120 Gallon tank Cut down

[smokincookie]

I have a 120 gallon LP tank it measures 76"long and my plans are to use a 48" piece cor the cook chamber and a portion for the fire box, I have the calculator but am having trouble understanding. I need to know how large of an opening to have at the fire box to cook chamber. Thanks for helping a seemingly incompetent builder

 

[smokincookie]

I just wanted to thank this forum for all the help I didn't receive, I suppose you I have to look elsewhere for help!

 

[imafishingfred]

Where did you get your calculations from? Try here, http://www.smokingmeatforums.com/a/reverse-flow-smoker-how-to-calculate-build-tutorial

down the page a little tells you about the football type cutout. You could also post your numbers here for everyone to look at. We haven't gotten enough info from you to be able to help.