Applying Polyurethane Coatings in Cold Weather – Trouble Shooting Guide

Jul 20, 2022 | News

As the temperature continues to plummet to freezing conditions this winter season – this can cause havoc when it comes to flooring applications. Below we go through some of the most common problems that can occur in cold weather below 15°C and offer a trouble shooting guide to remedy these problems.

Did you know the viscosity of a coating increases as the temperature decreases! This can cause:

  • Reduced flow with potential for ‘orange peel’ ‘trade marks’, etc.
  • De-aeration reduced due to air bubbles finding it harder to rise to the surface in a thick coating
  • ‘Quilting’ effect (non-levelling over timber pieces) can increase, especially with parquetry.

Curing / Drying is slower in cold weather and can cause “balling” when sanding or foot imprints can be seen the following day.

Solvent evaporation is also slower which can cause “Pimples” or nibs from dust due to wet surface being ‘open’ for a longer time

So, what can you do to remedy these problems? Take a look at our Trouble Shooting Guide for Cold Weather to find out some more reasons, causes and remedies.  

Problem Reason Cause Remedy
Poor Flow Cold floor &/or cold temperature &/or cold material

Viscosity in can has increased with time

Viscosity higher with lower temperature

Past shelf life of hot storage – never use products that have expired past their use by date!

Add up to 30ml per litre (3%) Wet Edge Extender 3320

Try Wet Edge Extender but may not work if material has reacted too much in the can

Orange Peel Cold floor, air or material

Film to thick

Viscosity high Add Wet Edge Extender 3320

Minimise film thickness

Low Gloss Low temperatures/’Dew Point’ reached

Possible if Dew is on grass outside

‘Dew Point’ if reached can deposit microscopic moisture particles on surface causing dulling effect Apply finish in warmer part of the day
Slow Drying Cold (an maybe dry) conditions Aliphatic (low yellowing) have slow cure in cold conditions Add DURAPOL 5995 Accelerator (speed up the dry time of DURAPOL coatings)

If compatible

So, what about oil modified products? Can you use oil modified products in winter?

The short answer is yes. It is recommended that NATURAOIL 1499 Accelerator is added to speed up the drying time – Add to NATUROIL 3100, 3115 & 3120 to reduce drying times. Cold and damp environments will have an effect on drying time. In cold temperatures the coating may have to be left longer to dry between coats. Failure to do so may cause issues with the next coating I.e. frying.

For more information about applying polyurethanes in cold coatings contact your technical service department or local Polycure account executive for further advice.