Laser Tube 3 part question

[Annette Thomas]

The tech that installed mine actually works at the factory manufacturing them so he was very knowledgeable. One of the owners of the business actually recommended the antifreeze. So far so good!

[Bill George]

The tech that installed mine actually works at the factory manufacturing them so he was very knowledgeable. One of the owners of the business actually recommended the antifreeze. So far so good!

Been on several Chinese laser manufacturers websites and they recommend anti freeze when temperatures are below freezing. Since modern car engines cooling systems use epoxy, plastic, aluminum and other materials now, I don't see how anti freeze of the current day and age can harm anything. Except your pets and you if you drink!

[Bert Kemp]

From what I read anti freeze conducts electricity and in the higher power tubes (80 watt+) anti freeze can arc and in some case's burn out your laser. Like those that know say beware it can happen. There are safer ways with less potential to damage the laser then by putting anti freeze in it. A wise man once told me that a 100 men can jump off the bridge and survive but that 100 and 1st hit the water wrong and died. So hey what ever blows your dress up, but I wouldn't be telling people its ok to put anti freeze in the laser water unless your willing to cover the replacement cost if things go bad

Been on several Chinese laser manufacturers websites and they recommend anti freeze when temperatures are below freezing. Since modern car engines cooling systems use epoxy, plastic, aluminum and other materials now, I don't see how anti freeze of the current day and age can harm anything. Except your pets and you if you drink!

[Matt McCoy]

Bert: Was that shared in a thread on this forum? Do you have a link or remember where you saw that?

I was under the impression that Ray Scott passed along that the tinted RV antifreeze reduced the power and possibly caused things to grow inside the tube.

I started using a mixture of clear propylene glycol this winter and have not had to adjust settings for engraving or cutting. I don't see anything growing in the tube or bucket either. I don't know if this is typical or not.

[Jerome Stanek]

I have been using the pink rv antifreeze since Sept and have not noticed any reduced power and now growth in the liquid. I don't see why it would grow anything when it is cold and dark.

[Rich Harman]

Ray had said that antifreeze lowers the resistance of the water which could lead to arcing through the water instead of through the laser. Someone else measured the conductivity of the antifreeze/water mixture and the result seemed to conflict with that theory.

Water is a good conductor of heat. Adding antifreeze reduces heat conductivity but is a necessary compromise when you need corrosion inhibition and freeze protection. As far as electrical conductivity, I don't know.

Regarding stuff growing in the water, it does. I would have thought that the UV radiation put off by the tube would keep the water free of life. UV lights are commonly used in pool and spa systems to kill critters. I guess our lasers don't put out enough UV to do the job.

[Bill George]

Current follows the path of least resistance, your HV 20K is headed for the perfect ground at the other end of the tube. Water (except for distilled) is a conductor, ask someone who is standing in it changing a fuse. Anti-freeze added to water might change the resistance some but I could not see the difference when I tested. Bert there is glass between the water and the high voltage. Glass (and porcelain a form of glass ) is used for HV insulators on power lines.

What I really said : Been on several Chinese laser manufacturers websites and they recommend anti freeze when temperatures are below freezing. Since modern car engines cooling systems use epoxy, plastic, aluminum and other materials now, I don't see how anti freeze of the current day and age can harm anything. Except your pets and you if you drink!

FYI I have had anti freeze ( a very light yellow tint) in my machine for six months or so.... nothing has blew up and I have not lost any power. Your results may vary, use with caution. Looks like Boss Laser uses it all the time.

[matthew knott]

This makes no sense, water is pretty good at conducting electricity at high voltages! Di water is better, but Di water doesn't like being DI water and will attack any metal in the water system and soon it's conduction will go up. Maybe the anti freeze could attack the epoxy but I doubt it's down to the resistance of the fluid in your water system. We stick antifreeze in ours, been 2 years and no problems! Our building never gets bellow 15 degrees C as the heater kicks in but always worry one cold snap the heater could fail.

[Bill George]

Well I went out and took a 1/2 of a 3 oz cup (waxed cardboard) of water / anti freeze mixture out of my bucket and same with tap water.
Hard to get real solid results but the tap water, not softened with lots of minerals and lime was around 900 K Ohms, not a really good conductor but at high voltage it could be. Same water with anti freeze, same meter (Fluke 75) same probes and as I could get same depth... the anti freeze mixture had a higher resistance over 1 Meg Ohm, even seeing 2 Meg Ohms at times.
So tap water or water other than distilled may be a conductor at times, certainly not a good one however. Anti freeze at least what I am using anyway seems to make it Less of a conductor.
Your results may vary, use this information at your own risk. No warranty expressed or implied.

[matthew knott]

Easy way to find out, tip a bag of salt into the cooling system! The epoxy if done properly it should easily be able to insulate from the water HT side, if it's not and a leak can occur I suspect that the addition of anti freeze is not really going to hurry things on much. Anti freeze is not as good at conducting heat so maybe localised heating that breaks down the epoxy! Obviously people on here with lots of experience don't advise antifreeze so something is probably a miss, so I guess it's personal choice, the way I choice to look at it is antifreeze may damage the laser but there are no hard facts to support this but if the tube does freeze you can be 99% certain that it will break. Horse for courses

[Bert Kemp]

All I know is Ray told me not to use it so I won't

[matthew knott]

That contradicts the advice on rabbitusa website! Maybe it needs updating as it clearly says "it is typical to use a mixture of water and glycol (antifreeze) as the coolant" or words to that effect, I can't copy and paste for some reason! Found that by googling laser tube + antifreeze and its high in the search. Just make sure it doesn't freeze and your fine,

[Bert Kemp]

Direct Quote from Ray Scott in this thread "I would recommend to NOT use any anti-freeze in the coolant for the 40 or 60 watt laser. There are definite problems with doing that. I haven't had issues with coolant in the 30 watt tubes yet."
I have a 60 watt and this is what he also told me.This is my last post on this subject.

That contradicts the advice on rabbitusa website! Maybe it needs updating as it clearly says "it is typical to use a mixture of water and glycol (antifreeze) as the coolant" or words to that effect, I can't copy and paste for some reason! Found that by googling laser tube + antifreeze and its high in the search. Just make sure it doesn't freeze and your fine,

[Bill George]

Well with almost 1,700 views as of this morning I'd say there was a little interest in the subject! My replacement tube was made by a different company than the one supplied with the machine. Perhaps with all the manufacturing of laser tubes in China and elsewhere there are different methods and materials used. My replacement tube was of much better quality than the OEM one which only lasted 3 months. The new one has a six month warranty.

[Annette Thomas]

Bill George it seems it is a very popular subject. Thanks for your input.

Annette