Take care of Mammoth Ivory on a knife.

T.A.DAVISON

T.A.DAVISON

Slip Joint Knife Maker
Joined
Oct 24, 2005
Messages
5,477
I have made a lot of slip joint knives with Mammoth Ivory for scales. Well a customer sends some of mine to me and they are closing very tight - have to push them shut?
The Ivory has swelled SO much that it is pushing the steel liners ( frame of the knife) in, and the knife is binding.
I have talked to Tony Bose about this. I told Tony that I was going to readjust the knife, touch up the Ivory and send them back. He told me I would just be fixing them twice.
Because when they dried back out, they would shrink.
I have talked to the collector also and have told him I will do what ever it takes to make it right. We are going to dry them out and see what happens?
Mammoth Ivory is not like Elephant ivory. It is more porous and will absorb moister or oil. Tony said high humidity can have an affect on the Ivory swelling.
I could not believe how much it swelled to push on the steel.
So i guess do not put any oil on the Mammoth ivory - UNLESS it is shrinking?
On these knives you can feel the Ivory over the edge and the shield is even down a bit.
Just wanted to let you guys to know it will have an affect on a slip joint knife. I send my knives out with a very good walk & talk and these are not even close.

So what should a collector do?

Shoe polish?
Good storage?
What?


TA


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Good question Todd. I havent seen any problems with any of the mammoth or elephant I have done but then again never made a slippie until today with mammoth. I hope it doesnt come back with swollen scales. I heard over on the guild forum not to dovetail the bolsters because the ivory can lift them up. I soldered and pinned mine and did dovetail a very slight amount.

One of my hunting knives came back with swollen scales after the knife fell in the cooler overnight. They were huge but shrunk back to nearly the same size after about a week of drying time. That was a full size hunting knife. These little thin scales are so close tolerance that if they move something has to give. Maybe we should leave some wriggle room.
My advice is to keep em dry I guess.
 
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First of all I know very little about knives and ivory, so take this with a grain of salt.

If you are building a knife to be carried a lot in a sweaty pocket, or if it is going to a very humid place compared to where you are, maybe you could keep the ivory in a humidor to keep it realistically moist/swollen. Then when you're doing the fitting it is already swollen....?

It seems from what you're saying that it is unavoidable - the stuff will swell with an increase in humidity. Is there any way to seal it?

I'm interested to see what the real answer is.

Austin
 
Bruce,

The swelling on these is really small, you just feel a very, very small edge.
But enough to push on the bolsters and distort the knife.

Some of the ivory I used was stabilized, maybe that's the only way I will use it now?

Later,

Todd
 
aus71383 said:
First of all I know very little about knives and ivory, so take this with a grain of salt.

If you are building a knife to be carried a lot in a sweaty pocket, or if it is going to a very humid place compared to where you are, maybe you could keep the ivory in a humidor to keep it realistically moist/swollen. Then when you're doing the fitting it is already swollen....?

It seems from what you're saying that it is unavoidable - the stuff will swell with an increase in humidity. Is there any way to seal it?

I'm interested to see what the real answer is.

Austin
Click to expand...

Good thought, but it would shrink and than you have gaps.
When you sale a knife you don't know were it will go? To a humid climate or a dry climate?

Todd


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High humidity is definitely not an issue for me - long, dry, moisture-sapping winters are. I have never had handle material of any kind swell. But boy, have I seen it shrink. Mineral oil is an absolute necessity for keeping my ivory and stag pieces from moving.

Roger
 
RogerP said:
High humidity is definitely not an issue for me - long, dry, moisture-sapping winters are. I have never had handle material of any kind swell. But boy, have I seen it shrink. Mineral oil is an absolute necessity for keeping my ivory and stag pieces from moving.

Roger
Click to expand...

Hi Roger, I'm really glad to hear this. ;)
 
Mr. Davison
Have you had any problems with the stabilized ivory? I'm curious as to your thoughts on it if you have. I've talked to two makers who I respect, and after hearing their experiences I don't even want to try stabilized mammoth. Both said after stabilizing the scales came back as "U" shaped. The thought of sending scales off and having them come back destroyed has me gun shy.

BTW thanks again for the help on flattening
 
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Todd, maybe just an odd experience. I've only had that problem on one folder and that
was 13-14 years ago. Have had only 2 or 3 with shrinkage problems over the years. This
is with over 1000 fossil ivory handled folders and a few fixed blades.

90% of my knives have fossil ivory handles, mostly mammoth but some walrus and I
just don't have any problems anymore.

I store my ivory for at least one year before I use it, usually longer. I don't get it hot
when working it. I oil it very good with mineral oil, sometimes soaking the ivory for a few weeks.
Hope this helps.
 
Don: Do you soak in oil after the yr period or as soon as you receive the scales or raw material? Does the soak help prevent splitting of scales during peining...oh yeah...you don't pein! Thanks
 
This is the first time I have had or heard of a problem with ivory on my knives.
I think? the collector soaked the knives in mineral oil and they swelled.

Ryan, never had a problem with it being stabilized.

Don, thanks for the help. I try not to get the Ivory hot when working it. I just put it on the knives with a very tight fit, Don't want any gaps any were.
And like I was saying to Bruce, the swelling is very small. But it sure had an affect on these knives?

Thank you all for the advice and the links, very much appreciated.

Have a great weekend.

Todd




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John L said:
Don: Do you soak in oil after the yr period or as soon as you receive the scales or raw material? Does the soak help prevent splitting of scales during peining...oh yeah...you don't pein! Thanks
Click to expand...

John, I soak in oil after a year or so, right before I'm going to use. I do use
Pins, just not in all my knives. I don't think the oil helps preventing cracks
while penning, but does prevent shrinking.
 
Good thread.

I live in a northern desert, which is dryer than a popcorn fart. Like Roger's experience, everything wants to shrink here. I sent off some well seasoned stag to a maker in the SE USA for several months, which came back shrinking faster than the value of the US dollar. Swabbing with mineral oil every couple of months did not work. Next will try Don's extended soak method.

My strategy now is to hold on to my scales until the the maker is ready to start my knife. Hopefully, the material will not absorb significant moisture in a just a few days.

Recently researched sheep horn and the travails it might present. Lots of horror stories with both stabilized and non-treated. The stuff is full of lanolin, and stabilization may not work. Ed Fowler ages his horn for several years, but at my age I may not have the years. Beautiful, but I think it may be better to live with a vengeful woman than capricious sheep horn scales.

I don't have ivory, but Base on Don's experience, I would try it, especially if I stumble onto a nice pair of tusks in my backyard.

ken
 
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Use paste wax on mammoth ivory. Make sure the ivory is dry before you use it. Ivory contains no oil naturally, and adding oil to it can soften and discolor it.
 
Todd,
If he did soak it,I'd guess, that is where he went wrong. If this is the case,Id do just as Tony says,let it dry out.
Also,a few guys I know that are Ivory "buff's",they say they only coat thier scales,with whatever,never soak.
I know the opinions of some,will say Mammoth Ivory is more stable than elephant ivory,because it is already fossilized. If this is the case,I can't see why you would need to stabilize it,as nature has,already.
-Vince
 
VCM3 said:
Todd,
If he did soak it,I'd guess, that is where he went wrong. If this is the case,Id do just as Tony says,let it dry out.
Also,a few guys I know that are Ivory "buff's",they say they only coat thier scales,with whatever,never soak.
I know the opinions of some,will say Mammoth Ivory is more stable than elephant ivory,because it is already fossilized. If this is the case,I can't see why you would need to stabilize it,as nature has,already.
-Vince
Click to expand...

I agree, as I don't immerse a handle just evenly spread a light coat of camella oil over the material and leave it to soak in. Never had a problem with shrinking/swelling/cracking yet. (knock on wood).

Considering the precise tolerances folder makers work within, I'm a bit surprised we don't hear of this problem more often.

I have always been a bit confused as to the term "fossil" as it applies to ivory? Fossil ivory such as used for handle material isn't actually a fossil?
 
The word fossil, as connected to mammoth and walrus ivory, means; found in the
ground, or unearthed. The fossil ivory we are using has been preserved in frozen ground
for many thousand years. It is full of moisture when unearthed and takes considerable
time to dry out. It is not fossilized, like fossilized wood that is millions of years
old and has turned to stone.

Probably not a good idea to soak a tight fitted ivory handled folder, a fixed blade would be fine.
I don't soak all my ivory, just some and only soak before I use the ivory and let dry out a bit before use.

The oil does change color sometimes, usually for the better.
As said, it will soften the ivory a bit but this can help prevent cracking.
 
Check out the Knife collection maintenance sticky thread. There is a lot of good info. Make sure you read all the pages.
 
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