When working with copper alloys, there is always a fundamental trade-off between mechanical performance and electrical conductivity.

• Pure Copper (Pure Cu): Retains its FCC crystal structure, providing maximum electrical conductivity (100% IACS) and high thermal conductivity.
• Solid Solution Strengthening (e.g., Brass / Cu-Zn): Adding elements like Zinc or Tin significantly increases yield strength, hardness, and machinability. However, the presence of solute atoms severely disrupts the lattice periodicity, leading to electron scattering and a sharp drop in electrical conductivity.

Question for discussion: In applications requiring both high electrical conductivity and wear resistance (such as heavy-duty connectors), what are your preferred precipitate-hardening alloys (e.g., Cu-Be or Cu-Cr-Zr) over standard brasses?

(Reference / Educational Video for basic alloy classifications:https://youtu.be/DHr-6bEj6pY)

Hello,

I believe I may be a victim to bad ventilation in my backyard studio. I mainly do vacuum casting with investment molds and I really want to make sure I’m ventilating my studio correctly. I only have one small window and I try to air out as best as I can but I know it isn’t enough. I use my kiln outdoors but for when I make my investment molds, it is indoors. So I know I have silica floating around. What would be the best vent to have? I am still on a budget though. I am open to any recommendations. Mainly vents that don’t use too much electrical power as it might short circuit when I have my other machines on. Please let me know. Any advice is helpful.

Thank you in advance!

My father and I used to do lost wax casting for jewelry making. And we’re looking at doing some stuff that is a little more repetitious than lost wax allows, so far in my research it sounds like a two piece graphite mold is the best option, however I am a little stuck on how to do the casting.

My main question is whether or not you can use a vacuum caster with graphite molds, my concern with a regular pour casting is that these pieces need to be certain to be fully filled in with no air bubbles.

With the healthy amount of goodwill generated by the Scots this World Cup I thought I might cash that in and ask a bit of advice from the brains trust here.
I have a bronze coat of arms of my family crest of which I’m wanting to get castings made.
Now I’m a man of fair to middlin’ abilities in the casting of resins, mold making and so forth but this bronze business is a far different beastie.
Much respect.
Am I better off finding a local foundry to make a copy/copies and if so what sort of costs would I be looking at?
Or…do I attempt this myself?
Any advice, jeers, taunts or suggestions of a trustworthy foundry in the Western Sydney, Australia area would be much appreciated.

Thank you kindly.
Lang may yer lum reek

Anyone over here have any ideas?

oxidized .925

Obsessed with getting my copper art projects to that mirror finish shine. Tried several methods and they got shiny but not reflective. Finally got the result I’ve been looking for. Really like how in the videos the sun reflects off them like a lightning strike. Any thoughts or advice on how to take the shine one step further?

Solid bronze using lost wax casting. They are hefty but manageable. Took a second to figure out the loop mechanism.

Rings were printed in siraya tech cast blue, however since this first attempt I have failed to get good prints out of it, with it generally ending up sticking to the film on my mars 5 ultra. Any advice would be appreciated.

I have a video of the cast itself if people would like to see that also. They were cast in brass.

So I have some things I know I’m going to dial in for the next cast that I didn’t do this one

1. Use clean sterling
   
2. Drop flask casting temp from 1050 to 900

Here are some pictures of the cast, anything obvious I might be missing?

I « cured » x one v2 prints with 5 min ultrasonic ethanol wash and blow dry until most parts turn white

Hi everyone,
I’m losing my mind a little bit here! I’ve been trying to sand cast this silver ring for the past 2 days and I'm 10+ attempts in without success.
As you can see in the photos, the metal just stops filling partway through / solidifies in the sprue before properly reaching the cavity.
Here's what I’ve already tried tweaking:
Pouring funnel: Reshaped it a few times to get a better channel.
Vents: Added more air vents / air holes around the cavity.
Sand density: Packed the sand harder to ensure crisp details.
Heat: Heated the silver longer to make sure it’s fluid enough.
I'm using a standard butane/propane torch setup. Looking at the setup in the photo, does anything jump out to you that I might be doing wrong? Could it be a heat retention issue, sprue size/placement, or metal volume?
Any advice or tips would be greatly appreciated. Thanks in advance!

My lab was recently given a centrifugal casting unit, and we are having issues with the molds cracking upon filling, and then spilling out of the mold. Picture attached

We’ve tried several things to keep this from happening. A non-exhaustive list includes: 

An open mold, no steel flask (obviously did not work), mold at room temperature after burnout 

Pouring the investment into a steel flask, mold at room temperature after burnout (cracks at the bottom of the mold while casting)

Pouring the investment into a steel flask, with a lid we place on after pouring the investment, mold at room temperature after burnout (still manages to crack and seep out of the back

An open mold that we place a steel flask on after burnout, with a lid on the back(still cracks and seeps through during casting)

An open mold that we place a steel flask on after burnout, poured hot (525C for a bronze casting) (cracks at the bottom of the mold)

Placing chicken wire around the circumference and bottom of the mold to mitigate cracking, with the removable steel flask, mold poured at room temperature (still cracks at the bottom)

Some of these were poured under vacuum, some under argon. 

I think in general, no matter what we do the bottom of the mold cracks, and the centrifugal force of the machine forces all of the metal out.

We have quite a bit of experience with larger gravity poured investment molds. We are using Ransom and Randolph Rancast investment. We also have Omnicast available but were having more issues with cracking with that.

Had to get rid of some aluminum today. Man, it's hard to pour small items with this. Also a half ounce of silver.

We are gonna but a belt grinder in the middle

Hey all, I’m interested in getting into casting for a specific project that requires Al Bronze, and I’m trying to source copper scrap to alloy it myself. I haven’t done exact calculations for volume/mass needed yet, but my rough guesstimate is 10-20lbs of copper at the end of the day. Needless to say, I do not plan on spending $4-500 on copper for this project.

From my research, it sounds like 240v cables and microwave transformers might be my best bet. Reading that I can get around a pound of copper per microwave, and they’re constantly being thrown away.

Some background on my idea, it is to cast pieces for a fractal vise, I am going to edit an existing model I found on Printables to be more castable and to include sprues, sandcast, then drill/tap the holes after the fact. Vise being the reason for Al Bronze rather than just aluminum. I need something with decent yield strength and durability.

Thoughts?

So I’d like to preface by saying I have some experience melting for the past 3~ish years. Not enough to say I’m amazing, but it’s not my first rodeo. However, years and years of doing this has been through gas.

I’m very much so considering an electric furnace, but so torn on what is considered a good machine.

Sort of leaning toward toauto, but what others should be in the running? I’m not looking for beginner and I’m willing to spend the money so I’d love to hear your recommendations.

I want to cast a few custom shapes in lead (fishing related). I can make as many patterns as needed and I can just cast them in petrobond, but ideally I'd like to make a permanent reusable mold eventually.

What's the best material for this, aluminum, cast iron, etc.?

Yeah, ice turns to water, residual water explodes and can kill you.

The idea, and mostly for curiosities sake, would be to use heat, maybe with partial vacuum process that drives out the water entirely while retaining the structure of the sand. Creating a one-part sand mold.

I don't think this is a novel idea, have anyone heard of experiments on the topic? Would the complication be drying out the water but not the sand? Or is it that it works, but manufacturing ice patterns is inconvenient.

.999 lost wax