Connecting a 1 1/4" plastic waste into a cast iron soil Drainage and wastage systems and plumbing help, advice and answers

[Johna7770]

Can anyone tell me if there's any way of connecting a waste pipe from a sink into an external cast iron soil pipe?

Thanks,

John

[thedoctor]

See our projects section on plumbing in a dishwasher and washing machine. You will see a strap on boss being used and this can be done with cast iron also. You will however need a very good drill with some expensive hole cutting drill bits. It is very often easier to replace the cast pipe with plastic.

[Johna7770]

What kind of hole cutting drill bit is recommended for drilling a 32mm hole into a cast iron soil pipe?

The pipe is in good condition, but is original 1930s. Do I stand a reasonable chance of drilling it without breaking it?

[ALDA]

J,

IT WOULD HAVE TO BE AN HSS OR CARBIDE FINE TOOTHED CUTTING TOOL.

CUTTING AT A CONSTANT LOW TO MEDIUM SPEED AND STEADY MEDIUM PRESSURE I THINK YOU WILL BE SUCCESSFULL.
(CUT DRY, DONT USE LUBRICANT OR WATER TO COOL)
(COMPRESSED AIR CAN BE USED TO COOL)

MOST BREAKAGES OCCUR THROUGH EXCESSIVE VIBRATION OR JARRING. SO TRY HARD TO AVOID BOTH.

BECAUSE THE SURFACE BEING CUT IS CYLINDRICAL AND THE END OF THE CUTTER IS FLAT, THE VERTICAL CENTRE OF THE HOLE WILL BREAK THROUGH FIRST AND THE SIDES LAST, SO TRY TO MAINTAIN GOOD DRILL SQUARENESS TO PIPE.

ANOTHER POINT TO WATCH OUT FOR IS WHEN CUTTER IS BREAKING THROUGH. TRY TO PREVENT THE DRILL KICKING AND BITING IN.

"ALL THAT AND A BIT OF GOOD LUCK".

ALDA.