Boss strap on iron waste

[gavingas]

I need to drill into an iron soil pipe for a 32mm waste. What drill bit should I use and which is the best boss strap to use?

 

[chrishutt]

Using a plastic strap boss on a cast iron pipe would be considered a bodged job. You would presumably use silicon to seal it, but the different expansion coefficients of plastic and iron might cause it to fail eventually. I'm not sure about cutting iron, but would think a hole saw, possibly lubricated with light oil. Blade will tend to overheat.

Hopefully other posters will be able to advise on proper way to do this.

 

[kevplumb]

plumbcentre do a strap boss for cast

 

[chrishutt]

Try this http://www.constructionbusinessnet.com/mechanicalexplorer/news/78.html

 

[gavingas]

Thanks for the advice. Thinking a little more on the problem: I suppose I'd just mark the hole and drill a load of small holes around it with a HSS bit. Plumbcenter's boss is likely to be as good as any.

Thanks again

 

[ChrisR]

CI is actually quite soft and quite easy to cut with a half decent holesaw.
I've failed on about 3 occasions to make a long-term leakproof seal with a plastic strap on a CI, even with lots of various silicones, and noticed that everyone else's seem to be the same - they leak eventually.