Tech: leaking bellows

Subject: Tech: leaking bellows
From: selby
Date: 06 Mar 05 - 01:14 PM

My son has just bought a old melodeon having fixed many major leaks he is starting to thing that the bellows have gone pourous is there any thing in anyones experiance what he can do ?

Subject: RE: Tech: leaking bellows
From: Little Robyn
Date: 06 Mar 05 - 01:31 PM

Contact Pete Grassby - he'll tell you exactly what's wrong and he can fix it too!
Robyn

Subject: RE: Tech: leaking bellows
From: treewind
Date: 06 Mar 05 - 02:02 PM

I've never seen a bellows go "porous". If anything the bellows will leak in a few places, e.g. at the corners where it's worn or where leather inner corners have dried up and cracked. You should be able to detect those leaks by hearing or feeling the air blowing out when you compress the bellows. Patching it with very thin leather might help. A bookbinder's supplier might be a good place to go for that (that's a tip from a friend who was repairing a concertina from scratch. N.B. concertina bellows are different from melodeon bellows, but we're talking spot repairs here).

Leakage is otherwise the sum of dozens of small leaks from worn and/or misaligned pads, and fixing them is hard work: basically replacing every one if you want to be sure.

If the instrument is not too old the bellows may be replaceable in its entirety, or a replacement can be manufactured as the bellows as a unit is easily separated from the rets of the instrument.

I'd recommend Dave Jolly (www.jollybox.co.uk) if you want a repairer.

Anahata

Subject: RE: Tech: leaking bellows
From: Bob Bolton
Date: 06 Mar 05 - 11:26 PM

G'day Selby,

Unfortunately (pace Anahata) the bellows of old melodeons can end up pretty well "porous". The bellows of most cheaper German instruments, of the early part of the 20th century, were almost entirely made of a single piece of cardboard - 'clicked' with all the folds and cutouts in a single pass of the clicking press, assembled round a jig/block and finished with the minimum of fine 'skiver' leather and coloured paper panels.

After many years of use the bellows, as on a circa 1930 Hohner #2915 (old blond 'pokerwork' model) I still have, eventually lose the necessary stiffness to compress the air - instead of bulging out at the pleats - and are so thin ... and now so worn ... that they begin to allow air to escape straight through the cardboard. I stuck with that bellows as long as I could ... because it was very pretty (a light warm green, complimenting the blond wood tones of the accordion) ... but eventually had to find a new firm bellows.

The improvement was astonishing (and ... No! There was nothing that would have saved that old bellows - short of totally covering every square centimetre with something like the ultra-fine kangaroo hide (0.1 mm to 0.14 mm - yet strong as silk!) I use for concertina bellows patching. Even with a leather as fine as this, the bellows would have ended up noticeably fatter ... and less flexible than a good new set.

Regards,

Bob

Subject: RE: Tech: leaking bellows
From: Liz the Squeak
Date: 07 Mar 05 - 03:00 AM

On no account should you ever try to spot repair with superglue.... Superglue is wonderful stuff for dental work, skin repair and malicious coin sticking to the pavement, but has no use in the craft box or repair shop.

LTS

Subject: RE: Tech: leaking bellows
From: selby
Date: 08 Mar 05 - 02:00 PM

we thought painting them with a pva and water mix might work