Saw off cast drainage pipe - jet coupling new

[nattugglan11]

Hi!

I might need to cut off a cast iron drainpipe in my kitchen that sticks out from the wall. I have a 15cm long crack in the pipe. (The pipe that goes from the sink's drain into the main stack in the house's wall.)

I think I have 2 options, cut it off, splice with a new plastic pipe and use a jet coupling as it's called. Or maybe weld the crack shut (?)

What do you think?

If welding, what type of welding is required?

If I need to cut off the pipe and make it new, how do I do it? Angle grinder or reciprocating saw? The pipe is quite thick and about 12cm in diameter, maybe. Besides the jet coupling, what is needed? Pipe reducers? Gaskets? Simple?

 

[Tompa01]

A regular hacksaw with a new blade works well for cutting. Welding cast iron doesn't work well. I have personally used a Fernco coupling when joining cast iron to plastic.

Tompa

 

[nattugglan11]

Ok,

I was thinking I might be able to avoid dismantling the kitchen, maybe I can reach to do an operation, but then I probably need an angle grinder/saw. It's a shame it couldn't be welded, that would help me immensely. Can I maybe grind the crack with an angle grinder? I mean, "smear out" the metal? Does anyone have experience?

Can't you do a repair in another way? Just a wider jet connection over the crack?

P.

 

[Koebes]

You can cheat with kallmetall (available for purchase at any fuel station). Clean thoroughly first. You can forget about smearing it I cut with an angle grinder and used a rubber transition. Simple and works well. Bauhaus had those at a good price.
Best regards, Nisse

 

[nattugglan11]

Hello again! Picking up the thread again.

I might try to cut my drainage pipe that is visible "in the air" under my kitchen cabinet. After cutting, splice with new plastic pipes. What do I need for this? Jet connection or some other rubber transition? Then you just buy pipes and assemble them? When you push two plastic pipes together, what do I need as a sealing mass in between at the joint? Nothing? Silicone?

 

[Milkshaken]

If you have a skarvmuff between the pipes, then there is a rubber seal in the muff; soap or dishwashing liquid is enough to easily insert the pipes... then the rubber seals... I recommend nothing other than a muff....

 

[nattugglan11]

If you have a skarvmuff between the pipes, you have a rubber seal in the coupling, then soap or dishwashing liquid is enough to easily insert the pipes... then the rubber seals it... I recommend nothing but a muff....

Is it called skarvmuff in professional terms? I can't find any results when I search on Google/images. Not plumbing items, at least.

 

[Spoon195]

I have cut cast iron pipes with an angle grinder, minimal vibrations.

Joint sleeve in the cast iron pipe that the plastic pipe fits into. Tight and simple, no problems.

 

[nattugglan11]

I have cut cast iron pipes with an angle grinder, minimal vibrations.

Connecting sleeve in the cast iron pipe into which the plastic pipe goes. Tight and simple, no problems.

The connecting sleeve is placed outside the iron pipe, right? ..and over the connecting plastic pipe.

 

[v-g]

It is indeed possible to weld cast iron, but then it's "filler welding" that can be done. Stick weld and the right rods can make it work.

To properly weld cast iron, it should be preheated and maintained.

However, in reality, there is no load on the pipe, so it _can_ work. The question is, why did it crack in the first place?

 

[nattugglan11]

You can indeed weld cast iron, but it requires "filler welding" which can be done. Stick welding and the right rods, it's possible.

To properly weld cast iron, it should be preheated and maintained.

However, there is really no load on the pipe, so it _might_ work. The question is why it cracked in the first place?

Ahh, finally someone saying something I want to hear :-D

But maybe these tools and techniques are overkill? MIG welding and gas welding are the ones I'm familiar with. Is stick welding the same as MIG welding?

No, no load on the pipe, the crack is in an "okay" position as well. I don't know how the crack happened, no force was involved since it has always been built-in under the kitchen cabinets. During renovation, no force was applied either. So I hope the pipe is good enough that it won't crack further. Otherwise, it will be angle grinder and new pipe.

 

[Spoon195]

The coupling sleeve is placed outside the iron pipe? ..and over the connecting plastic pipe.

maybe it's not called a coupling sleeve what I meant... I used something like this.
http://www.jula.se:80/e-Sales/esa/ItemDetails.jsp?@where.ItemID@EQ=450767


P.S
cast iron can be welded with a regular MIG welder, but it can't withstand any stresses! for example, you cannot get two cast iron pieces to hold together if they are to be subjected to any forces such as vibrations. But a crack you should be able to seal without major problems.

 

[nattugglan11]

maybe it's not called a union coupling that I meant... I used something like this.
[link]


P.S
cast iron can be welded with a regular MIG welder, but it can't withstand any stress! for example, you can't get two cast iron pieces to stick together if they're going to be subjected to any forces, like vibrations. But a crack you should be able to seal without major problems.

Ok, thanks!!

 

[v-g]

The tools are a welding transformer, slag chipping hammer, welding screen and gloves, as well as an angle grinder to clean thoroughly with. If accessible, you can grind out the crack (but not entirely through) to achieve the best possible little adhesion. You can essentially weld with almost anything, the problem is that it doesn't adhere much better than Plastic Padding, meaning it's just a layer on top.

The absolute best is if you can get hold of another piece of pipe of the same type and test weld on it.

I haven't welded with such rods myself but know that it's possible, for example, old engine blocks I know can be repaired this way. However, not, as noted, where there is a significant load.

Welders are available in many garages/Biltema/Clas Ohlson, etc. Rods can be found at the hardware store or similar.

 

[nattugglan11]

The tools are a welding transformer, slag hammer, welding screen and gloves, as well as an angle grinder to thoroughly clean with. If you have access, you can grind out the crack (but not completely through) to get the best little adhesion possible. You can basically weld with anything, the problem is that it doesn't adhere much better than Plastic Padding, i.e., it's just a layer on top.

The absolute best is if you can get a hold of another piece of pipe of the same kind and do a test weld on it.

I haven't welded with such rods myself but I know it's possible, e.g., I know you can repair old engine blocks that way. However, not in cases where there is significant loading.

Welders can be found in many garages/biltema/clasohlsson etc. Rods can be found at the hardware store or similar.

Thank you!!!!

But can one say that plastic padding might be as close as I can get to a welding result in my case and 20 times easier/cheaper? I have neither welded nor used padding ever, so I don't know the properties.