Cast iron for flashlights?

We have aluminum, titanium, brass, nickel silver, silver, stainless steel, aluminum bronze and probably a few other materials that small, custom, LED lights have been made of. Why not cast iron?

I would be in for a nicely made, fine grained smooth cast iron light with its outside left in the as-cast state (not machined) including a fine line gate mark broken cleanly off. The surface could be cast with a hammered or other textured finish where one would normally knurl the body. I am thinking of a sand casting but other methods might be possible and preferrable. The surface finish of a cast light would also be unique and the weight would be comparable to a brass or SS light. Finding a foundry to pour a very fine grained casting might be difficult.

If you have ever seen 19th century stove castings you have seen some cast iron "art". I think the same thing could be done with a modern flashlight body made of cast iron.

Any interest in the idea? I'm not going to make one but would buy one. What other materials would be viable for flashlight bodies?

Steve

Cast iron is brittle, good chance your light would break if it falls....

B@rt said:

Cast iron is brittle, good chance your light would break if it falls....

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How right you are. Make it out of malleable cast iron and that should help a bit. The main idea is to have a CAST light instead of machined one and cast iron would be different. Being a collector of old cast iron cookware and having an attraction to cast iron items in general, the thought came to me for a cast iron light. I have a small pile of early skillets from ebay with the handles broken off. Being small, rounded, tubular, etc. I think the chance of a small flashlight breaking when dropped would not be all that great if designed properly and made of the right type of cast iron. I know this is not something that flashoholics or others will be clamoring for. Just an idea or thought. It could be an interesting project for someone interesting in casting iron.

Steve

Probably for the same reasons no lead framed flashlights were developed. Portability normally excludes the heavier metals from consideration unless it is strong enough to be fabricated to thicknesses of less than 3/32" or thinner and cast iron will be fairly fragile at those thicknesses. I myself would be interested in seeing flashlight bodies fabricated of carbon fiber or G10. Look at some of the newer fishing rods with graphite veil construction, A maglite sized unit of carbon fiber might weigh one oz if it's designed to function as a club like the "normal" maglite is. Just think of the velocity you could attain swinging a flashlight that light AND strong.

Cast Beryllium? (passivated so licking it won't kill you...) Think of the golf ball shaped printing elements in the old IBM Selectric typewriters...

Ya know Steve, this might not be such a bad idea, cast iron! Seein' that you're a collector of cast iron cookware and, that the USL project is still in progress, I do think you should get in touch with bwaites to see what can be designed in terms of a USL PAN!!! This additon (possible option??) would certainly facilitate the egg frying capability of the USL and, might be just the thing to add to your cast iron cookware collection!! Heck, you'd be the first in town to have one!!! All you halfta to do is turn on the light and you'd have both the heat and the light to see what you're cooking in one unit!!! :laughing: :huh2:


Karl

I have always wondered about Tungsten but, then, I sure shouldn't be joking about the cast iron should I?? Heh, heh....just think, with a Tungsten-bodied light, you'd never, ever run out of material for the filament now would you? This just might make LEDs obsolete!!!


Karl

A cast iron flashlight would go great with my EDC ship anchor!

Cast iron doesn't have to be THAT heavy. But I do agree with it's fragility. Just don't drop it and it would be fine. Even with a drop good cast iron is still pretty tough.

The USL "stove" would be fine until the hamburger is half done and the batteries run down. I like the idea of a carbon fiber light. It won't be long until titanium lights are common enough that some collectors will be searcing for new materials. Copper berrilium might be a good material.

Steve

Whats the probability of your cast iron flashlight rusting after a good trip of saltwater fishing?

Illum_the_nation said:

Whats the probability of your cast iron flashlight rusting after a good trip of saltwater fishing?

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It should be ok if you season it first.

Illum_the_nation said:

Whats the probability of your cast iron flashlight rusting after a good trip of saltwater fishing?

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Absolutely no problem with rusting. It's sitting on the shelf while my Ti light is going fishing. I know, it's not a practical solution to what material to use for a light but it's different and I think it would work.

Steve

Trashman said:

It should be ok if you season it first.

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:lolsign:

Okay, boys and girls, I'll handle this--just in case some of you are taking this seriously. I am a metallurgist and spend a lot of time in iron foundries.

You really don't want a cast iron torch (the generic grade is gray iron or "grey" iron across the pond) because it is brittle (this is because on a microscopic level the iron is interspersed with tiny carbon flakes that act as tiny cracks and stress concentrators), AND it will rust. Because of the carbon, it will only rust so deep under normal conditions (there are cast iron water mains in service that are hundreds of years old because the rust only goes so deep) but it will be enough to look ugly, stain your pockets and rub off on your hands.

Malleable iron is white iron (the carbon is in the form of iron-carbide, Fe3C, in white iron) that has been heat-treated to turn the iron-carbide into tiny carbon spheroids. This will make the iron malleable (not at all brittle) but it will still rust.

Not too many foundries make malleable iron anymore because the heat treatment cycle is long and costly, and better properties can be found in ductile iron. The carbon in ductile iron (aka SG iron or nodular iron) also occurs as tiny spheres but they are smoother and the structure is normally made as-cast (without heat treatment) by carefully alloying a low sulfur base iron melt with a very small amount of magnesium. It too will rust enough to be unattractive.

IMHO, of all the materials out there, a good HAIII coated aluminum alloy is probably your best bet because it is light weight and dissapates heat far better than other materials.
Some aluminum bronze alloys make sense if you really want something durable (it is hard enough in some chemistries and heat treatments to be used to make hammers and other tools for use in environments where sparks would be dangerous). It will develop a nice patina over time, is reasonably good at heat dissapation, but it is a lot heavier than aluminum.
Some titanium alloys are nice from a durability and appearance standpoint, but Ti thermal properties are not all that good.
If you want to get fancy and have the money, very hard titanium nitride and similar Ti compound surface treatments can be made to some metals. TiN surface treatment is golden in color and very visually appealing. It is used in some jewelry and in industrial wear applications. It would make your torch wear and scratch resistant. You might even be able to fool some people that it is made out of gold.

Cobweb Hunter,
But I am going to season my flashlight first so it won't rust. I appreciate the information you gave on iron. I didn't really think iron would be a good material for a flashlight but I (that's me!) WOULD buy one if it were nicely crafted. But I doubt that others would. If one carried an iron flashlight and used it in places that weren't damp I would think it would stay pretty free of rust. My old iron skillets don't rust here in California as long as they stay dry.

Can you tell me about potential rusting of damascus steel flashlights? There are two or three such lights in the maching or planning stages now. These lights will rust, won't they, but probably not too readily in the enviornment that they are bound to be used in?

Steve

Nice to know we have a member that knows metals! :thumbsup:

SteveStephens: I reread your posts and see that you are quite into cast iron cookware. I had the occasion to visit a nice U.S. foundry that specializes in the manufacture of cast iron cookware within the last couple of months--just thought I'd add that little bit of coincidence.
So, yes, if you wanted a cast iron flashlight as sort of a novelty item, I certainly understand. Due to the limited market for such an item (like maybe 1? ), the problem would be that you would have a lot of labor involved manufacturing a torch using one of the cheapest metals available. (The primary raw material for cast iron manufactured in the U.S. is steel scrap.)
That being said, the idea of a cast (vs. machined) flashlight body and bezel, whether made out of cast iron, or brass or aluminum bronze, etc. is intriguing. The possibilities of making something with a unique and complex design are endless. I would envision the outer surface as-cast, the inside diameter drilled/reamed and further machining required for thread-cutting. Hand-rammed sand castings using a hand carved wood or polymer pattern is one possible way to go, but much finer detail could be obtained using the investment or "lost wax" technique used by jewelers and casters of small detailed parts.
Regarding Damascus steel, the term is so generic, and has evolved to mean things quite different from the original, that it is tough to make a blanket recommendation. In general, the term now can be interpreted to mean any two (or more) distinct looking steels rolled together in layers to create a pattern; or worse, any steel with a pattern in it. With careful selection of the proper steels (most likely stainless grades) with the desired properties, corrosion resistence, color, hardness, etc., a very nice presentation grade and somewhat practical torch can be made. I am aware of a project of this type on another forum that seems well thought out, and I would not hesitate to buy into it if it interests you and fits your pocket book.

Cobweb Hunter said:

SteveStephens: I reread your posts and see that you are quite into cast iron cookware. I had the occasion to visit a nice U.S. foundry that specializes in the manufacture of cast iron cookware within the last couple of months

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That must be the Lodge foundry in S. Pittsburg, TN. Our Wagner and Griswold Society toured the plant last fall while they were pouring iron. Very interesting and a well run company producing no waste product or pollution.

Yes, I'd possibly be the only customer for a cast iron light but your thoughts on other cast materials and methods (lost wax) might be something for someone to consider. In time the variations in machined lights may all get explored so a whole new process might turn out a nice light.

I am aware of a project of this type (damascus light) on another forum that seems well thought out, and I would not hesitate to buy into it if it interests you and fits your pocket book.

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I am making my wallet fit (it's much lighter now) and am in on that light. My understanding is that the steel used is not stainless but I may be incorrect about that.

Steve

karlthev said:

I have always wondered about Tungsten but, then, I sure shouldn't be joking about the cast iron should I?? Heh, heh....just think, with a Tungsten-bodied light, you'd never, ever run out of material for the filament now would you? This just might make LEDs obsolete!!!


Karl

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As a complete n00b I'm kinda wondering about tungsten's potential as a flashlight casing material. Is there something I don't know about that disqualifies it from theoretically being used? I know some rings are made out of tungsten, which is supposed to be extremely hard and scratch-resistant. Is it almost impossible to work with (excepting industrial-grade machinery), or could a tungsten light casing possibly be comissioned, maybe from a business that makes custom metalwork? Would it be obscenely expensive?

I love the concept of a cast light and agree with Cobweb Hunter's recommendation of investment casting. A cast light could incorporate unbelievable detail that would be extremely costly to machine (engrave). It need not have a rough "as cast" surface if the lost wax method is used. The texture could come from fine filigree, or fancy hand checkering. I would love to see a project like this come to fruition.

I'm not so crazy about cast iron, as it is an impractical choice of material due to its high melting temperature, poor thermal trasmission, and difficulty reproducing fine detail in small parts, but brass, bronze, copper, silver, or aluminum would be nice. What about a solid cast copper or sterling silver light with intricate detail? Geez that would be nice.

Bernie