Looking for pointers on laser cutting 0.060" thick sea snail, or alternative material

[Matt Walton]

Hi friends!

​Could anyone give me pointers on laser cutting 0.060" thick sea snail, or recommend a different material that might work better? My luthier friend is making me a guitar, and we've been wondering about the best way to cut the inlay material with a laser cutter.


So far, I'm planning on 0.060" thick sea snail (http://rescuepearl.com/seasnail.htm).


My main concern (as far as I know) is getting a clean cut without scorching on the edge. He has a 90W laser at his disposal, which he says is accurate to 0.001" with a beam width of 0.002". In y'all's experience, what cutting strategy gives the best results? Full power as fast as possible? Super low power with multiple passes? Something in between? Time to cool or blow out powder in between passes?


Another material I was considering for inlay is black mother of pearl (http://rescuepearl.com/tahitian.htm). The fretboard will be ebony, so my thinking is that it might be cool to have a flat black fretboard, with glimmers of black inlay when the light hits it. Unfortunately the black color is only a thin layer--I'd rather not have to worry about sanding through the top layer when radiusing the fretboard. Is there a similar material (natural, preferably) that stays black (relatively speaking) the whole way through? Ability to cut with a laser cutter is also appreciated. :p


In case it matters or you're just curious, the inlay will be my initials at the 12th fret, the maker's name on the headstock, and possibly knots and links as fret markers. I suspect the thinnest line will be 0.4" (1 mm) thick if I do the knot and link idea--though his headstock logo may be thinner than that, I'm not sure.


Thanks!

[John Noell]

The only shell I have laser cut with acceptable results is laminated shell. It is not as pretty as the solid blanks but it works for some things. I can blow up thicker shell, but not cut with a decent edge. Engrave? Yes! Cut? No. YMMV However, as far as I can see, the wavelength of a CO2 laser and the calcium carbonate are not a good match.

[Mike Null]

Cut it from the back side with moderate power and slow speed. Don't be in a hurry and expect to make 10 to 15 passes. I have cut .050" abalone with this method and got excellent results. I doubt that your friend can get a .002" spot. More likely a .005" or a little more. That is one of the reasons for cutting from the back.

If you have the means, it would be advisable to reduce the thickness to .030" before cutting.

The consistency of shell, abalone, etc. varies and that is the reason for the multiple passes so as to minimize the chance of blowing it up.
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[Bill Carruthers]

[QUOTE=Matt Walton;2639970]Hi friends!

​Could anyone give me pointers on laser cutting 0.060" thick sea snail, or recommend a different material that might work better? My luthier friend is making me a guitar, and we've been wondering about the best way to cut the inlay material with a laser cutter.


So far, I'm planning on 0.060" thick sea snail (http://rescuepearl.com/seasnail.htm).

I can't recommend this company highly enough - great products - personal, friendly service, and very reasonable (IMHO) prices . Give them a try if you want any shell products - http://www.oceanshell.nz/ - Their sheets of shell come in a number of colours and sizes and can have a self stick backing on them ()which I prefer) and they cut beautifully in the laser. Just FYI.350468350469

[John Noell]

+1 on Bill's recommendation. I've used oeanshell.nz for many years. They have laminates and they are not quite as pretty as solid shell, but very nice. And yes, it cuts really well!

[Klaus Madsen]

What Bill and John are talking about is New Zealand Paua which is beautiful material, try to look it up.

[Mike Null]

I think ebony at .060" is going to be more of a problem than the inlay.

[John Noell]

Oceanshell has far more than paua (abalone). The paua is pretty but I have little use for it. I still have most of the two sheets I bought years ago. However, the black lip pearl oyster shell is a pretty white that I use a lot.

[Matt Walton]

First of all, thank you all for your input, and so sorry I haven't responded sooner!


Thanks Mike, we'll definitely start with low and slow. As to the 0.002" spot, he also uses this machine when he makes guns, if that affects your thought process. In either case, it'll be plenty for what I want.


As for the inlay thickness, even 0.060" thickness gives me a little bit of pause. I realized I forgot to mention this in the original post, but the fretboard will have a radius of 16". This will result in the inlay having a bulge of 0.028" inches at the most extreme (high up the neck where it's widest).


My friend was recommending that I might should just go with crushed pearl in epoxy for the inlay. I'd prefer a "solid" material, but I might have to end up going that route.


Thanks Bill and John, I'll definitely give them a close look.


Regarding the fretboard thickness, I should have been more specific; the ebony fretboard will be much thicker. I don't know what thickness exactly, but probably around 0.25" thick plus of course the rest of the neck.

[Mike Null]

Matt

I should have been more specific. Engraving the ebony to a .060" depth is almost certain to cause charring. If you have a few scraps I would experiment before attempting the fretboard.

[Matt Walton]

Ah, that makes much more sense Mike! We will definitely experiment with that.

[John Blazy]

If you ever considered a highy colorful, Opal like alternative to Paua that lasers beautifully (because its an all polymer composite), you might want to look into Dichrolam. Google it + guitar, and you will see it used by PRS, Jens Ritter, Fender, etc as a lower cost alternative to pearl. Jens Ritter did an entire guitar body in it. Several color ranges to choose from. Google "Inside Paul Reed Smiths Dragon Models" and you will see it in a PRS in top pic, although PRS uses the blue version extensively in their fretboard inlays.

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[Matt Walton]

Thanks John, that Dichrolam looks promising.

For those curious, at this point, barring Dichrolam, I think my preference in material has switched to select color MOP. It's just as beautiful as sea snail, more easily found, and about half the price.