Flattening old horn scales

I'm currently restoring/rescuing a James Barlow with Sheffield faux tortoise horn scales. The blade appears to have been brutalized by a botched restore in the past, but I'm trying to bring it back.

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While taking a break from sanding I remembered that the scales were warped. They are bowed out at the pivot (probably from over peening of pin) and twisted about 20 degrees.

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I've flattened/untwisted a bunch of new horn so I'm comfortable with that part of it. But I have never flattened
old, dry horn before. The horn is still flexible, but it is pretty dry. Since I don't want to destroy 150 year old horn scales, should I soak the horn in neats foot oil for a few days before flattening them? Or should I flatten them in their dry state and then oil them?

Thanks

Unpin the scales. Clamp between two pieces of thin wood (1/8-1/4"). Submerge in hot water about 5 minutes. Remove from water and let cool. When totally cool remove clamps. Scales should be straight. If not repeat with warped scale.

There is a variety of techniques to straighten horn. I usually soak the old ones in oil before I try to straighten them and again after. I think it helps with the flexibility but also it helps to prevent further dryness from the heat used in the straightening process. I think all of the straightening techniques rely on heat.

I do them dry, if there's going to be any repairs done.

But a clothes iron is the best bet for flattening horn, hands down. :tu

For flattening horn, I bring a steel plate up to 325 degrees F. Put the horn on it and then put another piece of plate steel on it. Then let the everything cool to room temperature. Works every time with no delamination, no clamp marks.

But, still I'm not sure whether to oil these dry scales before heating them.

How are you heating your plate Chris? It sounds almost exactly the same as outback’s technique.

Electric heat treating oven since I don't like baking steel in my kitchen oven. :)

Or you could just combine all the techniques into one :)

Microbolted onto steel or brass, dipped in Hot Oil :)

Talked about it 5 years ago, started using it as a system 3 years ago, now it is a flawless system..

I soak them in Neatsfoot for a few days, then straighten them in a Fondue pot that I bought at Goodwill for $5 set it at 350° I use that cheap Vegi oil at Walmart

Make sure if there are repairs to be done using glue you do them first as mentioned above. leave them as they cool..

At 350 I dip them for 20 seconds so they donnot deform, I would rather repeat the process then wreck the scales

Recently I had a warped scale, new not vintage. Warped from the hot weather.
I placed it in the fridge for a day or two and bingo, it straightened itself.

Not sure what that means but I thought I'd mention it :)

After filling a few bug holes I soaked the scales in neatsfoot for over a week. The soak at least fixed the twist in one of the scales.
Then I cooked them at 325 for 25 minutes between two steel plates. They are now flat, the pin holes line up, and they are ready for a final polish.
Thanks to everyone for your input.

Before:
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After:
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or vice versa if I didn't attach the pictures in the correct order.