🔥 Effect of Temperature on Chemical Reactions (General Principles)

So, you have decided to clean the bore stain off the driveway, congratulations.

Have you considered the outside temperature? When is just 3 degrees you may want to consider waiting for a warmer day. Cold conditions slow down the cleaning process massively.

1. Reaction Rate Increases with Temperature

   • Chemical reactions generally proceed faster at higher temperatures because molecules move more quickly, collide more often, and with more energy.

   • The Arrhenius Equation in chemistry explains that even a small increase in temperature can significantly boost the reaction rate.

2. Solubility Changes

   • Some chemicals (including cleaning agents and the iron compounds themselves) dissolve better in warm water, aiding in more effective cleaning.

3. Viscosity of Fluids Decreases with Heat

   • Warmer solutions flow more easily, which can help distribute cleaning agents more uniformly throughout the bore or water system.

❄️ Challenges of Cold Weather When Cleaning Iron Stains

1. Slower Chemical Reactions

   • In cold weather, the cleaning reaction with iron deposits slows down considerably, reducing the efficiency of stain removal. This is especially true for oxidizers or acid-based cleaners (e.g., oxalic acid or hydrochloric acid), which react with the iron oxides.

2. Iron Oxides Can Be More Stable

   • Iron staining (like rust or iron bacteria slime) becomes harder to dissolve or dislodge because the reactions that would normally break them down are happening more slowly.

3. Reduced Effectiveness of Cleaning Agents

   • Many bore-cleaning products are formulated to work best at ambient temperatures (20–25°C). If the water or air temperature drops below 10°C, the chemical reaction may be too sluggish to be practical unless adjustments are made.

4. Risk of Precipitation

   • In cold water, iron may re-precipitate more easily (e.g., ferric iron coming out of solution), especially when oxidizing agents are used. This may lead to re-fouling if not flushed or managed properly.

🛠️ Practical Tips for Cold Weather Cleaning of Iron Stains

Pre-warm the Cleaning Solution (if safe and practical)

Use heated water to mix your cleaning solution (e.g., 30–40°C), which can significantly improve performance. Take care not to exceed safe temperature limits for plastic casings or liners.

Allow Longer Contact Time

Since the reaction is slower, extend the soak or circulation time of the cleaner in the bore to compensate.

Agitation or Recirculation Helps

Mechanical movement (like airlifting or pump cycling) improves reaction by exposing more surface area to the chemical and keeping particles in suspension.

Flush Thoroughly

Especially in cold conditions, make sure to flush well after treatment to prevent any residual iron from re-depositing.

🧪 Example: Using Common Hardware Store Cleaner in Cold Conditions

Stabilised oxalic acid works by reducing iron oxide (rust) back into soluble ferrous iron, which can then be flushed out. In cold borewater (e.g., 10°C or less):

• The reaction time can double or triple compared to warm weather.

• Some operators report needing overnight soaking rather than just a few hours.

• Using warm water and gentle recirculation significantly improves results.

If you're running a cleaning operation and expecting cold groundwater or ambient temperatures, it’s worth planning for these factors—both to improve efficiency and to avoid frustration.