Hardwater "killer of tubes"

[Pedro_Hernandez]

Morning

I found the old tube that was fitted to the
School's 1290 nefore I started their two years ago. Unfortunately the damage had already been done by the time I was able to get my hands on it.

As you may of guess down our part of the world the water is very hard.

It took less than a year for the limescale damage to render the tube to about 20 % power and a warped tube mirrror that gave a figure of 8 beam scorch pattern. To add insult to injury the mirror and optics didn't look like they had been cleaned and this was what was left of the lens !


Incredibly no one had thought to tap up the Science Dept for distilled water !

Needless to say I've used distilled water ever since and inspect optics every day and clean as required.

P.

[tweakie]

Hard water is not good news for tubes and distilled water will always be best.
However, the lime scale may reduce the effectiveness of the cooling water but because the water jacket is not directly in the path of the laser beam any scale produced cannot directly reduce the output power of the tube.
But, indirectly, the metal cooling jacket fitted to the business end of some tubes can be cause for concern because scale or corrosion builds up internally and reduces the water flow rate and this could cause the tube to overheat and lead to a reduction in the life expectancy.

Just a thought.

Tweakie.

[endcan]

we use de ionised and corrosion inhibitor which is in the coolflow antefreeze and have no issues. with our old aircooled unit the build up of dust in the laser dragged in by the cooling fans killed the last tube...

[Spooky]

On the lens Pete that's deposit by the look of it from the upper side rather than blowback from the lower side the best example of why a lens should be removed occasionally to clean BOTH sides

best wishes

Dave

[PhillyDee]

I always clean both sides personally. If its going to be done, it gets done properly! I find more deposits on the rear than on the front. The air assist sucks the air from the top in a venturi effect.

[Pedro_Hernandez]

I always clean both sides personally. If its going to be done, it gets done properly! I find more deposits on the rear than on the front. The air assist sucks the air from the top in a venturi effect.

Yeah I always clean both side's, it's a shame that it was alowed to get into such a state in the first place. It would seem that before I joined the department it wasn't treated very well.

Below is a pic of a test Chris asked me to send not long after I took over, doesn't need any explanation !.



Needles to say Chris came down with a new tube and fitted it, I got the Science block to distill me some water and not had any hardwater problems since.

Pedro