Problem Solving Forum
July 6 - July 9, 2021
If an atmospheric coating system of a zinc-rich epoxy, epoxy mid coat and polyurethane color topcoat has properly cured with no visual defects, should I be worried if the thickness of any coat exceeds any specified maximum?
MAHENDRA SOLANKI of INOXCVA on
July 8, 2021:
There are chances to cohesive strength failed. ...read more There are chances to cohesive strength failed.
Rob Francis of R A Francis Consulting on
July 7, 2021:
Epoxies and polyurethanes are fairly tolerant of o ...read more Epoxies and polyurethanes are fairly tolerant of over thickness. For atmospheric applications, you will probably be OK unless it is an application like aircraft or shipping where weight is critical. Tank linings subject to temperature fluctuations are a different matter.
Mike Beitzel of Modjeski and Masters on
July 6, 2021:
Not necessarily but you should always be concerned ...read more Not necessarily but you should always be concerned when the thickness exceeds the manufacturers maximum thickness for any coat. The manufacturer should be contacted for any remedial recommendations and / or any changes in curing time.
Spiros Pavlakis of HEMPEL on
July 6, 2021:
There is a reason why there is a maximum DFT for e ...read more There is a reason why there is a maximum DFT for each layer. Overapply and you ll have a system which vissually will be ok but depending on which layer has been applied outside the producer's reccomendations you can find yourshelf with a painting system which has different properties (anticorrosive / mechanical / aesthetics)