A rep from one company told me they do not use a sealer under OMU because "it causes peeling". They just put 3 coats of the finish directly on sanded floors. The president of this company is listed ion NWFA website as an inspector, so he must know what he is doing, and yet it sounds strange to me. What do you think?

The first coat put on any bare wood, is called the seal coat. It can be anything. Let him do what works best for his system. Don't try and tell him how to do his job.

Floorguy,

That partially answers and adds much clarity to my different post (re. douglas fir). It seems like there is flexibility and no clear and unique/distinct solution for getting good results. Other avenues of getting to a good quality finish are available. I will still default to the instructions when in doubt.

KS in NJ