Coating: Moisture Issues with Solvent Free Epoxies

Epoxy Linings - Solvent-free but not Problem-free. 

Solvent-free epoxy coatings have been widely specified and used over recent years in Australia as linings for a variety of immersion service exposures, specifically for potable water storage and tank linings for some petroleum products. However, they have not always delivered the durability or performance hoped for. There have been disappointments and some failures which could have been prevented if a wider understanding existed about the nuances of specifying and applying solvent-free epoxy materials.


Of key interest to Humiscope, is how climatic conditions are critical during certain phases of curing.


Certain solvent-free epoxy coatings are susceptible to high relative humidity and/or condensing moisture during a certain window of time after application.

This can create intercoat adhesion problems or blistering if the coating system involves multiple applications of solvent-free materials. If these critical issues are not properly addressed or understood, the coating may look satisfactory but it might not work as well or for a satisfactory length of time.

Thus, the problem of condensation on freshly sandblasted or painted tank surfaces needs to be addressed. In order for surface protection to yield good, durable protection, the surface must be kept clean and corrosion-free during the interval between grit-blasting (surface preparation) and painting.



Provide dehumidification so that the climatic conditions inside the tank are to be approximately 40°C and a low relative humidity. 

Humsicope provides rental dehumidification for this exact purpose. Our desiccant dehumidifiers not only lower humidity levels but also provide heating. This is as a by-product of the desiccant technology is heat gain to the process air stream.

You can improve your productivity and quality of coat with Humiscopes short and long term rental options. 


Advantages of Humiscope's Rental Systems:

  • Surface preparation can be carried out regardless of outside factors such as air temperature, pollution or season
  • Blasting can be done without double or triple shifts, which can save up to 20% in labour costs
  • The painting contractor can plan and carry out his work with no risk of expensive downtime.


We have a wide range of gear available. Call us on (07) 0531 1606 to discuss your project requirements.