Christmas Machine Shop Shutdown Checklist: Protect Your Coolant Over the Festive Period

As Christmas shutdown approaches, many machine shops will be sitting idle for days, maybe weeks. While production may stop, bacteria could be having its own Christmas banquet whilst you’re sitting down to your turkey. Poor shutdown preparation can lead to bacterial growth, degraded coolant, unpleasant odours, and unnecessary corrective work when you return in the New Year.

Taking a little time before switching the lights off can save a lot of hassle later. Here’s a simple, practical coolant-focused shutdown checklist to help keep your machines in good condition over the festive period. We’ve created this handy PDF download for you to print out and display on your shop floor.

1. Filter the Coolant

If you have access to a coolant vacuum system (such as a Freddy Coolant Vacuum), it’s well worth carrying out a full coolant empty and filtration before shutdown.

Over time, coolant becomes contaminated with fines, swarf and other debris. These contaminants provide the perfect environment for bacteria to thrive. Removing them before a long period of inactivity significantly reduces the risk of bacterial growth and coolant breakdown while the machines are idle.

2. Remove Tramp Oil

Tramp oil sitting on the surface of the sump can cause more problems than many people realise.

Skim off any tramp oil to prevent oxygen from becoming trapped in the coolant. When oxygen trapped, anaerobic bacteria can form, which rapidly degrades coolant and will lead to foul smells and poor performance.

A clean sump surface helps keep the coolant stable while machines are not running.

3. Check Coolant Dilution

It’s good practice to take a few minutes to check coolant concentration using a refractometer.

Compare the reading against the coolant manufacturer’s recommended concentration range and adjust if it’s out of spec. Correct dilution helps ensure corrosion protection, lubrication, and bacterial resistance are maintained throughout the shutdown period.

4. Top Up the Sump with Fresh Coolant

Aim to leave each machine sump at least 80% full before shutdown.

Topping up with freshly mixed coolant helps stabilise the system and reduces exposure to air. Where possible, use a pre-mixed supply via an automatic mixer, such as a Mixtron dosing pump, to ensure consistent and accurate concentration.

This step is especially important if machines will be left unused for an extended period.

5. After Christmas: Test the Fluid

Once you’re back in the New Year, don’t just press start and hope for the best. Carry out routine coolant checks to confirm that all parameters, such as concentration and pH are in spec. Record your test results and make any adjustments needed before full production resumes.

Starting the year with coolant in good condition helps avoid downtime, tool wear, and improves operator safety.

A Little Preparation Goes a Long Way

Christmas shutdown is the ideal opportunity to get your coolant systems into the best possible condition. By filtering, cleaning, testing, and topping up before you close, and then testing again on your return, you’ll protect both your machines and your coolant investment.

You can download our Christmas Machine Shop Shutdown Checklist here!

If you’d like more help with coolant filtration, testing, or shutdown preparation, our friendly technical team are on hand with helpful advice and tips on getting the most out of your coolant.

Call 0114 285 2987, email [email protected] or visit our website to find out more about we can help you get the most out of your coolant.