YAG Laser: Water Management

This thread is for discussion and updates around the YAG Laser Water Cooling and management.

I’ll move the posts from the megathread to here. atm the main person driving this is @Eris, but I’m sure he’d love help.

@riumplus if you’re still around, maybe you’d like to chime in on the water situation? Previous owner said they were told to use only distilled water and change it every 2 weeks. They just used tap water through a carbon filter and changed it every 2 weeks as advised.

I believe you use some manner of additives in the small laser cutter water loop to keep the water from fouling, which I’d imagine we should do rather than trying to constantly change the water in this.

I can get details on this from work, I know we do exactly that with our machines.

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I have an industrial water deioniser that was used for jewelry manufacture. I don’t have the water pressure to use it at home. It takes standard filters like the lasers existing filters, and the RO filter lasts about 5 years, we may need to buy a new one. Let me know if its a good idea and i’ll donate/set it up near a water / drain and the space can have RO water.

Jewellery also needs RO water, as does the electrolysis coating machine under some circumstances. Who’s the HSBNE “official” plumber ???

Just to clarify, is there an issue with the filtration system that came with the cooler?

Nah, it/the filters under the sink will be fine for filling the tank. I believe the best course of action is to use inhibitors etc in the water as @wixted previously mentioned to stop microbial/algae growth rather than constantly replacing it.

Going for a “don’t change the water weekly and let chemicals work their magic” option is going to be better in the long run for us, as it’s much less labour and maintenance intensive. Otherwise we forget to change the water and bam, full of nasty. Reverse osmosis would help reduce this, but still needs all the labour and wasted water from changing it all the time.


(YAG laser cooling) What are the inhibitors? Could ethylene glycol be used instead so we can forget about coolant changes?
Electroplating and casting jewellery uses so little deionised water that it would be easier to just buy jugs of it when needed.

Inhibitors fall into two broad categories - those used to inhibit microbial contamination and those used to inhibit cooling water circuit corrosion.

For anticorrosives, the inhibitor(s) used depend on the cooling circuit design and materials. Molybdates, borates and nitrite/nitrate combinations are typical, but plenty of different systems exist. If you can let me know the circuit volume and material composition I can recommend a formulation. I’m guessing it’s a relatively small volume circuit, so you won’t need much - I can probably supply it from sample stock.

For microbial inhibition, common agents are sustituted isothiazolines (MIT/CMIT) or QACs - these are usually incorporated into the standard “closed loop” solution or can be used as stand alone products. Ditto the comment above re sample stock.

SDS would also be provided (of course).

Ethylene glycol solutions still require inhibitors.

Also, I can let you have some DI water if you need it - we make plenty of it (about 12T/day).

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Love your work. The cooling circuit isn’t massive as you’d imagine, the largest part is the reservoir on the chiller. From memory that looked like stainless steel. Given it had been running without any inhibitors and there’s no major signs of corrosion I would assume the microbial inhibitors will be the main thing.

Will have a further look and try to scope out circuit volume/materials.