Slip Fitting On Top Of Black Tank To Toilet

[Radman]

I recently purchased a new black tank for the 72 overlander. I however ordered it with a 3" slip fitting that has a verticle lip of about 4.5" that sticks up from the top of the tank. No threaded (female) receiver for a threaded flange to secure the toilet to the tank. Live and learn. I guess if this is the worst thing that happens in my rennovation/ restoration than I am in good shape. BTW the tank is made of plastic and currently the floor is out as is the new tank. So access is not a problem. The new toilet that will replace the old one will also have a threaded flange set up like the old tank had.
Do I grind this thing flush with the top of the tank and epoxy or glue a new inlet adapter in it's place of what? Anyone dealt with this one before? What are my options at this point. I hope I have given everyone enough info. to get a wee bit of help. No pun intended.
What to do? What to do? I just want to do it right the first time. Thanking everyone in advance.

[markdoane]

If it's a 3" slip fitting, you should be able to slip a 3" ID ABS tube inside of it. Glue a closet flange on top of the 3" ABS and you should be able to make it work just fine.

You can shorten the 4 1/2" extension to about 2", enough that you can get two big hose clamps on it. I usually heat the slip fitting with a hot air gun to soften it up a little before I tighten down the clamps.

[Radman]

Now that is a great idea! Why didn't I think of that? Thank you for your help.

[Wabbiteer]

Looking at cracking pattern around the threaded flange of my old BW tank, I will be tempted to add weight to tank interior before any final toilet mount & pipe fitting occurs - allow everything that can crush down to get it over with, tank wall flex, hangers & box and insulation.... if there is rebound better to have empty tank weight pressing up then full tank hanging and bouncing; BW tank capacity is 17 gallons so 140 pounds of clean HOT water in tank and a few hours to settle before final fitting for this camper!!

Attachment failed; it was clean-ish BW tank flange...