'stiffening' soft leather for cutting..

[canonitr]

not sure if this is correct or whether it can help anyone .. 

so far i've only been working on buffalo (~4oz) as it is fairly stiff and easier to cut.. i've previously tried ~3 oz cow, but kind of hated it as whenever i put some pressure on the ruler to make a straight line to cut, it causes the leather the splay out ever so little, even when using a rotary cutter.

i've recently gotten some cheap chromed goat which is quite thin, probably ~2oz and it stretches quite a bit.. however, applying burnishing gum on the flesh side, and letting it dry, seemed to allow me to have a proper cut without much issues..

 

[niakulah]

I did slick the flesh side of a particularly fuzzy piece once and did notice it was stiffer.

Didn't think to do it to make cutting easier, thanks!

[canonitr]

i only tried it on 1 piece over the weekend, but don't know if it affects the ability to glue, tho to me the glue is in a way, temporary, to allow stitching to be done...

i  only tried it because i didn't want to be stuck only working with buffalo due to its stiffness..

[chrisash]

Hold the ruler or straight edge down firmly and use a razor sharp knife. Make sure your cutting table is flat

[fredk]

A straight edge with cork on the back helps to hold the thin leather in place. I use a rotary blade as well, but I only cut a hand-span at a time.

[canonitr]

i have a non slip ruler (saintograph) which is lined with something to prevent slipping .. 

unsure if it's true, but i've read that the reason why the leather splays out when cutting with a blade, is that the point of contact between the leather and blade requires a pull/push motion (depending on how u cut)  to cut into the material, and that motion is the reason for the slight pulling of leather when cutting .. the rotary cutter is supposed to be rolling,  hence supposedly no pulling on the leather.. however, which ever the method i used, i just can't seem to get it to cut cleanly.. might be i put too much pressure on the ruler when holding it down .. 

have yet to try it with my razor (ie shaving razor) blade yet. maybe with the thin and sharp blade, it requires less force to start the cutting motion...

[rodneywt1180b]

I don't think too much pressure is the problem.   Are you holding the end of the straightedge down firmly or just in the middle?

You might try something like a piece of packing tape on the flesh side to stiffen it up.  I haven't tried it myself though. I haven't needed to.  So far with a rotary cutter and holding my straight edge down tight I haven't had any trouble, including thin kidskin.  With a utility knife I did get that distortion at the end of my cut.

[immiketoo]

If you get a thick straight edge, like a meter long aluminum one, you can clamp it down in a few spots before cutting.  PITA but works every time for straight cuts.

[Aven]

On 11/19/2018 at 12:33 AM, chrisash said:

Hold the ruler or straight edge down firmly and use a razor sharp knife. Make sure your cutting table is flat

And that your ruler is flat.  Weaver Leather Supply sells a non-slip tape.  It's great for rulers and squares.  The leather doesn't move when you press down.  Hopefully you can find something similar locally.

[canonitr]

5 hours ago, rodneywt1180b said:

I don't think too much pressure is the problem.   Are you holding the end of the straightedge down firmly or just in the middle?

 

I move along for long pieces, but just in the middle for smaller ones

 

[rodneywt1180b]

You might be getting a bow in your straightedge allowing the ends of the leather to move on your short runs

[fredk]

Two things which helped my cutting of thin leather;

1. Using a rotary knife

2. Cutting away from myself. I've always had a tendency to cut towards me, but cutting away on the thin leather seemed to reduced the drag effect

3. Using the rotary knife very, very, lightly. It just about kisses the leather. The sharper the blade the better that this light pass will cut

  ok, so thats three !    

[brmax]

You might consider the use of a basting tape. 

I use this sparingly, 3 places about two inch long, on a four foot aluminum rule. The center tape really helps great, just as your issue. 

Seamstick; its called. I use it on my templates. This I wouldnt do without, many say it is handy on other seams in securing a bit. I pick it up from marine upholstery suppliers. 

After awhile it may need replaced because of lint and such from canvas etc. 

Also as fredk mentioned I also really like using the rotary knife. In other materials like vinyls or canvas, its a new tool. This I know can be infringing on tradition. But Im positive they will only see more usage.

Seamstick is available in several widths, basically double sided clear. Maybe a 1/32 thick and easily in 1/4, 1/2” etc widths. 

 

Good day

Floyd

Edited November 22, 2018 by brmax