casting of flatware - prototypes

Anyone have any good sources for casting something like flatware? - I would prefer the precision and ease of finish of say investment cast aluminum, however I am having a hard time finding anyone with the equipment capable of doing this. Perhaps there is somewhere overseas i should look? any help would be greatly appreciated.

Are you saying traditional investment casting vendors aren’t making the cut? I’ve seen some new technology that do sand casting with a thin plastic coating between the template and then with the molten metal and it seems interesting… advantages are in the finish and speed of production. I have the brochure back at the office if you’re interested

Travisimo -

Yeah, anything would be great. – I’ve contacted a few traditional investment casting companies, and they all seem to get sheepish after I tell them I’m only interested in 1 or two sets (3-6 parts). - I then tried contacting some jewelry casting facilities (thinking they would be more likely to do small batches) however the flasks they use were too small…
I’ve pretty much ruled out sand casting because of the cross-sectional thickness requirements and surface finish - but the process you’re talking about might be a compromise.

do they have to be cast?

Why don’t you do metal sintering… that would look just like a cast part, but they make it almost like an SLA - one by one. Costs are higher though

I get back on Friday and I’ll try to find the brochure for that other process

As you are looking for prototypes, try a search for metal rapid prototyping.
Protocam from a Google search supports Selective Laser Sintering (SLS), Plaster Cast Metal Parts, Sand Casting,etc

A prototype can communicate the final desired manufacturing process, without involving that process at all.

they all seem to get sheepish after I tell them I’m only interested in 1 or two sets (3-6 parts).

3-6 parts isn’t a whole lot of work. :wink:

ProCam looks like good source, if you have the budget. I’d be looking for a local “art casting house” that does bronze work, or better yet, the art department of a nearby college or university (some one there will know a foundry guy.) You might have to spring for a dedicated crucible for aluminum.

To be honest, in the thin section I am visualizing “flatware” to be I don’t think you are going to end up with a very strong piece with cast aluminum. Casting grades of aluminum (2xx.x., etc) are relatively soft, and there are wide range of alloys used (based on mechanical requirements). The “harder” grades of Al (7075) are billet, primarily intended for machined components and don’t cast well. Essentially, they do not cast at all (they lose all their mechanical properties when smelted.

All of the Al flatware I’ve seen (admittedly not that much) has been stamped from sheet material, which in effect hardens it. If you take a strip of 8" x 1" x 1/8" aluminum from the hardware store, and try to bend it with your hands you will find that it doesn’t take too much effort. Now consider cutting away “everything that isn’t the flatware” from that piece of aluminum strip you will have a pretty good idea what you are going to end up with. In addition, aluminum is highly subject to corrosion.

http://www.ctemag.com/pdf/2008/0805-CastAluminum.pdf

You know, I’ve actually seen a very cool sample of SLAs with a metalized coating. I had asked Protogenics about it and they said they could source that if you wanted to explore the process and need a place to start from

Again cost would be higher, but it wold have a very fine finish and metal strength/feel

To be honest, in the thin section I am visualizing “flatware” to be I don’t think you are going to end up with a very strong piece with cast aluminum.

right - i suppose i should have qualified my question a bit more - I’m not really concerned with the strength of the parts.

So i’m only really looking for finished visual prototypes - At the end of the day this is for photographs for my portfolio. I’ve been on a portfolio building binge but i’ve told myself not to start on the next project until the current one is DONE… all the way.

So I made tons of models - did some cad - had a buddy print out some parts - now I’m making molds for some wax patterns and looking for someone to cast them - but perhaps as I’m finding out this is not the path to go down. I have heard that it’s possible to chrome \ silver coat a urethane casting, however i’m not sure if this would look as good as an actual metal part sanded out perfectly… I’ve also heard of people casting pewter\lead in rtv molds however I’m skeptical about this also as far as finish goes.

thanks for your help so far, I’ll keep digging.

You don’t see pewter flatware that much anymore. Too bad, I like the “heft”, and the warm feel of it. It will polish but not to the “chrome-like” finish you may want. But it will accept chrome plating, although it must be pre-plated with several layers of copper, and then nickel, for it to accept the chrome. Additionally the there will be a bit of a problem getting the chrome to migrate into the tight area between fork tines. The “edges” of the tine attract the copper/nickel, chrome and do not allow it to move into the the vertical space between the tines (the surface created by the “thickness” of the metal).

Pewter is basically lead and tin; 75% and 25% respectively.

Since lead/tin melts at a relatively low temperature (550°-700°F) and be melted over an electric, or propane, burner. You can usually find a long-handled ladle in the plumbing section of most hardware stores.

I wouldn’t be too skeptical of casting it into RTV molds; How To Cast Pewter Into Mold Max® 60

The thin-section thing is sticking in my head as a possible “problem”, only because free-cast materials (urethane included) generally have a hard time flowing into thin sections. It’s easily solved by building a spin casting rig out of scrap plywood.

Ref.: plating process, chrome plating , nickel plating, copper plating , duplex nickel , strike copper, satin nickel , bright nickel , semi bright nickel, brush nickel , gold plating ,antique finish

Contenti Spin Casting (a good source for metal alloys and casting supplies in general).
http://www.contenti.com/products/spin-casting.html

edit - jg, Since this is a portfolio project you may want to consider designing for the material rather than trying to make one material look like another. i.e. Accept the appearance of pewter for what it is; darker than silver or aluminum, with an inherent warmth to it.

Some examples: http://images.google.com/images?q=pewter%20flatware&oe=utf-8&rls=org.mozilla:en-US:official&client=firefox-a&um=1&ie=UTF-8&sa=N&hl=en&tab=wi

If you have the molds, or at least the wax models and all you need is the aluminum poured, I have a furnace & routinely pour aluminum for my custom engine parts. -And I live in Seattle. Let me know if this interests you.

And I live in Seattle.

Serendipity ! :smiley:

You may have walked into something here nerd. What’s the biggest part you can pour? L x W x H

http://www.reliablecastings.com/index.htm

They do one off’s for UC students all the time. All you need is the rapid prototypes, They can use them to pack a sand mold and cast your parts in 5 minutes. You wont get many fine details with the sand casting but smooth surfaces can be buffed to look great.

I actually like the blueish look of pewter and the weight is nice, I think it would look and feel great. I may just go ahead and try it with my molds. The knife was what i was most worried about with the pewter work - i suppose i could thicken up the blade section for casting and sand it down after. thanks for the link to the spin casting rig - Either way I won’t do any pewter in RTV casting until AFTER I make enough patterns to have someone more experienced give it a shot in either sand or investment.

NerdSpeed! yeah this interests me ALOT! lets talk… I PMed you with my info.

thanks a bunch you guys this is super helpful.

The knife was what i was most worried about with the pewter work - i suppose i could thicken up the blade section for casting

or … laser cut the blade out of stainless (or other) and cast the “handle” around it; this is a common “flatware” manufacturing technique.

Have fun! Keep us posted on the outcome.

Hey, I looked for the brochure today but no dice, sorry. I think this was the process however - V-Casting http://www.industrialmetalcasting.com/vacuum-n-process.html


Here is a link for Metalized SLA found on google… vendor seems engineery, but I bet it could be used for a nice model with a metal feel. I’d really like to try the process on something sometime.

Metal Coated Prototypes

ProtoCAM does metal coating on plastic prototypes created from other rapid prototyping techniques such as SLA, urethane casting, and injection molding. Typical metal coated prototypes are plated with nickel, copper, and chrome.

I’ve had some prototype stainless parts made with an investment caster south of salt lake city. If you can make the wax parts they can add them to trees that they are making for other companies. It’s probably good to act like you are are going to make tons of them after you get the right shape.

For my patterns I had wax pattens made directly from a rp machine.

I recommend taking the previous poster up on his offer or call around more. Also alsa corp makes nice spray cans for metalized paints.

You should make them in stainless so they have a nice heft. For this, I think the feel is very important.