Rust can be every machine shop’s worst enemy. Home shop hobbyists and full-production manufacturers alike deal with corrosion and know how quickly it can eat away at machines. Rust not only causes expensive damage and downtime, but it also wrecks tolerances and accuracy. Learn how you can prevent rust in your machines and keep your lathe and mill working like new.
Similar to taking care of your car, it’s important to maintain your equipment to help extend its usable life. Rust doesn’t just look bad and impact the cosmetic finish of your machines — it also wreaks havoc on your precision ground ways, machining accuracy, repeatability, and even part finish. Fortunately, taking care of your machines and preventing corrosion is much easier (and cheaper) than fixing rust damage after the fact.
Why Is Rust Such a Serious Problem for Machine Tools?
Simply put, rust causes problems because it damages the very surfaces that allow our machines to operate precisely. Even small amounts of corrosion can impact tolerances and the smooth sliding action of machine components.
Machine ways, tools, tables, spindles, and other precision components are crafted to exacting standards so parts can be machined quickly and repeatably. Any rust that develops on these surfaces can impact tolerances by creating rough spots that impede movement and damage the machine.
Extended corrosion can even damage precision surfaces so they must be repaired or re-ground, costing you more time and money. Protecting your equipment from corrosion is one of the best ways to ensure it keeps running smoothly.
What Causes Rust to Form on Lathes and Mills?
Rust forms when oxygen, moisture, and iron-containing metals combine. While it’s a naturally occurring process, certain factors can exacerbate corrosion.
Humidity is one of the leading causes of corrosion in machine shops. Even if your equipment doesn’t come into contact with liquid water regularly, moisture in the air can settle on exposed machine surfaces and cause problems.
Temperature changes can also play a factor. If you live in an area with widely fluctuating seasonal temperatures, your machines could be at risk of corrosion as water vapor in the air condenses on surfaces.
Even small shops without giant temperature swings can experience this issue if their facility doesn’t have humidity control. This is especially true in coastal areas where humidity tends to be higher than in arid climates.
Of course, moisture isn’t the only cause of corrosion. Metal chips, fingerprints, cutting fluids, and coolant residue can cause microscopic moisture pockets to form on machine surfaces.
How Important Is Daily Cleaning for Rust Prevention?
Daily cleaning and maintenance are extremely important for corrosion prevention. When machine chips, coolant residue, and metal debris build up, moisture has an easy place to hide on your equipment.
Try to wipe down all exposed machine surfaces at the end of each day, and brush or vacuum away chips that have accumulated on your mill’s table, lathe ways, or workholding equipment.
Leaving wet chips on your machine overnight is one of the quickest ways to create a rust problem. A daily cleaning regimen will also allow you to spot developing issues before they become serious.
Many machining professionals consider regular cleaning to be the most important machine maintenance task.
Should Machine Surfaces Be Oiled Regularly?
Yes! Oiling your equipment is another surefire way to prevent rust and corrosion. Applying a thin layer of oil to metal surfaces will create a barrier between your machines and moisture in the air.
Machine tables, ways, chucks and vises, tool holders, lathe beds, and precision measuring devices are just a few common areas that can benefit from regular application of oil or another rust-preventative coating.
There are a variety of different products that can be used for this purpose. Many machine shops and owners use machine-specific oils or rust-preventative sprays.
You’ll want to reapply these coatings after cleaning or machining, as they can be wiped away.
How Can Coolant Management Help Prevent Corrosion?
Coolant management is another huge piece of the corrosion prevention puzzle. Using contaminated coolant or allowing coolant levels to become unbalanced can negatively impact your machine.
Many cutting fluids these days are designed to help prevent rust. However, if you allow your coolant to become imbalanced, the chemical makeup can change and make it less effective at protecting your equipment.
Dirty coolant full of bacteria, tramp oil, and metal chips can also damage your machine and promote corrosion. Try to regularly check and filter your coolant to ensure it’s providing the maximum benefit possible.
Does Shop Humidity Affect Rust Formation?
Yes! Humidity levels can have a major impact on corrosion. Higher moisture levels in the air lead to more condensation and rust formation on machine surfaces.
Machine shops in coastal areas or regions with high humidity will have a harder time keeping corrosion at bay than shops in drier climates. Many facilities use climate control or ventilation improvements to combat excess humidity.
Installing a dehumidifier in your shop can also make a big difference. Even small reductions in moisture levels can provide benefits.
What Role Does Proper Machine Storage Play?
All equipment should be cleaned and dried when stored or not in use for extended periods. Machines that aren’t used regularly are susceptible to rust because their protective oil can degrade over time.
If a lathe or milling machine is going to be put into storage or remain idle for a few weeks, take extra care to clean it down and apply a fresh coat of rust preventative.
Covering your machines can also help prevent dust and other airborne contaminants from accumulating on surfaces. Make sure that your protective covers are breathable so they don’t trap moisture against your equipment.
Regular inspections are always a good idea, even if your equipment is not in use.
Can Rust Damage Precision Surfaces?
Yes, rust can ruin precision surfaces. Ways, tables, spindles, column ways and other sliding surfaces are ground to very tight tolerances during manufacturing.
Any rust that develops can throw these tolerances off by creating uneven surfaces. Not only will rust affect movement, but it can cause pitting in machine ways as it grows. Once rust has damaged these precision surfaces, you may experience decreased accuracy and pay for expensive repairs.
Can machines be re-ground to correct this issue? Sometimes, but once precision surfaces have been compromised, you’ve lost valuable machine integrity.
How Can Operators Protect Machines During Seasonal Changes?
Seasonal changes can cause problems because they often lead to condensation. Temperature swings cause moisture in the air to settle on cool metal surfaces, which leads to corrosion.
Operators can limit these effects by maintaining a stable temperature in their shops. Avoid large jumps in temperature or humidity by using air conditioning, heaters, and dehumidifiers consistently.
You can also apply rust preventative prior to seasonal changes, perform frequent inspections, and ensure your machines are properly cleaned and lubricated.
Knowing what conditions cause condensation to form will allow you to prevent rust from developing in the first place.
What Warning Signs Suggest Rust May Be Developing?
The sooner you catch rust, the easier it will be to treat. Waiting for rust to become severe only leads to longer machine downtimes and bigger cleanup jobs. Keep an eye out for these warning signs of corrosion:
- Metal surfaces are discolored or show signs of orange/brown staining.
- Areas of metal that should be smooth feel rough when you run your finger along them.
- Rust pitting is present on machine surfaces.
- Machines feel sticky when moving parts along ways.
- Moisture is present on machine surfaces.
Periodically inspect your machines and catch rust in its early stages.
Are Preventive Maintenance Programs Worth the Effort?
You bet they are! Preventative maintenance goes a long way in caring for your equipment. Cleaning, oiling, and wiping down your equipment may seem like a hassle, but it’s worth it to protect your investment.
Most machine shops have some sort of daily, weekly, or monthly maintenance schedule they abide by. Preventive maintenance is a great way to not only avoid rust, but also improve machine longevity and reduce downtime over time.
Sure, it may be time-consuming, but repairing corroded machines or replacing damaged precision surfaces is a lot more work.
Why Does Rust Prevention Matter for Precision Manufacturing?
Precision machining depends on your equipment functioning the way it should. Moisture and corrosion can ruin tolerances and cut into your dimensional accuracy.
If you want to maintain a precise, reliable machining process and keep your equipment in great working order for as long as possible, rust prevention is key.
Partner With Thor Precision Resistors for Quality and Precision
Now that you know how to prevent rust and protect your lathe and mill from corrosion, you can start applying tips today to keep your equipment looking and working like new. Regular cleaning, wiping down equipment, controlling humidity, coolant management, and preventive maintenance are all important to keeping your equipment free of rust and corrosion.
At C. Thorrez Industries, we pride ourselves on quality engineering and precision manufacturing. Our resistors are used in industries where precision and reliability matter, so we make sure our products last. Contact us today to learn more.
