Casting metal kit parts

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Flush1974

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Greetings Pen Masters,

After watching some Youtube videos, I'm pondering casting my own aluminum kit parts for a pen idea I have. Has anyone here done that? Were they successful? I don't have a metal lathe or CNC machine or I would look at doing my project that way. Any thoughts, ideas, or experiences would be greatly appreciated.

Respectfully
Steve
 
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jttheclockman

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Boy it has been awhile since I did buy aluminum but there is different grades and off the top of my head I can not remember the grade that is fine for what we do. I am sure someone will step up and post for you. If I have time i will look it up for you.
 

jttheclockman

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Yes that is the number of the aluminum. I do get my metals from the place that Mark mentions. I also have bought aluminum from Home Depot. Usually the flat stock and it turns well too. Not sure what # that it is.
 

Jgrden

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But when it comes to casting, the process melting, pouring, evacuating air, cleaning, polishing - me thinks that is a really different avenue. I went to Kindle and found a book on casting bronze. It taught me how to build an oven, the heat source to reach the temp. needed, eliminating voids, building the mold, braking it and cleaning-shaping the parts. Soooo, if I am right, look for a free or cheap book on casting. Am I right or am I on the wrong street?
 

TurtleTom

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Right on the head

But when it comes to casting, the process melting, pouring, evacuating air, cleaning, polishing - me thinks that is a really different avenue. I went to Kindle and found a book on casting bronze. It taught me how to build an oven, the heat source to reach the temp. needed, eliminating voids, building the mold, braking it and cleaning-shaping the parts. Soooo, if I am right, look for a free or cheap book on casting. Am I right or am I on the wrong street?

In college I got into casting aluminum, bronze and even some iron art pieces. The best source of information is the public library. This is old tech and just about everything you would ever want to know about casting non exotic metals will be available from the library. I have read dozens of books on the subject, all from the library.
BTW, casting is great fun. Rule one: If you ever spill water, RUN! There is gonna be an explosion.
T6 aluminum is aircraft grade and is hard stuff.
 

Flush1974

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St Petersburg, Florida USA
But when it comes to casting, the process melting, pouring, evacuating air, cleaning, polishing - me thinks that is a really different avenue. I went to Kindle and found a book on casting bronze. It taught me how to build an oven, the heat source to reach the temp. needed, eliminating voids, building the mold, braking it and cleaning-shaping the parts. Soooo, if I am right, look for a free or cheap book on casting. Am I right or am I on the wrong street?

In college I got into casting aluminum, bronze and even some iron art pieces. The best source of information is the public library. This is old tech and just about everything you would ever want to know about casting non exotic metals will be available from the library. I have read dozens of books on the subject, all from the library.
BTW, casting is great fun. Rule one: If you ever spill water, RUN! There is gonna be an explosion.
T6 aluminum is aircraft grade and is hard stuff.

Thanks Gentlemen! This is going to be an intresting process for sure. The fust still will be creating the pieces, molding them in wax, building a furnace, and create the lost wax molds. This sounds awesome!!!! I'll let you know how it turns out.
 

ldb2000

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Laurence Harbor, NJ, USA.
Greetings Pen Masters,

After watching some Youtube videos, I'm pondering casting my own aluminum kit parts for a pen idea I have. Has anyone here done that? Were they successful? I don't have a metal lathe or CNC machine or I would look at doing my project that way. Any thoughts, ideas, or experiences would be greatly appreciated.

Respectfully
Steve

Hi Steve
Just wondering what parts are you looking to cast ?
Aluminum is too soft and when cast it can become brittle so clips won't hold up very well and as for any round components like bands and BP nibs they can be turned from bar stock far easier then cast . Aluminum is easily turned on a wood lathe using regular turning tools and don't require a metal lathe or cnc machinery .
 

ldb2000

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Finials (end caps) and sections (BP nibs) and center bands are very easily turned from bar stock on a standard wood lathe in both aluminum and brass . I have made clips from flat brass stock with regular hand tools that have held up well over the years . Casting simple aluminum or brass components is simply not cost effective .
 

Rockytime

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There are several in my machining club that cast aluminum. Not a very simple thing. First is making the pattern. I think lost wax casting would work. My father was a dentist years ago and as a kid I remember him casting in gold. I think at around $1800 per ounce gold it would be prohibitive. On the other hand it would be unique. :>)
 

TurtleTom

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Hot metal simply won't flow into a mould that small. It is always done by pouring and then spinning in a centrifuge to force the hot metal into the investment. Everyday work for a jeweler.
 

Skie_M

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I don't recommend you try any of this unless you know what you are doing and have done your research and have appropriate safety measures in place, should anything go wrong. Please don't try to hold me responsible for YOUR mistakes and misjudgements. I'm only presenting this information here because someone is interested in small scale hobby metal casting and may not know what they're getting into ... as someone has already mentioned, casting of very small parts is difficult, as the thinner and smaller your sprues and feed lines get, and the smaller the parts are, it's difficult to get the metal all the way into the casting before it begins to solidify.


To create home made Sodium Silicate (water glass)

200 grams of caustic lye (sodium hydroxide ... NaOH, or the main bad thing in BLEACH, only in it's PURE POWDER FORM - THIS STUFF IS VERY DANGEROUS)
300 grams of silica gel (the little dessicant pack bead thingies - you can substitute kitty litter crystals ... the clear ones)
400 ml distilled water (I used tap water, didn't really notice anything off or bad about it ... but my water here is OK to drink.)


DO THIS OUTSIDE OR IN A VERY VERY VERY WELL VENTILATED AREA

Pour all the water into a stainless steel or other suitable container ... using glass (pyrex) may work, but don't blame me if your wife kills you. SLOWLY stir the water while adding the caustic lye (sodium hydroxide - I get mine from Home Depot ... DEPP brand drain opener). This will be a very exothermic reaction and smell extremely strongly of bleach, which it basically is. It will get hot, it may even BOIL ... do NOT get it on you or on your clothing. This can cause bad chemical burns!

After all the caustic lye has been dissolved, slowly add the silica gel beads perhaps 40 - 60 grams at a time, stirring them and letting them dissolve to create sodium silicate and heat ...

You may need to actually add MORE heat to help speed the reaction towards the end, and dissolve almost all of the silica gel into solution, as well as to cook out almost all of the water. There will be a little silica gel at the end still left over that wont dissolve because you ran out of caustic lye in solution, which is a good thing .... that stuff is nasty.


Once you have it, you can use sodium silicate and compressed carbon dioxide gas to help solidify your moldings, giving them a bit more durability during the pour ... mix the sodium silicate into your disposable greensand, keeping the majority not in use in a sealed container. It will "cure" in the presence of carbon dioxide, if it's dry enough.


Small castings can be made through several different types of methods ... centrifugal casting is one such method, where the heavy liquid metals are pulled into the bottom of a molding by the use of centripetal force. Another method is via lost wax casting, where a wax positive is created and the molding is created around that, which is then hardened or cured. The wax is then melted and poured from the mold immediately before the metal is poured into it ... the key to this method is to KEEP THE MOLD HOT so that the metal stays liquid until it has filled every detail within the molding.

Final method that I'm aware of would be pressure casting or injection molding, where the metal is injected into the mold at pressure to ensure that it fills the entire cavity completely. The use of sprues and risers all around the molded part help ensure that air has sufficient time to escape. This method is NOT easy to do or practical to attempt for the home foundry enterprise.


I don't recommend you try any of this unless you know what you are doing and have done your research and have appropriate safety measures in place, should anything go wrong. Please don't try to hold me responsible for YOUR mistakes and misjudgements. I'm only presenting this information here because someone is interested in small scale hobby metal casting and may not know what they're getting into ... as someone has already mentioned, casting of very small parts is difficult, as the thinner and smaller your sprues and feed lines get, and the smaller the parts are, it's difficult to get the metal all the way into the casting before it begins to solidify.


If you are having SOME difficulty with a mold that has some thinner sections .... keeping the entire mold hot or at least uncomfortably warm MAY help. If you are using greensand this is a bad thing, as driving off all the water will cause it to lose it's integrity. Use of sodium sililcate for the molding rather than greensand will be more effective with a hot mold, but then you'll want to discard the used sand rather than reconditioning it and reusing it like with greensand.

Lost wax process requires wax and a good plaster of paris mix with refractory sand and pearlite to assist in keeping the mold's form. The wax itself is NOT lost in this process, as the melted wax can merely be poured back into a container and saved. The mold, however, is destroyed when the item is removed at the end. A process can be carried out where you simply create a "master mold" that you use for casting the wax positives, and then you can make a bunch at a time.

I don't recommend you try any of this unless you know what you are doing and have done your research and have appropriate safety measures in place, should anything go wrong. Please don't try to hold me responsible for YOUR mistakes and misjudgements. I'm only presenting this information here because someone is interested in small scale hobby metal casting and may not know what they're getting into ... as someone has already mentioned, casting of very small parts is difficult, as the thinner and smaller your sprues and feed lines get, and the smaller the parts are, it's difficult to get the metal all the way into the casting before it begins to solidify.


Yes, I repeated that paragraph 3 times, but it bears repeating. People DIE every year, experimenting in their back yards with things they don't fully understand ... chemical spills and exposure, fires, molten metal accidents, ect ... I'ld rather NOT log on to IAP and find your (anybody's) obituary. If you don't REALLY KNOW what you're doing, leave it to the professionals ... or at least an amateur who does know what they are doing.
 

Flush1974

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St Petersburg, Florida USA
The caps that I wish to cast will have ornate designs that I can only produce by casting. My VERY limited art skills will not support carving, milling or etching. I might start out producing the caps in cast aluminum and then the clips in brass.

I purchased my foundry parts for around $100.

There are several recipes forSodium silicate online so I will try that.

Aluminum cans are cheap. Brass would come from spent brass from the local firing line (inspected for spent firing caps)

I am not looking to produce the nib sections or anything that small. I mainly am looking to produce the Finals, center bands (if I create a design with one).

So I'm creating my molded parts using different mediums to get the designs right. I will then cast them in wax and use styrofoam as the filling blocks.

I'm hoping to start in the next couple weeks. I'll post progress pictures here for anyone interested.

This project is for a line of pens I am hoping to create. It is for prototyping only as a means of proof of concept.
 
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Skie_M

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Aluminum cans are, by weight, approximately 40% metal ... and it's cheap metal that won't turn very well, will melt down full of dross (the paint), needs to be degassed and purified, possibly in several steps, and even then you're never sure of what type of quality of aluminum you have in hand.


Try checking around your local scrap yards for aluminum lawn chairs and screen doors, or drive down some side streets before "spring cleaning" trash pickup and grab anything that is metal and non-magnetic that people are tossing out ... free metal is hard to beat, and it's MUCH purer and better working than aluminum cans, but if that's all you have then that's all you gots.

Old plumbing works have a good deal of copper (pipe) and brass (fittings) to play with. Old junked motors have a good deal of wound copper wire which is extremely high purity stuff, and check again with local junk shops and thrift shops for brass figurines (tell em you don't mind damaged ones, at a discount). Heck, you can have fun just molding the damaged ones, repairing the mold itself, and then melting it down to cast it back into a repaired shape, or making a fixed copy using another metal! (or multiples!!)

I'ld stay away from trying to cast any kind of iron or steel ... the required temperatures are quite high compared to the MUCH lower temperatures needed for aluminum, copper, and brass. Even silver and gold are easy to melt in comparison to steel.


Certain bronze alloys are very beautiful and functional. There's one I've been wanting to make, but couldn't melt the copper properly ... it's an aluminum bronze (called thusly because aluminum is the next most plentiful material in it) that looks like a bright yellow gold when polished up. It's only about 12% aluminum, 88% copper ... something like that.

The resulting bronze was stronger than either metal by a decent amount, had more of the corrosion resistance of aluminum than copper. I didn't see anything concerning it's machineability, but it seems to cast quite well.
 
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