Thread: Clear coating of natural scale materials

Originally Posted by pixelfixed

I work with Ivory on a daily basis,it has to breath or it will crack.
The coating of choice is mineral oil.

I use mineral oil also. If you google it you will find it is the recommended oil and other useful tips.

Originally Posted by dirtychrome

When keeping it open to breath, keeping one side exposed and one side covered would be ok?

Thinking of a piano key as an example where only one side is left to breath. If it is important to breath, would think inbound of scales left uncovered would be fine then.

To a point yes,Ivory can be funny stuff,It actually moves I:E it expands and contracts with changes in humidity and temp.
Have made quite a few solid Ivory brushes,you can mic them and see changes over several days of +/- .003.even a 100 yr old pce of ivory has a water content,if the pce is sealed the water has to get in and out somehow,if it cannot get out the pce will crack and unlike wood it cannot be kiln dried (will turn to powder),
Just sent a large pce of Ivory to a blade maker in montana,first thing I asked was,whats the humidity,he said 40%,mine was 70%.
told him to be carefull, you cut it, you can rough shape it,but wait a couple weeks to do the final fitting,or your project will be ruined.
This can be very problematic when doing inlay work

Intersting about Ivory expanding and contracting,breathing etc, but what about natural shell, as abalone and mother of pearl, Are they subject?
Do we know?

Originally Posted by sharptonn

Intersting about Ivory expanding and contracting,breathing etc, but what about natural shell, as abalone and mother of pearl, Are they subject?
Do we know?

The masecraft paua and abalone shell lvs is air tight. If not familiar it's a thin veneer sandwiched between clear and solid color acrylic. May be too thin to compare to your application.

When doing shell inlays, "cover in finish of your choice" is often mentioned. A few months ago I had research shell techniques, sorry, dont recall links i had found

Originally Posted by dirtychrome

When doing shell inlays, "cover in finish of your choice" is often mentioned.

Thanks. Sounds like shell materials are ok sealed. Here is my sample piece of ivory. I think 2 layers of CA were about right. They went on and stayed fairly smooth after drying. The 3rd coat, however, kinda crazed as can be seen above the shiny part. The pin hole up is natural.I have never coated with CA before and was amazed how hard it was when sanding. A rubdown with scotchbrite seemed about right before polishing. Now to run it through some cycles!

Originally Posted by pixelfixed

Ivory can be funny stuff,It actually moves I:E it expands and contracts with changes in humidity and temp.
Have made quite a few solid Ivory brushes,you can mic them and see changes over several days of +/- .003.even a 100 yr old pce of ivory has a water content,if the pce is sealed the water has to get in and out somehow,if it cannot get out the pce will crack and unlike wood it cannot be kiln dried (will turn to powder),
Just sent a large pce of Ivory to a blade maker in montana,first thing I asked was,whats the humidity,he said 40%,mine was 70%.
told him to be carefull, you cut it, you can rough shape it,but wait a couple weeks to do the final fitting,or your project will be ruined.
This can be very problematic when doing inlay work

My experiment seems to confirm this! The piece had a slight bow when I started.I only applied CA to the top and stopped sort of the pin hole.I have given the piece many temperature cycles as well as humidity changes at random. The CA seems to keep the top from expanding, but the bottom is! The natural bow in the sample has been obviously exaggerated.(sorry for the cruddy pictures) I shall forgo coating my current project with CA as my Ivory piece is about this size, but would like to attempt some scales of smaller bits of old razors in the future and try coating them as I hate to throw old materials away. Thanks to all who responded

Interesting,mammoth ivory is even worse (much closer grain pattern called shreager lines (SP)
If you have a need I have vintage ivory scale material,do not do scales but use it for inlay work etc.