally goes for me. I get a harp OOTB. I do a quick gap to make it easily playable (especially in the 123 hole area) and the bends easier to hit accurately (especially the 3 & 2).

Then I'll usually leave it be and play it for a while before messing with it. But if its just not playing right after 2 weeks or so..... ill flat sand the comb n straighten and sand the plates. Aswell as shape the reeds so they close the slot evenly. (Since I Have it apart already) maybe tune it if im feelin froggy.

Now this will usually do a pretty darn good job, but its tough to get a comb 100% flat. Its hard to get it 90% flat, who am i kidding. You can do it, but it s very tedious. So i usually settle for good enough. I spend a good amount of time on it. dont get me wrong. Im not half assin it, but its not as easy as it sounds.

However, after all that its still not going to be perfect.

With harps i perticularly like, after doing all that, if its still a bit off ... I may drop a custom comb in it. And thats how you can guage exactly how much the comb did for performance. And the comb is most of it. A good perfectly flat comb with flat reedplates just makes the harp IMO.

I have done a harp ootb straight to custom comb, flat sand, tune, etc. But the point i guess is that if you do the reedwork without the comb/reed flattening (and its a leaky harp) it will play better, but still leak. Idk its kinda hard to explain, but you CAN feel the differences of each upgrade/tweak.

I suggest that you do it in stages like that the first time so that you can feel the difference each makes for yourself. It's more time consuming this way ofcourse. But i think it's something you just have to feel and learn the hard way.

And once you have done one upgrade, put it back together, played it a little while.

Done the next upgrade, put it back together, played it a while, ... etc.

Until you have a "fully customised" harp. (Personally custom or whatever you wanna call it. Surely not a joe spiers custom.)

Then you ll be able to feel what each upgrade is doing when you do the next harp and do all the upgrades you want in one shot.

Then when something doesnt feel right you ll be better suited to diagnose the problem based on how it feels.


Sorry ... that kinda went way off on a tagent, but ..... i ve typed it now ..... so here it is .... lol.
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"Trust Those Who Seek The Truth. Doubt Those Who Say They Have Found It."
Killa_Hertz
711 posts
Mar 08, 2016
2:58 PM
If you don't wanna read all that. Lol. The short answer is ...

Yes. I do because i have done the upgrades one at a time. So i can kind of feel what each one is doing. But also without embossing, virtually all of the airtightness will come from the comb/reed plate mating.
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"Trust Those Who Seek The Truth. Doubt Those Who Say They Have Found It."
SuperBee
3498 posts
Mar 08, 2016
7:58 PM
i believe there is a principle of diminishing returns.

i have a little collection of wise words:
"its easy to not care about trade secrets when you don't have any" (Joe Spiers)

”every customiser has their own truth” (Dick Sjoberg)

“you can always improve a harmonica”; and
“its easy to spend too much time trying to improve a harmonica” (Gary Lehmann)

"You can't get there from here" (unknown)

if you want to improve the harp, i think its best to assess the situation first. if you know what a good harp plays like, you have a basis for comparison. you need that i think.
if you know what an ideal reed gap is, and how to tell a good one from a bad one, you can judge whether that is a problem. whatever else you do, if the gaps are bad, the harp isn't going to play well. same goes for reed shapes. you have to know what works, what doesnt, what the symptoms are of bad reed shape. you also need to consider other aspects of reeds and slots and the interactions thereof.
i believe this is where most of the action is in a harp.

If i was preparing a harp for someone else, i might start at a different place, because i would be doing the whole thing, but if its just for me, i'll be satisfied when i am. i'm not especially interested in building the ultimate harp per se. some people are...
for me, comb/plate issues are a long way behind reed issues usually. sometimes i have a harp where the comb/plate interface is a problem, so i address it. and i will address it as part of the routine if i'm fitting a new comb.
Usually leaks between chambers are more of a deal than leaks through the back.

MTG, i like your application of logic and method.
Killa_Hertz
716 posts
Mar 08, 2016
9:11 PM
Bee you summed my rant up pretty well.

You hit on some specific points that i did not. Like leaks being between chambers. Etc. I also agree that most of the action is in the reeds. I don't think anyone would disagree. As i said sometimes thats all i do, tweak/shape the reeds. But the OP was about airtightness.

As for knowing what a good harp / gap should feel/look like. I think i have a good idea. But mine came from trial and error. Refinement and more refinement. I haven't yet had the opportunity to play an actual pro custom harp. But you kno if you could make a harp that good in the amount of time it likely takes him (spiers), you would.

I ve got it boiled down to a Pretty good science now. I can make MY best version of a harp rather quickly. I don't spend alot of time trying to make them perfect. And really only go that far If needed. Or when a small issue just bugs me to the point of messing With it.


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"Trust Those Who Seek The Truth. Doubt Those Who Say They Have Found It."
MindTheGap
1261 posts
Mar 08, 2016
11:04 PM
Thanks both. I'm storing up things to tackle for a rainy day, or if I get in a long term rut and want to do something practical.

- Replacing reeds (I've know what I need for that now, from the other thread)

- Customising a sandwich-type harp. I think I'd start by specifying one custom harp and keep it in a bell jar as reference.

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Last Edited by MindTheGap on Mar 08, 2016 11:05 PM
SuperBee
3499 posts
Mar 09, 2016
3:11 AM
sure, the OP was about airtightness, and mentioned my comment about slots...thats what i'm saying...thats what getting the gap and the reed shape is about too...well, tied into that concept of flow you mentioned MTG ...i guess that flow is why the reeds are arranged the way they are...
that Harrison B-radical i had here the other day was in the shop due to a bent 10 blow. it was bent so badly it wouldnt play...a slip during an attempt to adjust. there was a kink, at an angle. the reed was about 35-40 degrees to the plate. a great big hole under it...but the reeds are so tightly gapped and play with such light pressure, the draw reed was still quite playable. same lot had a session steel with a 7 blow snapped off about 1/4 up from the rivet. all the air in that chamber entered and exited out that hole, without exciting the draw reed enough to make a sound.
I own a few customs...a couple of early Henry Slim's...i know Henry wont be offended if i say they are fairly ordinary harps...not that they are by any means 'bad'. i achieved my first overblow on one of them, and that harp is so tight it chokes if i play hard...which is probably how i began to regulate my breath
I have an AZ marine band, not the full overblow job, but the 'overblows as passing tones' model. it took me a while to appreciate this harp. Frankly, at first i was mildly disappointed with it, but as my playing improved i became more appreciative of it.
i have 2 JSstage 2 harps. yes, they are very good. i didn't put them in a bell jar. for a while i played them almost every chance i had. and of course i have inspected them carefully. i'm going to have another look...and when they need work, i'll probably do it myself.
i dont mean to imply anything that detracts from Joe's reputation. He is up on top of the heap sure, but not simply because he knows whats going on. i believe his real genius (and trade secrets) is around his workshop practices, rather than his ability to make a harp that is great to play. that is, his methods rather than the end result per se.

in addition to these harps, ive been privieged to see and work on a couple of Neil Graham harps. as player's harps, to the extent that i can play enough to assess a good harp when i play it...Neil produces a harp that is right up there with Joe's.

i also was lucky to see some older tim Moyer customs. different era, but pretty damn good harps. special 20 combs with marine band plates and covers. fully embossed, as a non-overblower i was able to get the 4,5, and 6 on both the D harp and the A harp. unfortunately Tim suffered a stroke and told me he no longer has the fine motor skills to do this work, but he was pleased to hear i was keeping some of them in circulation.

oh, and the Harrison. i dont know who did the reedwork on that but it was outstanding. the most breath sensitive harp ive ever played. i manage to save that reed and sent it back to its owner with full function restored...but i fret the reed has probably had its life expectancy somewhat shortened.

sometimes they come up for sale...i dont know how much i'd be prepared to pay for one. maybe $400?

anyway...all the great playing customs ive seen have some things which seem similiar, but also some differences...the easy way at the moment is to get Joe to work on one for you and see if you can work out what he made different
MindTheGap
1262 posts
Mar 09, 2016
3:32 AM
Regarding motives and end products, I'm still wary of going for 'most responsive harp' as the goal, without question.

I saw a comment from someone thanking a customiser, he said, 'My other harps now seem unplayable'. May have been a throwaway line, but that doesn't sound helpful.

I want to know what I get, musically, from a more responsive harp. Better tone? I've read that tightening the tolerances makes the timbre sharper. Overblows, I don't use them much currently. Faster? I don't play fast although there are some particular things I could see - like my twiddles. They are easier to do on a higher-key harp, which tends to respond faster by nature.

Of course I'll only find out by trying it. I might be a convert. I'd rather know, and then decide not to do it, than not know and speak from ignorance.

So you're persuading me that there is responsiveness to be had, but whether that's what I want or need - I'll have to try it.

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Last Edited by MindTheGap on Mar 09, 2016 3:36 AM
MindTheGap
1263 posts
Mar 09, 2016
3:53 AM
...But anyway the OP was specifically about plate/comb airtightness. I'm not after your trade secrets folks! But if and when I get a MB to work on, I'll be testing that first, then replacing nails with screws and testing again.

If the seal is good I don't see any sense in flat sanding. I'm kind of hoping the seal ISN'T good, so I can improve it and feel the result directly.

It would seem obvious to make sure this is right (either verify it's ok, or fix and verify). As otherwise it would undermine any subsequent reed work. I wanted to get a sense for how 'right' it needs to be.

Also I like the idea of doing this simple test on my OOTB harps to see what's what. It's received wisdom that Lee Oskars are 'leaky'. If they are, it's not the reed-comb interface, at least on mine. So it must be the reed-slot interface.

Last Edited by MindTheGap on Mar 09, 2016 3:59 AM
Tiggertoo1962
39 posts
Mar 09, 2016
12:50 PM
Maybe doesn't quite belong in this thread, but since it actually has to do with gapping and shaping reeds, I'll stick it in here to save me starting a new one.

Got a new SP20 today in A, which plays so well OOTB, it makes me want to leave my other A harps - BH MS and Seydel Blues Session - sitting in their cases. What I'm wondering, is whether I can study the reed shapes and gaps on this harp, and try to apply it as a kind of template to the other two.

I've already flat sanded the draw plate and comb of the BH MS and tried gapping the reeds and, although it has made a substantial difference and the bends are all there, I still can't get the air tightness and response on the 2 and 3 draw the way it is on the SP20.

I get the feeling sometimes that my attempts at gapping are a bit like the "even a blind chicken gets an occasional corn" kind of thing, and just thought that using a well playing harp as a reference, even though they are completely different models, might make the whole thing a bit easier.
SuperBee
3500 posts
Mar 09, 2016
1:23 PM
If you have a harp that plays well, by all means, study it and try to copy what you see. If you get good results, maybe you are onto something. If it doesn't work, you're missing something.
MTG, I agree on the point of no point flat-sanding if already well-sealed. I routinely sand the draw plate when converting to a custom comb, but I don't deal with the blow plate. If there is a problem with the blow plate though, whatever else I do is not gonna be especially effective. (In the case of my Lo Eb I suspect the problem is me, because I was hopeless with LoF too but now, without working on the harp at all I found I can play it OK...LoEb continues to defeat me though...that's quite a bit lower than LoF. I don't understand how people play LoC...)
I think...it hasn't been my experience that my other harps seem unplayable but having played a good harp, custom or ootb, one does raise expectations of how a harp should play. Even response, good tuning, easily obtained and sustainable bent notes, pleasant timbre...
And it's timbre where I personally have some questions. In 'reed material' discussions I'm sceptical even though many I should respect are adamant. But...have 2 marine bands on corian combs, same key (G) one built by JS, one by MP. The JS harp is superior in several ways, but not in timbre. The MP harp sounds much smoother to me. And that is why I stopped picking up the JS harp as often. Because when I play G harp acoustically, I want round, smooth, warm tone. But The JS harp is probably louder. My AZ A harp is somewhere in between, and I do enjoy it's timbre.
Dynamic range is another big factor in a custom harp.
Easy to play, good dynamic range, easy bends, well tuned...that's what there is to like about a custom harp. Something that allows you to play and enjoy music more and not have to concentrate quite so much on overcoming the deficiencies of the instrument.
SuperBee
3501 posts
Mar 09, 2016
7:56 PM
Btw, at Joe's suggestion I put a different comb on that G harp I mentioned above, and it did mellow out a bit
MindTheGap
1264 posts
Mar 09, 2016
10:57 PM
Yes, increased dynamic range - that would be worth something definitely.

While pondering all this, I played and recorded the same phrase on three different harp models. As usual they all felt different to play but the recorded output was surprisingly similar - and this morning, listening again, they are more notable for their similarities than differences.

One of them is a Crossover, and objectively it is the most responsive. A teacher recommended it as something like the closest thing to a custom, without being a custom.

What I'm going to find out is whether a custom is like a Crossover but a lot more so, or just a little more so.

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Gary 62
118 posts
Mar 21, 2016
1:48 PM
Talking about replacing reeds what tools do you need? You need an awl or something like that to get the reed out but how do you install it. Also where do you get replacement reeds as i've only seen full reed plates for sale!
SuperBee
3523 posts
Mar 21, 2016
2:04 PM
Ive listed all the tools somewhere...try searching on 'repairing harps'. Andrew zajac does a kit.
Use salvaged reeds or buy new from hohner and seydel. Suzuki, lee oskar dont sell individual reeds. Hohner sell individual reeds in packs of 5, but only for chromatics and handmade diatonics, ie not MS harps.
Gary 62
120 posts
Mar 21, 2016
2:40 PM
SuperBee: Thanks Bee. It seems a shame to to have to buy a new reed plate if just one reed flakes out. Just makes more sense to replace them individually, if you have the tools handy of course. I couldn't do it at the moment because i don't have the tools. Saw Tinus do it on a video but he had a couple of specially milled items to help with it that someone custom built for him. Also don't know what he used to snap the rivet in, it seemed like a hand tool rivet thing and he just pressed it.
SuperBee
3524 posts
Mar 21, 2016
7:21 PM
I have a little more time now.
You can use screws or rivets. I used screws for a few years but I'm using rivets whenever possible now. Joe uses screws I believe. I use screws if rivets are out of the question.
Richard Sleigh recently produced a specialised tool for riveting.
Removing rivets is not such a big deal but you need to take care to minimise deformation of the reedplate. A punch, a flat surface to support the reedplate, with a relief to receive the rivet. There are pliers with a hole in one jaw and a pin in the other, and a stopper. I used those for a long time but also had a sheet of brass with a slot and a small hole. I could lay the plate with rivet heads in the slot and position the rivet in question over the hole, then use a punch to tap the rivet out.
So you can harvest reeds this way too, and if you're careful you can even reuse the rivet in the harvested reed.
Richards tool is a narrow anvil with a receiving hole and a vertical punch held in bracket lined up with the hole. The tool has 2 arms, on anvil doesn't have the hole, and there are 2 interchangeable punches...one is for tapping out rivets, the other is flat for installing them.
It's not a cheap tool but it doesn't take many repairs to pay for itself. It's not strictly necessary but does make the job pretty straightforward and takes some of the easy pitfalls out.
If you use screws, you need some screws. I use 1.4 mm diameter and 1.5mm long. But length could be longer if you don't mind cutting them or especially if you want to use a nut.
Andrew Z has a good video on using screws to fasten new reeds.
Richard S has video showing how to use his tool.
Greg Jones told me he never uses screws and recycles the Seydel rivets. Greg is the Seydel factory repairer for North America I believe.
I recently mended a Suzuki pro harp using a rivet..,but I had a backup plan. It worked fine, but I think I'd use a screw if I was doing it with no fallback position. Suzuki reeds are too hard to get to be taking risks with them.
That's the only thing about rivets...less margin for error...but I think the upsides outweigh the risk and if you get the rivet wrong...you can fall back on the screw as plan B.


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