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Laser Cutter

Water replacement
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The pump uses a magnetically coupled plastic impeller but the housing is epoxy painted metal. It's rated for mildly caustic liquids. Not so much for electrolytes.

We used to be having electrolysis issues with the copper coils that was leaving a green deposit everywhere but with the new pump arrangement the ground potential has moved to the pump and it's attacking that so yes the deposits we are seeing is likely from the pump. To stop that you would have to remove the grounding from the pump and the chiller and that's simply not going to happen. We could try a full-duty glycol pump as all-plastic models are available but without solving the electrolysis issue permanently it will just go back to attacking the chiller coil again.

A flush with CLR or possibly even engine flush should work but it would likely dissolve the surgical tubing in the system.

Speaking of which, the air line has hardened and is quite dirty. It would be advisable to replace that soon.

You were saying earlier that there was corrosion on the pump impeller. This could be the metal being redeposited. It could be ordinary scale. A quick rinse with CLR might clear it up. We should also add RV antifreeze for corrosion resistance. Its not recommended to use automotive antifreeze.

Water replacement has been completed. The last replacement this year will be in December.

I am starting to notice a buildup of white material inside the laser tube's water jacket. I cannot tell what the contamination is however because it is not a greenish tint it isn't anodizing of the copper cooling coils. It may very well be that deposits from elsewhere are developing and we have no mechanical way to clean it out.

May water replacement has been completed.

Next scheduled replacement is in August

The pump I installed last fall is smaller than the other larger units you probably found, so none of the components are interchangeable if I can recall.
It would be advisable to get another pump at some point as a backup. I believe you can read out the make and model by taking the cover off the chiller and peeking at it with a flashlight.

Please keep note that if the corrosion on the pump gets worse between inspections it's a clear sign that we have an electrolysis problem as Grant warned we might have. This is partially whey I change the water so often. If we start to find a lot of oil in the water the pump housing has failed.

I cleaned out the Fab shop yesterday and all the pumps under the table were non functional. I removed and kept the fittings. Do we need to try to source a backup pump? Is there any other parts we may want to keep before I dispose of them?

Just a heads up that I washed the chiller out and changed the water in the chiller system at the beginning of the month. This needs to be done every three months to ensure it continues to run smoothly. Please note as well I have added a dual float switch into the reservoir so we can now wire in the laser lockout for low water levels. The pump was also replaced late last year.
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