Super tiny tube bubbles

[Keith Winter]

I installed my new efr glass tube in my Chinese laser I had some super tiny bubbles circulating through every now and then. (less than half a mm) I cannot see anymore after circulating for 10 minutes. Is this anything to worry about them happening again or is it no biggie unless they are get stuck in the tube?

[Bert Kemp]

I wouldn't worry , I had some big bubbles when I fire this up again after a 2 month shutdown they went away after 10 mins or so. I shut my pump off after each use and sometimes I get a bubble when I start it back up but as long as the pumps running the bubbles stay gone.

[Dave Sheldrake]

Even a fully submerged pump can cause bubbles Keith, it's Cavitation (the same thing that erodes ships propellers) I tend to keep my pump units switched on 24/7 to reduce it.

Yes it can happen when the machine is running over time but in general due to the housekeeper joints on the output coupler and stainless full reflector cap there isn't any danger of any glue bonds letting go quickly. So keep an eye on the tube but it's nowhere near as dangerous to the tube as it would be in a full glass pipe :)

[Keith Winter]

I haven't seen them appear again but if they don't get caught up it sounds like they are ok. Thank you.

[Ron Gosnell]

You are good to go Keith. I had them for the first 30 min or so on the new install.
I just kept the pump running and like you they went away. They may return if you
don't run the machine for few days but now they instantly disappear in under a minute or so

Gozzie