Diary of a Casting Pot Construction

[Texasflyboy]

05/13/2020 Update: The link to this article is here:

https://www.hensleygibbs.com/TCD/art...castingpot.htm


I am building a new casting pot, and wanted to document my experience in this post for all to see.

Why am I building my own pot when I can purchase a Lee or Lyman pot? I wanted a pot that held at least 100 lbs of lead, and also could be foot activated for production purposes.

What I am trying to construct is an improvement over the pot I have used for many years. Here is a photo:



This pot works great, but has a few faults. One of which is that it takes way too long to heat up for use. Half filled, it takes about 2 hours for the pot to come up to temperature. That fact, and along with the other problems I have had with it, I decided to build an improved (I hope) design.

Here are the materials laid out:



Last week I concentrated on getting all the raw materials. Here is a list of materials, and their associated cost. I will add more materials as I purchase them.

$25 - 12" x 12" x 3/8" Steel Pipe Section (I cut this in half for my pot)
$25 - 13" W x 60" L x 1/4" Steel Plate
$45 - 3 - 6" 1500 Watt Electric Range Elements
$45 - 3 - Maytag Ceramic Element Connectors
- 2 - 5/8" x 24" All Thread Rod
- 26 - 5/8" Hex Nuts
- 1 - 3/8" x 24" Angle Iron
- 1 1 1/2" x 24" Angle Iron
- 2 - 3/8" Round Rod
$25 - 1 - 220V Switching Relay (Part of Temperature Control
$10 - 3 - LEE 20lb Pot Spouts (I need 3 to ensure spares)
$10 - 2 - LEE 20lb Pot Spout Rods
$50 - Consumables (Welding Rods, Grinding Pads, etc...)

This week I cut the 12" x 12" pipe section in half. My pot dimensions are 12" Diameter, 5.5" tall, by 3/8" thick. I also cut the bottom plate and the top shelf plate. This is what they looked like after grinding all the pieces:




Today I completed tacking the top shelf, the pot, and the bottom plate together. Here is a photo with a 16oz bottle of coke for scale:



This weekend I expect to do the welding on the pot base, shelf, and anywhere else it needs.

Here is a photo of testing out the element placement:



More to come....

[Topper]

Good luck on your project
Looks like your off to a good start.

[Blacktail 8541]

Nice start to your project, loking forward to the updates.

[Buckshot]

...............Texasflyboy, really tidy work so far. I appreciate your taking the time to lay everything out so well to create the documentary of the construction. I'm really looking forward to seeing the balance of your posts on continuing construction. Pictures sure as heck add to the interest and information value.

................Buckshot

[Texasflyboy]

Well, I am about 95% done after a long day of work.

Here is the result:



I have about 48 photos on my web server showing the progress of construction.

Rather than eat up bandwidth here, I will post a listing of the URL's.

Here are the links to the article & photos:


https://www.hensleygibbs.com/TCD/art...castingpot.htm


I will post later text to go with the photos. Tomorrow, or later this week, I will drill and tap the spout hole and begin assembly of the temperature control mechanism will will consist of the following parts:

Partlow 0F to 1000F Temperature control thermostat
220V Switching relay
Individual on/off switches for each heating element
On/Off switch for Whole Unit
Small Switchbox with 30A Circuit breaker.
Cord and plug to tap into a 30A dryer outlet

[Heffe]

I’m not sure which is more impressive the quality and workmanship, or the fact that you stopped and photographed it so thoroughly. When I’m working on something like that I hate to stop. Great Project!

[versifier]

IT'S ALIVE!!!! Or just about. Now it needs a name. Make it a good one as it's sure to be copied. I feel like an uncle.

[Texasflyboy]

IT'S ALIVE!!!! Or just about. Now it needs a name. Make it a good one as it's sure to be copied. I feel like an uncle.

Yep, you sure are. Your help in solving my little electrical problem allowed me to finally set up and use my 220V arc welder, which allowed me to weld the pot. My little cracker jack 110V arc welder would never have done the job.

You are granted "Uncle" status on this one for sure...

[Texasflyboy]

Ok,

On to the spout. After much teeth grinding and wailing, I decided not to reinvent the wheel and try and use off the shelf components where I could.

Lee makes some pretty good pots, and I was able to access their spare parts page online. I noticed that they sold the 20lb. spout and rod as separate parts. So, I ordered three of each.

I was happy with the spout, but disappointed with the rod. The rod looks almost like an afterthought.

So, time to make my own rod.

Here is the result:



The lee rod is at the bottom. My new rod is on top. It seals at both the tip end on also at the flange end. I prototyped the inside of the spout with a wax cast to see what a rod SHOULD look like.

This is the wax cast:



My rod is not nearly what the wax cast is, but patient work on the drill press with 600 grit sandpaper, a caliper, a Swiss flat needle file, and patience, patience, patience got me two sealing surfaces on the new rod. The stock material (the new rod) was found rolling around the bottom drawer of my tool box. I think it’s a leftover handle from those kits you buy to take off bathroom water valves, it’s the handle part.

I may take another crack at this tomorrow to see if I can't closely duplicate the wax impression. If anyone here is a machinist, I could sure use some help.

[jar-wv]

Will the thermostat controll all 3 of the heating elements? Also what exactly is the funtion of the switching relay? Could one just use the controls for each element like is on a stove? I'm hoping you will detail the electrical stystem.

Your going to end up with an AWESOME pot. Very good looking work.

jar

[Texasflyboy]

Here is a photo of my current electrical setup. It uses a 220V switching relay (made in 1962 according to the stamp on the side) a Partlow 0F to 1000F temperature control, and miscellaneous wiring.



The temperature control (Partlow) has an adjustable setting to set the temperature at which the Partlow switches the power to the (in this case) single heating element on my old pot. It's either on (High) or off. There is no in-between.

I *could* use rheostats off of a stove to control temperature, in fact, I was thinking about that today. That would truly be the low cost option, as the Partlow temperature control is about $250 (ouch!). I thought that by using a casting thermometer, I could fine tune and calibrate the rheostats to discover which combination of settings would translate to a corresponding melt temperature.

I don't know which way I will go yet. The Partlow control, once set up, just does its job, switching the relay on and off to keep the temperature where it needs to be. The rheostats are an attractive lower cost option, but would always need to be on. There would be no "off" while casting unles I messed with them.

Don't know the answer, more thinking required.

02/23/06 Update:

Thanks to a touch of insomia, I spent the last few hours on E B * Y and discovered that temperature controllers can be had pretty inexpensively. I even found the exact same model as pictured above (the Partlow MF-4) which is obsolete and discontinued. It sold for $35!!!

I emailed one of the temperature control vendors and for about $75, I can get a modern digital readout, relay output, K Type (0F to 1250F) Thermocouple Temperature controller. If I go used, the price drops to about $50.

With prices like these, I don't think I am going to use stove rheostats. I just may not use the expensive Partlow temperature controller.

Tah for now....ZZZZZzzzzzzz.

[454PB]

Glad to see you are making progress, what a monster. I think you should call it "The Therminator"

Did you consider using three 15 amp 120 volt switches to manually control the heating elements?

[Buckshot]

.................TFB, most impressive. Looks REALLY industrial, and that's a compliment. What are you going to use for heat insulation?

Have you considered having the spout mouth approx 1/4" up off the floor of the pot? While it would keep you from totally emptying the pot without tipping it, it should help to keep the crud out of the spout. I think this is 95% of the cause of leaking and dripping, crap in the spout.

..................Buckshot

[Texasflyboy]

What are you going to use for heat insulation? Have you considered having the spout mouth approx 1/4" up off the floor of the pot?

1. Insulation...Hmmmmmm

I had in the back of my mind that I might need to insulate this thing for better performance. But until you raised the issue, the thought never made it to the surface. Well, it has. I did a little reading on the 'net and discovered Rock Wool Insulation. It's used in old stoves, blast furnaces, boilers, etc... The temperature rating appears to be in excess of 1500F. So, I think that is what I will use. My plan is simple, unless someone points out a flaw in my thinking. I am going to cover the bottom of the heating elements with a thin plate of steel (1/8", or 3/16th plate) I will extend that out past the all thread just enough to allow about 1" to 2" of space past the circumference of the pot base. Then, I hope to use sheet metal to cover the outside of the pot, leaving 1" to 2" of gap between the sheet metal and the pot wall. I intend to pack this gap with Rock Wool Insulation.

This is a quickie drawing of what I am contemplating:



That's the plan so far.

2. On the spout I agree. The problem is that Lee only threads about 1/4 to 3/8" of the spout. To raise the spout off of the pot floor and create a "ledge" to keep dirt out I was thinking of using a flat washer bored out to act as a step. This would raise the height of the spout by one washer thickness. Which, isn't much, but better than having the spout level with the floor of the pot. I would use two washers, but I don't think I will have enough thread left on the spout to engage.

[powderburnerr]

You might want to leave a little air around the elements .I have repaired a lot of stoves that burn off the connectors when a big pot is set on them they need air circulation...... Dean

[jar-wv]

With the wall thickness of the pipe you're using, it would seem that once it came up to temp, it would hold pretty steady without any insulation. Though I guess it would save a bit of time getting it hot.

jar

[Texasflyboy]

You might want to leave a little air around the elements .I have repaired a lot of stoves that burn off the connectors when a big pot is set on them they need air circulation...... Dean

thanks. This is a quick drawing of what I intend to do with the elements.




The bolts I welded to the bottom of the pot to hold the elements in place are long enough to place a double nut on the end, leaving about 1" of bolt sticking out. I will cut the plate to fit the red square (from each corner of the all thread) and drill three holes where the red triangle has corners. I will use that 1" of bolt sticking out to hold that plate in place. I don't think I will use insulation here, just the plate cover to block the elements should be sufficent.

[Johnch]

For insulation you might try ceramic ( spelling ) sheet insulation.

We use it for around boilers , when we repair them and destroy the old insulation.

It is a soft white insulation , that dosn't cause me to itch
But is real hard on utility knife blades .

It comes in different sized sheets .
A local plumbing or heating supply house should have it .
A local boiler repair man might be sweet talked out of enough scraps to do the job for free .

We pitched all the scraps last job or I could give you enough .

Another Idea to think over , a insulated lid or cover , mabe for 2/3 or 3/4 of the top .
I have a insulated cover that I made for the Lee 20 lb pot , I have turned the pot off and came back 1/2 hr later and the lead was almost hot enough to cast yeat .

It looks like you are doing a great job .

Johnch

[floodgate]

Texas:

johnch said: "For insulation you might try ceramic ( spelling ) sheet insulation.

We use it for around boilers , when we repair them and destroy the old insulation.

It is a soft white insulation , that dosn't cause me to itch
But is real hard on utility knife blades .

It comes in different sized sheets."

I think you can get batts of the same stuff, or something similar, through your local woodstove store. I got a 24" square of it about 3/4" thick - a bit pricey, though - a few weeks back to refurbish an old stove I had stored out in the garage that the mice had nested in.

floodgate

[Texasflyboy]

I think we are all talking about the same product. Rock Wool is made from blown Basalt & Slag in a furnace. From what I understand, the process is somewhat similiar to making cotton candy. The stuff is blown in a superheated state and formed into strands.

Rock Wool has been used as stove insulation for years, especially older stoves. It comes loose, or in bats, or in semi-formed blocks. I just found some on eBay, so no problem finding some. I am still trying to decide if I need to insulate at all. More thought required...