11 replies to this topic

[Paul_Hardy]

I've just acquired a basic Lachenal treble from eBay. It is serial 52313 (originally misread in the description as 58313). It was described as "for parts or not working" and it certainly will require work and investment to get it playable. See my description. The biggest problem is a major split in the pad board (pad area of action board). See picture.

Dave Elliot's Maintenance Manual suggests 'plastic wood' for filling such cracks. My question is does this mean using the kind of plastic wood that sets by evaporation of solvent, or for a crack of this size, would it be better to use a two-part epoxy resin wood filler that sets quickly throughout, and wouldn't shrink?

Anyone done this sort of repair before and has advice?

I note that someone has tried to repair the cracks (presumably when they were smaller) with inserted veneer. I plan to remove that and do a single filling.

Regards,

[d.elliott]

I've just acquired a basic Lachenal treble from eBay. It is serial 52313 (originally misread in the description as 58313). It was described as "for parts or not working" and it certainly will require work and investment to get it playable. See my description. The biggest problem is a major split in the pad board (pad area of action board). See picture.

Dave Elliot's Maintenance Manual suggests 'plastic wood' for filling such cracks. My question is does this mean using the kind of plastic wood that sets by evaporation of solvent, or for a crack of this size, would it be better to use a two-part epoxy resin wood filler that sets quickly throughout, and wouldn't shrink?

Anyone done this sort of repair before and has advice?

I note that someone has tried to repair the cracks (presumably when they were smaller) with inserted veneer. I plan to remove that and do a single filling.

Regards,

Hi Paul,

when I quoted using plastic wood I was certainly not envisaging major splitting as your picture shows, The technique using plastic wood is for minor cracks a matter for maintenance, not restoration. It was Steve Dickinson of Wheatstone who gave me the tip of plastic wood and sellotape.

For this form of repair I would true up each section of he split using a scalpel or razor saw. Then I would glue in strips of wood (ice lollipop sticks are good for this) ensuring the wood strip is wide enough to stand proud of both faces, and thin enough to be an easy slip fit into the split.. Take care to clamp the pad board wood flat across the split at each glueing stage - to avoid forming a step in the pad board.once the glue is fully cured - then gently flat back any wood that is proud of the pad board surfaces, or standing into pad holes.

You need to deal with the shrinkage between the pad board and the outer casing similarly.

I seem to recall that Theo Gibb wrote an article on this subject in a similar thread.

Dave

[Chris Ghent]

If you want the holes to return to round you might need to detach the small part of the padboard from the outside of the action box and close up the crack. You could then put your packing between the padboard and the action box side.

I have one of these cracks in a better concertina and my plan is; close up and glue the crack getting the top and bottom surfaces as even as possible, groove the underside of the crack with a V cutter and put in a triangular piece of wood, scrape it level. Bend or remove the lever arms and using a cnc machine counterbore around the remains of the pad hole to about 2mm. Put a disc of wood into each of the couterbores, redrill the hole. Can anyone see any flaws in this?

Chris

Edited by Chris Ghent, 29 June 2012 - 08:25 PM.

[d.elliott]

If you want the holes to return to round you might need to detach the small part of the padboard from the outside of the action box and close up the crack. You could then put your packing between the padboard and the action box side.

I have one of these cracks in a better concertina and my plan is; close up and glue the crack getting the top and bottom surfaces as even as possible, groove the underside of the crack with a V cutter and put in a triangular piece of wood, scrape it level. Bend or remove the lever arms and using a cnc machine counterbore around the remains of the pad hole to about 2mm. Put a disc of wood into each of the couterbores, redrill the hole. Can anyone see any flaws in this?

Chris

Chris,

On the topic of Paul's question, I have found that closing up cracks by releasing part of the pad board can have several issues:
1. splits rarely glue up well, wood fibres are irregular, some stretch across or into the split, and the split has a lot of ingrained dust & muck.
2. taking the good joint apart between the section of pad board to be removed and the outer casing can cause the casing to come apart, and break corner blocks.

I find it easier overall to true up the split as needed and in lay a bit of lollipop stick, or soft wood strip. You are right about the resultant holes being a bit out of round I should have mentioned it. Usually not a problem, when it is, I fit the next sized up of pad, trimming the pad a little if needed.


Your very sophisticated repair procedure for the higher grade instrument seems (to me) over complex. I have needed to replace a section of pad board. I made sure that all dimensions and coordinates for the hole centres are recorded so new holes can be correctly centred, I fretted out a square of the damaged wood. I then dressed the cut the edges true but put a taper on the hole sides the wide 'face' of the hole being the action plate side, about 20 degrees of slope. I then cut a piece to inset. slightly thicker and a tad over size. and made the edges tapered equally. Thus the inset was a large tapered plug the top face being the widest and being the pad face. The purpose of the taper was two fold, to increase the gluing area, and to make the inset a positive fit into it's space - ensuring adequate flatness inside the action box.

I then sanded the plug edges until the pad side was flush with it's surround, and thinned the plug so that the reed pan face was just proud of its surround. it was then a simple glue, finish the reed pan face of the pad board, pilot then bore new holes.

With your fancy kit, why not simply bore a single oversize hole, fit a plug cut across the grain, and re-bore? or go for an oversized pad? Your fancy kit is probably a lot of fun, so play away. My solutions are geared to 'home' skills and basic craft skills an age thing.

Dave

[Andy Holder]

I've just acquired a basic Lachenal treble from eBay. It is serial 52313 (originally misread in the description as 58313). It was described as "for parts or not working" and it certainly will require work and investment to get it playable. See my description. The biggest problem is a major split in the pad board (pad area of action board). See picture.

Dave Elliot's Maintenance Manual suggests 'plastic wood' for filling such cracks. My question is does this mean using the kind of plastic wood that sets by evaporation of solvent, or for a crack of this size, would it be better to use a two-part epoxy resin wood filler that sets quickly throughout, and wouldn't shrink?

Anyone done this sort of repair before and has advice?

I note that someone has tried to repair the cracks (presumably when they were smaller) with inserted veneer. I plan to remove that and do a single filling.

Regards,

Paul
I just wrote a reply tending towards Chris's suggestion but then completely did a U turn (sorry Chris). The crack has been caused by shrinkage (wood only shrinks across the grain, not along it). I've measured your photo on my screen and it appears that across the flats it is exactly the same each direction. That's very important as the action hasn't shrunk so if you were to close up the crack it wouldn't be right. In my humble opinion you should have as much wood as possible and minimum glue or filler. Find a bit of Sycamore or Maple and sand it to a very slight taper until it will wedge in the crack. Glue all faces and push it in firmly. After it's set, take off the excess with a very sharp chisel, then sand flat. Make some oversize pads and you're sorted.
Andrew

[Chris Ghent]

With your fancy kit, why not simply bore a single oversize hole, fit a plug cut across the grain, and re-bore? or go for an oversized pad? Your fancy kit is probably a lot of fun, so play away. My solutions are geared to 'home' skills and basic craft skills an age thing.

Dave

Dave,

You might be right about over complex but I use the cnc to compensate for my lack of motor skills. I respect the old ways, or should I say, I respect the people who are in command of them! I also suspect we are of an age..!

Cheers

Chris

[apprenticeOF]

I repaired a Lachenal with an almost identical split using Dave's method, and it worked very well. The only variation was that I used maple strip cut from some stock that I had on hand. The out of round holes didn't prove to be a problem. Simple, quick and effective method.

[d.elliott]

With your fancy kit, why not simply bore a single oversize hole, fit a plug cut across the grain, and re-bore? or go for an oversized pad? Your fancy kit is probably a lot of fun, so play away. My solutions are geared to 'home' skills and basic craft skills an age thing.

Dave

Dave,

You might be right about over complex but I use the cnc to compensate for my lack of motor skills. I respect the old ways, or should I say, I respect the people who are in command of them! I also suspect we are of an age..!

Cheers

Chris

Chris,

I am actually envious of your cnc capability, I would love to have kit like yours to explore and play with. I am sure I could invent all sorts of jobs to do on all sorts of materials and for all sorts of purposes. However, in this case, the over complexity I refer to is primarily drilling from both sides when a single through hole onto a backer would do the business nicely. As most people do not have access to your extensive workshop facilities, I also wanted to stress that an out of round hole is not a show stopper, you can true the hole up, most cannot without the risk of further splintering, so the over sized pad solution was put forward.

It is true that I find my hands not quite a steady and the eye not quite as easily focussed as they were even 10 years ago, and I have may ways to compensate, we probably are of an age, I retire (early let it be said) from industry in three weeks time. I have number of squeaking, rattling and wheezing projects to work on so retirement? What's in a word? I shall still envy your CNC capability and make do.

all the best

Dave

[Chris Ghent]

Dave

if you are looking for an audience for repair seminars might I recommend a quick trip across the Irish Sea. I saw many people there recently coping with issues in their concertina because of lack of repair expertise. Some of the modern wave concertinas have been played hard and long now and while they are not cracked or bowed they have leaks, tuning, valve and pad issues.

I would not describe my workshop as extensive, its a small garage with a few key machines including a tiny Taig CNC.

Cheers

Chris

[d.elliott]

Dave

if you are looking for an audience for repair seminars might I recommend a quick trip across the Irish Sea. I saw many people there recently coping with issues in their concertina because of lack of repair expertise. Some of the modern wave concertinas have been played hard and long now and while they are not cracked or bowed they have leaks, tuning, valve and pad issues.

I would not describe my workshop as extensive, its a small garage with a few key machines including a tiny Taig CNC.

Cheers

Chris

Chris,

I am envious of your small garage then, mine has been taken over by my youngest daughter who is a stained glass artist.

Dave

[Chris Ghent]

Sounds lovely, tell her the rent is a really nice stained glass concertina...

[d.elliott]

Sounds lovely, tell her the rent is a really nice stained glass concertina...

That would be putting the Squeeze onto her.

Dave