Talk Composites - The Forum for Advanced Composites

Epoxy coating resin application

http://www.talkcomposites.com/Topic17248.aspx

By Maria Julia Ferreira - 5/20/2015 6:25:16 PM

Hello,
I'm trying to apply an epoxy coating resin (bisphenol A epoxy resin) onto mild steel, with a bar coat of 100 micra. The resin to hardener ratio is 2:1.
When the surface begin drying some defects appear as the photo show. The surface preparation was done according to  ASTM- G1- 03, and I tried to repeat the process with a bar coat of 200 micra and the result was the same. 
What is wrong? 
Can you help me?
Many thanks
By Warren (Staff) - 5/22/2015 2:14:22 PM

Even the slightest trace of grease could cause that problem.  Also if the surface is too smooth it can happen, although in our experience, you shouldn't have any problems once the metal has a good key and is free from all contaminants.