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Baffles - Pine Thickness?


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Hi Bob

 

You might want to have a look at http://www.concertinamuseum.com/CM00010e.htm in the listing for individual instruments there is a tab that describes the baffles and has a photo of each one. It does not, unfortunately, describe their thickness but gives a good idea in terms of grain width etc If there is a trend then Wheatstone in particular seem to have gone for fine grained pine (certainly in terms of grain width that we would think of for guitar sound boards).

 

Were you considering a retro-fitting of baffles?

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The baffles that are made out of pine - how thick are they. Do they have a tight grain like a guitar top or are they grained more like building material?

 

Pine? Or could it be spruce, or fir?

 

I don't know if it makes a difference, or whether the subtype of any of those would be significant, but I wonder.

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I measured the thickness of a baffle from an 1870 (+/-) Lachenal, and it measures .080" thick.

 

It appears to be tight grained pine in color and grain structure when compared to the stock I have on hand.

 

However I only have British Columbia pine, fir and spruce to compare it to. Not a likely source for Lachenal. Certainly doesn't look like B.C. spruce or Douglas Fir. Too dark for one, and not reddish enough for the other. I'd bet on pine, but given the age, couldn't rule out spruce that has absorbed the smoke from many an old pub session...

 

Doug

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  • 1 month later...

If the spruce is that old, and bone dry, a thickness sander in gentle passes should take it down without much risk.

 

A lot of the older spruce for soundboards came from pretty big trees, and was always extremely stable.

 

40 odd years ago I was working in logging in the north coast area of BC, and we were still logging spruces that required 8 ft bars on a Stihl 090. 8-12 ft diameter trees were common sawmill stock at the time. Same stuff they used in WW2 for Mosquitoes and other aircraft. If it's that sort of wood, you can do things to it that would make small tree modern cut lumber just disintegrate.

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Many years ago, I bought a lovely Wheatstone baritone English concertina, with wooden ends and brass reeds, dating from 1854. It was missing its original wooden baffles, which had been sadly removed at some time in its history, presumably in an attempt to make the concertina sound louder. A respected concertina restorer told me that the original baffles would most likely have been made from Russian pine. I managed to obtain a large enough offcut of a piece of spruce used for a guitar top, to make replacement baffles for both sides. It was slightly too thick and duly sanded down to the correct thickness to fit inside, though I can't recall the exact thickness. Anyway, they do their job and look nice and original.

 

Chris

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OK - Lots of questions. I spent a lot of time on the Concertina Museum site looking at baffles. It looked as if pine was used on the less expensive concertinas, while the upper end instruments used chamois or fabric. I'm assuming the chamois was thicker and stiffer than that used on the reedpan.

 

Just trying to test the waters, I made a set of baffles out of 80 lb paper cardstock using the same methods Robert Gaskins used with leather. They seem to work fairly well, but I doubt they will hold up in the long run. (They should make good templates though). When I first put them on, they hit the lever arm and sounded a note. I used a thinner 2 sided tape and that seemed to solve the problem, but makes me think I don't have much room to play with in terms of thickness. I hadn't mentioned this, but I do have some gauze covering the inside of the end fret which adds some thickness. Should I take it off? I know that theoretically it's supposed to be acoustically neutral and not mute the sound ( it was installed by Button Box, but whenever I remember having some on a button accordion once that definitely muted the sound.

 

I have a set of spruce baffles partially made, but in order to fit them I would have to either cut down the pillars or cut a hole in the baffles to go around the pillars. Interestingly, there is a spacer glued to the top of the pillars, which I imagine was put there when the original baffles were taken out. So putting spruce baffles on would probably be closer to the original, but since I am doing the work, why not just use leather? Leather would be a lot less work and easier to reverse than the spruce and hopefully sound better. I imagine that the pine was cheaper than leather when they were first making them - does anyone know?

 

My main interest in having to reduce volume, but to help the tone. On the museum's site, I saw some circular baffles made out of leather or fabric that actually don't cover much of the endfret. Probably for tone rather than volume?

 

Another question - there are 3 pillars, Two that connect to the thumb strap and finger rest. Some of the concertinas in the museum had a screw going into the 3rd pillar, but only 1 or 2 of them had that screw going from the outside of the endfret. I don't get how the 3rd screw connects or if it is necessary.

 

Any thoughts?

 

Bob

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Bob, You explain that your aim is to ' reduce volume and help the tone ' . My metal-ended, steel-reeded Anglo was manufactured with a very thin, very finely-woven silky, ( but probably man-made ) fabric fixed securely to cover the entire inner surface of the fretted ends. The instrument has, to my ears, a very pleasant gentle tone. I have no wish for the more strident tone which I believe to be associated with a Jefferies type instrument. I like the ease with which the intrument can be played very softly. I guess the fabric has a significant effect upon the tone and volume of the instrument but not to such an extent of course as would be expected from wooden or leather baffles. The tone and volume of my intrument would presumably be altered if the woven fabric was of a different thickness and constitution. The fabric also performs the valuable function of acting as a filter to prevent unwanted foreign matter from gaining access to the mechanics of the instrument. It would be relatively easy to experiment with a variety of fabrics in order to hopefully achieve the effect that suits you.

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OK - Lots of questions. I spent a lot of time on the Concertina Museum site looking at baffles. It looked as if pine was used on the less expensive concertinas, while the upper end instruments used chamois or fabric. I'm assuming the chamois was thicker and stiffer than that used on the reedpan.

 

Just trying to test the waters, I made a set of baffles out of 80 lb paper cardstock using the same methods Robert Gaskins used with leather. They seem to work fairly well, but I doubt they will hold up in the long run. (They should make good templates though). When I first put them on, they hit the lever arm and sounded a note. I used a thinner 2 sided tape and that seemed to solve the problem, but makes me think I don't have much room to play with in terms of thickness. I hadn't mentioned this, but I do have some gauze covering the inside of the end fret which adds some thickness. Should I take it off? I know that theoretically it's supposed to be acoustically neutral and not mute the sound ( it was installed by Button Box, but whenever I remember having some on a button accordion once that definitely muted the sound.

 

I have a set of spruce baffles partially made, but in order to fit them I would have to either cut down the pillars or cut a hole in the baffles to go around the pillars. Interestingly, there is a spacer glued to the top of the pillars, which I imagine was put there when the original baffles were taken out. So putting spruce baffles on would probably be closer to the original, but since I am doing the work, why not just use leather? Leather would be a lot less work and easier to reverse than the spruce and hopefully sound better. I imagine that the pine was cheaper than leather when they were first making them - does anyone know?

 

My main interest in having to reduce volume, but to help the tone. On the museum's site, I saw some circular baffles made out of leather or fabric that actually don't cover much of the endfret. Probably for tone rather than volume?

 

Another question - there are 3 pillars, Two that connect to the thumb strap and finger rest. Some of the concertinas in the museum had a screw going into the 3rd pillar, but only 1 or 2 of them had that screw going from the outside of the endfret. I don't get how the 3rd screw connects or if it is necessary.

 

Any thoughts?

 

Bob

 

Bob,

 

Spruce was used on the OLDER concertinas, Later lamb/ sheep skin baffles were fitted on certain models but later a fabric (silk) was fitted presumably to reduce dust intake and to show off the fretting. Chamois was never used as a baffle.

 

I have seen spruce used on bass concertinas to modulate the volume between the high & low notes, and it was commonly used on concertinas made in the mid 1800-1900 period. Baffles are fitted as close to the fretting as possible whilst leaving an air gap. Chamois or felt off cuts were used as spacers. Gauze was used much later on in the 1900's.The problem with baffles is that the lever arm end leather bead can strike the underside of the baffle an can sound quite percussive, as well as giving irregular key travel heights.

 

The purpose of the pillars is to trap the fretting between the thumb strap or finger slide in a carefully spaced position so that the wood lies without stress when forces are applied by thumb or little finger to move the bellows. Without the pillars, or where the packing is wrong, then all the playing forces go through the delicate fretting in it's weakest direction which can then crack. The third pillar is another early instrument feature, some times screwed through the action box cover, some times not. It was dropped from the design later, but its main function was simply to support the action box cover from handling damage and thus preserve the delicate fretwork.

 

The spruce baffles that I have seen are usually about 2 mm thick and are cut around the pillars, although I have seen the odd instrument where the baffle is part of the pillar height packing. Leather baffles do mellow tone, presumably by absorbing harmonics. It was the successor to spruce. Fitted shiny side out wards it looks well, and it is fitted onto chamois or felt packers (a lot of packers stuck all over the place) to give the air gap and to hold it evenly.This sheep skin is soft and floppy but works.

 

Which ever route you take, please be sure that the pillars are in place, and properly packed up to the underside of the action box cover.

 

Dave E

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Just to back up what Dave says about the pillars, the Lachenal that I took the baffle from to measure does not have the baffle cut out arround the pillars, and to boot it uses chamois discs right on top of the pillars for spacing. The end result is that the fretwork is badly cracked and split!

 

I wouldn't see it as a big deal to drill some holes to work around the pillars. Of course that would leave the baffle unsupported. The way I would approach that would be to add small blocks of wood to the pillars in a spot (or spots) that are clear of the action, perhaps about 1/4" long, topped with pieces of chamois (double layer?). Glue those to to the pillar so that they support the baffle (with chamois or felt spacers on the face side against the fret areas) just snuggly.

 

That would mean that absolute minimum has been done to alter the concertina, and the blocks could easily be removed at a later date if required. Which follows the general rule with these old instruments - don't do anything that can't be undone.

 

Dave's comment that the wooden baffles are 2 mm thick confirms my measurement of .080.

 

The Lachenal in question also has brass reeds, and the combination with the baffles gives it a very mellow sound. Not much volume though.

 

Hope your project goes well.

 

Doug

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The baffles are usually mounted off the fretwork with felt or chamois pads as described before. I forgot to mention that baffles also often have small triangular wooden corner blocks mounted to trap the baffle against the felt spacer pads, one on in each corner of the underside of the action box cover.

 

Dave E

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Dave, Doug - Thank you for your replys. No danger I'm going to leave the fretwork unsupported. I am curious as to the effects on sound the different materials have. The cardstock I'm using certainly decreases the volume more than I would like.

 

What about the gauze? As I said it was put on by the button box. They did a good job. But was it ever common to have both gauze and baffles. I imagine the gauze also helps the fretboard hold together structurally.

 

BTW How thick was the felt used to hold the baffle off the fretboard?

 

Bob

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Felt thickness, around 2mm,

 

gauze is a dust come fly screen, never seen it used in combination with baffles, as to volume, is your instrument steel or brass reeded?.

 

I think I would for a sheep skin solution, easy to mount, cut /shape and remove

 

Dave E

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Refitting the original pine baffles in my Wheatstone Baritone didn't seem to make a lot of difference to the volume, but it did improve the tone of a couple of reeds that were a bit harsh, seemed to balance the tone

 

Forgot to say that they are brass reeds

Edited by chris
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http://www.concertina.com/gaskins/baffles/index.htm

 

Bob, this article might give you some useful information.

 

My guess is that the most appropriate choice to start with, and certainly one of the simplest will be sheepskin or goatskin. If I were to tackle it, I would go with goatskin (because I have it on hand) and treat it to stiffen it (various methods/formulas on the internet). But I haven't tried it.

 

No matter what you use for baffles, they will almost certainly reduce the volume a bit. The Lachenal English I have still has the original tight weave silk(?) cloth baffles, which you often see removed in the search for more volume.

 

The Wheatstone I have still has the original sheepskin baffles, and has a lovely tone to my ear, and good volume, but that's not a useful comparison as the reeds etc. are all significant upgrades.

 

Notice in the above referenced article that leaving a 2 mm gap around the edge of the leather baffle has minimal effect on the volume, but still has the tone changing effect.

 

Hope that helps,

 

Doug

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