Leaking joint between strap-on boss and soil pipe

I have no idea if it would work, but how about mixing shavings of the right plastic with the solvent and using it as a filler?

Are you sure both parts - the down pipe and the boss- are solvent weld type?

Some pipe systems us plastic which doesn?t ?melt? when you apply the solvent , both need to melt so you get a weld.

I?ve not encounter it with soil pipe but I?ve made the mistake with other waste fittings !

If it hasn?t welded, that would be my guess.

How to fix it. Either get the right boss or try ensuring the waste goes into the stack a gnats and try silicone but that isn?t something I would rely on long term.

I've come across polyethylene pan connectors that are pretty much insoluble in every known solvent. PVC and ABS, if you use the right solvent, are soluble and so weldable.

I believe the orange/brown underground soil pipe (I used it for the stack pipe because I had it left over) should be solvent weld'able (according to M'sieu Google). Although I was very tempted to squirt some PU glue all around the fitting I decided to do the job properly and have just cut-off the old boss (what did we do before multi-tools?) - parts had welded but others hadn't. I'm now about to buy a mechanical boss but have the problem of converting a 54mm hole in an awkward location into an accurate'ish 57mm hole without being able to recreate a centre.

I thought the orange pipe was for underground, and always used push fit sockets?

If you're using a boss connector it doesn't have to be accurate. A Dremel with a carbide bit will help speed things up.

In fact it was fairly easy to enlarge with a sharp, rigid, knife and a half-round rasp and file. The boss is now fitted and all is well with the world, but it very nearly wasn't; the expanding bung requires the fitting tool to be rotated *anticlockwise, initially I turned it the "normal" way and the top-hat bush and rubber bung came close to falling inside the pipe!

My understanding too (although I am fairly sure it won't be PE, and therefore either ABS or PVC, and solvent weldable). The problem is that it will not be fully UV resistant.

It is made stronger for underground use but everything I have read suggests it is OK with solvent adhesive. When I removed the failed joint some of the solvent had "melted" the downpipe but there were gaps elsewhere. I can only surmise that either the thing didn't seat properly or I didn't leave it long enough.

In my application it's internal and inside boxing.

Maybe the non-stuck parts needed degreasing?