Thread: Warped Scale Press....

I was answering a question here in the Workshop about how to straighten warped horn scales...
This little contraption is what I use for Natural scales, the dimensions on this one are 6 x 3 x 1/2 inches for each side.. but if I were to do it again I would do 7 x 3 x 1/2 inches...
The holes are 1/8 inch don't to too many as to weaken the wood...
The clamps are 2 inch

The only other thing you need is a Steam Iron, and don't worry you won't hurt it any, so the SWMBO will be OK with it

Set everything up as shown in the pics, and then hit both sides with steam, tighten the clamps gently, steam tighten, steam tighten, then steam a bit more... If you are using a Shot-o-Steam iron I do 3-4 blasts per... The 1/2 inch thickness of the wood and the limiting factor of the holes helps with control

Leave it alone for a FULL 24 hours and everything should be fine... Do not open it to check it, resist the urge

I have done Horn, Bone, and Ivory, in this contraption, there is a another thread for Celluloid in the Workshop Sticky... I have tried a heat gun but it doesn't work quite as well as the steam with the Naturals..















Take your time and everything should go well

Thank you sir, I've been waiting all day to see your version. I'll be darned if it almost looks like the one I had made some time back.
I've also used a set of iron plates to do this but they get to hot and are a pain to handle.

I do something similar, but over a big pot of boiling water for the steam instead of an iron. I'll place a lid over the boards to retain steam for how long I like. I also have my boards a little longer so they dont drop in the bucket of boiling water.

Being a widower, certain I have a steam iron someplace, just don't know where, lol.

If steamed too longer, the horn will get too soft, and imprint of wood grain or vent holes will also press into the horn, so use care. In a similar regards, if you want to press an inlay object into the horn, this works great.

Originally Posted by gssixgun

Great additions gents keep them coming if ya got em.. I will put this in the Workshop sticky thread after a couple of days worth of ideas...

That being said, figured I should edit with some old images with steps of my process

Great additions gents keep them coming if ya got em.. I will put this in the Workshop sticky thread after a couple of days worth of ideas...

This is a great thread, thank you two for the great ideas and methods. I am gong to be changing my horn flattening method for the better because of you two sharing information. Every now and then a thread comes along with some prime nuggets of information. Thanks Glen and Dirtychrome.

Charlie

Thanks guys! This is just in the nick of time. Today I was looking at an old razor with a cracked blade but perfect horn scales except they are warped a bit. I was wondering how I could best straighten them.

Has anyone tried putting the scales in a microwave for a bit to warm them up first?
Soaking in Neatsfoot oil first?

Thanks for sharing!

Thanks guys, for adding to my bags of trix. Some days one thing will work better than another. I don't think I would want to use the microwave for anything else after horn!! But, seriously, using that method, there would be no way to control the internal temperature of the horn.


From Wikipedia:

""A microwave oven works by passing non-ionizing microwave radiation, usually at a frequency of 2.45 gigahertz (GHz)—a wavelength of 122 millimetres (4.80 in)—through the food. Microwave radiation is between common radio and infrared frequencies. Water, fat, and other substances in the food absorb energy from the microwaves in a process called dielectric heating. ""

Horn, by nature, is not of even density nor fluid retention.

In the methods shown above, about 200+ degrees is the steam temperature hitting the horn and board. Some old horn will come apart (de-laminate) at much over that. Much old horn is already partially de-laminated.
You may notice opalescent reflections within the horn. that is de-lamination.

And yes; they, back in the day, pressed "fresh" horn into iron molds at a much higher temperature to form convolutions and contoured 3D scenes into the outside surfaces of scales. Manipulating the shape of a horn scale does not require that much heat. Heat allows molecules to move and the flattening form used in the illustrations above allows them to set into a new configuration as they cool and the molecules slow their motion. Like steam bending wood..

Couple of clarifications on this...

Walt and I both eluded to it but let me say it clearly... Don't over heat the horn and Don't over tighten the clamps.. You don't want to soften the horn too much, and if you crank down on the clamps you do stand a chance of cracking scales, flattening the tops or imprinting them.... Steam bending is one of the oldest processes used by mankind, and working slowly and gently is the key to it...

Straighten the scales first, then sand and polish them..

Remember for your first time especially "Less is More", (I think that should be the straight razor mantra) so what if it doesn't work the first time through, do it again the next day

Originally Posted by gssixgun

The only other thing you need is a Steam Iron, and don't worry you won't hurt it any, so the SWMBO will be OK with it

I'm afraid you have brought logic to the issue. This may be one where you don't win the argument by winning the argument.

It's a valuable idea, and I can think of only one or two minor details which might be useful in certain situations. Some materials work best if a slight reverse curvature is applied, and this can be done by a single clamp in the centre, and two small blocks of wood spacing the ends from a more rigid piece.

Laboratory rubber tubing clamps can be useful. They probably allow you to do only one scale at a time, but they do offer advantages in some situations. For example, they reduce the size of the assembly, and allow you to obtain a higher temperature than boiling water at atmospheric pressure, by placing it above water in a pressure cooker. I think this would be worthwhile with bone, although you should try it on a pieced of scrap first.

When I was building ship models I had to bend 36in. strips of wood. I did it in a piece of steel pipe. with a pipe reducer threaded onto one end, and into that a gas-fitting for rubber tubing, which could be connected to the fitting on the pressure cooker from which the valve is removed. A heavy damp cloth over the other end will stop your steam leaking out too quickly. Of course I was single then.

LABORATORY TUBING CLAMP - HOFFMANN CLAMP STYLE - 30MM | eBay

Thank you so much, i finally found the time to make the press, the scales survived they are straight, and the crud super glue fill in's are still there. your the man thank you for sharing this.