cloud on mirror

[Marc Myer]

I normally have cleaned the mirror on my Epilog Mini in place, following the instructions and being very careful.
But I pulled out the mirror this time and found a light halo or cloud effect that shows on the mirror, and it won't come off.
It's about 1/2 the size of the mirror, roughly ovoid in shape. Is this a problem that would warrant replacement? I haven't noticed a significant performance difference, but I don't do much repetitive work.

[Bruce Volden]

It gives you time to start looking for a good price on a replacement mirror as most likely you will need one in the future. I had the same thing happen on one of my machines and ended up replacing the mirror a couple months later. HTH

Bruce

[Kim Vellore]

When my laser tube was dying I was with the tech support on the phone and one of the things I was asked to try was to put a masking tape in front of the mirror and fire the laser to see the alignment. After I did that there was a small cloud like a smoke mark on the mirror, I thought I would clean it later. It never came off when I tried to clean. Now years later it is still there but I do not see any degradation. I guess there are different type of cloud marks that could happen on the mirror, some are benign.

Kim

[Martin Boekers]

These mirrors are what they call "front surface" mirrors. They should be handled carefully, avoid fingerprints or other contaminants.

When you clean it make sure it's absolutely dry before you laser with it.

The laser can vaporize any liquid (or glue from tape) and cause a clouding.

Marty

[Dave Johnson29]

Hi Marc,

Can't help with the mirror, but you may be surprised how little difference a cloud on the mirror actually makes. Probably less than 1%. It is not until the goop builds up sufficiently to absorb some heat that the losses become noticeable.

If it is still doing what it used to and the goop will not come off then keep going until you need two passes for cutting something you used to do in one.

Either that or spend the money and keep the clouded one as a spare. Personally my view of your problem is, ain't broke yet. :)

[John Noell]

If you do need a new lens, I bought mine from these guys: www.laserresearch.net. Good price and excellent service.

[Rodne Gold]

The mirrors are normally polished steel with a gold plating
You can try something other than lens cleaner on em , like acetone , thinners , benziene etc - IE a solvent ..just be careful if the mirror is glued to the backing plate when using solvents
Use them the same way as you would clean the mirror - ie the drop and drag method. lay the lens cleaner tissue on the mirror , drop the cleaner on where the lens is an drag the tissue along the mirror.