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Matt S

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    nr. London, England

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  1. Veg tanned leather is mildly acidic -- usually around a pH of 3 in my experience. I'm no tanner but I'd be willing to bet that there's a good reason behind that. In the trade certain premature degradations of the leather are associated with low pH ("red rot") and with excessively high pH. For comparison human skin is around pH5.5, regular vinegar pH2-3, distilled water neutral at pH7 and a saturated solution of baking soda mildly basic at pH8-9. I think it's a very good idea to keep leather as similar as possible a pH as it came out the tannery when we're mangling it, for longevity. I don't remember the pH of iron acetate (the active component of vinegroon, i.e. the result of reacting iron with acetic acid [vinegar]), nor can I find it from Google. The pH of any particular batch of vinegroon might be anything within a wide range though, dependant on things like the amount of unreacted vinegar present. The simple version of the chemistry of vinegroon and other similar strikers is that excess tannic acid in the leather (left over from the tanning process) reacts in the presence of water/moisture with iron to form iron tannate, which is a blue-black in colour. Iron tannate is not water soluble, so can't wash out of the leather. This same reaction is used on tannin-containing wood like oak and chestnut. There's nothing magic or unique about vinegroon -- many different ways of getting iron to react with the leather work. Iron filings are a common accidental reaction in workshops and tanneries. Blood is also common, though usually again an accident. I've used iron sulphate crystals from the garden centre before, and have heard of good results from dietary iron supplement tablets (same stuff). Will Ghormley simply uses a barrel of rusty water. I greatly prefer the idea of using either largely neutral reactants (like rusty water) or consistent off-the-shelf components like ferrous sulphate, for which there is no brew/wait time, are consistent in their behaviour, whose pH can be predicted, measured and controlled. (Incidentally a 10% solution of ferrous sulphate in water has a pH of around 3.5, which is very similar to veg tanned leather.) Immersion of leather in basic solutions of unknown or uncontrolled strength doesn't seem like a good idea to me. I've tried it as the "received wisdom" way to "neutralise" a vinegroon bath and ended up with stuff that seemed fine initially but cracked and split far too early. No amount of grease will knit broken leather fibres back together.
  2. Glue diluted in water has been standard in the UK for over a century. Traditionally gum arabic or hide/pearl/rabbit glue but these days normal white PVA wood glue is more common. It works very quickly, is very long-lasting and so cheap it's pretty much free.
  3. Matt S

    Using sinew

    Real sinew has the advantage of shrinking as it dries, so a seam sewn with wet sinew will tighten. Arctic indigenous groups use this technique for making near-watertight clothing. It also has the advantage of not requiring the growing and processing of flax, which I imagine was a boon in times and locations where agriculture was not practised.
  4. @Kovant if you truly want a variable speed you might need to look at a 3 phase motor/machine and a variable frequency drive (VFD). Those little machines with "variable speed" tend to bog down under any appreciable load because they have a very simple variable speed circuit that just cuts out a proportion of the wave according to the dial setting. Also, in my experience, those small DIY/"light/occasional trade" bench grinders have a short duty cycle meaning you can't operate them under load for long before they overheat. Alternatively some higher-end machines are available which allow selection of a couple of speeds (using pole switching I think), but I don't know if these will give you the needed range or granularity of options. A pair of cone pulleys between motor and wheel will give you a wider range of speeds with the added advantage of higher torque at low speeds but the disadvantage of fiddly speed changes and general bulk. As I'm sure you know, professional shoe makers and repairers use a big finishing machine for this purpose, with wheels and attachments for grinding/sanding a polishing. They are large and expensive however. I believe that they turn relatively slowly, as I was recommended to not turn one of the big horsehair polishing brushes faster than 900RPM and they tend to share an axle with the sanding wheels. Depending on your budget and space, maybe consider a good quality belt sander with variable speed. The 2x72" types that knife makers use look great. Or, for a cheap option not used very often, stick a sanding drum in a basic bench/pillar drill with variable speed. Prolonged radial force will wear out the bearings but that'd take a while to do. Plus the drill has many other uses. There is no particularly ideal RPM for leather. Machinists talk about "surface speeds" (how fast the cutting edge of their tooling moves) which I think is more useful, and use the spindle speed to calculate it. If you have a 2" sanding wheel and a 8" sanding wheel on a 3,000RPM motor the sandpaper on the 2" one will be doing 1,572 feet per minute and the 8" one 6,288FPM. With equal pressure applied the 8" wheel will remove material faster than the 2" one but will be hotter and more likely to burn. Within a certain window it's possible to adjust your pressure to not burn the leather on whatever speed sander you have. I have one of those ubiquitous little 1x30" belt sanders which can either burn leather in seconds or be make a beautiful clean edge depending how heavy handed I am that day.
  5. There's a comprehensive UK-oriented resource list on the Leatherworkers UK Facebook group.
  6. If it's a rebadged German skiver it may be a Fortuna, the archetypal bell knife skiver. Original parts are available, if pricy.
  7. That's a good point. How long before your edges shag out? I found that adding glue makes the burnish go faster and stay slick for longer in use.
  8. Pretty much! Bullock is from Old English buluca (from bulla + the diminutive suffix -uc -- "little bull"). Can mean either "young bull" or "castrated bull". Usually the latter in the modern era. Bollocks is derived from Old English baluc (bal meaning "swell" or "inflate" as in "ball" or "bellows" and same diminutive suffix -- literally "little swellings"). That's far too similar for me to think that it's entirely coincidental, especially considering my ancestors' love of a good pun and their earthy sense of humour. There's also "ox", of similar Saxon antiquity, which is a (usually castrated) bull trained for draught work. We haven't done that here for a long time, yet J & FJ Baker specifies that they select "ox hides" . Having been there, got the tour and nearly fallen in the liming pit the fresh hides I saw were mostly from black-n-whites and somewhere around 40-50SQFT. That can't be a young calf (calfhides I buy are around 20SQFT). The colouring implies either Holsteins or Fresians which means dairy but they claim to only use oxen so I'd say they use hides from "surplus" dairy bullocks raised to optimum meat value. You sure that's not creosote you're thinking of? Bitumen is the thick stuff they use on roofs and roads, usually either melted or mixed with solvents to make it workable. I can buy a can of bitumen from a DIY shop but creosote has to be bought from agricultural factors... or you just buy it online and claim "yeah sure I'm a farm, honest, please deliver it to my suburban flat" It's the stuff that telegraph poles and railway sleepers are soaked in and makes a lovely whiff on a summer's day. Depending how cooked off it was of those two I would imagine bitumen would be a lot more palatable in a bottle but I'd be bloody thirsty before I chose it. Most people I've spoken to who make blackjacks and costrels today use beeswax or brewer's pitch.
  9. Looks like someone scavenged the feed wheel driver shaft, with its associated worm drive, to supply another machine. Maybe you can track them down and steal them back? The other issues aren't so bad -- the presser feet and guide can be ordered if of the standard design or probably wouldn't be too tricky to make. If the slop in the knife-pulley arrangement is in degrees of rotation (i.e. not slopping left and right or up and down) that's normal -- a result of the coupling which allows the knife to be adjusted left and right. The knife guard can be built too if you really want one -- my skiver is too old for a guard so the previous ownerpanelbeat one from brass. I wonder how close to fitting the "standard" Chinese replacement parts would be? Otherwise again it wouldn't take too much trouble to get a piece of bright shafting of the right size (probably a standard inch size, but if not turn it down on a lathe until it fits) and needs a cross pin at the business end to mate loosely in the slot at the back of the wheel. The gear would be expensive and hard to replace but you could just leave the shaft long hanging out the back of the head driven by a separate motor. Or failing that just replace the feed wheel with something smooth that closely matches the shape of the stone and you may be able to feed the leather manually. If it's for a hobby and you like tinkering it could be a fun project.
  10. I've taken the word "minimal" literally. Possibly too literally... You'll need something for making small round holes for rivets, studs etc. Punches (the sort you hit or the sort you squeeze) are ideal, but with care you can drill these too. You'll also need a substance for burnishing your edges. The usual Tandy answer is "gum tragacanth" but I've never got good results with it. Almost any water-based glue diluted in water works well. Have had good results with gum arabic, woodworkers PVA, and hide/rabbit/pearl glue.
  11. @TonyD1948 Is that leather definitely veg tanned? As a general rule only veg tanned leathers can be edge burnished. For other tannages (e.g. chrome, which looks likely judging by that photo) you have to go with another edge finishing method -- edge paint, fold, bind etc.
  12. Kid as in "young goat"? I don't know where in the world you are but here in Britain most leather suppliers will do at least one type of veg tanned russet goatskin. Usually around 1mm thick. I don't know exactly what properties are required for leather for making a pair of 1880s kidskin evening gloves but goatskin seems to me like a logical place to start.
  13. No problem sir, we all start from somewhere! Ah, in which case the 168W would have a slightly increased accessibility advantage over a 206 than a 207. I've never used a 168W but I'd lay money on it having very similar upper limits to your 206 in terms of max thickness and max thread size. Probably a smidge lower, plus no reverse feed. Unfortunately I'm not sure it'll be up to that. There are heavier post-bed machines but they're not very common. For a holster you'd be looking for what I think of as the "harness" weight class. A Singer 45K, Singer 7, Adler 4/5/104/105/204/205/304/305, Juki 441 (or one of its many clones), that sort of thing. Flat-bed is more common but cylinder-arm tends to be more versatile.
  14. That's a price I would consider acceptable... if I had a use for such a machine. The 168W is a post-bed upholstery-weight machine. Designed for sewing shoe uppers (not soles), hat crowns, bag bottoms that sort of thing. With care (or building a little add-on table) a person could use it for sewing wallets, purses, dress belts etc., but not anything heavy like holsters, knife sheaths or gun/tool belts. Apart from the ability to sew "into" certain hollow shapes I don't know how much utility you'd get out of it beyond what your Consew 207 can do.
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