Valve sizes in a lachenal tutor

[njurkowski]

Well, I went and did something that I'm sure will end up consuming all of my free time: I acquired an old, beaten-up 48-key Lachenal English (tutor model with colored buttons and brass reeds, serial number 36981), since I don't think I'll have the money for a fully restored vintage model any time soon. I bought the thing sight unseen (the price was right, and who doesn't like a good gamble now and again?), I ended up with a model that needs new springs, valves, and pads, as well as some wood filler on the padboard, but with (most importantly) great looking reeds and no damage to the finish. The bellows are in quite a state, and I'm not sure yet if I want to try patching them or just replace them (probably from David Leese's site if I go that route), but one step at a time; I'm turning my attention to the valves and pads.

 

I'm putting together a list of measurements of valves and pads so I can order them from the concertina connection, but I notice that some of the valve sizes don't match the standard sizes available on Wim's site. For instance, there are a number of valves that are 24mm - the corresponding valves on the other side are 25mm, and one (which was cut to fit) seems to have originally been 27. Now, it seems to me that some of the original valves maybe were just not cut as carefully, or the craftsman didn't have any more 25mm on hand and used other sizes, but I wanted to make sure this wasn't done with some inscrutable yet crucial reason before I decided to "correct" the original handiwork.

 

Thanks!

[Greg Jowaisas]

Well, I went and did something that I'm sure will end up consuming all of my free time: I acquired an old, beaten-up 48-key Lachenal English (tutor model with colored buttons and brass reeds, serial number 36981), since I don't think I'll have the money for a fully restored vintage model any time soon. I bought the thing sight unseen (the price was right, and who doesn't like a good gamble now and again?), I ended up with a model that needs new springs, valves, and pads, as well as some wood filler on the padboard, but with (most importantly) great looking reeds and no damage to the finish. The bellows are in quite a state, and I'm not sure yet if I want to try patching them or just replace them (probably from David Leese's site if I go that route), but one step at a time; I'm turning my attention to the valves and pads.

 

I'm putting together a list of measurements of valves and pads so I can order them from the concertina connection, but I notice that some of the valve sizes don't match the standard sizes available on Wim's site. For instance, there are a number of valves that are 24mm - the corresponding valves on the other side are 25mm, and one (which was cut to fit) seems to have originally been 27. Now, it seems to me that some of the original valves maybe were just not cut as carefully, or the craftsman didn't have any more 25mm on hand and used other sizes, but I wanted to make sure this wasn't done with some inscrutable yet crucial reason before I decided to "correct" the original handiwork.

 

Thanks!

 

Better to go a little longer than to have too short of a hinge on your valve. Perhaps more important with a brass reed instrument is to go with thin, light valves. A heavy valve can absorb sound and will take more air to activate. Most likely you will want to set up your instrument to be the quickest and most responsive it can be. Light valves will help.

 

The wood filler has use in repairs but it is important to use it in the right situations. What repairs will you be attempting with filler?

 

Best of luck,

 

Greg

[njurkowski]

The pad board seems to have shrunk over the years and pulled apart, across the holes for the pads. The gaps aren't especially wide, but I need to fill it with something to make it airtight. It seems like the cracks might be a little too wide to just fill it with wood glue, but I could be wrong.

 

Thanks for the advice!

[Greg Jowaisas]

Theo gibb runs The Box Place and is an excellent repairman. His site has a repair section illustrating some of his repairs. There are several pictures of repairing cracks in a button board (sound board) which may give you some insight on how to approach this task. http://www.theboxplace.co.uk/typical-cracks.htm

 

It is important to stabilize the repair and action board. I'd recommend clamping on a steel plate or some other level, substantial surface when gluing. Wax paper can keep glue from sticking and surfaces from attaching. Next most important is getting the inside wood around the pad holes as level and smooth as possible. This can be difficult if the crack has moved and displacement of the wood has occured. Sanding or scraping the surfaces where the pads will seat must be done with care to keep things level.

 

If it is a hairline crack with no displacement then sometimes rubbing glue in it or glue with some sawdust will suffice. Wood fillers vary but my impression is that they are just that: fillers. They will not offer much in strength or stability. Theo's technique of using a splint provides strength, stability and fills the gap.

 

In a worst case scenario more extereme measures can be employed drilling out the pad hole; plugging it and redrilling the hole. Not for the amateur or the faint of heart!

 

I don't want to discourage you but encourage you to plan the repair, execute it well and help the concertina play properly for generations to come.

 

Best of luck,

 

Greg

 

As soon as they download I'll post several pics of a repair I did to show you what is possible:

 

Edited December 16, 2009 by Greg Jowaisas

[njurkowski]

The cracks really aren't that extensive. I actually think that glue mixed with sawdust would be just right, given the amount the wood has pulled apart. There is a bit of displacement in a few places, though it isn't by that much. If you think that careful sanding might work, I'll try that. I like the idea of the wax paper to keep things contained. Luckily, the damage really isn't that extensive, so I don't think I'll have to be drilling anything out.

 

I appreciate the tips - I definitely want to do this right!

[chris]

Hi

Have you got a copy of Dave Elliott's repair manual? If not I suggest that you get a copy before doing to much.

chris

[njurkowski]

Hi

Have you got a copy of Dave Elliott's repair manual? If not I suggest that you get a copy before doing to much.

chris

 

I do. It actually just arrived yesterday. Seems quite handy, and I'm making my way through it.

 

Today was the first day I did anything (just cracking the box open to measure the valves).

Edited December 16, 2009 by njurkowski

[Theo]

Theo gibb runs The Box Place and is an excellent repairman. His site has a repair section illustrating some of his repairs. There are several pictures of repairing cracks in a button board (sound board) which may give you some insight on how to approach this task. http://www.theboxplace.co.uk/typical-cracks.htm

 

It is important to stabilize the repair and action board. I'd recommend clamping on a steel plate or some other level, substantial surface when gluing. Wax paper can keep glue from sticking and surfaces from attaching. Next most important is getting the inside wood around the pad holes as level and smooth as possible. This can be difficult if the crack has moved and displacement of the wood has occured. Sanding or scraping the surfaces where the pads will seat must be done with care to keep things level.

 

 

In those pictures I used slips of veneer to fill the cracks. I sand the end of the veneer strip to fit the tapered part of a crack.

 

If the cracks are not open enough to require a slip of veneer then I find low viscosity superglue (cyanoacrylate) is excellent as it will capillary itself into the finest cracks. Greg's point about clamping onto a stable flat surface is very important. Test out all your clamping arrangements before applying any glue!