|
Dirty-South Blues Harp forum: wail on! >
Flattening Blow Reed Plates
Flattening Blow Reed Plates
Page:
1
Sherwin
23 posts
Feb 17, 2013
11:23 AM
|
Anyone out there have any tricks for flattening blow reed plates, beyond making the long edges straight by careful bending by hand?
I work on Marine Bands and have noticed sometimes plates are "cupped" so to speak, front to back. I hand filed the worst one I encountered with good results(plate was bent at coverplate groove), but pretty much wrecked a beautiful little four square file, all clogged with brass.
It has occurred to me to remove all reeds, flatten the plate, then replace reeds. Never done this, will this process (reinstalling the ten reeds) itself make reed plate lose the flatness just established?
I am going to take a promaster comb and file a slight concave "trough" end to end, so that I can put a reed plate on it then massage (push down) the material between the reed slots in order to flatten them front to back.
I couldn't care less about destroying the promaster comb, it strikes me the plate straightening will still be a bit of a pain though, but with some concentrated effort I can see it working.
I would love to hear how some others have tried to address the blow reed plate to comb air tightness issue/problem, without resorting to gasketing.
Thanks.....
Sherwin
|
arzajac
986 posts
Feb 17, 2013
3:40 PM
|
"I work on Marine Bands and have noticed sometimes plates are "cupped" so to speak, front to back."
Just to be clear, when you hold the plates to the comb and press on the back, this causes the reedplate to be off the comb in the front - there is space between the reedplate surface and the surface of the tine where they should be in contact. It causes the harp to have really bad tone and play poorly. Correct?
That used to happen to me all the time when I first started out working on MBs. I changed how I went about removing the nails and that solved the problem. You really need to be careful about warping the reedplate as you pry off the nails.
That being said, I am working on a harp from a guy who tried to restore his Grandfather's pre-MS blues harp and distorted the reedplates like that. He mostly took care of the draw plate by flat sanding it.
I think it's better to just shape the reedplate back the way it was supposed to be. If you consider where the pressure was put to cause the plate to bow, you can reverse the effect using hand tools. Don't overdo it - aim for halfway with every try and keep trying to get it closer and closer.
When you no longer can appreciate the distortion of the reedplate when it's on the comb visually, try blocking the upper and lower slots of a hole with your finders and puffing into the hole. Your mouth will feel the airtightness and you can judge if it's still leaky.
Anyway, that's my take on the topic. I hope it helps.
----------
|
Sherwin
25 posts
Feb 17, 2013
8:41 PM
|
Thanks arzajak for responding, gee I have to say the condition I am trying to correct is the opposite of what you described.
I crank the nails out carefully with a pair of flush cut nippers, mine are like a pair of mini side cutters. Turning the nails a little back and forth as I pull them out, I can't imagine I'm bending the plates in the process, I'm finding the odd blow reed plate lately that is far from flat and this cupping results in contact between the plate and comb being made only at the front and back of plate. So putting the plates on the comb everything "looks" fine.
I want to establish contact with the plate on the entire surface of the comb, something that many of us do routinely with the draw reed plate by sanding it flat to mate with our flattened comb.
That being said, I find most draw reed plates I sand are very good to start with, and most often so are the opposing plates, now what to do when you discover when examining a blow reed plate that there is this cupping? when the blow reed plate is out of whack worse than the other plate it's not an easy fix is it? Certainly gasketing comes to mind, or I could put the thing in a drawer and grab another harp hoping for the best.
I trust I will arrive at a solution, I would still love to hear from y'all about what has and hasn't worked for you trying to adress this issue.
I can't imagine I am the only one ever to have run into this problem.
If I find a reasonable method of straightening blow plates, I won't be the first to have done so.
Luckily I don't feed myself makin' custom harps, and even the problems I run into don't come close to takin' the fun out of the whole business.
Thanks......Sherwin
|
HarveyHarp
464 posts
Feb 17, 2013
10:37 PM
|
If I get a bent reedplate, I use a good size drill press vice, the one with about 6 inch flat jaws, and clamp the plate in that pretty hard. I make sure that I stay far enough from the rivets, so as to not distort the reeds. On the draw plate, I can acutually tilt the plate, and sort of go across at an angle. Then I press the two ends, and if it still needs more, which I have never seen the I would have to get a bar that would go between reeds and press on that. Etc.
----------
HarveyHarp
|
lor
173 posts
Feb 18, 2013
7:06 AM
|
I haven't done this, altho I've changed combs, taken apart harps, cleaned, etc., but I would take an unwanted reed plate, remove the reeds, and drill the rivet holes to a larger size, then I could use that plate over the face of the plate to be flattened so the rivets and reeds would lay into the spaces in the drilled plate, then press the pair in a flat-faced vise. If the springiness of the bent plate prevented complete flattening that way, I'd consider using a couple of shims under the too-high edges to force a slight over-bend which would spring back to flat.
|
Sherwin
26 posts
Feb 18, 2013
10:30 AM
|
Wow thanks Harvey, I can't believe I hadn't thought of using a vice. I think it's because the tools I have been using are all kinda small, and somehow I wasn't letting myself include some of the larger tools I have at my disposal.
Yes why not bring out the big guns.
Lor I like your idea as well, now I have a number of approaches that make very good sense.
Thank you .....Sherwin
No it ain't rocket surgery
Funny though, I actually did make a harp for a guy who is an astrophysist, he got his first overblows on it and was happy about that, me too!
Toodiloo
|
Post a Message
|
