So the 2nd time this has happened and I know once bitten twice shy and all that.
I have now had 2 x laser tubes break due to the water coolant within the tubes freezing, expanding and breaking the inner glass tubes.
Does anyone have a solution besides draining the water everytime the temperature gets below freezing.
The laser is currently situated in a external garage with no heating. Are you able to fill the water cooler with any anti freeze solution and will this effect the laser itself ?
Has anyone else expereinced this, I can only imagine it isnt that cold in the UK.
I don’t know if they add anything extra in addition to Ethylene Clycol, but I don’t want to test using pure Ethyene Clycol myself. I just know that coolant antifreeze intended for cars must not be used for laser!
I’ve been running this stuff from OMTech for a couple years.
You don’t want to use automobile antifreeze because the additives for engine use lowers the dielectric constant of the coolant. There is know occurrences of the anode voltage getting into the coolant making all the surfaces touched by the coolant at the anode voltage.
This is still poison to people and animals. If I could afford the shipping, someplace in the EU has this that has an additive that makes it non-poisonous to life.
This year, I drained my tube of the distilled water for 5 days while we were in the single digits. Now that we’re back up above freezing, I added water to my chiller, and I’m running. This is not a production Laser though so I could afford the downtime.
I use two electric tubular heaters - both are 20 watts. One is mounted permanently just below the laser tube, the other is placed adjacent to the chiller. I’m in the U.K., so we get down to around -5°c outside temp on cold winter nights at times. So far this year I’ve had both heaters on for a total of around four or five days, so maybe a few £’s. My workshop is pretty well insulated but can still get down to 3-4°c on a cold night.
The chiller is filled with distilled water plus a capful of household bleach, and is three years old.
I have heard of people installing an aquarium heater in the water tank of a chiller, but of course that would do little to protect the tube itself.
My cnc router has a water-cooled spindle with a separate tank and pump - that is filled with an antifreeze solution but of course there is not the worry about high voltages with a router.
You can get RV antifreeze effective to -50 degrees for 3.50/gallon at Menards. Worked great for me, even when it was -8 here last month. It is ethyl alcohol and it won’t freeze and won’t expand.
I guess us stupid guys will just continue being stupid without all the restrictions of the knowledgeable guys.
The issue is with it degrading plastic. 3 months out of the year won’t be an issue. Should be flushing ANY coolant, even water, every 3 to 4 months, according to the knowledgeable guys.
Ethylene glycol is also some pretty nasty/toxic stuff, and is pretty corrosive to metal when it degrades. I wouldn’t use it.
Wasn’t meant to sound derogatory, but couldn’t think of a better way to put it…
I used to use propylene glycol, which they feed to milk cows to treat ketosis.
Helping many people with problems, I have seen too many get across the high voltage from using automobile engine antifreeze. The OMTech is pretty much that without the additives that allow it to conduct electricity.
I don’t change mine out, it’s not supposed to break down…
Generally they come ready to use… One of the things you want with a DC excited laser is coolant that doesn’t conduct… so you don’t want to mix it with anything.
Things like automotive antifreeze has additive for the enging, but use in this application as a coolant, it conducts. If that happens, anywhere the coolant touches metal it’s at the hv anode voltage. Most people don’t like that or even the idea of that.
