Small Job Cast Iron Foundaries

[TorontoBuilder]

First let me apologize if this is not the appropriate location to post this question. If not would a moderator please let me know what thread this should be posted to?

I have made some simple custom patterns that I wish to have sand cast in gray cast iron. I have tried unsuccessfully to locate a "local" foundary that accepts small jobs from hobbyists.

Does anyone here know of a commercial foundary in the eastern half of North America that does accept such work? Or is are there any amateur foundaries with gray iron capabilities that may accept a small job or two?

Thanks you,

John

 

[aonemarine]

John, get on alloy avenue forum and post you needs there. There are many back yarders including myself that csn help you out. How large is the part and how much will it weigh? Does it have cores?

 

[Tin Falcon]

you can try these guys:
do not know much about them other than I drive by once in a while.
http://www.bbfoundry.com/about/
Tin

 

[aonemarine]

Hang on to your wallet with b&b is all I can say. The cat tail foundry is near them and a lot cheaper but the cant do ductile iron.

 

[TorontoBuilder]

Thanks for the tip on the alloy avenue forum AOne.

I haven't calculated the volume of the patterns or the resultant weight of the castings yet, but they will typically be in the smaller sizes you can expect with scale engines and models. A couple patterns such as steam cylinders will use very simple cores... but only for the main piston bore. It will be some much easier to machine the steam ports than to make and cast the cores for those.

The largest pattern I am currently working on is a angle bed plate for the Hemingway geared 4" rotary table. I bought a set of plans and just the worm gear from Hemingway several years ago and have never gotten around to completing the project because I wanted to modify the base from that which Hemingway has designed.

BTW, I have relatives near Townsend DE. You live in a nice state to visit...

 

[TorontoBuilder]

Hi Tin,

Thanks for the tip on the commercial foundary.

 

[aonemarine]

It's a nice state to visit lol agreed. I'd rather be more south though.
Have you made your patterns yet?

 

[TorontoBuilder]

I have a flywheel, engine base, stanchion and cylinder patterns made from extruded polystyrene from when I was thinking of casting them in aluminium using lost foam process. I now plan to convert those to reusable resin patterns. At some point I can use water displacement to calculate the volume and completed casting weights for each part.

I am midway through the design stages for a couple of other patterns which I would like cast. I have no set time-frame for completion of the patterns and castings, so I'd be very happy to work with an amateur foundary person who works on a limited basis.

 

[Herbiev]

"I'd rather be more south though".
Not at the moment Aonemarine. Come too far south and you've got temperatures around 45 deg Celsius (113 F). Too hot to enjoy foundry work. Rof}

 

[aonemarine]

Sounds like something I could easily cast for you provided your not looking for a large quantity of them.
But id like to see your patterns before I commit to anything, just to make sure the draft is good, allowed for shrinkage, gateing, machining allowance ......are they split patterns?? Maybe next time you come to DE swing by with them or something.

 

[TorontoBuilder]

Because I was going with lost foam casting the patterns are solid. If you recommend split patterns I can split them during the process of casting them in resin. The patterns are mostly symmetrical and have a good draft. I have done plaster casting in the past and made fiberglass boat moulds so I know all about avoiding undercuts. The concept of providing adequate draft to the pattern so as not to disturb the sand while removing the pattern from the moulding sand is not much different.

The patterns are somewhat overly fat, because I wasn't sure what alloy would be used or the correct expansion rate... that and I have heard of others who had problems with castings that lacked sufficient material or that had inclusions that made it difficult if not impossible to machine the parts to spec. I have read a little about gating, and haven't planned this yet... further down the road input would be appreciated.

I think a single pour could cast all the parts at once, even if several sets were cast. Sprues and gating would need to be determined for this, which I haven't done.

I haven't been to Delaware in years, so it would be better for me to send you pics and drawings first, then I could send you copies of the patterns, after which you could decide if you'd be willing to undertake the project.

 

[aonemarine]

I'm hoping to do this with my small furnace which melts about 12 lbs of iron per shot. My big furnace will do near 60 lbs but requires a helper to to the pours and is a real pain trying to find a help at times. Little furnace is cheap to run also. If you have Cad images you can e mail them to me at myforumname at AOL dot com. Hmm hope that keeps the spam bots away... Allow 1% for shrinkage and about .030" for areas to be machined. My castings will usually clean up in .010-.020" unless I screw something up, but then ill just re cast. And don't forget the core prints. I did fiberglass for a number of years as well, still have a boat mold in my back yard just begging to get laid up in. Wherry mold for possible steamer project at later date.

 

[TorontoBuilder]

I was able to do a quick weight check for the cylinder casting which is the second largest casting I have for the engine and it is just under 1 pound.

I realize that I will have convert everything to split moulds and make core boxes for several parts, but I think I have a good understanding of what to do for this. The core for the cylinder appears to be the easiest.

I am attaching a a pic which has the original cylinder plan, to which I have added the new part line for the pattern with a solid purple part line. I have indicated the core in solid light purple. I hope a core 1.5" wider than the cylinder will be sufficient.

I understand that this also means what i had planned to be a void in my lost foam pattern must now become a filled solid area. The new solid areas in the pattern will create a 1 " void in the mould to the left of the cylinder, and a .5" void to the right of the cylinder across which the core will be set and secured.

It should be simple to make the core box for this core using a 1" dowel to create a split mould, does your core sand hold it shape if the top half of the mould is opened to expose the material to CO2 during the setting of the core?

 

[aonemarine]

I have a simple core box made up all ready that will work for your project. Just make your core print .900" diameter.
The sand doesn't like to be dumped from the mold until its is cured either by gas or heat.

 

[aonemarine]

Whoops, make that 1.150" core print. Don't worry have that one too. Something tells me I have a cylinder pattern too, ill have yo dig it out and measure it up. It's from like 5 years ago so I don't remember the exact dimensions.

 

[TorontoBuilder]

Maybe, from my understanding a lot of people have made this vertical steam engine, which is from Popular science magazine 1947.

I plan to use this to power a 1:32 scale model of the steam tug Hercules. I really should use a triple expansion engine but that is beyond my current skills.

 

[aonemarine]

Is it the one with the bent steel supporting the cylinder?

 

[TorontoBuilder]

Is it the one with the bent steel supporting the cylinder?

I think it may be... but a picture says so much more.

See the image attached...

 

[aonemarine]

I remember this engine, seen it built many times. this isnt the one to the cylinder I have though.

 

[TorontoBuilder]

Well, for me half the enjoyment is in the planning and creation of the complete job.

That includes making the patterns and core boxes... If I had the room I'd love to have my own furnace to cast this myself, but I am very space constrained. Of course the next best thing would be to have the parts cast by by someone and to be there to assist and document the process. Better yet, end the day with a mess of steamed crab and bass ale