On Sun, 3 May 2009 20:12:30 -0700 (PDT), bob haller
wrote:

On May 3, 5:01?pm, "Don & Lucille" wrote:
Get a reciprocating blade desingen for cast iron!!"HeyBub" wrote in message

m...



MiamiCuse wrote:
I need to cut a 3" cast iron vent pipe to tie to a new PVC vent.

I am using a Milwaukee sawzall with a metal blade and it kept
skidding and wouldn't start the cut at the right place. ?I then used
a 4-1/2" angle grinder with a metal blade and cut a little notch and
now I can engage with the sawzall without skidding.

However after 15 minutes of cut I don't think I am making a
significant dent at all.

I used the same sawzall and cut through copper and EMT electrical
conduits like knife through butter. ?But this CI pipe I am not making
any progress.
I can't use the angle grinder there is simply not enough room around
it.
I went to HD and they recommended a "grit iron" blade. ?Got that and
it seems to cut a little bit, but again after 15 minutes, I am not
even 10% through the pipe. ?The way I am going it would take 10 hours.

I remember seeing another blade named "ugly metal blade" I wonder if
that would be better.

Is there a better way to do this?

I know a chain cutter may be used, but I want to avoid it. ?Part of
the reason I am cutting this is because the lower section was cut by
a plumber who used a chain cutter but created a vertical crack line
and now I am trying to cut away all the damaged section.

If all else fails, try:

* Thermite
* Primacord- Hide quoted text -

- Show quoted text -

some is tougher than others because it may have been recycled stell
from something really tough.

scrap varies a lot depending on what the scrap came from.

cast engine blocks make tough drilling and cutting in their second life


Even more important than the content of the cast is the processing.
Chilled cast is a REAL bugger to cur. Case is hard like glass