#leather paring

[zhalfirin-binds]

Paring/sanding leather

There are 2 ways that I know of to get nice and crisp edges with leather bindings.

One feels kind of like the classic way to do it. Use a sharp knife and thin the turn-in area until it's thin enough to wrap around the edge without looking too round or bulky and the end is thin enough to not show under the paste down.

The other is sanding the edge pretty much only where it's needed and even out the leather with a piece of cardboard (of a fitting thickness)

For these I did a bit of both. First I marked up the case (a Bradel case as you can see by the already assembled case) on the backside of the leather to see where all the edges and the hinge will be.

Then I clamp it with the edge marking pointing up in a press. I made roughly 12mm thick board of finn board (any board will do, but finn board is easy to sand to shape that's why I picked it), sanded it to a round shape and glued some soft leather to it to protect the surface of the leather from scratches but also protect the board from getting sanded. The rounded shape is to get a soft transition between the sanded and the un-sanded parts of the leather.

Then I sanded it until the marking is taken off and checked for thickness.

I sanded one marked up area until I was satisfied and then moved on to the next, all around until they were all done.

So how do I know the leather is thin enough? For one, it can be measured. There are nifty little gauges for that. This leather started out with 1mm and I sanded it down to perhaps 0,7-0,6mm at the edges and hinges. Thinner feels nicer to me, but if the leather gets too thin, it's not holding up to wear and use as much so I stick to that range as much as I can. That's one way to do it, but there's also the experience way. When rolling over the leather, the thinned parts should visibly and palpable roll easier than the rest of the leather. that's what I check for.

Last for that step I thinned the turn in areas of the spine, which needs to be even thinner, since the leather is going to be 2 layers on in the hinges and on the spine.

[conservethis]

(via https://www.youtube.com/watch?v=0grFcCXJwdk)

Do you hate leather paring as much as I do? Then you’ll love the Scharffix. 

Also, this video really should be subtitled: “Schmedt After Dark”, because of the music. 

[zhalfirin-binds]

Leather paring tools I use

As requested by @simply-sithel some quick pics of the paring tools I use. To be honest, I am playing favourites here. Mostly I use Schärffix and the scalpel, but I do use all of them depending on what needs to be done. I’m not exceptionally good at sharpening my knives and you definitely want a sharp blade for paring leather.

So the big bonus a scalpel and schärffix have is, you can exchange the blades The Schärffix works with razorblades and you can turn them three times to use each edge on both sides (just don’t forget to mark the side you already used so you don’t loose count or, if the tool is used by more than one person, they know too). Leather is dulling the blade really quickly though so I’m exchanging or re-sharpening my blades really often to avoid the leather from stretching too much or ripping apart. You don’t neccessarily need a paring tool to work leatherbindings though. You can thin out the parts that need thinning with a sanding plate, that works fine too. It’s less tricky (you basically just need to fix it firmly so your leather stays in place while you’re working), but it takes longer. Which is  equally a pro and con, a con because, well, it takes longer, and a pro because you can hardly mess it up without doing so for quite some time. So basically you can start out with nothing but sanding paper and a cutter knife (for the corners).

[risilovesink]

riversarms replied to your photoset: We have to use the spokeshave to pare the leather...

Oh my god, I would die without the Brockman paring machine. For other stuff I use knives only.

Our instructor said that machines would leave very subtle straight lines and be a consistent thickness and it would be completely inappropriate on a period book, and also calf was hell on the blades, but I gave up and used the Brockman because I would prefer to have the skin in one piece and also not take three days.

What style of knife do you use? I have two English and a small Swiss, but I only really use the English. I also made them myself so the bevel is like seven degrees instead of thirteen so I have to sharpen it all the time but it cuts really well when it's actually sharp?

[risilovesink]

Old and Tenuously Related III: Knives

12 November 2011

(We just had Peachey back and modified spokeshaves for leather paring, and Jim Croft is coming in the spring and that is amazing.)

Jeff Peachey came by after Stan­dards to teach us all how to make knives. It is a the­o­ret­i­cally sim­ple thing. Set the bevel, then pol­ish, he says. And of course he would know, because he is the local god of knives. He later wrote a help­ful post on his blog about it, with links to some more help­ful posts by Ron Hock and Mau­rice Fraser. And they’re right. All you actu­ally need is a very flat sur­face and sandpaper.

My pro­duc­tiv­ity: sharp­en­ing sys­tem, four knives, three hera.

The sharp­en­ing sys­tem Jeff Peachey uses has two very flat alu­minium plates with 80, 40, 15, and 5 micron microfin­ish­ing film, then a horse­butt strop with .5 micron chromium oxide hon­ing com­pound on it, which comes in a green crayon. We also made lit­tle stands for the plates.

The knives are made of inch and half inch hack­saw blades. Most mod­ern hack­saw blades are only hard­ened at the very cut­ting edge, which makes them use­less for knives, because they will never hold an edge. Starrett’s Red Stripe blades are fully hard­ened, and so broke the inch and half-inch blades in half to get two knives out of each.

We started on the grinder, some­thing like this bench grinder or this belt grinder, to set the ini­tial bevel. Thir­teen degrees is ideal for leather par­ing, Jeff says, and so we make thir­teen degree angles on our knives. The grinders are less scary than they first appear. I did have some trou­ble with burn­ing the thin steel at the very edge and then hav­ing to grind it back to get rid of the burned part. You could do the whole thing on the alu­minum plates but it would just take forever.

Then you take it to the plates. You run it across the plate at a dif­fer­ent angle for each grit, so that it is obvi­ous when you have elim­i­nated all the scratches from the pre­vi­ous grit. You get to go on to the next one when you have elim­i­nated all the scratches from the pre­vi­ous grit, the scratches from the cur­rent grit go all the way to the edge, and you feel a burr on the edge, which means that the edges meet. That wasn’t very clear. I would advise the sharp­en­ing notes men­tioned ear­lier if you want clar­ity. (See also: failed hol­low grind­ing.)

This knife was fur­ther along when I took its por­trait. The scratches are shal­lower, and the sur­face is closer to mirror-finish. Both of the pic­tures are of the flat bot­tom, rather than the side with the bevel.

But here is a pic­ture from the other side. You only need a mir­ror fin­ish on the eighth-inch or so at the very edge. The rest is for show. I can’t remem­ber whether this was sharp or not, but I resharp­ened all of them later any­way because they did not cut very well. Some of them still don’t. But now I know how to sharpen knives, and I will be able to apply this in the future!

Mean­while, we made some hera, which are bam­boo lift­ing knives, and Jeff Peachey’s new hobby. They are pleas­antly flex­i­ble, but strong. We split pieces of bam­boo to get lit­tle squares, then used a chisel to cut the end down and shape the tip. We used sand­pa­per to fin­ish them off. They are sweet lit­tle things, and quick enough to make. I have used mine a few times to turn in cloth at the spine and put glue in tight places.

Jeff brought along his friend Jim Croft. Jim Croft is our new stan­dard for ded­i­ca­tion to craft. He is unsat­is­fied with the qual­ity of our mod­ern world, and is deter­mined to learn to make every­thing in it him­self, so that it will be bet­ter. I know he grows flax and then beats it to make paper. He finds elk and deer antlers or bones in his yard in Idaho and turns them into per­fect bone fold­ers. I have never seen him with­out a bone and sand­pa­per stashed some­where on his per­son. He makes gor­geous books with wooden cov­ers he cut from a tree him­self. He prob­a­bly planted the tree. I adore Jim Croft.