Exhaust exit in hush box

[silversport]

I am looking for input on what members who built hush box for their genset on how you exited the exhaust pipe. How much room did you allow around the pipe and wood/insulation box, I am thinking 1 inch and wrap the pipe to seal the box. Thoughts ?

[Geoff]

I think I used 4" truck exhaust pipe and made a center cover on top that fit the gen exhaust and sealed the opening.

--Geoff

[silversport]

I like it.