Sunday, October 26, 2014

Step-by-Step: Staining & Finishing

There's so many ways to stain and color leather these days that it's practically absurd.  This step is probably the only stage that's appreciably different from the ye olde days of classical yore.  Back then about all they could/would do was boil and/or bake the leather and work some oils into it.  Now-a-days I have 4 different categories of pigment, all with different properties, spread across 3 brands and encompassing an array of colors (particularly browns).  I have those oils too (though probably better ones than they had in 12th century Ireland) but there's not much call for them these days.  A full summary of these modern options would require a treatise more expansive than I could fit in a blog post.

So to skip the theory and get right to the practice, I figured I would use a Watercolor stain to form the base for the bookmarks, then go over the letters in acrylic, and seal it all in with some Super Sheen.  I don't use the watercolor stain terribly often because it's A) expensive and B) stupendously messy.  I have strategies and cleaners that work for every other stain in my arsenal, but leave any watercolor on any surface (even my silicon gluing mat) for more than half a minute and it'll never come out.  On the upside, it's great at giving an even, smooth base coat that other elements can build on and it's infinitely mixable.  Like most stains it's applied with a sponge and it's always a good idea to have ample water on hand.  I usually use a silicone mat to keep my workbench as unstained as possible, but I've learned that watercolors will stain even that so I use sheets of parchment paper instead.  It's important to work the stain into the leather with a little elbow grease so it can take awhile to go through 51 bookmarks.

Once the watercolor has cured overnight the painting can begin.  Acrylic's a pretty straightforward medium and the trickiest part is mixing it to get the right balance between smoothness and opacity.  Too thin and it goes on very smooth but just tints the leather.  Too thick and it cures opaque but tends to clump.  It generally takes 2-3 coats to get a good application and between my wife and I it took the whole weekend to get through the whole lot.  Somehow I didn't get any pictures of us hunching with brushes in hand but the result came out pretty well.

The last step is certainly aptly named: finishing.  Even after it's been tooled and stained, leather remains pretty susceptible to water, sweat, etc.  So to keep it from degrading over time a finish is generally applied to seal the pores and fibers.  Different finishes have different properties but in this case I'm using one called Super Sheen.  As the name implies when it dries it leaves the leather a bit shiny.  There's a few different ways it can be applied but I used a sponge to have more control and wound up giving the front 2 coats and the back 1 coat.  It takes a few hours to fully cure between coats but the result is pretty nice.

As of this writing I'm still working on the second half of this order, 50 key fobs you may have noticed in the transferring post, but these bookmarks are on their way to their destination.  Starting in November they can be purchased through the Talk Nerdy store.  The key fobs are soon to follow as soon as they're complete.  Thanks for talking the time to read through these posts and even if you don't have much need for a bookmark or key fob you should give Talk Nerdy a listen sometime.

Friday, October 24, 2014

Step-by-Step: Decasing & Signing

Once all the carving itself is done it's time to let the leather decase.  The simplest way to do this is to just set it on the workbench and wait for it to dry out.  However doing so risks leaving the leather to the whims of random fiber arrangements.  Leather, like wood or paper, is made up of lots of little fibers and while most of them run in one direction (the grain) they don't -all- run in that direction.  As the leather dries the fibers contract and those "cross fibers" can wind up causing the leather to twist or warp.

To prevent this I generally put the leather into some sort of traction overnight.  In most cases that entails piling old D&D books (and sometimes a few weights) on top of it and leaving it to sit overnight.  It isn't always fool proof, I still get some warping from time to time, but it's a big improvement over having no traction at all.  With enough pressure it even tends to burnish the rough flesh side of the leather.

Assuming veg-tan is involved I usually sign the piece as soon as it's done decasing.  Like craftsmen of ye olde I've come up with a makers mark that I use to, fairly literally, brand my work with.  This is done using a brass die with my mark and an old soldering iron.  In it's most basic sense it's a simple as just pressing the brand onto the leather but it takes some practice to get the hang of.  The density, thickness, and any remaining water can all affect how the leather takes the imprint.  In the worst case scenario the fibers of the leather can be scorched by the heat, but that only happens if the leather's still pretty wet or the iron is heated over 300C.  Otherwise it's just a matter of practicing the stamping, rocking motion necessary to get a clear, clean imprint.

Wednesday, October 22, 2014

Step-by-Step: Beveling

Anything more involved than line art usually involves some degree of beveling.  Beveling uses an angled stamp to raise an element of the tooling above whatever's around it.  Changing the depth and angle of the bevel can alter the prominence of that element as well and with all sorts of different stamps giving different effects beveling can be pretty darn versatile.  It can be pretty tedious if you have a large area to bevel but when done well it makes a pretty profound and subtle effect.

In this case I was using two of my higher quality bevels.  They aren't as robust as some of my other bevels but they make clear and smooth impressions and aren't as prone towards "chop".  For each bookmark I'd use the longer bevel along any flat edges to make sure they were nice and straight.  Then I'd go back over the interior of the letters with the smaller beveler pressing down by hand to flatten out the interior of the letter and bevel the curves. 

Monday, October 20, 2014

Step-by-Step: Cutting

Now it's finally time to get down to the proper leather carving itself.  Everything that's been done so far has just been to ensure the next couple of steps come out as well as they possibly can.  The leather carving, aka tooling, itself involves various stages and steps depending on the desired outcome.  There's roughly 8 or 9 categories of stamps used to accomplish differing effects for general tooling and an unending array of specialized stamps for specific styles like sheridan carving.  No matter which stamps you're using though, tooling first starts by cutting the design into the leather.

To do this we use a tool called a swivel knife.  As the name implies, the knife is made so that it can twist or swivel as it's cutting through the leather.  By taking advantage of this the leatherworker can cut clean curves into the leather and isn't restricted to straight angles.  Cutting the grain of the leather (the smooth, strong top side) makes a clean border in the surface of the leather that the rest of the carving is built on.

The swivel knife needs to be kept razor sharp in order to cleanly cut the leather so every few minutes it gets passed over a strop of some sort.  Sometimes it's a peice of scrap leather but I find a bit of scrap brown paper seems to work better.  Whatever I use, it's liberally treated with jeweller's rouge which is a sharpening agent.  Any of the microscopic imperfections that are dulling the edge get whisked away by the rouge.

Due to subtleties in the leather and the fact that all this is done by hand it's virtually impossible to cut any design exactly the same way twice.  Accordingly every piece comes out just a little different from the others guaranteeing a unique product in the end.

Sunday, October 19, 2014

Step-by-Step: Transfer (Stylus)

I mentioned yesterday that there's another technique I tend to use pretty often to transfer a design onto a piece of cased leather.  Tap-offs work great for large or simpler designs but they don't really work at all for designs of any complexity.  For that, I have to apply a somewhat more modern technique (in so much that paper is more modern than leather) and trace the design onto the leather from a print-out using a stylus or scratch awl.

This is about as tedious as it sounds but what I dislike most about it are the replication errors that tend to pop up.  This is really only relevant for symmetrical designs but using this method means going over the design at least two or three times by hand.  It's kinda like playing the old school yard game of telephone in that way; all the details tend to get a bit fuzzy.  For most designs I can work around that by incorporating any transfer errors into the design on the leather, goodness knows I've had enough practice, so there's no harm done in the final product.

In this case though, I'm attempting to transfer the Talk Nerdy logo onto a 2.125" wide key fob.  This logo worked really well on a ~3" wide buckle, but at just over half that size it's taken on entirely new challenges.  A lot of care has to be taken to make sure none of the lines overlap or cross each other where they're not supposed to.  The design has a fair amount of symmetry and precision that's going to make it a fair challenge to reproduce at this scale 50 times.  Well, as the kids say these days: challenge accepted!

Saturday, October 18, 2014

Step-by-Step: Transfer (Tap-Off)

Our leather is formed and cased so now we're ready to start making marks on it.  The transfer process is how we apply our design to the leather just prior to tooling.  There's a few ways of going about it but for these items I'm using a tap-off.  The common alternatives are tracing a print-out (which I'll probably show in a few weeks) or drawing directly on the leather with a stylus.

Tap-offs are best used when you need to rapidly reproduce exact but simple designs.  They're particularly handy for designs with repeating elements but if the design is too complex they tend not to work very well.  A tap-off is made using a piece of heavy leather (often from some scrap) and cutting the mirror image of the design you want to tool into it.  I like to bevel the grain-side edges and sculpt the tooling as well but this is mostly to keep the impression as clean as it can be.

In the image above the piece on the left is the tap-off and the other three bits are awaiting their imprints.  Applying the design as as direct and simple as you might expect.  The tap-off is placed face down on the leather and then whacked with a mallet but good.  Once you've found the trick of it you can transfer the design directly the leather with just a minute or two (and while only minorly annoying the neighbors).

Thursday, October 16, 2014

Step-by-Step: Casing

Once the leather is shaped it needs to go through one more stage called "casing" before its ready for tooling.  This involves wetting the leather and could be as simple as applying water with a sponge and waiting 20 minutes.  Different leatherworkers seem to have different preferences for how they accomplish their casing but for the best results it usually takes at least a day to prepare.  To make things trickier, once the leather is cased it's necessary to complete all the work on it before it dries out (aka decases).  There's some tricks to helping this happen but it's never recommended to re-case the leather as that damages existing tooling.

To be honest, I'm not 100% sure what is happening chemically when leather is cased.  I suspect it has something to do with saturating the collagen fibers that make up the leather.  Perhaps it allows them to shift and compress around each other in a somewhat more fluid state.  I've been curious enough to try to find some studies on the topic but I haven't yet found a satisfactory explanation.

In any case, my casing process involves dipping the leather in a casing tub containing a casing solution (mostly water but with an additive to assist with the casing) and then leaving them in open air for some hours.  You can probably see that the water in my casing tub has turned kinda orange-y from the tannins left by the leather.  It's important to get just the right saturation of water in the leather, not too much and not too little, so I've worked on a practiced "dip and shake" motion that's been working pretty well.

Once the leather's good and saturated it sits out on the workbench for some hours.  This is to allow the water to penetrate deeper into the leather.  We'll know this has happened when the leather has returned to the same color it was dry.  Depending on the leather and the day this could take anywhere from 2-9 hours.  I like to keep a dry cut-off from the side next to the casing leather as a sort of "color guide" so I know when it's done.

Once the leather reaches that point it goes into a casing bag.  In times of yore this was a box made of wood and galvanized steel that could keep just the right amount of moisture inside the box.  In modern times it tends to mean a big ziploc.  By putting the leather in an air-tight container we're effectively able to "pause" the decasing of the leather and allow the water to soak through the entirely of the leather.  In order to be sure the leather is cased through and through it's left in the casing bag overnight.  I try to get all my tooling done on the following day but it's possible to leave the cased leather in the bag for several days if necessary.  We wouldn't want to leave it too long though or there's a risk that mold could grow on the leather (or so I'm told, I've yet to have that happen).

Tuesday, October 14, 2014

Step-by-Step: Shaping

It's been a little quiet around here lately largely due to Thanksgiving (here in Canada anyway) and a particularly large order I've been working on.  Without going into too many details, I've been making a fair amount of stock for Cara Santa Maria's "Talk Nerdy" store.  The items are relatively simple but I'm making a heckuva lot of them so this is going to take up most, if not all, of the month (baring commissions).  Since this has certainly cut into my "Make New Things" time I figured it might be interesting to do a step-by-step of how these things are made.

At this stage, leatherworking is the same as it's been since vegetable tanned leather reached high enough quality to permit tooling (sometime during the roman empire).  I'll be describing each stage to go from a side of leather to a finished item and each new article should come out every other day or so.

We begin with a side of veg-tan leather and some cutting implements.  As the name implies, veg-tan leather is leather that's been tanned using vegetable matter, generally oak or hemlock, which contains large amounts of tannin.  This process produces a leather that takes and holds impressions quite well and burnishes nicely.  It's definitely the defacto "canvas" for leather carving.

I use a tool called a strap cutter to slice 1" wide strips off the long side of the side.  In this case I needed to wind up with about 50 1"x5.5" pieces so some simple math tells me I needed about ~300" of strap.  Sides vary in length but mine was about 40" or so wide, at least where I was going to be cutting.  The leather does originally come from a living creature so it's not uncommon for it to have blemishes or holes that need to be cut around so in the end I figured I needed about 8-8.5 straps to get all the pieces I needed.

Once I had the straps cut I used a very sharp trim knife and a square to cut the bits to length.  By the time I was done I had 51 rectangular pieces of leather that were all 1" x 5.5" but they're still what I like to call "rough cut".  So in order to clean them up a bit I used an old woodworking tool I've kept around to round out all of the corners.  I have wood forms and knives specifically for rounding larger corners but for little bits like this I find this old gouge works pretty perfectly.

The last step of shaping the leather is beveling the edges.  I find that beveling the edges lets the leather fit a little easier in the hand and it tends to clean up the flesh side of the leather (the rough side).  To do this leatherworkers use a special tool with the inventive name of "edge beveler".  It's designed to ride down the edge of the leather with a sharp blade at a 45 degree angle to the top and side.  Afterwards you're left with a clean, comfy bit of leather and a small mountain of leather shavings.

Sunday, October 5, 2014

Musical Belt Buckle

My father-in-law's birthday was just this last week and after making a belt buckle or two over the past month or two I figured it'd make a pretty good little gift.  Long ago I'd made him a belt and now he'll have a personal buckle to go along with it.  My wife came up with the pattern, which was good because I wouldn't've known the proper pacing for the organ keys otherwise.

Saturday, October 4, 2014

Chemical Formula Coasters

Sometimes you just have to do something geeky and nerdy and goofy and fun.  That's my position anyway.  I'm not convinced there's a huge market for coasters (outside of informal christmas gift exchanges) but I rather liked the idea of tossing some chemistry in.  At first I was going to do include tea, coffee, and soda but that didn't quite work out.  The first molecule I picked for tea, Theflavin, turned out to be too large to fit on a coaster.  Seriously.  And of course soda is a complex, unholy solution of ichor and other not-so-good things.  And it occurred to me that nobody's probably going to need a coaster with their coffee, so I dropped those three and went with Catechin (tea), caffeine (pretty much everything) and ethanol (boozes) in addition to sucrose (sugar) and good ol' dihydrogen monoxide (water).  I figure this way, no matter what someone's drinking, they'll probably have a constituent molecule on their coaster.

One Big Sale Day

Today's the day!  For the next 24 hours anyone who uses the coupon code OBSD4OCT2014 will get 25% off any order of $25 or more.  Sounds pretty cool, right? =)