abs glue drip problem

We need to raise the closet flange on our toilet because we are remodelling and the new floor is more than an inch higher than the current level of the closet flange. We cut off the old closet flange, and managed to do this without removing the subfloor. The soil pipe is 3" ABS. The idea is to add a coupler where we cut off the soil pipe, then add more ABS to get it to the right height, and finally another coupler and a new flange.

Here is the problem. There are numerous ABS glue drips from the original installation that is preventing us from sliding the coupler on. Does anyone have any good ideas on how we can get the coupler on?

Thanks for any help!

Linda

old drips of glue

I dont know how much higher you are planning on raiseing
up this flange....


but you can take a fine hack saw blade and simply
cut --grind the drips of the pipe ...

then the coupling will go on...

A sharp knife or box opener can be used to shave them off. When you get them cut off and find a few small strips are still there, just scrape them.

sanding or solvents ok?

We will try these methods, but we don't have a lot of room to work, so I don't think we can get a hacksaw down in the hole (we cut the soil pipe from the inside with a drill attachment). A utility knife would fit, though. We are worried that we will shave off more than glue and will no longer get a leak-free fit with the coupling. Is this a valid concern?

We are thinking that sanding the glue off might work, but again, would we get a good fit that way? Or maybe there is some solvent that might disolve the glue but not the ABS pipe?

If we can't get the coupling to dry fit to the pipe, can we attempt to go ahead and glue it anyway with the hope that the glue solvent will disolve it enough to go on? And if we put the glue on the pipe and coupling and then still can't get the coupling on, are we in even worse trouble?

Right now the soil pipe is cut off about 3 or 4 inches below the subfloor and there is a 5 inch (or so) diameter hole in the subfloor. We took a large section of plywood underlayment off, which we will replace.

Slicing and scraping the drips won't take off that much of the pipe. When you solvent weld the fitting to the pipe, that process will take care of small scratches.