Re: atm V1 #146

Richard Schiek (richard@chemeng.Stanford.edu)
Mon, 3 Jul 1995 08:54:03 -0700

|
| >I've made an 8" telescope tube out of a 10" diameter 'sonotube',
|
| Does anyone have any advise as to the best way to cut a 15"ID length
| of sonotube, making it clean and square?
|
I used the wax paper method in Berry's book, "How to make a telescope". Take a long sheet of wax paper and wrap it at least twice axially around the tube--for a 15"ID tube, the wax paper should be about 2*(2 * 15 * 3.1415)=188 inches long so you can go around the circumference twice. When all the edges of the wax paper "sandwich" are aligned and the wax paper is pulled tight, the edge of the wax paper is perpendicular to the tube's axis. Mark the tube with a pencil and cut it slowly with a hack saw to get a nice even edge.

| How about the best way to finish it, so that it is good and flat
| black on the inside, and waterproof all over?
|
Just peal off all the wax covering that was on the tube when you bought it and put several coats of wood primer on it. After about three coats of primer it should be very waterproof.

Hope this helps,

Rich