I try to avoid thinning down the epoxy because if you thin it too much it will never get hard when it sets. It will just remain soft. I prefer to put down the un-thinned epoxy on the area I want to cover then heat it with my heat gun which will cause it to thin out, and while it is thinned I will spread it with an epoxy brush. Be aware that this will accelerate the setting time for the epoxy so you wont' have 30 minutes to work it. I will try to do smaller areas at a time than doing one huge application.

Hope this helps

Ken