Solidol is a universal lubricant based on calcium soaps, which is widely used to protect metal parts from corrosion and reduce friction in bearings and hinges. However, its thick consistency often makes it difficult to apply to hard-to-reach areas or through lubricants. Liquefaction of solid oil allows it to be evenly distributed over the surface, extending the service life of mechanisms and saving material. But not all solvents are equally effective - some can destroy the lubricant structure or damage seals.
In this article we will look at 7 proven methods liquefying solid oil, including household and professional methods, and also warn against mistakes that lead to damage to parts. You will learn which solvents are compatible with rubber and plastic, and which ones absolutely cannot be used in closed systems. We will pay special attention safety precautions — working with volatile substances requires ventilation and protective equipment.
If you plan to thin the grease to treat suspension, ball joints or guides, it is important to consider further operating conditions. For example, lubricant diluted with kerosene is washed out faster with water, and compounds with silicone can negatively affect brake pads. We have compiled compatibility table solvents with materials so that you can choose the best option for your task.
1. Classic solvents: kerosene, gasoline, white spirit
The most accessible and time-tested solvents are: kerosene, gasoline (AI-92/AI-95) and white spirit. They effectively reduce the viscosity of solid oil without destroying its lubricating properties, but have restrictions on use.
✅ Kerosene (lighting or aviation) - the optimal choice for liquefying solid oil for open mechanisms (for example, chains or cables). It evaporates slowly, allowing the lubricant to stay on the surface longer. Proportion: 1 part kerosene to 3-4 parts grease. The resulting mixture retains its protective properties for up to 6 months when stored in an airtight container.
⚠️ Attention: Kerosene is aggressive to some types of rubber (for example, nitrile rubber seals). Test compatibility on a small area before use.
⛽ Gasoline (pure, without additives) acts faster than kerosene, but evaporates in 1-2 days, leaving grease in its original state. Suitable for short-term liquefaction before application. Proportion: 1:5. Do not use gasoline with octane-boosting additives - they can oxidize the lubricant.
🧴 White spirit - a less aggressive alternative to gasoline. It evaporates more slowly and does not dry out the rubber as much. Ideal for diluting solid oil before placing it in grease nipples or syringes. Proportion: 1:4. After mixing, let the mixture sit for 10-15 minutes - this will improve homogeneity.
- 🔧 Pros: low cost, availability, do not require special storage conditions.
- ⚠️ Cons: fire hazard, pungent odor, partial evaporation after application.
- 🚫 Not suitable for: sealed bearings, high temperature systems (above 80°C).
To accurately dose the solvent, use a medical syringe without a needle. This will help avoid overdose and maintain proportions even with small volumes of solid oil.
2. Professional thinners: solvent, nefras, silicone additives
If you need to thin the grease for industrial equipment or heavy-duty applications, conventional solvents may not be suitable. In such cases, specialized compounds are used that not only reduce viscosity, but also improve the performance properties of the lubricant.
🧪 Solvent (nefras S4-155/200) is a universal solvent that is often used in car repair shops. It mixes evenly with solid oil without destroying its structure, and slowly evaporates. Proportion: 1:6. Suitable for lubrication cardan shafts and CV joints, but requires ventilation - solvent vapors are toxic.
💧 Silicone additives (eg. Liqui Moly Silicon-Spray) - liquefy solid oil and give it water-repellent properties. This composition is ideal for processing threaded connections and electrical contacts in high humidity conditions. Proportion: 1:10 (10% silicone additive). Important: silicone can negatively affect brake systems - do not use it to lubricate calipers!
🔥 Nefras S2-80/120 — highly specialized solvent for high-temperature lubricants. It can withstand heating up to 120°C without loss of properties. Used in industrial gearboxes and plain bearings. Proportion: 1:8. Due to its high cost, it is not suitable for domestic use.
| Solvent | Proportion | Rubber compatibility | Temperature limit, °C | Evaporation time |
|---|---|---|---|---|
| Kerosene | 1:3–1:4 | Moderate | up to 60 | 3–7 days |
| White spirit | 1:4 | good | up to 50 | 5–10 days |
| Solvent | 1:6 | Bad | up to 80 | 10–14 days |
| Silicone additive | 1:10 | Excellent | up to 100 | Minimum |
| Nefras S2-80/120 | 1:8 | Average | up to 120 | 14+ days |
Critical error: mixing solid oil with brake fluid or antifreeze. These compounds contain glycols, which completely destroy the structure of the lubricant and lead to metal corrosion.
3. Household method: heating without solvents
If you need to thin the grease without changing its chemical composition, the safest way is heating. At temperature 40–60°C Solid oil becomes fluid without losing its lubricating properties. This method is suitable for bookmarking oil cans or processing large parts (for example, when preserving equipment).
🔥 How to heat solid oil correctly:
- Place the jar of grease in a container of hot water (not boiling water!).
- Maintain water temperature 50–60°C within 15–20 minutes.
- Stir the lubricant periodically with a clean wooden stick.
- After liquefaction, use the composition immediately - when it cools, it will thicken again.
⚠️ Attention: Do not heat grease over an open fire or in the microwave! This may result in fire or decomposition of additives. Also avoid overheating above 70°C - the lubricant may separate.
💡 Advantages of the method:
- 🔹 Does not require the purchase of solvents.
- 🔹 Retains all the original properties of solidol.
- 🔹 Safe for rubber and plastic parts.
🔧 Where to apply:
- 🚜 Conservation of agricultural machinery.
- 🔧 Lubrication of large-sized mechanisms (for example, gates or winches).
- 🛠️ Refilling press grease fittings manually.
Use a water bath rather than an open flame|
Monitor the temperature with a thermometer (max. 60°C)|
Stir the lubricant for even heating |
Store heated grease in a heat-resistant container -->
4. Alternative methods: oils and special additives
If you are looking long-term liquefaction without the risk of solvent evaporation, pay attention to mineral oils and specialized additives. They not only reduce viscosity, but also improve the protective properties of the lubricant.
🛢️ Mineral oils (eg I-20A or I-40A) — the optimal choice for diluting grease under long-term operation. Proportion: 1 part oil to 2 parts grease. The resulting mixture retains its consistency for years and can withstand temperatures up to 100°C. Suitable for lubrication gearboxes, chain drives and open gears.
🧴 Graphite additive - if you need not only to dilute the solid oil, but also to improve it anti-wear properties, add 5–10% graphite powder. This composition is ideal for low-speed mechanisms (eg jacks or screw drives). Important: graphite is incompatible with aluminum alloys - it accelerates their corrosion.
🌡️ Lithium supplements (eg. Litol-24) - when mixed with grease in proportion 1:3 a heat-resistant lubricant is formed that can withstand up to 120°C. This composition is suitable for wheel bearings and constant velocity joints (CV joints). However, lithium greases are aggressive towards copper and its alloys.
🔍 How to check compatibility:
- Apply a small amount of mixture to the test surface.
- Leave for 24 hours at room temperature.
- Check for corrosion, changes in color or structure of the material.
What happens if you mix grease with motor oil?
A mixture of grease and motor oil (for example, 5W-40) will provide short-term dilution, but after 1–2 weeks the lubricant may separate. Motor oils contain detergents that break down the calcium soaps in the grease, leading to a loss of protective properties. This composition is absolutely not suitable for sealed bearings or highly loaded components.
5. Errors that destroy grease and parts
Even experienced mechanics sometimes make mistakes when liquefying solid oil, which leads to premature wear of parts or loss of lubricating properties. Here are the most common mistakes and their consequences:
🚫 Using water or soap solution:
Water does not mix with grease, but forms an emulsion that accelerates corrosion. Soap destroys the structure of the lubricant, turning it into a useless mass. Exception: water-soluble lithium-based lubricants, but they do not belong to classic grease.
🚫 Overheating above 70°C:
At temperatures above 70°C, the grease begins to separate: the oils are separated from the thickener, and the lubricant loses its homogeneity. Outwardly, this manifests itself as the formation of solid lumps in the liquid fraction.
🚫 Mixing with brake fluid or antifreeze:
The glycols in these fluids react with calcium soaps to form abrasive deposits. This leads to bearing jamming and shaft corrosion.
🚫 Storing liquefied solid oil in an open container:
Solvents (kerosene, white spirit) evaporate, and the lubricant thickens again. In addition, dust gets into an open can, which turns grease into an abrasive paste.
⚠️ Attention: If you have diluted grease with a silicone additive, do not use it for lubrication. brake system rubber seals. Silicone softens the rubber, which leads to brake fluid leakage.
6. Safety precautions when working with solvents
Working with volatile solvents (gasoline, white spirit, solvent) requires precautions. The vapors from these substances are toxic, flammable and can cause chemical burns if they come into contact with skin.
🛡️ Mandatory protection measures:
- 😷 Work in well ventilated area or on the street.
- 🧤 Use nitrile gloves (rubber and latex are dissolved by gasoline!).
- 👓 Wear safety glasses - Solvent splashes may cause eye damage.
- 🔥 Exclude sources of open fire (including smoking) within a radius of 5 meters.
🧯 What to do if it gets on your skin:
- Immediately wash the affected area with plenty of soap and water.
- Apply moisturizer (solvents degrease the skin).
- If there is redness or itching, consult a doctor.
💨 How to dispose of leftovers:
Do not pour liquefied grease or solvents down the drain! Collect waste in sealed containers and take it to hazardous waste collection points. Gasoline and white spirit are 3rd hazard class (moderately hazardous substances).
Never mix solvents with each other (for example, gasoline + white spirit). This could result in an unpredictable chemical reaction, release of toxic gases, or even a vapor explosion.
7. Practical advice on the use of liquefied solid oil
Diluted grease behaves differently than the original lubricant. Here practical recommendations, which will help to avoid problems during operation:
🔧 For suspension and ball joints:
Use a mixture of grease with white spirit (1:4). Apply with a brush or syringe, then remove excess with a rag. Repeat treatment every 3–4 months — diluted lubricant is washed out faster with water.
⚙️ For threaded connections:
Optimal choice - solid oil with silicone additive (1:10). It prevents sticking of nuts and bolts and also protects against corrosion. Clean threads with wire brush before application.
🚗 For guide supports:
Here it's impossible use diluted grease - only specialized high-temperature lubricants (for example, Slipkote 220-R DBC). Solid oil, even diluted, loses its properties when heated and can jam the caliper.
🔩 For chains and cables:
The best option is kerosene mixture (1:3). It penetrates the chain links and is retained for a long time. After application, allow the kerosene to evaporate for 10-15 minutes, then remove excess.
📦 Storage of liquefied solid oil:
- Use sealed plastic containers (metal cans may rust).
- Store in a cool, dark place (temperature no higher than 25°C).
- Shelf life of the liquefied mixture - up to 6 months (except for formulations with mineral oils).
Before applying liquefied grease to parts with rubber seals (for example, CV joint boots), check the compatibility: apply a drop of the mixture to an unnecessary piece of rubber and leave for a day. If the material has not softened or cracked, the mixture can be used.
FAQ: Frequently asked questions about grease liquefaction
❓ Is it possible to dilute solid oil with diesel fuel?
✅ Yes, but with reservations. Diesel fuel (diesel fuel) dilutes solid oil in the proportion 1:5, but has two drawbacks:
- It evaporates slowly, leaving a sticky residue that attracts dust.
- May damage some types of plastic (eg polycarbonate).
🔹 Where to apply: for lubricating rough mechanisms (chains, cables) at low temperatures (diesel oil does not thicken in the cold).
🚫 Where you can't: in sealed bearings, electrical contacts, brake systems.
❓ How long does liquefied solid oil last?
Shelf life depends on the solvent:
- 🕒 With kerosene/white spirit: 3–6 months (solvent gradually evaporates).
- 🕒 With mineral oil: 1–2 years (composition stable).
- 🕒 With silicone additive: up to 1 year (silicone does not evaporate, but may delaminate).
💡 Advice: Stir the mixture before use - heavy fractions will settle to the bottom.
❓ Is it possible to dilute solidol with vegetable oil?
❌ No, this is a bad idea. Vegetable oil:
- Oxidizes in air, forming sticky deposits.
- Attracts dust and dirt, turning into abrasive.
- Destroys rubber seals faster than mineral solvents.
🔹 Exception: in a desperate situation can be used castor oil (proportion 1:10), but only for temporary protection against corrosion (not for rubbing parts).
❓ How to remove excess liquefied solidol from parts?
🧹Cleaning methods:
- Rag + white spirit: Effective on metal, but dries rubber.
- Soap solution + brush: Suitable for plastic and painted surfaces.
- Steam washing: Best option for complex mechanisms (such as chains).
⚠️ Do not use acetone or solvent 646 - they destroy paintwork and rubber.
❓ How to dilute solid oil for winter use?
❄️ For operation at temperatures below -20°C:
- Add 10–15% winter diesel fuel (Arctic diesel fuel) - it does not thicken in the cold.
- Or use silicone grease in spray (for example, WD-40 Specialist Silicone) in a ratio of 1:8.
🔹 Important: After liquefaction, check the viscosity - the lubricant should remain flexible, but not flow like water.