Leak in vacuum system (diffusion pump?)

[Dennis P Brown]

While excess volume isn't desirable, the real killer for any system is the number and size of connections! This is where 99.9% of all leaks occur. Making good connections isn't always easy and leak checking is essential and not always easy; and even then, very minor leaks can occur (a damaged surface) require special methods that aren't easy to do.

Not that volume isn't a serious issue for any fusor - virtual leaks from the vast wall area is a killer, too. But for high vac systems (bake outs, inert gas flushing, and rare exposure to air) this isn't the problem for reasons given. Not so for most fusors. They are often open to the air, few have bake out abilities nor dry air flushing. As such, as Richards and others point out, large volume vacuum components aren't good.

The only way to deal with it is costly - adding bake out wraps, creating dry air flushing and good leak detection methods - in the short run, it is far less costly and easier to do as Richard suggests and get the adapter made to eliminate as much large volume parts as possible.

[Thomas Sheeleigh]

I will write this first build down as a learning experience. Luckily, most of the fittings and hoses I have were bought used and cheap so although it is money wasted, it is not as much as it could have been. However, I am still not certain that there is no leak in my diffusion pump as I still haven't been able to make sense of that popping noise. I will have to inspect it more closely when I rebuild. Thanks again!

[Richard Hull]

Not problem, first builds are always time consuming, costly and disappointing. Learning always involved time and treasure. It is the norm in vacuum work.

Richard Hull