Winter Antifreeze Guide for Lasers in Small Laser Cutting Machines, Maintaining your Small laser machines in winter is critical because if the water in the cooling system freezes, it expands and can shatter the glass laser tube or crack the internal pipes of the chiller.
Here is a comprehensive guide to winterizing your small laser cutting machines.
1. The Three Main Strategies
Depending on your workshop conditions, choose one of these three methods to prevent freezing:
- Method A: Maintain Ambient Temperature (Recommended)Keep your workshop temperature above 10°C (50°F) 24/7. Use space heaters or improve insulation. This is the safest way to ensure no components—including electronics—are damaged by cold.
- Method B: Keep the Chiller RunningKeep the water chiller powered on 24/7. Moving water is much harder to freeze than standing water. Set the water temperature to a “low” setting around 5°C–10°C to save energy while preventing ice.
- Warning: This fails if there is a power outage.
- Method C: Add AntifreezeIf the room temperature cannot be guaranteed, you must add a specialized antifreeze to the cooling water.
2. Antifreeze Selection (Crucial)
Never use automotive antifreeze. It has high electrical conductivity and contains additives that can damage laser tubes and seals.
- Recommended Types: * Industrial-grade Ethylene Glycol: e.g., Antifrogen N (commonly used in fiber lasers).
- Propylene Glycol (RV Antifreeze): Often used in CO2 glass tube lasers. Look for “Pink RV Antifreeze” which is non-toxic and generally safe for glass tubes.
- Proprietary Coolants: Brands like OMTech or AP Lazer sell pre-mixed coolants designed specifically for lasers.
3. Mixing Ratios for Winter
The more antifreeze you add, the lower the freezing point, but also the lower the cooling efficiency. Use the minimum amount needed for your local climate:
| Lowest Local Temp | Antifreeze : Distilled Water | Resulting Freeze Protection |
| -5°C (23°F) | 2 : 8 (20% Antifreeze) | Provides safety margin to ~-10°C |
| -15°C (5°F) | 3 : 7 (30% Antifreeze) | Standard for moderate climates |
| -25°C (-13°F) | 4 : 6 (40% Antifreeze) | For severe cold zones |
Note: Some brands (like specific RV Antifreezes) are designed to be used 100% undiluted. Always check the label.
4. Step-by-Step Installation
- Drain the System: Turn off the laser and chiller. Open the drain port and empty all existing distilled water.
- Clean the Tank: If the water looks murky, flush it once with fresh distilled water to remove any algae or debris.
- Pre-mix: Mix your antifreeze and distilled water in a separate clean bucket before pouring it into the chiller. Stir thoroughly.
- Fill and Circulate: Fill the chiller to the “Normal” level. Turn on the chiller (keep the laser off) and let it run for 15–20 minutes to ensure the mixture reaches the laser tube and all internal lines.
- Check for Bubbles: Ensure there are no air bubbles trapped in the laser tube, as these can cause “hot spots” and crack the glass.
5. Post-Winter Maintenance
Antifreeze is a temporary solution. It is more corrosive than pure water and can degrade the cooling efficiency over time.
- Flush in Spring: Once the temperature is consistently above 5°C (41°F), drain the antifreeze completely.
- Clean and Refill: Flush the system 2–3 times with distilled water to remove all traces of glycol, then refill with pure distilled or deionized water for the summer season.
Pro-Tip: If your machine is stored in a very cold garage and not used for weeks, it is safer to completely drain the water and use compressed air to blow out any droplets remaining inside the laser tube.