Step 3: Exhaust gasket and prepping the sheet metal

Here are some close up pictures of the exhaust gasket. Garages that do a lot of exhaust work might have some spares or know how to get one. Take the Coke bottle with you to make sure it fits.
The gasket measurements are:
inside diameter- 2 9/16"
outside diameter- 3 1/16"
height- 17/32"
ring width- 7/32"

(Not pictured) With the Sharpie trace the outside diameter of the PVC onto the sheet metal. Cut out the circle with a jig saw. File and shape the circle on a grinding wheel or with a Dremel tool. The diameter should be 3 1/2".

Center the exhaust gasket on the sheet metal. Holding a mechanical pencil straight up and down, trace the inside of the gasket. There should be a small gap between the line and the gasket. Cut out the center of the sheet metal. I drilled some holes around the center then cut it out with a cutting wheel on the Dremel. File and smooth the edges with the Dremel. The inside diameter should be approximately 2 3/16".
to me that gasket looks familiar. I used to weld pipes. at that work place, we had to bevel the ends of the pipes to prep them for welding. sometimes the pipes had to be cut really short, like 3/4 of an inch long, and still bevel the ends of the pipe and they would look just like that gasket. many times we would cut it wrong and not know till it was beveled. we threw away many pieces that looked almost exactly like this part. with a lathe i could easily make this part. with a hand grinder i could manage to make the part with a lot of patience. but who says it has to be metal. paint can make anything look like metal. so there should be a lot of options with other materials too, right?