Thread: Shaping Inlay For My Carvings

6. Here's the set-up: bottom cut out of a 2liter plastic milk jug is the pickup. Splines cut in the neck and connected by hose to a 4.5Hp/45l ShopVac. Fines bag meant for plaster dust. The coarse grit stone wheel spins from right to left, throwing the shell dust straight into the opening. I use the corner edges for the crude cutting. Any cuts at all are really easy to see in transmitted light. Running 1100rpm and a 2" stone. Fine stone or slower does not work well at all.
7. OK, suppose I cut a shell. The shell dust packs up in the coarse grit. That effectively stops the cutting action. DON'T push harder = friction cooks the dust into the abrasive and you are done with that stone.
8. Use the crepe rubber stick (Lee Valley) on the running stone to erase the shell dust and cut again.
9. Switch to an 80 grit x 2" x 3" sanding drum ( or another coarse stone.). Just barely touch the shell to the abrasive. Wearing gloves, your hands take up the shock and the shell never breaks on me. Plus, I'm not in it for a manicure.
10. Same deal = use the stick to clean the drum. I counted, maybe need to clean the drum 3X in the course of rounding the edge of a 1" eye.
Fit and finish
11/12. Couple of pix of eyes 1"/25mm.
a) They might need a little more very careful sanding to fit a 1" Forstner hole.
b) paint the inside of the rim of the Forstner hole with black acrylic. This is an optical illusion that helps to hide the joint between the shell and the wood.
c) Because the back of the shell is rough with some thick spots and some thin spots, I carve a pit in the eye and fill the void with your choice of adhesive behind the shell.
d) go upstairs, have a slurp and make something to eat. Come back tomorrow.
That's about it. I could make hexagons or ovals. There are other sawing methods but everybody phreaks out about the shell breaking. This way, never broken one yet.
Questions still? Ask away.

Thanks Rob

I understand it all now except for the first cut.
So for the original cut with the 2" x 80 grit stone you carefully hold the shell on the right angle edge or the verticle edge of the stone? Sorry. Don't quite get that bit!
So are you cutting the rounded outside of the shell where you originally marked it?
I'm guessing - the outside of the shell with the right angle edge of the stone?

Correct. The lower edge, the right angle edge, of the stone, so I can see what I'm doing. Yes, the first big fret cuts are done on the outside to release the panel of shell that I will eventually sand down.

I have made the final circle on the inside, from the very start.
I guess and sketch +/- 8mm/1/4" extra on the outside with a pencil.
As I cut frets to that outside pencil line, I hold the shell up to the light so I can see the big cuts in the translucent shell. Eventaully, the big cuts make the whole thing crumble in my hands and I have the piece I want. Then comes the sanding drum part.

Thanks for provoking me to do this. I needed to believe that it is as easy as I describe = 5 minutes to set up. I have no need for more eyes right now but who knows what I learn tomorrow. The lower edge of the stone is quite pooped = rounded off. Shell is more stone-like that I ever imagined. However, the stone is bolted to the shank so I can undo it, flip it over and the unused top edge becomes a fresh edge for carving!

You should know that some people cut shell with a jeweler's fret saw. Some people try to cut shell with a Dremel and a cut-off wheel or a diamond wheel. They tell me that the shell shatters/explodes. My way, I'm holding the shell panel in my gloved fingers and gently, gently sanding off the excess. My fingers cushion the vibration as well.
I hope that you see some things here that help you on your way.

Thank you Rob

Yep got it! Understand now.
What a fantastic tutorial, this opens a whole new door for me. Thank you for your patience and wisdom.

By the way, your relief fish carving is brilliant the way you fitted the tail and head is a great concept and the design is beautifully done.

You're most welcome. I hope this is useful. From what I've seen and from what I've heard, this appears to be a reliable method. The sanding drum is very aggressive at 1100rpm. So, just the slightest touch produces results.
I predict that pieces 12mm and smaller can be done: wrap masking tape on the jaws of a hemostat or needle-nose pliers to hold the shell. I will try that when I need to.
The fish was a color exercise based on a drawing that I did long ago.
Pacific Northwest Coast Native artists appear to make restricted designs/carvings for 2 reasons: one, like me, the wood isn't big enough. More commonly they do a design to completely fill an available space. . . . . that's where I see real artistry.

Well done RV. Nicely explained and illustrated. Only used the stuff once.. for a 'Tiki'-like design on a stick shaft. It was a commission and I was given the design by the client. It had Paua shell eyes...about 6 or 7 mm in diameter. I had some shell pieces that were big enough so it was just a case of holding onto the shell with your fingers and shaping on the rounded end of a bench-mounted sanding belt while trying not to sand the end off your fingertips. Worked ok but I've never done any work with it since.

I REALLY like the dust extraction you've set up for your drill press. That's brilliant mate! I'll definately have to pinch that idea!

Thanks, Whittling. Pinch away! I don't care about the larger, sand-grain sized shell fragments, it's the smoke-like dust that I wanted to control. I rest my hands on the drill press table so I get reasonable precision for cutting and sanding.
Paua shell is beautiful. The Rock & Gem Shop in the city wants $2 each for small, odd-shaped pieces. I wanted to use BC shells (my D1 & D2 collect on the coast for me.)
I'm sure that a finer grit sanding drum would be OK but slower for the task and a lot more friction.
I got the process and a piece of crepe rubber stick from the diamond willow shop down my street. He might be sanding for 30 days straight! Every kind of drum, spindle and sheet sanders there are. In the LV catalog, I see the smaller crepe rubber blocks are $6.95 each. By now, I could have ruined more than $200.00 worth of stones and drums. Still happy with stone #1 and drum #1. It's magic.

Just a little update:

I decided that I needed some slate/stone eyes. Starting with relatively small broken pieces of a nice
black but iridescent slate, possibly 3mm/ 1/8" thick.
Bypassed the stone part and shaped them with just the sanding drum at 1100rpm. Worked like a charm except far harder on the drum abrasive. If it was 60 grit to start, the drum is now about 220. But I can use that.
I've just made 4 eyes @ 9mm/ 3/8". One broke but 4/5 is not too bad at all. May have to change drums again as I want a pair 1" or bigger.