Planning to replace some broken bellow tapes(damaged by metal bellow srtap). The old tapes (40-50+ years) is not hard to remove. PVA glues are recommended here but will they be too good in case I need to remove the tapes again in the future? Especially the Green label (water resistant). Any chance the applied glue will cause damage ( to the bellow fabric/paper) in the future process of removing the tape. Thank you.
Glue question?
- Thread starter Canbox
- Start date
Cheap white glue (PVA glue) that is *not* water resistant works well, when you apply it in two "lines" to the tape, then smear out with your finger, leaving the center of the tape without glue. The glue hardens and you don't want the fold (that has to open and close as you open and close the bellows) to have hard glue on it. There is also special (also PVA-based) book-binding glue that supposedly does not become so hard and can be simply smeared all over the tape. (I have not yet tried that.)
KiwiSqueezer
Active member
Well, that's a coincidence - I was just about to ask about bellows tape glue... I share Canbox's very real concerns.
I've read that, in the factory, the tapes are stuck with a glue that allows subsequent easy removal, by peeling off the tape, which accords with Canbox's experience. I don't know when PVA advesives became available, but I think well after WWII days, so other glues must have been used in days of yore. So, what was used in 'the old days'?
I would be worried that modern PVA adhesive would not let go easily, and would expect significant damage to the substrate if an attempt were made to rip off the tape. PVA-glued joints between most woods generally fail, not by the glue failing, but by the wood breaking. PVA is strong stuff! Perhaps the tape is designed to not stick very firmly to PVA. But, even if that's the case, you'd be left with PVA residue on the bellows, and using water to remove it doesn't sound like a good idea. If PVA is indeed OK, acid-free, flexible grades are available, often being sold as suitable for book-binding, as has been said. My instincts say that PVA may not be a good choice. My scepticism says that it's probably widely used, however, in the hope that subsequent tape removal will be someone else's problem.
Adhesives are a minefield, as I've mentioned in another post.
I've read that, in the factory, the tapes are stuck with a glue that allows subsequent easy removal, by peeling off the tape, which accords with Canbox's experience. I don't know when PVA advesives became available, but I think well after WWII days, so other glues must have been used in days of yore. So, what was used in 'the old days'?
I would be worried that modern PVA adhesive would not let go easily, and would expect significant damage to the substrate if an attempt were made to rip off the tape. PVA-glued joints between most woods generally fail, not by the glue failing, but by the wood breaking. PVA is strong stuff! Perhaps the tape is designed to not stick very firmly to PVA. But, even if that's the case, you'd be left with PVA residue on the bellows, and using water to remove it doesn't sound like a good idea. If PVA is indeed OK, acid-free, flexible grades are available, often being sold as suitable for book-binding, as has been said. My instincts say that PVA may not be a good choice. My scepticism says that it's probably widely used, however, in the hope that subsequent tape removal will be someone else's problem.
Adhesives are a minefield, as I've mentioned in another post.
My experience with tape removal on fairly old accordions (like the Crucianelli I inherited that's from around 1970, and some Hohner Morino N accordions from the 60's and 70's) is that whatever glue they used in the Italian factories at that time certainly did not allow for easy removal!
What I have been using is white glue, suitable for kids. It sticks well enough so that it doesn't come off by itself, but when you make the bellows tape a bit damp the glue should let go quite easily.
What I have been using is white glue, suitable for kids. It sticks well enough so that it doesn't come off by itself, but when you make the bellows tape a bit damp the glue should let go quite easily.
Dingo40
Been here for ages!
Here's something:
www.stringsandboxes.de
Adhesive for Accordion Bellow Tapes • 160 gram
• Type: Adhesive for Accordion Bellow Tapes • Quantity: 160 gram • Properties: • for Accordion Bellow Tape • Delivery: 2 Box a. 80 ml.
Ventura
Been here for ages!
there is also a fancy type of white creamy type glue used in construction
to install (tack and hold) Foam type moulding in place on the wall
and ceiling.. it is very high tack and holds well but nver fully hardens
and allows for re-positioning comfortably
i have thought to try it the next time i have a Bellows touch-up project,
since i have the rest of the bottle sitting here after a home improvement project
other than that i have just used simple Elmers wood glue with no problems,
as did the Luthiers i am familiar with who worked with acoustic guitars
and violins in music shops i have known.. they use it because you can
take things back apart without damage using a bit of steam in the right spots
i have some nice pre-cut folded cardboard and thick Wax Paper which
i use to compress the bellows folds until elmers dries, to protect
from stray glue sticking something together in the wrong place
the thicker wax paper came from saving Post Office Wax envelopes
but normal wax paper is fine too, it just wears and tears quicker
i need to use it because i am rather sloppy no matter how careful i try and be
to install (tack and hold) Foam type moulding in place on the wall
and ceiling.. it is very high tack and holds well but nver fully hardens
and allows for re-positioning comfortably
i have thought to try it the next time i have a Bellows touch-up project,
since i have the rest of the bottle sitting here after a home improvement project
other than that i have just used simple Elmers wood glue with no problems,
as did the Luthiers i am familiar with who worked with acoustic guitars
and violins in music shops i have known.. they use it because you can
take things back apart without damage using a bit of steam in the right spots
i have some nice pre-cut folded cardboard and thick Wax Paper which
i use to compress the bellows folds until elmers dries, to protect
from stray glue sticking something together in the wrong place
the thicker wax paper came from saving Post Office Wax envelopes
but normal wax paper is fine too, it just wears and tears quicker
i need to use it because i am rather sloppy no matter how careful i try and be
KiwiSqueezer
Active member
Like automobiles, I suspect accordion manufacturers thought ease of repair and maintenance a secondary consideration when designing the things. Apparently, PVA was discovered/synthesized in 1912, but I don't think it was used as an adhesive much in those days. Pre-WWII furniture makers preferred animal hide glue, aircraft manufacturers liked casein glues and bookbinders used all sorts of stuff, including starch-based adhesives. These preferences were to do with the different properties of the adhesives.
Starch-based adhesives can be 'reversible' - although just how easily, and with what collateral damage, I don't (yet) know. Note that flour-and-water paste, often loosely called 'starch adhesive' is not considered reversible - the gluten in flour makes cross-links. Hide glues are reversible, with heat (often steam). PVA sets to what is in effect a thermoplastic substance, and can be softened with heat. (You can't really wash bellows, to get rid of the stuff...).
PVA is a wonderful adhesive, and will surely do the job of sticking bellows tape. But too well! Also, removal is a problem, because it relies on its adhesive excellence by soaking into the substrate's fibres. Re-application of PVA over cured PVA may disappoint, because the new layer won't adhere well to the cured stuff.
Since accordion manufacture seems to me to be more the product of artisan than scientist, I'd bet that tradition played a large part in adhesive selection, at least in the early days, and I suspect that something like a starch-based adhesive, or wallpaper paste, was used - not new-fangled PVA.
Any alternatives of PVA glue you can think about besides the hide glue in the bellow tape application?
KiwiSqueezer
Active member
I'm not suggesting traditional, hot glue-pot hide glue - it shrinks as it sets, is brittle, and is reversible by heating. I know nothing about the 'hide glue' you can now get in plastic bottles. I think that a starch-based adhesive sounds promising. It's easy to brew a basic one up at home, but its properties can be modified by the addition of sodium hydroxide, borates and I don't know what, and I also don't know what properties are most desirable. So, as I keep saying, adhesives are a minefield. They keep getting 'better', but I think we want one that's really not very good (by modern standards...).
More research and experimentation is needed, unless someone can tell us the most appropriate, reversible, easily-available adhesive. I still think one should use an adhesive that will let go without collateral damage, when it's time to replace a tape. I don't think PVA fulfils this crucial requirement, although it will certainly stick the tape well. If that's all you're interested in, fine, but I think it's ethical to consider what happens in the future, when it's time to replace tapes. I wouldn't be too surprised to discover that some manufacturers cynically use PVA.
More research and experimentation is needed, unless someone can tell us the most appropriate, reversible, easily-available adhesive. I still think one should use an adhesive that will let go without collateral damage, when it's time to replace a tape. I don't think PVA fulfils this crucial requirement, although it will certainly stick the tape well. If that's all you're interested in, fine, but I think it's ethical to consider what happens in the future, when it's time to replace tapes. I wouldn't be too surprised to discover that some manufacturers cynically use PVA.
Dingo40
Been here for ages!
Here you can see how badly the tape started coming off this 1970's Crucianelli accordion...
I tried to get the tape off without damage to the fabric, but right from the get go that turned out to be impossible.
But here is the final result of my first complete tape replacement:
Apart from the issue that I didn't know there was directionality to the pattern in the tape (about half of the strips are actually upside down) I am very pleased with the final result. (That pattern issue I only came aware off after a discussion on this forum a few weeks ago, that's 5 years after I completed this job.)
I wouldn't worry too much about the glue issue. The tape only needed to be replaced after about 50 years, and if my job with PVA glue lasts another 50 years I consider it good enough.
I tried to get the tape off without damage to the fabric, but right from the get go that turned out to be impossible.
But here is the final result of my first complete tape replacement:
Apart from the issue that I didn't know there was directionality to the pattern in the tape (about half of the strips are actually upside down) I am very pleased with the final result. (That pattern issue I only came aware off after a discussion on this forum a few weeks ago, that's 5 years after I completed this job.)
I wouldn't worry too much about the glue issue. The tape only needed to be replaced after about 50 years, and if my job with PVA glue lasts another 50 years I consider it good enough.
jollyrogeraccordions
Member
Nice job Paul. I really hate re-taping bellows… It’s a horrible job.
I don't like doing this either. But this is very likely going to be the only time I have done a complete bellows re-taping.
Typically the underside (rubbing on your pants) and sometimes the back (rubbing on your clothes) are worn and require re-taping. When everything is plain black doing just the back and underside is enough and these two sides are not seen by the audience during a performance so it matters less to deliver a perfect job.
During my time with Keith Anderson, he looked at the tape on my Morino on the bottom... it is literally perfect all around except for 2 sections of maybe 1/4", worn out because a small 13-year-old had to wear it at such angles that it wore down slightly.
We were talking about reed valves and then I looked down... suddenly I heard "rrrip-rrrrrip!" and Keith tore off the tape off the bottom of my Morino stating he did not like how that one tape looked so they all came off the bottom.
Then, he took some precise measurements and then cut all the tape to the exact same size and replaced it. Literally, he finished the entire bottom of my bellows in a few minutes and I could not tell the difference between the new and old tape plus he really put his heart in to it. To my eyes, it was perfect, but he said the next time I come he wanted to trim a 64th of an inch off one of them... I can see it being a pain to do, but its no harder than doing other tasks on an accordion... meaning, anything that you do is labor intensive and meticulous.
Respect to you Paul and others here that work on your accordions!
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I was never so lucky as to be able to simply rip a whole series of tapes off like that. Even with carefully trying to put a knife under the tape (after the first inch became loose on one end) I could never get a whole side to come off in one go, let alone both sides at ones. The worked on small sections, but not on a complete length of tape.During my time with Keith Anderson, he looked at the tape on my Morino on the bottom... it is literally perfect all around except for 2 sections of maybe 1/4", worn out because a small 13-year-old had to wear it at such angles that it wore down slightly.
We were talking about reed valves and then I looked down... suddenly I heard "rrrip-rrrrrip!" and Keith tore off the tape off the bottom of my Morino stating he did not like how that one tape looked so they all came off the bottom.
...
But now that I think of it, I once did the underside of a Hohner Morino IV N and the tape did come off a lot more easily than on my Crucianelli. Must be a different type of glue that was used...
KiwiSqueezer
Active member
debra said "But now that I think of it, I once did the underside of a Hohner Morino IV N and the tape did come off a lot more easily than on my Crucianelli. Must be a different type of glue that was used..." [my italics]
Well, that's the whole point, isn't it? We should be using whatever Hohner used - or its modern equivalent. I'm finding it frustrating as hell, trying to find out anything really useful about the technical properties of available adhesives. I suppose the manufacturers like to keep their secret recipes to themselves.
Can anyone here, with connections to the manufacturers, possibly find out more about glues? (I'd still put money on PVA being used by manufacturers on bellows tape, but we need to know about the adhesives that let go in a safe manner.)
Just a thought... Copydex is a latex adhesive that is strong and flexible. It can (usually) be removed from substrates without damage, by rubbing it off - it balls up into a somewhat gooey lump. It would probably be a reasonable choice. However, I don't think it would produce a 'rrip-rrrrrip' noise on failure, so I'm still thinking that the old-timers would have used something like starch glue). There are substances that crystallise when stressed, and I'd think that the consequent chain of brittle fractures would be the cause of the characteristic noise. I think that some animal or vegetable-derived glues do this, but more research is needed. It would save a lot of effort if someone would tell us the answer!
Well, that's the whole point, isn't it? We should be using whatever Hohner used - or its modern equivalent. I'm finding it frustrating as hell, trying to find out anything really useful about the technical properties of available adhesives. I suppose the manufacturers like to keep their secret recipes to themselves.
Can anyone here, with connections to the manufacturers, possibly find out more about glues? (I'd still put money on PVA being used by manufacturers on bellows tape, but we need to know about the adhesives that let go in a safe manner.)
Just a thought... Copydex is a latex adhesive that is strong and flexible. It can (usually) be removed from substrates without damage, by rubbing it off - it balls up into a somewhat gooey lump. It would probably be a reasonable choice. However, I don't think it would produce a 'rrip-rrrrrip' noise on failure, so I'm still thinking that the old-timers would have used something like starch glue). There are substances that crystallise when stressed, and I'd think that the consequent chain of brittle fractures would be the cause of the characteristic noise. I think that some animal or vegetable-derived glues do this, but more research is needed. It would save a lot of effort if someone would tell us the answer!
The Hohner Morino IV N was (for the most part) made by Excelsior. But very few accordion makers produce their own bellows. There are a few bellow makers in Italy (and some more in other countries, Slovenia being one if I'm not mistaken). I visited Galassi (as part of the ACA course) and of course they don't tell you what glue they use. What the Galassi tour made very clear is that when bellows are very worn (not just tape but also the metal corners, the leather corner inserts, the fabric...) the only economically viable solution is to have new bellows made. For just tape of course you do it yourself.
Dingo40
Been here for ages!
FWIW,
Here's a pro at "Serenellini Accordions" making a set of bellows. His pot of glue is clearly visible in the frame from about 0.25 onwards.
The glue looks very similar to that shown in another in-factory video from another maker.
Here's a pro at "Serenellini Accordions" making a set of bellows. His pot of glue is clearly visible in the frame from about 0.25 onwards.
The glue looks very similar to that shown in another in-factory video from another maker.
He didn't do all at the same time, sorry if I gave that impression, it was one stripe at a time and he didn't waste time for sure, it was a couple of minutes and the stripes were off... followed by some gentle sanding.
Probably because it was the same glue used to hold the pads to the pallets... haha!
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