Bolt hole damage

[SteveS]

I have this concertina on my bench at the moment.

 

Features:

 

- 35 key Lachenal baritone (probably a band instrument)

- very large reeds (much larger than in other baritones I've seen)

- deep reed chambers

- steel reeds (3 of which are broken) - double action

- interesting bellows papers

- serial number 50020

 

Someone at sometime has obviously had some severe problems with leaks. Instead of addressing the leak by treating the chamois gasket, pads, springs, etc. on the right hand end, they have placed felt directly beneath the bolt holes. This has then further compounded the leak - it looks as though in an attermpt to cure the leak someone has been very handy with a screwdriver and has screwed the end bolts down so much that they have drilled the bolts through the ends and deep into the substrate of the action box hoops, only stopping by the lack of remaining thread on the end bolts. You can see this in the 2 pictures of the worst of the 6 bolt holes. Suffice to say they weren't very successful in curing the leak.

 

This is perhaps the worst example of end bolt brutality I've seen.

 

So how to repair it? My thoughts are as follows:

 

- remove the end plate on the right hand end

- remove the veneers from the action box hoop

- drill out the holes in the action box hoop sides to a given depth and introduce a dowel

- drill out the damaged bolt holes in the end plates and introduce new rosewood

- refit the end plate, action box side veneers and drill bolt holes through the new dowels

- strip and refinish both right and left hand ends

- replace all end bolts and nuts with new (the current end bolts don't look original and some of the nuts have worn threads)

 

Any other ideas about how to go about repairing this kind of damage.

Steve

Edited July 3, 2011 by SteveS

[david robertson]

 

 

 

Any other ideas about how to go about repairing this kind of damage.

Steve

 

 

What I do in cases of this kind is to drill out the holes to an appropriate size, and sleeve them with glued-in lengths of brass tube, available from model-makers' suppliers. The gap around the brass tube, where the wood has been butchered, can then be filled with Loctite 4105 and sanded to the correct profile. The compression is then exerted on the tube, not the woodwork, preventing further damage. If you're not familiar with 4105, it's a viscous black liquid activated by a hardening spray - Mike Acott put me on to it a few years ago. It cures in a minute, can be easily sanded, and takes a French polish finish. The drawback is the cost - around £30 for a 25mm bottle- but then, you never use much of it at a time.

With best wishes,

David

[SteveS]

What I do in cases of this kind is to drill out the holes to an appropriate size, and sleeve them with glued-in lengths of brass tube, available from model-makers' suppliers. The gap around the brass tube, where the wood has been butchered, can then be filled with Loctite 4105 and sanded to the correct profile. The compression is then exerted on the tube, not the woodwork, preventing further damage. If you're not familiar with 4105, it's a viscous black liquid activated by a hardening spray - Mike Acott put me on to it a few years ago. It cures in a minute, can be easily sanded, and takes a French polish finish. The drawback is the cost - around £30 for a 25mm bottle- but then, you never use much of it at a time.

With best wishes,

David

Thanks David for the reply.

 

Good idea to line the bolt hole with brass tubing, but because the ends are rosewood I cant use the Loctite idea (not on exposed woodwork)

 

My present thinking is then as follows (minimising the amount of work I do):

- drill out the bolt holes in the action box hoops to a given depth and line with glued-in brass tubing - the end of the tubing will be flush with the part of the action box hoop closest to the end plate and which is exposed by the damaged bolt holes

- since the holes are essentially not much larger than the diameter of the heads of the bolts, I think I can limit drilling out the holes in the end plates to just ensuring a good clean edge using a drill bit just slightly larger than the bolt head diameter

- fill these holes with rosewood plugs

- strip, sand, fill, stain, as appropriate, French polish finish (both ends)

 

Steve

Edited July 4, 2011 by SteveS

[RAc]

 

Good idea to line the bolt hole with brass tubing, but because the ends are rosewood I cant use the Loctite idea (not on exposed woodwork)

 

 

? Couldn't you still use the loctite but sand it down so it is a little lower than flush with the top and put a very thin layer of wood filler on top of it to flush up with the top?

[OLDNICKILBY]

Perhaps they Counter-bored the screw holes as the screws had broken and this was a Bodgers repair. Why not turn some Rose-wood Dowels and plug the holes and then re-bore?

[SteveS]

Perhaps they Counter-bored the screw holes as the screws had broken and this was a Bodgers repair. Why not turn some Rose-wood Dowels and plug the holes and then re-bore?

Nic & Ruediger

 

Thanks for the contributions.

 

I think drilling out the bolt holes and inserting with a rosewood plug is the way to go.

I like the idea of a brass sleeve in the action box hoop too.

 

I'll post pictures of the repair as I go.

 

Steve

[Theo]

Perhaps they Counter-bored the screw holes as the screws had broken and this was a Bodgers repair. Why not turn some Rose-wood Dowels and plug the holes and then re-bore?

 

Using a plug cutter and matched drill will help achieve a neat fit. For example:

http://www.axminster.co.uk/axminster-8-piece-matching-plug-and-bit-sets-(8-15mm)-prod840922/

[SteveS]

Perhaps they Counter-bored the screw holes as the screws had broken and this was a Bodgers repair. Why not turn some Rose-wood Dowels and plug the holes and then re-bore?

 

Using a plug cutter and matched drill will help achieve a neat fit. For example:

http://www.axminster.co.uk/axminster-8-piece-matching-plug-and-bit-sets-(8-15mm)-prod840922/

Thanks Theo - good idea.

Steve

[OLDNICKILBY]

Steve

If you are struggling for some Rosewood try the local Car Boot Sale , rummage through the junk tools for an old Try Square with a rosewood stock and hey presto.

I personally would not use a plug cutter as a simple drill will do the job as well and save the money. Do Not drill all the way through but just make a pellet , leave proud and finish off to the right profile

[SteveS]

Steve

If you are struggling for some Rosewood try the local Car Boot Sale , rummage through the junk tools for an old Try Square with a rosewood stock and hey presto.

I personally would not use a plug cutter as a simple drill will do the job as well and save the money. Do Not drill all the way through but just make a pellet , leave proud and finish off to the right profile

Nic - thanks for the contribution.

Just so happens I'm going to a boot sale this weekend, so I'll keep my eyes peeled.

Steve

[varney]

Hi Steve,

 

Did you successfully sort out those nasty bolt hole problems? I'd be grateful to hear how it went as I have an instrument with very bad gouges around the bolt holes. Any pictures of your progress?

 

Thanks,

Michael.

[d.elliott]

I have this concertina on my bench at the moment.

 

Features:

 

- 35 key Lachenal baritone (probably a band instrument)

- very large reeds (much larger than in other baritones I've seen)

- deep reed chambers

- steel reeds (3 of which are broken) - double action

- interesting bellows papers

- serial number 50020

 

Someone at sometime has obviously had some severe problems with leaks. Instead of addressing the leak by treating the chamois gasket, pads, springs, etc. on the right hand end, they have placed felt directly beneath the bolt holes. This has then further compounded the leak - it looks as though in an attermpt to cure the leak someone has been very handy with a screwdriver and has screwed the end bolts down so much that they have drilled the bolts through the ends and deep into the substrate of the action box hoops, only stopping by the lack of remaining thread on the end bolts. You can see this in the 2 pictures of the worst of the 6 bolt holes. Suffice to say they weren't very successful in curing the leak.

 

This is perhaps the worst example of end bolt brutality I've seen.

 

So how to repair it? My thoughts are as follows:

 

- remove the end plate on the right hand end

- remove the veneers from the action box hoop

- drill out the holes in the action box hoop sides to a given depth and introduce a dowel

- drill out the damaged bolt holes in the end plates and introduce new rosewood

- refit the end plate, action box side veneers and drill bolt holes through the new dowels

- strip and refinish both right and left hand ends

- replace all end bolts and nuts with new (the current end bolts don't look original and some of the nuts have worn threads)

 

Any other ideas about how to go about repairing this kind of damage.

Steve

 

I get rosewood, or ebony lace maker's bobbin blanks from a local wood turning craft outlet. I turn wooden plugs or hand cut wooden plugs, glue them into place with good wood working glue.

Then jig drill back through the pad board.

Shape the upper surface to match the scribed moulding of the action plate.

Then cut the bolt head seating.

 

 

The bolt head masks the un-polished seating.

 

 

 

Dave.

Edited August 5, 2011 by d.elliott

[SteveS]

Hi Steve,

 

Did you successfully sort out those nasty bolt hole problems? I'd be grateful to hear how it went as I have an instrument with very bad gouges around the bolt holes. Any pictures of your progress?

 

Thanks,

Michael.

 

Michael

I haven't yet got around to the actual repair of the bolt holes yet (pressure of work recently has prevented me concentrating on more fun things!). I've done a few repairs to other bits of the ends.

 

I'll post some pics as I progress with the bolt hole repairs.

 

Steve

[varney]

Thanks folks,

 

Dave, you make it sound so easy! How do you drill out the existing bolt holes to take the plugs? Do you take out a section the whole way through or just down below the damaged area? Any tips on how to cut the plug to fit the hole tightly? My woodworking skills are rudimentary so any help most appreciated... especially of the picture format!

 

thanks,

Michael.

[d.elliott]

Thanks folks,

 

Dave, you make it sound so easy! How do you drill out the existing bolt holes to take the plugs? Do you take out a section the whole way through or just down below the damaged area? Any tips on how to cut the plug to fit the hole tightly? My woodworking skills are rudimentary so any help most appreciated... especially of the picture format!

 

thanks,

Michael.

 

I always have a fear if breaking up the fine edge of the action plate, so all I do is use an drill bit of the rights size clamped in a small tap wrench, or sometimes a hand reamer, thus to clear any debris BY HAND, no power tools,- from the over sized 'counterbore' so the glue will take I then shape what ever depth of wood I need, glue and clamp it to plug the hole from the top. Making sure that there is plenty of wood proud of the finished surface.

 

Some times a plug can me made and set from epoxy modeling putty of a carefully matched colour- just to fill a clean hole which has enlarged a little under the bolting forces , (not used on top quality instruments).

 

Tip of the day: black nail varnish (my youngest dabbles in Goth Kit) is good for dodging in ebony repairs, clear nail varnish or nail strengthener is good for other woods (my wife's claws), dries quck, easy to blend in, but keep off surrounding polished areas. It is possible to pre-polish a bit of veneer, then shape it, glue it, then finally blend it back with coloured wax stopping.

 

Dave

 

Dave

[SteveS]

Attached is a an update picture.

Ends stripped of the old French polish, bolt holes repaired.

Ends now ready to receive the new French polish.

[Greg Jowaisas]

Attached is a an update picture.

Ends stripped of the old French polish, bolt holes repaired.

Ends now ready to receive the new French polish.

 

Brilliant! Looks as though some nice work is being done at Teesside.

 

Keep us informed.

 

Greg

[shelly0312]

Just seeing / hearing you guys working on those fine edges makes me perspire. Do you ever use a clear two part epoxy and that resin cloth stuff to reinforce everything from just underneath? Or would even that add too much bulk? Michelle