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Cutting slabs from bone and antlers

Posted: Thu May 10, 2012 5:50 pm
by almyjmoore
I've been experimenting with cutting, dyeing and jigging cow bone. The biggest problem I have encountered so far is cutting off nice even slabs. The bandsaw blade keeps wandering off and I end up wasteing a lot of time and material because I have to flatten the slab with the belt sander. I've been using a 3/8" blade with 8 teeth per inch. I'm thinking I need a 1/2" blade with more teeth per inch. I have to set the upper blade guide to about 3" above the saw table (to give the bone room to pass through) which allows the blade to turn. I found that going real slow helps but that's not the answer and neither is using a fence. I hope I can get some advice from some of you who have encountered and solved these problems. Should I be using a metal cutting blade? What's a good range of teeth per inch? Is a 1/2" blade better than a narrower blade? I tried a couple of 1/4" blades and they both broke before cutting 2" [they were also about 6 or 8 teeth per inch]. The (3) slabs in the picture are 6"-7" each and are 1/8" to 3/16" thick. That's about what I want. I appreciate any advice. Thanks, Al

Re: Cutting slabs from bone and antlers

Posted: Thu May 10, 2012 6:55 pm
by Iron Hoarder
Try a table saw or radial arm saw. That or get a thicker band saw blade.

Re: Cutting slabs from bone and antlers

Posted: Fri May 11, 2012 12:30 am
by muskrat man
thicker blade, tighter blade, free hand it slow, you'll still have to clean it up on the belt or disk sander regardless.

Re: Cutting slabs from bone and antlers

Posted: Fri May 11, 2012 12:36 am
by 1967redrider
Nice jigging, did you do it by hand? What kind of dye are you using?

Re: Cutting slabs from bone and antlers

Posted: Fri May 11, 2012 2:28 am
by almyjmoore
Good advice iron hoarder and MM. I've tried the table saw. It sounds terrible while cutting. I'll have to get a cross cut or plywood blade instead of my rip blade. I used up a lot of bone with the kirf but it cuts a nice flat slab. I'm going to try the wider, finer cut blade on the bandsaw as soon as I get where I can buy one.
Thanks RR. I used Rit dark brown liquid dye [one TBS of liquid dye to a little less than one qt of hot water]. I did the jigging with a Dremel tool and a ground down cutting disc. I'm still in "trial and error" mode. Al

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 12:16 am
by just bob
This has been posted on here before but a good way to cut bone on a table saw is to lower the blade and then put a thin - 1/8 pc of masonite or something similiar over the blade. Turn the saw on and slowly raise it through the thin material. This will give you a new work surface where the smaller pcs of bone won't fall into an opening. I use a fine blade and still can use the fence on the saw. Clamp the masonite down. I can cut straight 1/4 strips. I try to cut the knobs from the bones with a chop saw prior to the table saw. Also the bones need to be boiled and then allowed to dry out first. Cutting the bone stinks to high heaven so move the saw outside. If I was going to cut a lot of bone I would look for a meat saw. Watch the butcher cut meat the next time you're in the meat dept. Straight as an arrow with no binding.

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 1:22 am
by almyjmoore
Thank you just bob. I was hoping for some specific ideas from someone who has done it. A couple of stupid questions -Why do you boil the bone? How long do you boil the bone? How long should it dry? Thanks, Al

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 1:29 am
by Miller Bro's
The way to cut bone is with a wet saw, like they use to cut tile with.

This is how the factory did it, it keeps the dust down and you can make nice smooth cuts. They sell them cheap down at Harbor Freight ::nod::

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 6:37 am
by orvet
They boil the bone to get the fat out of the bone. The bone marrow has a very high fat content.
If the fat remains in the bone the dye won't penetrate well. Adrian Harris recommends boil in the bone for 15 to 20 minutes. I have also heard of adding TSP (tri sodium phosphate) to the water when boiling the bone to help remove more fat. TSP is probably available at your local paint store. Painters often use TSP mixed with water to wash walls prior to painting, especially in kitchens where grease and oil on the wall is a problem.

One note: if you had TSP to the water when you boil the bone, you might want to do it outside. I am not sure if the vapors are harmful, but I know the chemical itself can be.

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 1:00 pm
by almyjmoore
Thanks Dale. I have used a TSP solution to remove old wall paper and I don't recall any adverse odors or complications. I have discovered the fat and marrow problem and boiling to remove them makes good sense. I thought it may have been to help prevent splintering. I'm guessing that the drying is just to remove excess moisture for handling and not a curing process like kiln dried lumber [to prevent warping].
I'm still new at this rescaling but bone seems to be the most versatile product for making knife handles. It's cheap, tough and easy to obtain. It's easy to work with [except for the initial slabing]. I think it looks nice without dye or jigging. Every piece has it's own distinct grain and natural coloring pattern. Jigging and dyeing open the field to almost limitless variations. I've seen jigged bone that looked just as good as jigged Derlin [ha ha]. Thanks, Al

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 2:29 pm
by coffeecup
I have a crew of bone-cleaning specialists (they don't like to be called "dogs" anymore) take care of de-marrowing and de-greasing the bones, then saw it on a bandsaw using a sliding sled. The sled is pretty much just an improvised copy of the sliding sled on a meat saw. (Actually, if I were thinking, I'd have the bone prepp'd and saw it on the meat saw after we butcher, but I can't seem to remember in time.)

A wider blade is nice, but within reason blade tension is perhaps more important than blade width. I just use whatever nearly-worn out blade is on the saw, usually a 1/4"x6ppi. No way I'd try it freehand on the tablesaw; I wouldn't approach that with anything less than a jig that clamped the bone and kept my hands well clear. In the cab shop my bench was right in line with one of the tablesaws, and I saw a couple of people butcher their fingers when they were trying to cuts on small pieces freehand. Nothing spoils a coffee break like having to wash bits of bone and meat off your mug . . .

Jim

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 3:11 pm
by jerryd6818
Bandsaw

Re: Cutting slabs from bone and antlers

Posted: Sat May 12, 2012 9:27 pm
by almyjmoore
You guys are starting to scare me. I always use push sticks but a sliding jig sounds good too. I've had semi serious injuries on both the table saw and on the bandsaw. Every time was when I was in a hurry or taking shortcuts. Thanks for your input. Al

Re: Cutting slabs from bone and antlers

Posted: Sun May 13, 2012 12:48 am
by orvet
When sawing odd shaped antler or burls I use a piece of ¼” plywood with a piece of 1 X 2 or 2 x 4 glued to it. I use super glue to tack the burl or antler to the plywood and 2 x 4. This holds it secure on the plywood and I use the 2 x 4 up against the fence or against the miter gauge and push it slowly through the blade. It isn’t fool proof, but it does help especially with desert ironwood burls.

The deeper the blade and the slower you push, the less the blade tends to wander.

Re: Cutting slabs from bone and antlers

Posted: Sun May 13, 2012 1:08 am
by Miller Bro's
Image :lol:

Re: Cutting slabs from bone and antlers

Posted: Sun May 13, 2012 2:54 am
by almyjmoore
I got a plywood cutting blade for my table saw today. It's not like cutting butter but it's much better than before and I cut some nice flat, thin ( 1/8" ) bone slabs. Also, I increased the blade tension on my bandsaw (per muskrat man and coffeecup) and tightened the blade guides some and I get a much more controled cut on that saw. I'm still going to get a 1/2" wide bandsaw blade to see if that adds more blade stability.
A couple of the slab pieces came out looking a little like a letter opener. Maybe I've come up with a better idea for an anniversary present than more stupid gold trinkets. ::tu:: Thanks, Al