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I need some .040 tortoise celluloid binding all i can get is .060 here in the UK is it possible to thin this down,if anyone has,what is the best way ?All the best Roby.

Thickness sander with 120 grit works nicely, if you need, a sharp scraper will finish to a sheen

I would not use 120 80 may be better , but tortoise is celluloid or acetate If you get this to the flame point it will burn and you can't put it out easy once it starts. The safest way to do this is to make a rabet with a table saw blade . Then adjust this against the rip fence to your desired size. Use another rabbet to hold the binding in position. Run the first rabbet in the blade and secure use the 2nd as a cap and feed the binding into the slot you created. Once it comes through the blade you can pull it from the other end.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I'm curious about the flammability of celluloid tortoise binding. I've read a bunch of stories about celluoid binding igniting (even spontaneously) and it's shipped as hazardous material. A couple years ago, after I ripped lengths of tortoise celluloid binding on my band saw with no sign whatsoever of ignition, I became curious about this both because I'm a guy and I have a background in chemistry. I put a lighter to the end of a small piece of binding. No flame just a bit of melting and charring. So I did what any chemist would do and turned some binding to powder with 80 grit to increase the surface to volume ratio and when I had a small pile, I put a flame to it. It just smoldered and turned black. No open flame. Nothing of any note. So I'm wondering if there are different types of celluloid with different degrees of flammability or if maybe whatever it is that's added to create the tortoise look of tortoise binding reduces the flammability.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

When we thin celluloid for repairs, we mill a piece of maple shim material 2-3 inches long by 1/2" wide to the thickness desired plus 0.001-0.002 inches (to account for the hooked edge and shim compression), cut in half, glue about 5/16" apart to a short length of scrap plywood, and clamp the ply to the bench. We turn a good edge on a card scraper or - for jobs where there's only a few thousandths to remove, prep a razor blade scraper. Place the binding material to be thinned between the two shims, place scraper on the shims, and working from around the center of the strip, pull through and raise a shaving...reverse...repeat The last passes are made full length. As the material gets down to desired thickness, the scraper comes to rest on the shims and cutting stops. The angle of the scraper and size of hook turned controls the aggressiveness of the scraping action. The cellulose nitrate scrapings are great fun to play with, and the camphor smell from the scraping is quite pleasant to my nose.

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A constellation only takes shape when one maps the whole.
- Beth Brower

depends on the manufacturer. I have had experience with this burning

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

thanks guys

I was sanding ivorid binding on a small drum sander a few years ago. I didn't let much dust build up but there was a bit on the bed of the sander when the drum started to clog. It reached the flash point quickly and I had a small explosion. It was small and no damage was done but a lesson learned. Be careful with this stuff.

Kent

From what you describe, I don't think your "Tortoise" binding was celluloid nitrate - the dangerous stuff.

Here's a link to a quick video of some Tortoise that I have which is celluloid nitrate. When you scrape or sand it, it smells like Vick's Vapo-Rub IMO.

https://drive.google.com/file/d/0B24aMI ... sp=sharing

Kevin Looker

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I'm not a luthier.
I'm just a guy who builds guitars in his basement.
It's better than playing golf.

Real celluloid (cellulose nitrate) has camphor added to stabilize and plasticize it. The camphor smell is a good way to identify celluloid....provided it is not too old. Over time, the camphor will out-gas, and in extreme cases, the celluloid will become unstable. This may happen in 20 years or over 100. Unstable celluloid tends to smell like vinegar, since nitric acid is released. Nitric acid fumes in a guitar case can corrode metal and discolor finishes. The last stage of decomposition is when the celluloid turns yellowish clear, and crumbles. It can actually spontaneously combust.
Celluloid is classified as a flammable solid. IMHO, the hazardous shipping requirement is a crock, because finished goods like a pickguard are exempt.
A scraper is the safest and most efficient way to thin celluloid. I cut a groove in a hardwood block to the depth of the desired thickness of the celluloid strip. This groove is slightly wider than the celluloid strips. I put a celluloid strip in the groove hold a scraper on top of the block. I pull the celluloid strip through the block, adjusting the scraper angle to shave off the excess. It will take several passes to cut 0.020" off, but the thickness will be consistent, and the surface finish is better than coarse sanding.
Alternately, just install the binding proud, and scrape it flush afterwards.

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John

The stuff I've used is from LMI and it didn't behave anything like the material in the video even though LMI describes it as celluloid nitrate and ships it as a hazardous material. Which doesn't make much sense based on my attempts to ignite it. It does have a very distinctive smell when cutting or sanding it though.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

A few years back, a banjo maker named Arthur Hatfield ended up with very serious burns that kept him from being able to work for a long time resulting from cutting celluloid binding on a table saw. He had done this for years, but this time he reached the flash point. I've intentionally ignited a small pile of tortoise celluloid shavings just to see how easy it is to ignite, and it is indeed very easy. The flash is pretty spectacular too!

I'm in the "thin with a sharp scraper" camp. It works quickly, well, and doesn't get hot.

Dave

Could LMII be selling cellulose acetate? Both materials are technically known as 'celluloid', although I don't believe cellulose acetate is a hazardous material for transport purposes, so perhaps not. Did the process of making the dust result in a strong smell of camphor? When we make up pick guards from cellulose nitrate stock, the smell released by scraping and sanding is quite pronounced.

The materials differ in the nitrate and acetate radicals - both will decompose over time, but cellulose acetate is more stable and much less flammable. The nitric acid released by decomposing cellulose nitrate is an irritant, and may smell to some a bit like chlorine as the nitric fumes hydrolyze in the moist tissues of the nose (hence the burning sensation of higher concentrations). Decomposing cellulose acetate smells like vinegar, due to the release of acetic acid.

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A constellation only takes shape when one maps the whole.
- Beth Brower

The following comes from "Simple tests for identification" in "Plastics: Common Objects, Classic Designs, with a Collector's Guide," by Sylvia Katz, 1984. New York: Henry A. Abrams, Inc.

HEAT TEST (pyrolysis)

This test must be carried out very carefully on a fireproof surface, and fumes must never be be inhaled while the plastic is burning, but sniffed quickly afterwards. [See comments below.] ...Small shavings scraped off in powder form with a very sharp knife from a part of the moulding where it will not be noticeable can be placed on a saucer or in a glass test tube...

Celluloid: usually the whitish powder "pops" with minute explosions and burns with a sooty, yellow flame. Catch the smell of camphor before it evaporates; sometimes it is confusingly absent.

Cellulose acetate: sparkles when ignited and gives off the aroma of vinegar (acetic acid). It is made from cellulose treated with acetic acid.

Cellulose acetate butyrate: smells of acidic, rancid butter (butryic acid).

[Tim comments: I would not suggest conducting these tests is unless you are certain you can do them it safely. As well as the fire danger, Inhaling fumes in any amount could be hazardous, and I would recommend against it. The observational parts could be useful, however.]

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Tim Allen
"Never hurry, never rest."

I use my binding scraper for stuff like this, it works fine on wood or plastics. The picture is a bit misleading, the scraper works better if you pull the binding through the other way, towards the non-beveled side of the iron.



I don't like sanding celluloid either, its a bit scary. A fun 'experiment' is to set fire to some celluloid shavings (do it outside! ).

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Rian Gitar og Mandolin

About 5 years ago I made a trimmer using a cheap laminate trimmer. After several reworks it could make reproducible cuts on plastics and wood. Then I saw SM had one and I added a gauge, much easier than the silly rulers I used. The bit must be very sharp or it can chip wood.
If I was looking now I would buy the SM unit and added my laminate trimmer