I tried engraving and cutting leather after taking Kim’s class yesterday, and found that masking tape makes a huge difference in terms of preventing scorch marks.
But if I’m going to cut a larger piece, covering it with masking tape doesn’t seem like a great idea. When I looked it up, I found a thread on the Dallas makerspace’s forum where someone said:
I always case my veg tan leather before cutting it on the laser.
Wet your leather until it’s completely wet but not dripping wet. (vague much?)
Set it flat on a table and leave it until the outside is dry"ish" but not the inside. It should feel cold to the touch.
Then cut it on the laser.
Does that sound right? I hadn’t thought about putting something damp on the laser table bed.
I don’t think we’d want something that’s dripping wet in the laser or to have something wet sitting on the bed for an extended time.Other than that, I don’t see that it would do any harm.
As far as reducing scorching, I don’t have experience with the method but I’d like to hear of the results after you try!
I know some people like to go maskless on acrylic and instead rub dawn dish soap on both sides and stick it in the laser. So I have heard of some wet ish things going in. However, I have not tried this method yet.
I think they tell you to completely wet your leather (wet the full piece evenly) because partially wetting it will cause uneven swelling of the material, making your cuts less likely to be as even as you expect. I would further suggest that since leather is a dynamic, sponge-like material, that you should avoid complex or multi-directional cuts when the material is wetted - although I would bet that highly complex cuts like designs would work out. Wet leather will require a longer/more powerful cut, and steam given off may also cause some leathers to bulge at the surface of the cut.
I’d definitely start with an experimental piece first. If I had to guess the wetted leather will bear less prominent scorch marks.
Well, on a small scale at least, dry leather with tape over it performed better than damp leather without tape in terms of reducing scorching.
The examples on the left are all dry with tape, while the ones on the right are damp without tape.
It’s harder to tell on the dyed leather, but the cuts caused significantly more scorching without the tape, and I’m not sure that the dampness actually made much of a difference.
But the masking tape also pulls a bit from the surface of the leather, so I’m thinking of using a massive roll of painter’s tape instead. Using tape also seems to cut down on the odor.
However, I looked back at the comment from the Dallas maker space and they specified “dry on the outside, damp on the inside,” which I didn’t do. So that might produce a different result, It would also, I think, be possible to tape over damp leather if it’s dry on the outside.
I sponged the pieces down or soaked them until they were saturated, then pressed the water out and let them dry off for a bit (but not completely) before doing the cuts.
