Does anyone have some Babbitt?

[pontiac428]

Okay, I'm convinced. I can use a piece of a soft pine paint stirrer to read the babbitt. How about the base metal, how much should I preheat it?

It's crazy how expensive casting clay is here. It's sold as a product called Gun Gum in Europe for a couple bucks an ounce. I think JB Extreme Heat is its US market equivalent. I need to make an internal mold/plug to form the drive hex inside the shaft. I am prepared to use aluminum 7/8 hex with a concentric plug on the back, sealed with casting clay, and make the plug for the other end out of casting clay with a wooden backer. Then I will pour into the sprue hole that can be seen in this pic.

I've been rushing to get projects completed so I can be without my lathe while I do this, and I'll give it a go next week.

I learned all about why moulds should be dried with heat back in high school. A kid named Chuck was making some lead fishing weights in our foundry class where the warning about water was issued. This other kid who was nothing but trouble named Pierre decided to spit in Chuck's mould when he wasn't looking. These were big 3 oz trolling sinkers, and he was sprayed in the face with hot lead. Chuck was lucky he wore glasses.

Thanks for the input, guys. I'm excited to do this.

 

[Charles scozzari]

I never really preheated the area other then to make sure it was dry. If their was a situation where I was unable to seal the area with fireclay I had great success using Teflon rope packing/seal around large shafts. It comes in many sizes and is not a lot of money. maybe in some way/shape you could make use of it.

 

[pontiac428]

How about adhesion? To prevent adhesion to the inner form, I was planning to smoke it black with acetylene flame. My thoughts on preheat are to promote adhesion to the inside of the tube. Is fluxing a good idea, or a bad one? I have borax and Sta-Silv. Those would be water based fluxes, so probably not a good idea. I can dope with dry borax by torch heating and dipping the part in powder, it sticks that way. I just want to make sure I get a solid grip between the geared shaft and the babbitt.