Mammoth Tusk

Fish30114

Fish30114

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Jan 5, 2014
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I wanted to check an see if any of you folks have experience in working with Mammoth Tusk and if so have any advice, specifically on drilling it and shaping it. I bought enough that I had some left over for a pen blank and it was a booger bear to drill, so base on that experience I am now asking for advice! Same thing on shaping the scales--the pen blank was tricky, but it ended up being a beautiful pen, that's for sure!
Thanks for any and all input and advice!
 
I didn't think it was any more difficult than bone or ivory to drill. Like Ivory and Bone you need to grind slow and not burn it. I've used it on slipjoints 1/8" thick or there about with no problem drilling pin holes I use new bits.
 
Well, maybe because I've used a lot but I enjoy working mammoth tusk. First off it can be easily cut with saws without the worry of it shattering or chipping out. There are a few "strange" things to it as any material.I often use a 60 grit on my grinder to shape rather than fine grit belts that won't do much and may load up in a hurry However to get the full benefit of the color you must do the sizing for scale thickness from the bottom until the top is very closed to the finished size wanted. This will mean having guards and bolsters down to finished size at say 220 grit or smoother. If you go to a finish of 800 hand sanding it will polish well with green on the buffer or even better with pink. Any cracks should be "filled" (?) given some first very thin C A glue and then some medium or thick. It is not necessary to try to level the surface the glue in this case is to just glue the pieces together. I will however after fine sanding polish along with the ivory. With mammoth ivory it is a good idea not to overheat as with most materials. It can be safely placed in water to cool as often as you wish. Unless you have really cooked the ivory in grinding this will not cause it to warp. Working with mammoth tooth is a very different procedure by the way. If you got along will the methods you used, continue with them and perhaps just add on if there is something you think may help.
Frank
 
Some mammoth ivory is heavily mineralized- meaning minerals have seeped into the ivory and fossilized it. This can make it very hard.
It can usually be filed and sanded to final shape.
 
Yeah to add to what Frank and Bill said: It's usually quite easy to work with, but if it's really old and mineralized, it can be much more difficult. That's rarely the case though. Just use really sharp tooling. Sharp cheap AO belts are best for shaping, don't use Zirc or Ceramic belts, they're actually horrible for most handle materials, but really bad for most ivory, unless it's so old (actually fossilized, as opposed to what most of the stuff we use is, barely mineralized), that it feels like rock.

For handle work I typically use the same premium drill bits I use for steel, since I have lots of them on hand, and buy in large packs, typically the split tip style used for aggressive steel cutting. On the other hand, if I was trying to drill a long hole for a pen or something, I'd want to use premium bright finished bits used for wood or similar. Always use new bits or ones you've set aside for ivory. Trying to cheap out and use some dull as crap you've been using for everything under the sun is a guaranteed way to screw up the ivory.

If it was, as you describe; "a bear to drill" don't be surprised if stress cracks show up later. Getting ivory hot, building up stress in any way, can manifest as cracks days later.


Also, one note on the cutting/shaping issue; Personally I've found it best to avoid super aggressive belts, or super course saw blades, due to the potential for chip/tear out. I typically do my rough shaping at 60-80 grit. I've had issues with tear/chip-out when using 36 grit belts, simply because of the loose density of the grain and the size of chunks it's trying to rip out of the ivory.

I've said this before, but cheap blue AO belts that cost $2 each are what you want for handle material, keep a separate group of them that never gets used for metal, and they'll last a very long time. I buy a small handful every year or so, and use them for the same stuff repeatedly. Usually after I start feeling like they're not super sharp, then I'll finish them off doing some profiling on steel or something, but that's after many handles typically. All you need are course belts for this, and you can use the same j-flex belts at 120 and above that you use for steel for the higher grit shaping, although I still recommend keeping them separated, or at least use them first for handle work.

Many many problems people face with finishing can be attributed to dull or loaded belts.
 
Appreciate the feedback folks, the mammoth tusk I have must be fossilized because it acts very much like rock, for the pen I made I went very cautiously and used brand new drill bits, Norseman top grade, which I think are high grade (like grade 8) steel and cooled them frequently with Blade Cote and water--it took a long time to drill the pieces and they were 10.5 mm and 12.5 mm about 2" long and 1 1/4" long but even being short pieces took quite a while. In turning the pieces I ended up going to very high speed on the lathe and using carbide tools to get them close, and then used 80 grit abralon to get them to final dimension--after that I finished then like a Tru-stone piece or a fine acrylic with wet sanding and micro mesh for the final stages--it came out beautiful. I figured drilling scales might be a little easier since it was a smaller bit and a shallower hole, I just wasn't sure about shaping the scales---I guess we'll see--thanks again I appreciate any help I can get.
 
I often superglue my scales between two layers of fiber spacer material. This allows ya to drill without the danger of chiping out. The bottom layer of the fiber becomes a liner and the top layer gets ground off. Did this on a end cut piece of ivory the other day as it was chippy.
 
Hmmm, interesting approach Dave, I may consider that for some of it--hadn't thought of that-had thought of using a backer when drilling it though....
 
Yes sir that's true. Works excellent on mammoth tooth as well. I don't often use it on ivory but have done so when I felt the piece would be chippy or brittle, like the end cut pieces I mentioned. Here are a couple done with end cut pieces of mammoth ivory I did a while back. If ya look close ya can see the red liners too:

TnTEbKq.jpg


5sqrA6u.jpg
 
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