Hot Work Cart
The term "Hot Work Cart" conjures up a couple of visions in my imagination. This one is easy to figure out form the pictures. It's a shop cart with fire brick on the top. The cart provides a portable place to do very hot work like welding, brazing and my latest interest melting and pouring molten non ferrous metals.
I had mental plans (not drawn) to build one of these when I first started construction on the Pennsy A3 in 3/4" scale locomotive way back in the beginning of time. (My shop time.) I bought the 24 fire brick back then too with this project in mind. I you look close you will see some heat marks on a couple of bricks I used in some of the A3 work. I don't have much info on the brick. They are the same kind used in my kiln. I bought 24 of them years ago from the Sheffield Pottery, Inc in Sheffield, MA. I have no idea on price today.
If you are wondering, yes I plan to get back to work on the A3 project after I retire. It takes total and uninterrupted dedication to build a big loco. It's currently in a safe place and condition and could be picked up immediately. I have ALL the tender material in a stockpile.
Back to the Hot Work Cart. This is a tool and not a project although I did have to assemble the cart and load the bricks. I have a photo essay following that will show how I intend to use this tool.
I searched around for a suitable cart. There are many types available. Of course I needed one that is all metal (except the wheels.) I choose a product Edsal Brand that is a bolt together Industrial Service cart - 800 pound load. I didn't want a flimsy consumer home version. I bought this from Uline P# H-592, where I buy my shipping materials. Price class is $150.00
Here is a link to the Assembly Instructions. It's an easy job to assemble the cart.
|The cart alone took about 2 hours to assemble without help. Yes it can be done. Additional time required for installing the brick and determining how I wanted to lay them out.
|The bar handle and swivel casters are on the same end. It's just a typical industrial cart - this is the 40x24x32 size.
|I finally decided on this layout. Feel free to do it your way if you try this. This is not a "pound on" surface so the soft firebrick should hold up well.
|I like the large 5 inch poly wheels. No wheel locks so I will build small wood boxes that the wheels will set into (like chocks) if movement becomes a problem. It will be easy to lift the cart into the box or leave one end open and roll in.
|The bungees provide some temporary security from movement. This is not a racing cart. A metal band will be easy to make if necessary. This is not for long term storage, just when working. I don't want the tank to be hard to remove.
|This is my turbo torch. That big tip is a monster. 45,000 BTU's from that baby. Here is the story about the torch from over in the machine shop blog.
|Here you can see I have positioned the regulator toward the middle of the cart this will protect it from most damage from getting hit.
|That's a large ceramic floor tile I placed on the firebrick so I can put the vacuum table on the cart without damaging the soft brick. It doesn't have to withstand high heat.
|This is the Rio Grande small vacuum table and 9" bell jar on the floor tile. The 3 CFM vacuum pump is on the shelf below.
|On the Vacuum pump you can see the oil sight glass and various ports. The exhaust port is actually through the handle. The far end bell on the motor has a rocker on/off switch.
|The bell jar can be used to draw a vacuum on anything that fits inside. I will probably write a report on the various ways I use this chamber.
|What looks like an electrical switch is actually an air toggle switch. No electrical here. The gauge reads vacuum.
|The view you never see in the catalogue. Actually a very simple design. just the right KISS.
|The rubber square is removed (it just lays there) and this rubber ring is used to expose the hole and permit the vacuum draw on solid flasks. The casting investment is microscopically porous to air.
You can be certain I will be showing and explaining the lost wax casting process in a later review.
In addition to the propane system shown here, I also have two complete oxy-acetylene torches, one for heavy gas welding and cutting and the other is for aircraft welding. I have a nice set of double action regulators if I ever go back to gas welding. I used to be very good as it was a part of my pipefitter/refrigeration trade. I also gas welded aircraft steel tubing. I was factory certified by the now named, Harris Products Group (manufacturer) for brazing and soldering materials.
My desire at this point in time is to be able to melt non ferrous metals here on this cart. Then vacuum cast the molten metal into lost wax molds using the vacuum table shown here.
Actual production will tell me what works so the setup is subject to change. It's a great brazing table as it now looks. I hope others get a few ideas for their shop.