Clean out caps

My Question is what will work better for sealing the gases in the clean out caps that go on the out side or the ones that go inside like a cork?


Thanks

David Marin : I worked off and on for years in a small hometown type hardware store ! Generally what happened was the big box store sold an appliance,
and then we had to help them find the " Goes into " that would finish the installation, with a 30 mile round trip to the next big box store if we couldn't sell
them what they needed !

In this case, while you might have to fight to get the two parts together the most important part of the build is getting the '' Ts " that you need and then the
caps that fit. If all you can buy is the un-crimpt ones that works better than two crimpt ones and you need to hammer the crimping out without stretching
the metal !

Ask at the hardware store if they have a stovepipe crimper ! Do NOT be surprised if they want a $50 or $100 Dollar deposit to loan it out for 24 hours !

A # 10 vegetable can is 6'' inside diameter, and I have used it inplace of a cap when I had failed to account for all the clean outs I needed !

Also! It is more likely that you will need a pair of straight and curved sheet metal cutters, a saber saw sucks at cutting Pipe ! Big AL