TromboneChat

How similar are 3B and 606 Bells? They appear to have the same taper, just the stem of the 606 is a couple inches longer due to the way the bell section is built.

I have a 3BF that experienced some damage in shipment and the bell rim cracked in 2 spots due to the creasing. It plays well, but I am worried about long-term issues, especially while using bucket mutes or extended plunger playing. Just trying to figure out a remotely economical way to make it durable for everyday playing needs.

Any other ideas/suggestions? I was also thinking a screwbell mod, but have not been comfortable with the added weight that the hardware adds.

A couple of inches could have profound consequences for the tuning of the horn afterwards. I'm just not thinking that a 3BF and a 606 have enough in common, even if the dimensions of the bells were identical, to make such a modification something someone would want to perform with. Horn (French) players cut bells and make them removable all the time and consider the added weight of the collar trivial. The collar of a French Horn bell attachment is at least double or more the size of the collar of a Trombone bell attachment. FWIW. You would still need to find a suitable bell in any case. You might be better off trying to find an entire bell section with F att. used that will work with your slide. You realized of course at that point you are more than 1/2 way towards a new bone ...

Get a good repair person to patch it.

Allied lists a replacement bell which retails for over $200, but for some reason, they label it as a 607.

Conn/Selmer notes the same thing. The 3B bell is cross-listed with the 607, (TM09016) while the 606 has its own designation (TM15016). The 3B bell is significantly more expensive than the 606, so I assume there's a clear difference between the two.

If it were me...
I'd do the screw bell and use the flare from the 606.