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RWL

Adventures in Bellows Patching

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It was a steamy Sunday afternoon with summer thunder showers here in central PA, so what better time to work in the shop where it's at least a little cooler.

 

 

I have hide glue from some previous violin work, so I got that heating. Hint - you can store hide glue frozen in small aliquots for use at a further time. Just zap it in the microwave in 15-20 second increments until it feels the right temperature, and put it in the water bath to maintain its temperature (140º - 160º) The patching material was provided by Johanna Miller from her previous patching project and originated from Concertina Spares. As you can see, it measures 0.006" thickness. In the other photos you can see the Lachenal EC to be repaired, and some holes in the points. A previous owner had filled them with hot melt glue. It worked for awhile. I'll add additional photos in subesquent messages so I can comment on specific photos.

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I applied glue to a longitudinal patch and laid it over the point, but had trouble with bulges in the center, so I removed that and tried a patch about 7x50 mm parallel to the crease. That worked fairly well as you can see in the photo below. It's the point farthest to the right. It still wanted to bulge up a little in the center, so I put a longitudinal patch over that. Again, I had problems with the center wanting to bulge. No matter how I folded and molded the bulges with wet fingers, or tooth picks, I couldn't get them to lie down. With the magnifiers on, I noted that someone had done a professional looking repair at some time in the distant past using a diamond shaped patch. No lifted edges or bulges in that. I tried to duplicate that with the leather, but wasn't entirely successful. I tried folding paper and making various snips to make it lie better. One attempt seemed to work a little better. That was a square with little notches cut out of the sides as you can see in the photo of a leather patch partially cut below. It didn't work so well. After doing three points, and not being satisfied with my results, I put the instrument away for the day, clamping the concertina shut with wax paper between the repaired pleats.

 

Maybe some of you have some hints at what worked for you to get the bulges out of the patches. Maybe removing the papers and using larger patches would have worked better. What experiences you you all have to pass on?

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The strip of leather should run along the top of the fold, parallel to the fold, you'd appears to go at right angles. If you stretch the leather as you fix it, then many of the creases will be removed. This is much easier to do with a continuous length the goes round the complete circumference of the bellows. I think using hide glue means you hav to work much faster because there is only a very short open time before the glue jells.

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Leather tends to stretch on one direction more than the other. Make sure the patch stretches in the direction that will be along the top of the ridge. Glue it down before the corner leaving the rest of the patch free of glue. This gives you somethng to pull against when stretching the piece. Wait for the glue to go off and then put glue on the rest of the patch and stretch it around the corner. There will be few if any bulges to contend with. As Theo says, much easier to make a good job by going right around. Hide glue has one very nice attribute, it is very reversible.

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As Theo says, much easier to make a good job by going right around. Hide glue has one very nice attribute, it is very reversible.

 

I've just been cutting strips from the piece of leather that was sent to me by another forum member to use for patches narrow enough to stay off the papers, but I'm wondering if I'd be better off removing all of the papers and putting a wider patch the whole way around each of the pleats. What width of leather is used to go around each pleat? What's the best method to lift the papers and still keep them intact and unwrinkled? .....or for practical purposes is it just a lot easier the buy replacement papers? If I need to patch any of the valleys (and I'm suspicious that there's one valley that may need it) what width / type leather for that? If I buy the replacement strips from Concertina Spares, do I have to bevel (skive?) the sides of the strips?

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As Theo says, much easier to make a good job by going right around. Hide glue has one very nice attribute, it is very reversible.

 

I've just been cutting strips from the piece of leather that was sent to me by another forum member to use for patches narrow enough to stay off the papers, but I'm wondering if I'd be better off removing all of the papers and putting a wider patch the whole way around each of the pleats. What width of leather is used to go around each pleat? What's the best method to lift the papers and still keep them intact and unwrinkled? .....or for practical purposes is it just a lot easier the buy replacement papers? If I need to patch any of the valleys (and I'm suspicious that there's one valley that may need it) what width / type leather for that? If I buy the replacement strips from Concertina Spares, do I have to bevel (skive?) the sides of the strips?

 

RWL,

 

The leather you are using is probably too thin to have much life to it on an outer corner. by fully re-binding the folds with top run (sold the correct size by the usual suppliers) you will effectively re-life the bellows subject to the condition of the gussets etc. Small corner patches have a small gluing area and easily get rubbed off. The outer valley hinges need a thin layer of leather, 0.2 mm, and either lift the gussets where they meet the valleys, or feather the ends of each new valley piece to nothing. do this before redressing the bellows, or lift the old papers first if you wish to preserve them

 

To get the old papers off you will need lots of wet blotting paper, and a blunt wide bladed scalpel, patience an a good dose of good luck.. This wetting brings the risk of weakening the glue on the other leather joints, and the papers are never really the same again.

 

If you are putting this much care, love and effort into this instrument then I suggest you do the job fully and properly by redressing the bellows with new papers. Just make sure that the old ones are properly stuck down first. If you try to unpick & tear the old paper off then please beware of leaving an uneven and rough substrate that will show through the new papers and make the new papers look pretty grim.

 

to summarise:

 

it is easier, quicker and better to re-bind folds.

 

valley hinges are a pain, but can be repaired with thin leather properly prepared

 

new papers will look much better ad disguise both forms of repair, just make sure that the old papers are secured first

 

Dave

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Wow, Theo, Chris and Dave--that was a wealth of information that I really appreciated reading and envisioning. And I'm not even repairing a bellows! thanks guys for these interesting replys. Shelly

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If you are putting this much care, love and effort into this instrument then I suggest you do the job fully and properly by redressing the bellows with new papers. Just make sure that the old ones are properly stuck down first. If you try to unpick & tear the old paper off then please beware of leaving an uneven and rough substrate that will show through the new papers and make the new papers look pretty grim.

 

 

Dave

 

 

Let me see if I'm understanding this correctly. Rather than removing the existing papers, I would glue new top skive over the existing leather and partially covering the existing papers. I would do the same with thin leather in the valleys, then glue new papers over the old ones. Correct?

 

 

 

to summarise:

 

new papers will look much better and disguise both forms of repair, just make sure that the old papers are secured first

 

Dave

 

 

I don't see any papers at Concertinaspares that match the pattern of my Lachenal papers. Do most people try to match the original papers? If so, is there another place I could obtain Lachenal papers (mine are green plus signs with connnecting dots on a white background). As an alternative, how well does lifting one paper and then copying it with a scanner / computer / printer work?

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If you are putting this much care, love and effort into this instrument then I suggest you do the job fully and properly by redressing the bellows with new papers. Just make sure that the old ones are properly stuck down first. If you try to unpick & tear the old paper off then please beware of leaving an uneven and rough substrate that will show through the new papers and make the new papers look pretty grim.

 

 

Dave

 

 

Let me see if I'm understanding this correctly. Rather than removing the existing papers, I would glue new top skive over the existing leather and partially covering the existing papers. I would do the same with thin leather in the valleys, then glue new papers over the old ones. Correct?

 

Yes, as long as the old ones are firmly glued down.

 

 

to summarise:

 

new papers will look much better and disguise both forms of repair, just make sure that the old papers are secured first

 

Dave

 

 

I don't see any papers at Concertinaspares that match the pattern of my Lachenal papers. Do most people try to match the original papers? If so, is there another place I could obtain Lachenal papers (mine are green plus signs with connnecting dots on a white background). As an alternative, how well does lifting one paper and then copying it with a scanner / computer / printer work?

 

What are the papers you are trying to match?

 

 

Lachenal 'L' gold on black

green,gold, black 'fancy'

or gold dot and cross on white

gold dot and cross on black,

zig-zag gold on black art-deco

 

post a pic, send an email to me, and we will see what we can advise.

 

be warned, scanning and printing off does not work, not where golds are concerned, pantones and RBG etc. are a dead loss for this sort of work

 

Dave

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What are the papers you are trying to match?

 

 

Lachenal 'L' gold on black

green,gold, black 'fancy'

or gold dot and cross on white

gold dot and cross on black,

zig-zag gold on black art-deco

 

post a pic, send an email to me, and we will see what we can advise.

 

be warned, scanning and printing off does not work, not where golds are concerned, pantones and RBG etc. are a dead loss for this sort of work

 

Dave

 

 

Thanks for your advice.

 

Some of the photos above show the pattern pretty well. Green Pluses / X's with connecting dots on an off-white background. If those aren't clear enough, I can email you some larger photos.

 

 

I have some further questions about the leather. Concertina Spares lists "Thin Leather" and "Binding Leather" as two of the choices, both of which come in 3/4" and 1-3/8" widths. Which type and which width for the top of the bellows, and which one for the valleys? Neither listing says anything about the edges being skived to nothing as your book mentions, and the strip from ConcertinaSpares that Johanna sent me wasn't skived on the edges either. Is there a better choice of leather for this repair somewhere?

 

 

And just confirming - when I glue both the top run and the valleys down, there is no need to lift the papers, just glue over top and then put new papers over that. .... of course assuming that the existing papers are well stuck already.

 

 

All these questions I generate will be fodder for the 3rd edition of your maintenance manual.

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What are the papers you are trying to match?

 

 

Lachenal 'L' gold on black

green,gold, black 'fancy'

or gold dot and cross on white

gold dot and cross on black,

zig-zag gold on black art-deco

 

post a pic, send an email to me, and we will see what we can advise.

 

be warned, scanning and printing off does not work, not where golds are concerned, pantones and RBG etc. are a dead loss for this sort of work

 

Dave

 

 

Thanks for your advice.

 

Some of the photos above show the pattern pretty well. Green Pluses / X's with connecting dots on an off-white background. If those aren't clear enough, I can email you some larger photos.

 

 

I have some further questions about the leather. Concertina Spares lists "Thin Leather" and "Binding Leather" as two of the choices, both of which come in 3/4" and 1-3/8" widths. Which type and which width for the top of the bellows, and which one for the valleys? Neither listing says anything about the edges being skived to nothing as your book mentions, and the strip from ConcertinaSpares that Johanna sent me wasn't skived on the edges either. Is there a better choice of leather for this repair somewhere?

 

And just confirming - when I glue both the top run and the valleys down, there is no need to lift the papers, just glue over top and then put new papers over that. .... of course assuming that the existing papers are well stuck already.

 

 

All these questions I generate will be fodder for the 3rd edition of your maintenance manual.

 

 

 

Sorry I forgot your photos, the green, was once gold, you need gold dot and cross papers, which you can get through concertina-spares, concertina connection or myself.

 

Binding leather is also called 'top run' or 'top skive', 3/4 ins wide for the folds and the 1-3/8 ins is for binding the bellows frames over onto the first panel size at each end. The thin is used for light facing work, light local patches, valley hinges and I use it for internal gusset repairs. Gusset replacements are best ordered pre-cut.

 

Concertina Spares leathers are all right, when you order specify 3/4 ins fold binding leather, I suspect that the sample was just that a sample of the leather so you could feel and see the leather type. I never specify skived as such, it just is. If you are unsure then state skived both edges. The thin is around 0.2mm thick.

 

Yes for the valley repairs, just clean out the dust and muck, and any loose debris, make sure that any loose bits of the old papers are rubbed off and / or fully glued down, common sense to apply, and apply your repairs, most of the gluing is to leather only a small part is onto paper. I split thin leather 3/4 down to 3/8 ins for valley repairs.

 

DO NOT USE SUPER GLUE it makes every thing brittle

 

Dave

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What is the currently recommended glue for repairs?

Malcolm

 

As with many different types of instrument repair, there are differences of opinion. I used hot hide glue because it's reversible - and I have it already from another project. I've read that you can soften PVA with acetic acid (vinegar) and Super Glue with a certain solvent (nitromethane?) so in theory they're reversible, but not as easily and not without potentially harming the finish / structures to which they've been applied.

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