What chemical do you add to your laser chiller?

Hello,

What chemical is most common to add to a laser chiller to keep it running properly--that is a laser chiller for a small laser engraver? I have read so many conflicting comments about different chemicals and about what not to use. I heard that antifreeze (inexpensive and easily purchased from the auto parts shop) does a good job. But some websites say it is no good.

Also, how often do you change your water? The Chinese manuals say every three months--but that may be a suggestion because of their water supply quality.

But, I have also seen the aluminum cooling parts of the laser optics corroded (these are not anodized). The corrosion is more apparent when you pull off the coolant line. A heavy dosage of Dowfrost is recommended by Coherent for their Gem series lasers as they have internal aluminum parts for cooling.

A laser engraver sign guy customer decided not use anything and see what happened in the photos.

Another laser cutter customer that cuts fabric asked about reduced laser power then provided the photo with the pinched hose.

Any suggestions or comments appreciated.

Thanks.

contamination_1.jpg


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contamination_3.jpg

pinched_contaminated_coolant_hose.JPG

aluminum_parts_corrode.jpg

Attached Images

• pinched_contaminated_coolant_hose.JPG‎ (11.7 KB)
• contamination_1.jpg‎ (50.1 KB)
• contamination_2.jpg‎ (58.5 KB)
• contamination_3.jpg‎ (52.2 KB)
• aluminum_parts_corrode.jpg‎ (67.2 KB)