A rusted nut or bolt seizes because rust bonds the threads together. A penetrating spray that creeps into the threads and breaks the rust bond usually frees it, given a little time. Micron M.A.M.A Multi Application Maintenance Aid (4102) is a multi-purpose penetrating lubricant whose page says it penetrates and loosens jammed or stuck parts and releases rust-metal bonds. Once a hinge or linkage is free, a clean silicone lubricant such as Micron 4500 keeps it moving.
Why it happens
- Rust bonding the threads. Rust takes up more space than the steel it came from, so it locks threads and pins tight.
- Moisture ingress. Water gets into threads, hinges and linkages, especially on vehicles washed often or used in the monsoon.
You will see a fastener that will not turn and starts rounding off, or hinges and linkages that are jammed.
How to fix it
- Seized nuts, bolts, hinges and linkages: Micron M.A.M.A (4102). Its page lists loosening rusted and jammed parts, says its low surface tension lets it penetrate cracks and crevices, and describes it as breaking ferric oxide bonds to simplify disassembly. It comes in several pack sizes, from 30 ml to 400 ml.
- A freed hinge or linkage that needs a clean, non-staining lubricant afterwards: Micron 4500 M.A.M.A Silicon Spray. Its page lists door hinges and says it reduces friction and prevents rust.
The 4102 page has no step-by-step directions. Follow the instructions on the can and the TDS. General fastener practice around it:
- Clean loose dirt and rust scale from around the fastener so the spray can reach the threads.
- Apply the spray as the can directs and give it time; rust takes time to penetrate.
- Use the right size spanner or socket, preferably six-point, to avoid rounding the head.
- Try a little tightening movement first, then loosen. Small back-and-forth movements are less likely to shear the bolt than one hard pull.
- Reapply if needed and wait again rather than forcing it.
Once free, clean the threads and protect them. The 4102 page also lists rust and corrosion protection and moisture displacement.
What to avoid
- Do not use on brake friction surfaces. Keep penetrating spray away from discs, drums, pads and shoes.
- 4102: treat it as flammable until the SDS says otherwise. Keep it away from sparks, flames and hot surfaces, use ventilation, and let exhausts and engines cool first.
- Do not use heat or flame on a fastener you have just sprayed.
- Do not keep forcing a fastener that is starting to round off or twist; stop before it shears.
When to ask an expert
Take it to a mechanic if:
- the bolt has sheared or the head has rounded off;
- the fastener is safety-critical, such as on brakes, steering, suspension or wheels;
- the part is seized by damage or distortion rather than rust.
FAQ
How long should I let penetrating spray soak?
The 4102 page does not give a time. Give it a few minutes at least, and longer on heavy rust. Reapplying and waiting works better than forcing.
Can I use the same spray to lubricate afterwards?
The 4102 page lists industrial-grade lubrication and rust protection, and describes a non-sticky finish. For rubber parts, hinges and channels you want to stay clean, 4500 Silicon Spray is an option.
Will it work on rusted hinges and door locks?
The 4102 page lists loosening rusted and jammed parts. For door locks, sliding windows and hinges after they are free, 4500 lists those uses.
Is it safe to spray near the exhaust?
Let the exhaust and engine cool first. Treat 4102 as flammable until the SDS confirms otherwise, and keep it away from hot surfaces.
See the product: Micron M.A.M.A 4102. Related: 4500 M.A.M.A Silicon Spray. More vehicle maintenance fixes: vehicle hub.