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.

Thanks,

MC

On May 2, 9:43�pm, "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.

Thanks,

MC

all blades are not created equal, what brand of sazall blade are you
using?

lubing blade with oil may help prevent blade dulling like it does with
drilling in steel.

"MiamiCuse" wrote in message
...
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.

Thanks,

MC

Ratchet cutter http://www.plumbingsupply.com/snapcutters.html Ratchet
cutters would be best. If you have access all the way around the pipe a cut
off wheel in a peanut grinder.

"Sac Dave" wrote in message
...

"MiamiCuse" wrote in message
...
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.

Thanks,

MC

Ratchet cutter http://www.plumbingsupply.com/snapcutters.html Ratchet
cutters would be best. If you have access all the way around the pipe a
cut off wheel in a peanut grinder.

Thanks but I cannot use this. I am trying to cut away a section that was
damaged by using a chain cutter. I need to cut it the old fashion way
instead of relying on it to break at the weak spot.

MC

On May 2, 8:26*pm, "MiamiCuse" wrote:
"Sac Dave" wrote in message

...



"MiamiCuse" wrote in message
. ..
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.

On 2009-05-03, MiamiCuse wrote:

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 have had good success cutting new cast iron DWV using a Lennox
reciprocating saw blade marked 800RG, "Medium Carbide Grit Tile, Clay
& Pipe". Took me a minute or two to cut through 2" CI with low to
moderate pressure. Or you could try Lennox's new diamond
reciprocating saw blade, which is supposed to work even better,
although I've not tried it.

Cheers, Wayne

On Sat, 2 May 2009 18:49:38 -0700 (PDT), bob haller wrote:

On May 2, 9:43?pm, "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.

Thanks,

MC

In the metalworking/machining trade, cast iron is not THAT hard. It does,
however produce no "chips" when being cut. Rather, it's a powdery residue that
clogs saw teeth and drill flutes. I'd select a bi-metal (high speed steel
teeth) sawzall blade with about 10 teeth per inch and use a lubricant such as
kerosene to keep the teeth flushed out. Cast iron can be cut dry, but, again,
keeping the saw teeth clear is important. I've had some success with candle wax
at times, too. But it requires a helper to hold the candle next to the blade
while it's sawing. Blasts of compressed air work, but everything within 10 feet
is gonna be black. Your face included

Wayne Whitney wrote:

On 2009-05-03, MiamiCuse wrote:

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 have had good success cutting new cast iron DWV using a Lennox
reciprocating saw blade marked 800RG, "Medium Carbide Grit Tile, Clay
& Pipe". Took me a minute or two to cut through 2" CI with low to
moderate pressure.


I think 'low to moderate pressure' bears repeating. It is
instinctive to add pressure when things aren't cutting- but light
pressure and pipe cutting oil are your friends.

Jim

Get a weld cutting thin abrasive disc for the grinder. Done in
seconds if you can get all the way around the pipe. Grit edge
Sawzall blade will work fine, but slow. Regular steel cutting
Sawzall blades won't work as you already know.

--
______________________________
Keep the whole world singing . . . .
DanG (remove the sevens)




"MiamiCuse" wrote in message
...
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.

Thanks,

MC

"MiamiCuse" wrote in message
...
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.


Some pipe is just tougher than others. I have cut through many of them
using a 6tpi Lennox blade that I buy at the plumbing supply store with no
problems. Cutting a well baked vent stack in an attic this past summer I
even broke down and bought a Lennox diamond dust blade which eventually cut
through it. It was still a long process.

Keeping the blade lubed with a water mist from a spray bottle helped. It
still took a long darn time.

Colbyt

MiamiCuse wrote:
"Sac Dave" wrote in message
...
"MiamiCuse" wrote in message
...
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.

Thanks,

MC

Ratchet cutter http://www.plumbingsupply.com/snapcutters.html Ratchet
cutters would be best. If you have access all the way around the pipe a
cut off wheel in a peanut grinder.

Thanks but I cannot use this. I am trying to cut away a section that was
damaged by using a chain cutter. I need to cut it the old fashion way
instead of relying on it to break at the weak spot.

MC

If you are only removing a chunk off the
end, say less than about 4", you can
use the method I used in a toilet pipe
in a concrete floor. I needed to install
an offset flange. I used a 2 1/2" cut
off wheel in a 4" drill bit extender. I
chucked the whole thing into a router.
You can't run the router at full speed
as slight unbalances will destroy the 4"
extender. It could also be quite
dangerous if it flied apart. I used a
adjustable auto-transformer
(Variac) to keep the speed slow. I
worked from the inside of
pipe from the open end and slowly but
surely, cut through. I did have a nice
flat spot to set the router faceplate
while going around (the old flange). As
I recall, it only took about 10 minutes.

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

On May 3, 12:22*pm, Art Todesco wrote:
MiamiCuse wrote:
"Sac Dave" wrote in message
. ..
"MiamiCuse" wrote in message
.. .
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.

Thanks,

MC

Ratchet cutter *http://www.plumbingsupply.com/snapcutters.htmlRatchet
cutters would be best. *If you have access all the way around the pipe a
cut off wheel in a peanut grinder.

Thanks but I cannot use this. *I am trying to cut away a section that was
damaged by using a chain cutter. *I need to cut it the old fashion way
instead of relying on it to break at the weak spot.

MC

If you are only removing a chunk off the
end, say less than about 4", you can
use the method I used in a toilet pipe
in a concrete floor. *I needed to install
an offset flange. *I used a 2 1/2" cut
off wheel in a 4" drill bit extender. *I
chucked the whole thing into a router.
You can't run the router at full speed
as slight unbalances will destroy the 4"
extender. *It could also be quite
dangerous if it flied apart. *I used a
adjustable auto-transformer
(Variac) to keep the speed slow. *I
worked from the inside of
pipe from the open end and slowly but
surely, cut through. *I did have a nice
flat spot to set the router faceplate
while going around (the old flange). *As
I recall, it only took about 10 minutes.- Hide quoted text -

- Show quoted text -

Interesting, I had to cut out some PVC pipe to replace a toilet flange
and did the same thing using. I had started a bathroom remodel and
wasnt having enough free time to finish the job so I hired a
contractor. He told me he was going to have to charge me extra for
demolishing the floor around the toilet flange so he could replace it.
Once I rigged up a way of getting the cutoff blade deep enough in the
hole it took less than a minute to do the job.

JImmie

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

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

wrote in message
...
On May 2, 8:26 pm, "MiamiCuse" wrote:
"Sac Dave" wrote in message

...



"MiamiCuse" wrote in message
. ..
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.

Thanks,

MC

Ratchet cutter http://www.plumbingsupply.com/snapcutters.htmlRatchet
cutters would be best. If you have access all the way around the pipe a
cut off wheel in a peanut grinder.

Thanks but I cannot use this. I am trying to cut away a section that was
damaged by using a chain cutter. I need to cut it the old fashion way
instead of relying on it to break at the weak spot.

MC

if snapcutter is out, try lennox diamond blade for sawsall.

I found one at Lowes and bought it. That one did the trick and cut in about
10 minutes. Thanks!

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