Investment Casting: Everything You Were Afraid to Ask or Didn't Know

[CollectiveBorg]

I was a dental technician for 35-40 years. College trained. Looking back, I hated the job and everyone in it and I hate dentists now. My Dental PTSD aside , before I retired and my mortgage was paid off, I did a lot of lost wax castings and used detail nonprecious metal to make periscope and radar masts. the metal is perfect fo this. super strong, no corrosion, super lightweight. Made of stainless steel like alloys.

Bob Martin comments in his 'The sub guy' on my Argonaute' RC build that finally was completed thanks to him and money. Bob however got one thing wrong, the masts are not dental resins, they are metal stainless steel like alloys. Same used in crown and bridge dental work. (or used to use then).

It required centrifugal broken arm casting machine, acetylene and oxygen torches and experience how to use them. a Dental hot burn out oven. Tongs for holding the red-hot casting rings. Casting rings, investment materials, vacuum to suck bubbles out of the investment as you pour into rings to invest parts. Alot o infrastructure here, waste of money for just one or two projects. It maye be best to find a dental lab that still casts and work out something, making a lab your new best friend. The oxygen for the hotter flame was mandatory to metal the dental metals.

Dug up some archive photos of the parts made then decades ago for the Argonaute eventually completed by Bob and his son and assistant only a few years ago. Thanks again. The dental nonprecious metals were cheap and was allowed to cast parts the few times I needed for free. 'Waxers' would sprue my parts fit to be inside a casting ring and invested.

The parts were made out of plastic and green dental wax (same used probably used in your Jewelry work Anton.

To be honest, I got into jewelry making specifically because I wanted to create the models of my dreams without spending a fortune on equipment (although I ended up spending money anyway =))) ).

These days, of course, most people use 3D-printed wax patterns.

I absolutely love technological progress. Now I can open SolidWorks, design a model, send it to a printer, invest it, and end up with a finished metal casting! It's the kind of science fiction I dreamed about after watching Small Soldiers (1998):



Tomorrow I'll start preparing photos and videos for the first step and show how I do it.

Honestly, in my opinion, setting up your own casting operation isn't nearly as expensive as many people think. The biggest challenge is having a suitable space—a workshop.
.

[JHapprich]

Yep. Casting in the lab was always fun...

[Albacore 569]

I was a dental technician for 35-40 years. College trained. Looking back, I hated the job and everyone in it and I hate dentists now. My Dental PTSD aside , before I retired and my mortgage was paid off, I did a lot of lost wax castings and used detail nonprecious metal to make periscope and radar masts. the metal is perfect fo this. super strong, no corrosion, super lightweight. Made of stainless steel like alloys.

Bob Martin comments in his 'The sub guy' on my Argonaute' RC build that finally was completed thanks to him and money. Bob however got one thing wrong, the masts are not dental resins, they are metal stainless steel like alloys. Same used in crown and bridge dental work. (or used to use then).

It required centrifugal broken arm casting machine, acetylene and oxygen torches and experience how to use them. a Dental hot burn out oven. Tongs for holding the red-hot casting rings. Casting rings, investment materials, vacuum to suck bubbles out of the investment as you pour into rings to invest parts. Alot o infrastructure here, waste of money for just one or two projects. It maye be best to find a dental lab that still casts and work out something, making a lab your new best friend. The oxygen for the hotter flame was mandatory to metal the dental metals.

Dug up some archive photos of the parts made then decades ago for the Argonaute eventually completed by Bob and his son and assistant only a few years ago. Thanks again. The dental nonprecious metals were cheap and was allowed to cast parts the few times I needed for free. 'Waxers' would sprue my parts fit to be inside a casting ring and invested.

The parts were made out of plastic and green dental wax (same used probably used in your Jewelry work Anton.

[trout]

I agree, you are welcomed here. I was a jeweler and had a repair shop late 1980’s to mid 1990’s. I look forward to learning from you as well as maybe sharing to. I know some of us have wide diversity in our political views, but we are singular in our thoughts here. We build RC subs and share what we know. So, do not worry about whether you fit in or not, you do. I am glad you are here.

[MFR1964]

Anton, politics is not my thing, just love to build models just like you, in my opinion it doesn't matter where you from, we all have a common goal to share experience so other people can benefit from this.
Welcome aboard the madhouse, enjoy your time here.

Manfred.

[CollectiveBorg]

I hope I'm accepted here as a modeler. Without my nationality. And even if I am, well, you have buttons.

[CollectiveBorg]

No sweat, Anton. We share similar life experiences. You spent a military career preparing to kill guys like me. I spent a military career preparing to kill guys like you.

Our respective play-time is over. Time to build some awesome models!

I doubt it. I've been a soldier since graduation. Just like my entire service. But I always laughed when the sailors told me:

"Don't worry! The shore starts in the middle! It just rises. Gradually."

I'll be honest. As a landlubber, I never liked that joke.

[He Who Shall Not Be Named]

I was hesitant to fully introduce myself... We're not exactly popular these days because of the political situation. That's why I filled out my profile instead.

I'm here for only one reason: to learn from you and to share what I know with you.

No sweat, Anton. We share similar life experiences. You spent a military career preparing to kill guys like me. I spent a military career preparing to kill guys like you.

Our respective play-time is over. Time to build some awesome models!

[CollectiveBorg]

I was hesitant to fully introduce myself... We're not exactly popular these days because of the political situation. That's why I filled out my profile instead.

I'm here for only one reason: to learn from you and to share what I know with you.

[He Who Shall Not Be Named]

*looks reproachfully*

I asked you not to comment, so as not to disrupt the management structure.

Unfortunately, no. I'd like to, but I'm not participating.

*takes a deep breath." And then he decided to speak.

I'm Russian. They don't like us. We're mean and all that (I don't want to talk about politics).

I love modeling, I was asked to do something I'm good at, so I started this post.

Now they'll probably delete me and ban me.

... and I'm a Martian, yet nobody from the Government has strapped my green ass to a gurney (yet)!

Management structure? Have you looked at this chaotic mess? WHAT STRUCTURE! It's every man for himself at this site.

Join in.... you'll fit in just fine CollectiveBorg.

[CollectiveBorg]

Will you also be part of tomorrow's Zoom meeting?

*looks reproachfully*

I asked you not to comment, so as not to disrupt the management structure.

Unfortunately, no. I'd like to, but I'm not participating.

*takes a deep breath." And then he decided to speak.

I'm Russian. They don't like us. We're mean and all that (I don't want to talk about politics).

I love modeling, I was asked to do something I'm good at, so I started this post.

Now they'll probably delete me and ban me.

[He Who Shall Not Be Named]

Tomorrow, I will post the next part of this guide, where I will do my best to thoroughly explain all the methods used to create a wax pattern for investment casting.

Will you also be part of tomorrow's Zoom meeting?

[CollectiveBorg]

Tomorrow, I will post the next part of this guide, where I will do my best to thoroughly explain all the methods used to create a wax pattern for investment casting.

[CollectiveBorg]

Hello everyone.

At the request of forum members, I will try to explain, in full detail, how to master investment casting.

I will describe the complete process from start to finish, including all necessary consumables, tools, equipment, as well as examples of how to replace purchased items with homemade alternatives to save money.

So, let's begin.

A little about myself. My name is Anton, and I have been working as a jeweler in a private jewelry workshop for the past five years. I have never completed any formal courses related to this profession.

The only profession I have that is officially confirmed by a state-issued diploma is that of a career military officer.

Everything I know and everything I do, I learned from publicly available sources.

I will explain the entire process with a focus on scale modeling rather than jewelry making, so it will be easier for you to understand. However, everything described here works just as well in the opposite direction.

ATTENTION!

This material will be very extensive. To ensure that the entire guide remains available in full and in the correct order, I strongly ask everyone not to comment on this topic until I write in the final post that I have shared all of my experience and that questions are welcome.

If someone decides to begin working on their own before I finish writing this guide and needs my advice, you can always send me a private message.

Later, this topic may evolve into a question-and-answer discussion, but I would like the first page and the complete guide to remain intact and uninterrupted.

So, let's begin.

What is investment casting?

Investment casting is a process in which a disposable wax model is destroyed during the burnout of the mold, and the resulting cavity is then filled with molten metal during casting.

Here is the complete sequence of operations required to produce a metal casting using the vacuum casting method:

(Each of these steps will be explained by me in detail, with examples, different implementation options, pictures, and videos, exactly as I perform them in my day-to-day work.)

1. A wax model is made.
2. If only one model is being cast, it is attached to a sprue, which is then attached to the flask base.
   2a. If multiple models are to be cast at the same time, a "tree" is assembled. This consists of a thicker wax rod serving as the "trunk," onto which the models are attached using a wax pen. Each model is connected to the trunk through its own sprue.
3. A perforated flask is placed onto the flask base. The flask is usually wrapped with either masking tape or regular tape beforehand. I use regular tape because it is more reliable.
4. The investment material is prepared and poured into the flask using a vacuum.
5. After the investment hardens, the rubber flask base is removed, the tape is taken off, and the investment is trimmed with a knife to remove any excess material that has flowed onto the flask.
6. The flask is placed into a burnout furnace equipped with a controller that allows temperature stages and their durations to be programmed.
7. After the burnout cycle is complete, the furnace program transitions to a holding temperature suitable for casting molten metal into the flask.
8. The flask is removed from the burnout furnace and filled with molten metal using either vacuum casting or centrifugal casting.
9. After cooling, the investment material is broken away using water or mechanical methods, and the casting is removed.
10. The castings are separated from the sprues, cleaned, and finished.

This is a brief overview without going into the details of each step (which I will, of course, cover later). Using this process, I made the propellers for my Project 941 model:






By the way, casting jewelry in gold or silver is actually easier than casting a complex model like this.

This model contains several mistakes, starting from step one and continuing through other stages of the process. I will point them out and explain them to you.

I hope you will find it informative and educational.