How to Join cast-iron pipe?
These days, cast-iron pipes are joined with easy-to-use neoprene gaskets, or no-hub couplings. Both approaches replace the traditional method of packing the joints with oakum and lead wool. While the lead-and-oakum system makes for a tight and durable joint, it takes skill and experience to execute properly. Even though neoprene gaskets are easier to use, they do have one drawback; they grow stiff in cold weather. So keep them in a warm location until just before you use them.
The tools and materials you will need: neoprene gaskets, lubricating soap, small paintbrush, file, hubbed piping, shovel, fittings.
1. Before installing the gasket, smooth the inside of the fitting with a file or abrasive paper. Then push the gasket into the fitting. Roll up the bottom half and press in the top half until it's flush. Then push the bottom half down in place.
2. Before joining the pipe and fitting, lubricate the gasket with liquid the dish soap(inset). Don't use a petroleum-based lubricant because it could damage the neoprene. Push the parts together using a shovel until the pipe bottoms out.
3. Fittings are installed just like pipe sections. First lubricate the gasket; then push the parts together until the fitting bottoms out in the end of the pipe. If the fitting binds a little, simply wiggle it from side-to-side as you push it in.