Advice for thickness of leather for bellows

[Rod Pearce]

PAAUDIO

 

Thanks for your response, one for the future perhaps?

[JoachimDelp]

On 2/13/2020 at 7:18 PM, paaudio said:

I recently bought a few trial pieces from here......

Thank you for your enquiry. We manufacture the leather bindings mentioned but in a softee hide leather not goatskin.

If you would like to let me know the sizes required I can advise the cost. We either split thin at .2mm across the whole width or centre split to .6/.7mm with both edges bevelled.

Please send your address and I can send samples.

I look forward to your reply.

Kind Regards

 

Lynda

 

Lynda Cornish

C. A. CORNISH  |  21 High Street  |  STREET  |  Somerset  |  BA16 0EF

Tel: +44 (0)1458 442746  |  Fax: +44 (0)1458 443850

sales@cacornish.co.uk  |  www.cacornish.co.uk

 

[JoachimDelp]

Hallo from Germany

 

I am sarting building my fist set of bellows, repairing 20 button Lachenal. I sahh try and trust to succed to replace its old 5 fold  bellow.

Fou nd in time today this topic and want tell you that I found very helpful all the information here exposed.

May inform laer my expereince.

Less bad, taht I have two Concertina Makers not too far from my place, eady to give me their advise.

 

I try it inspite of my Low Sight handicap, so thir guide and control is needed.

However I trust, taht making the third set, I may be not a master, but able to produce smeting satisfying my needs.

Regards and good wihes to everybody.

 

Case my work has acceptable results, I may take fotos and show it here, for others whjo wánt to do teh same.

[Theo]

Going back to paring knives, I've had a similar frustrating experience with a Scharf Fix and now use one of these simple knives.  It took me a long time to learn how to sharpen it properly but once sharp it's very quick and effective and just needs the edge to be refreshed on a leather strop after every couple of metres of cut.  My sharpening mentor describes the degree of sharpness to be such that if you drop the knife your would be worried about your feet!

 

https://www.hewitonline.com/Standard_English_Paring_Knife_p/tl-070-pk.htm

[Geoffrey Crabb]

Crabb paring knives. Adapted carving knives etc.

Kept in Leather sheaths when not in use 😉

 

Geoff

 

[Jake Middleton-Metcalfe]

2 hours ago, Geoffrey Crabb said:

Crabb paring knives. Adapted carving knives etc.

Kept in Leather sheaths when not in use 😉

 

Geoff

 

 

Now that is fancy. Mine is literally just a broken hacksaw blade which I ground in a similar way!

[alex_holden]

What sort of work surface are people using to skive onto with a handheld knife? I sometimes use a sheet of glass but it seems to dull the edge and the leather slips too easily. More often I use a sacrificial piece of wood, which gets chewed up in the process and produces annoying splinters. I've heard of leatherworkers using a lithographic stone, but I don't have one of those. I've tried using a very fine Arkansas oil stone (the same one I use to put the final polish on the edge of the knife), and that seemed to work fairly well but I worried it might be a bad idea for the longevity of both the blade and the stone.

[Alex West]

3 hours ago, alex_holden said:

What sort of work surface are people using to skive onto with a handheld knife?

I use a marble wall tile. Flat enough and the leather doesn't seem to slip too much.  I've not noticed the edge dulling, but then I strop the knife fairly regularly

 

And like Jake, I use a saw blade, ground to a shallow profile.  I've made a few in curved, straight cut and also in right and left hand angled versions

 

Alex West

[Mike Acott]

Around 24 years ago I purchased  a Chinese copy of a certain German made machine ( spare parts I believe are ok for both machines), It still serves me well doing all skiving well. The only item I use from a UK companyis is the very thin facings on the trapeziums of the bellows. 

[Chris Ghent]

I find .5mm a little thin for gussets.  I think there is a chance if they are too thin they will absorb some of abruptness of a bellows change by moving slightly.  .7, even .8 sounds right.  

[AndyNT]

I'm an occasional hobbyist leatherworker! I use a piece of kitchen worktop offcut (a composite material similar to marble) for skiving. It is very flat and solid. I've glued thin leather to back of it to stop it slipping on the table or work surface.

Over the years, I've tried a variety of knives and skivers with mixed success for thinning edges. I've found a simple angled knife works best for me. It needs to be really sharp, and stropped very regularly during use. I practise on scraps of leather for a while to test the blade sharpness, and get the skiving angle and 'feel' right before attacking the workpiece.

 

[JimR]

What about the green, ruled cutting mats?

[alex_holden]

51 minutes ago, JimR said:

What about the green, ruled cutting mats?

 

I use those for actual cutting, but in my experience if you try to skive on one, the blade digs in and shaves little slivers of plastic off the surface.

[David Hornett]

I use kangaroo chrome tanned leather, skive to .5mm for the cover leathers, and use .3mm kangaroo gloving  leather for the gussets. David Morgan on his website details the physical properties of roo skin https://www.davidmorgan.com/shop-content/comparekangaroo/  Elsewhere I have read even more robust figures. The skin, either chrome tanned or veg tanned skives very well, and in fact the .3mm gloving leather also makes for good bellows strapping.  It comes in many colours.

 

Packer Leather is a certified supplier: https://packerdirect.com.au/collections/kangaroo-leather

 

(I recognise there is a repugnance for some against hunting roos, but, I personally have witnessed the absolute devastation roos cause to farmed and natural country, including National Parks, if left unchecked. Their numbers have increased astronomically since European settlement because of a now plentiful water supply, bores and dams, and cropping land. Further, in their natural setting their natural predators have been wiped out and in the bush their only control is now starvation and drought, or with exploding numbers to invade the farm next door and be hunted for meat and leather.

 

David

[Rod Pearce]

I would be interested to know how people achieve a consistent 'skive' across the width of the leather using a knife. I use a knife ( the one Theo describes above) with acceptable results to skive the edges of the workpiece, but less success with the rest. Gussets are easier, but trying to get the bindings to a consistent thickness is hit and miss. I don't use a Scharf fix as I cant get on with it.

 

I have to admit that I had my leather thinned by K Baggs Trimming of Poole, Dorset to get a conistent thickness across the hide before I started working with it, so I only had to worry about the edges of each workpiece.

 

Out of interest, do people us the word 'skive' when they mean 'thin'or 'split'?

[alex_holden]

10 minutes ago, Rod Pearce said:

I would be interested to know how people achieve a consistent 'skive' across the width of the leather using a knife. I use a knife ( the one Theo describes above) with acceptable results to skive the edges of the workpiece, but less success with the rest. Gussets are easier, but trying to get the bindings to a consistent thickness is hit and miss. I don't use a Scharf fix as I cant get on with it.

 

I've never used a handheld knife for splitting. I used to use my Scharffix 2000 for both skiving and splitting, but since I invested in a vintage Fortuna bell skiver I now do the majority of it with that and reserve the Scharrfix for a couple of delicate tasks that the Fortuna struggles with (it has a bad habit of mangling very thin soft leather). The main thing I still use a handheld knife for is skiving the narrow ends of the top and end run strips.

 

23 minutes ago, Rod Pearce said:

Out of interest, do people us the word 'skive' when they mean 'thin'or 'split'?

 

I think 'split' or maybe 'pare' is technically correct when the blade is held parallel to the leather to uniformly make it thinner, and 'skive' when it's tilted over to produce a feathered edge, but I often write 'skive' for both techniques (and use a 'skiving machine' to do both tasks).

[Wally Carroll]

For ribs, we start with a Fortuna type machine to remove the bulk and to create the tapered profile but then finish with a Scharfix to get a finer skivved edge.  For gussets we only use the Scharfix.  I’ve found it too difficult to get a consistently fine edge using just the Fortuna type machine.  For someone new to bellows making, I would start with a Scharfix (not sure about Chinese knock-offs as I have no experience with them) and the blades recommended by others.