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Alaisiagae

stupid question about using diamond chisels

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So, I tried using my diamond chisels on some thin (2-3oz) veg tan. I am making a pouch with 2 pieces, so I lined up the front and back piece, rough side touching rouch side (grain/grain facing out) and used the chisel to punch through both from the grain side of one piece through and out the back of the grain side of the other piece. Aside from make a total disaster out of it (diamonds are angled all wrong, my bad), the holes out the back piece look bad: the leather on the grain side got distorted and wrinkled around the holes. What am I doing incorrectly? I feel like I keep making rookie mistakes, is there a big list of "never do the following things"?

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Did you glue the seam together first?  It doesn't have to be uber strong, just keep the leather from shifting around while you punch your holes.  How large are your chisels?  What were you using as a backer while punching? 

Pictures help.

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1 hour ago, Aven said:

Did you glue the seam together first?  It doesn't have to be uber strong, just keep the leather from shifting around while you punch your holes.  How large are your chisels?  What were you using as a backer while punching? 

Pictures help.

I used double sided tape ("Tanner's Bond") along the edges to secure the two pieces. I punched on top of a poly cutting board. My chisels are these ones  (diamond hole chisel set) from Tandy. I dyed after punching, not before.

20200829_182319_edited.jpeg

Edited by Alaisiagae

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I'm not familiar with Tanner's Bond.

Are the small marks where you expected the chisels to come through on the back?  I'm assuming you are showing the back piece.

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When using diamond punches it helps to first mark your line where you're punching and then line up your punch with one prong in the hole you perviously punched. Also, how are you removing your punch? Sometimes the way you remove the punch affects your holes.

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Are the teeth really sharp? Those holes suggest they are not. Sharpen them and polish the teeth up, both the cutting end and the sides. Also press into wax before every, or every other, strike. It becomes a rhythm; into wax, punch holes, punch holes, into wax, punch holes, punch holes, into wax. . . . . 

Mark your line on front and back. After the first set of holes check that they are coming out on the line. If not adjust how you hold the chisel. Use the side of your hand to press the leather down and the fingers of that hand to guide the chisel. Hold the chisel lightly, just enough to keep it upright.

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31 minutes ago, Aven said:

I'm not familiar with Tanner's Bond.

Are the small marks where you expected the chisels to come through on the back?  I'm assuming you are showing the back piece.

Yes, that's the back piece. It's medium strength tape, it can be removed and isn't a permanent or super strong bond.

31 minutes ago, Leather20 said:

When using diamond punches it helps to first mark your line where you're punching and then line up your punch with one prong in the hole you perviously punched. Also, how are you removing your punch? Sometimes the way you remove the punch affects your holes.

Yes, I had some trouble negotiating the curves... it's easy when it's a straight line! I did put one of the prongs in the previous hole,  but as you can see I erred when turning the corner and flipped the chisel so the slant changed. I tried to pull out straight up-and-down, but it's possible I yanked at an angle. I poked the chisel in beeswax to help ease pulling the chisel out. 

1 minute ago, fredk said:

Are the teeth really sharp? Those holes suggest they are not. Sharpen them and polish the teeth up, both the cutting end and the sides. Also press into wax before every, or every other, strike. It becomes a rhythm; into wax, punch holes, punch holes, into wax, punch holes, punch holes, into wax. . . . . 

Mark your line on front and back. After the first set of holes check that they are coming out on the line. If not adjust how you hold the chisel. Use the side of your hand to press the leather down and the fingers of that hand to guide the chisel. Hold the chisel lightly, just enough to keep it upright.

The teeth are electro plated, so to sharpen them I'd end up scraping that off... I'm a little reluctant to do that. 

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First of all, you did not err by flipping the chisel when turning the corner. Actually, you can't. Prove it to yourself by holding your chisel, punch a set of holes, rotate the chisel by 180°, and then punch another set next to the first set. They will look the same. On you piece the holes go from upper right to lower left or //// as seen from the front. This occurs all around your piece and is easily seen if you look at the holes while rotating the leather to keep the edge on top.

My guess is that the problem you do see comes from two sources. The tape has some thickness and allows the thin leather surfaces to move a bit with regard to each other. The holes look odd on the back side because you are cutting directly on a poly mat. This does not allow the chisel to penetrate very far past the leather and since the tips of the prongs are sharpened if they penetrate to different depths, they result in holes of different sizes.

I suggest you try gluing the two pieces together and then place a sacrificial piece of leather between your work and the poly mat. This will allow the prongs to penetrate beyond the sharpened tips to give a more uniform hole.

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18 minutes ago, GatoGordo said:

First of all, you did not err by flipping the chisel when turning the corner. Actually, you can't. Prove it to yourself by holding your chisel, punch a set of holes, rotate the chisel by 180°, and then punch another set next to the first set. They will look the same. On you piece the holes go from upper right to lower left or //// as seen from the front. This occurs all around your piece and is easily seen if you look at the holes while rotating the leather to keep the edge on top.

My guess is that the problem you do see comes from two sources. The tape has some thickness and allows the thin leather surfaces to move a bit with regard to each other. The holes look odd on the back side because you are cutting directly on a poly mat. This does not allow the chisel to penetrate very far past the leather and since the tips of the prongs are sharpened if they penetrate to different depths, they result in holes of different sizes.

I suggest you try gluing the two pieces together and then place a sacrificial piece of leather between your work and the poly mat. This will allow the prongs to penetrate beyond the sharpened tips to give a more uniform hole.

Gatogordo hit the nail on da head

place a piece of thick leather under your work,  a ploy board is for cutting on

my pounding leather strip

20200829_195133.thumb.jpg.876adcb9db3fb63df2879bf3d0a6a4f1.jpg

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Yeah, I'm in the "used a piece of leather between the work and the poly board" camp too. Also partially in the "not sharp enough" camp. Once I polished up the teeth on my one set, which sucks and is quite tedious, it worked far better...then I ended up getting Sinabroks and now I just don't worry :) !

@Frodo, do you mean they used too many teeth on the corner, say, the 4 tooth instead of the 2? If not, I don't know what you mean they used the incorrect chisel so please elaborate on that if you could.

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3 hours ago, Alaisiagae said:

The teeth are electro plated, so to sharpen them I'd end up scraping that off... I'm a little reluctant to do that. 

a. they are not electro-plated

b. nor are they 'electrophoresis' coated

c. they have a chemical blackening

d. you need to ignore all that and sharpen the teeth. You need a very sharp cutting edge and smooth sides to each tooth

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Averagely priced stitching chisels such as Tandy only come with a basic finish or sharpness, so they can be improved by polishing & sharpening the prongs yourself

Make a small file by gluing some 600 grit wet & dry paper to a thin sliver of wood like a lollipop stick; or a piece of thin, stiff plastic; or a thin strip of aluminium. Than carefully polish all the prongs. This is a bit of a tedious job, but worth doing. This will remove the black coating, but that doesn't matter

Lubricate the prongs before use by stroking them over beeswax

When removing the chisels, hold down the leather by pressing down with a piece of wood right next to the prongs, to avoid distorting the leather and the holes

I work on an old magazine. They are effectively free; and have just the right combination of resilience and support, but soft enough not to blunt the prongs. Just replace it when it's worn

Mark the line of stitching with dividers. Place one tip against the edge of the leather, and the other onto the leather, with a gap of about 3 or 4mm

Search on YouTube for using stitching chisels, there are several videos. Also for making pouches and wallets, you'll see how other people stitch thin leather. In fact as you watch YT videos on making any leather items you'll see the tools & techniques used

Nigel Armitage has a series of videos on making pouches, starting with a simple 2 piece model, then building up to more complicated designs

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These chisels aren't bad.  They are a durable set that can provide decent holes, and they are a good starter set.  You can achieve stitching that will impress the entire public and all but the finest leatherworkers with such a set.

*** WALL OF TEXT WARNING.  TL;DR: step by step how to improve your stitch hole makin'. ***

Before you start, you need a sturdy, non-bouncy table or surface.  I would rather punch holes on the sidewalk or a tile than a folding card table.

First, scratch a line to stitch along, at the same distance from the edge as the distance from tip to tip on your chisel, or barely closer.  Don't use wing dividers as a beginner to scratch a like, or a groover.  Instead,.use a straight edge and a scratch awl or pen with no ink in it, drawn backwards.  Don't use wing dividers because beginners need to get better at cutting straight edges and curves first, (but you will).

Second, overlap by two prongs, not one, and rest the prong at the other end right in the center of your line.  You should by looking down the line while doing this... pointed toward you and not side-to-side.

Third, have belt-thickness leather under your entire project so it is laying flat.

Fourth, if you have a two prong chisel, use that in the corner, exactly centered on the corner where your straight lines would cross, i.e. each one the same distance from the corner.  End the lines just before they cross--ideally, so the two prong chisel will barely touch the ends.

If you don't have a two prong chisel, use your scratch awl to poke a hole just inside of where your straight lines would cross, so the awl hole barely touches both lines.

Fifth, Punch the rest of your holes from each corner out.  When you are punching, first rest the head of your mallet on the top of the tool, and then raise or lower the handle until it is exactly horizontal.  The chisel must be exactly vertical, the mallet, horizontal.  Then, try to raise your mallet using just your forearm and swing down along the same path, firmly but not heavily... enough that more than just the tips penetrate the other side.  Pick up the project with the fork still in it and check at first.  (If you don't ensure this you will need to use a diamond awl at least as big as the holes and very carefully insert it straight into the diamond holes so they are the same size.)  This is to ensure that you are hitting your chisel straight down instead of hitting the edge of the tool (which can bump it at an angle and make your holes on the back wobbly).

If you have to fudge the spacing of a hole, err on the side of a short stitch or two instead of a long ones. They are less noticeable than in a corner or the middle of a line.  Next time, make a pattern that include punch holes measured/marked/made to avoid fudging the spacing.

Sixth, when you pull the chisel back out of the leather, press your finger firmly near the teeth, so that you don't distort the leather by pulling at and angle.  Or, use something like your bone folder laid flat.

Seventh, stitch.  In choosing between two thread sizes, it usually looks more refined to choose the thinner one, and more rugged to choose the thicker one.  Watch Leodis' Leather and Nigel Armitage's Youtube videos to get incredible instruction from two of the most prolific and experienced leatherworkers on Youtube.  Both seem to genuinely want to help preserve this craft by teaching, and are generous with their knowledge. 

Eighth, tap down your stitches lighly with a smooth faced mallet or hammer.  If needed, go back over your holes with a matching overstitch wheel, or by very lightly pushing your dull chisels into the stitching, or by using a dull stylus or a ballpoint pen with no ink in it to push down the space between each stitch equally so they all look the same.

Ninth, eventually put some sealer over your leather, like acrylic Resolene.  This will help keep your stitching in place and help slow down any discoloration from jeans, etc.

Tenth, freely share to others, as others have with you.  The better the results we all get, the better it is for our future customers' satisfaction and loved ones' delight, and the greater the demand will be for well-made, beautiful leather goods... which helps us all.

 

This was long, but I hope it was worth it.

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8 hours ago, battlemunky said:

Yeah, I'm in the "used a piece of leather between the work and the poly board" camp too. Also partially in the "not sharp enough" camp. Once I polished up the teeth on my one set, which sucks and is quite tedious, it worked far better...then I ended up getting Sinabroks and now I just don't worry :) !

@Frodo, do you mean they used too many teeth on the corner, say, the 4 tooth instead of the 2? If not, I don't know what you mean they used the incorrect chisel so please elaborate on that if you could.

YES, that is what i meant.   Sometimes i think others can read my mind LOL  

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Thanks, @johnv474, @Frodo, @zuludog, @battlemunky. @fredk This actually is electroplated rather than chemical blackening. I used one of the interchangeable chisel heads in my arbor press, the ram has a hiole and set screw, and I tighted the set screw. The pressure caused the set screw to squish the threading on the interchangeable chisel head and the black coating flaked off in some areas. I do have chemically blackened tools, and these are indeed different.

I will use the techniques you all have described, and punch some holes today to see if that solves the wrinkly-back-hole problem. My poly board is thick (about 1/2 inch) and I've driven my chisels and hole punches into it before - it's not like a thin cutting mat. Nonetheless, I'll use a thick piece of leather (I've got some scap belly I practiced stamping on) under my project piece, and coat the chisel prongs in beeswax more frequently. I'll also follow johnv's excellent tutorial for how to hold my chisel and mallet - I am definitely guilty of striking at a slight angle (my poor mallet head). 

I glued (Fiebing's leather glue/cement) the two pieces together last night, which raises a question: do you make your chisel holes before or after dyeing? If I use a strong permanent glue, I can't separate the two pieces to dye them (specifically, if I want to dye the flesh sides).

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4 hours ago, chrisash said:

Have a look at jo's video's on this youtube link, she covers most of what beginners need to make

https://www.youtube.com/c/JHLeather/videos

 

Yes, Jo's videos are good, and an added bonus is that you get to hear a perfect Middle Class English accent

If you ever want to upgrade from Tandy, have a look at Weaver Leather Supply and Rocky Mountain Leather Supplies

I dye before I glue and make the stitch holes, whether it's just one side or both

Edited by zuludog

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Okay, so I did all the recommended changes, and here's the back side of the piece. I see that when the chisel punches through, it's pushing the leather outward into a little dome around each hole. Is this normal, or does the tool just suck?

I recall having this same wrinkling/bowed out problem when I used a leather drive punch (round) on the flesh side; the grain side look really crappy. 

 

EDIT: same thing happens with my thonging chisels, they're brand new.

20200830_102731_edited.jpeg

Edited by Alaisiagae

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Try stitching a couple of scrap pieces, then "set" your stitches with a smooth faced mallet. Do this on your marble and I think those "little domes" should go away.

That being said, it does look like a sharpness issue.

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You could try just using the chisel as a pricking iron, then making the actual holes with an awl.....but that does mean using a sharp diamond/saddler's awl, something like an Osborne #42 or #43, which you would need to sharpen & polish before use

There are plenty of YT videos on how to prepare & sharpen an awl blade

Edited by zuludog

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The doming is also affected by the surface below.  If the cutting board is a little too hard, the teeth do not penetrate past the tips.  Hence, belly leather (or a firmer smack with the mallet).

The domes mostly go away when you tighten your stitches.

I usually dye before gluing because glue usually interferes with dye and I tend to get glue a few places I don't mean to.

You can also make your leather have a little more give by dampening the edge with hand sanitizer, which gives a minute ot so of the fibers being relaxed.  For a slower-drying option, slightly dampening the leather all over with water (all over to avoid water spots).  Don't overdo it on the moisture. Or, use saddlr soap to lightly wash all over.  Any of these will help the chisels go through more smoothly.

You'll definitely notice a difference if you polish the tips, especially rounding the angle from the tip to the shaft of the prong.  They will enter and exit easier.  Don't worry about removing the plating-- just put a little sewing machine oil or other light oil like WD40, or some wax, to protect the tips from rust.  Or, brush with clear nail polish after polishing and polish lightly when dry.

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6 hours ago, johnv474 said:

The domes mostly go away when you tighten your stitches.

This^^^ it should tuck 'em right back in and you won't really notice.

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