A friend of mine has refinished her deck.  By this I mean, she put down all new cedar boards on top… after removing the old ones….   Then proceded to put down a stain on the deck to seal it.  That didn’t work too well so she spent a few days with a random orbit sander and sanded the entire top of the deck.

Then she put down one of those Thompson sealers for Cedar decks.  The problem is, on part of the deck it absorbed like it was supposed to and on other parts it just pooled on top.

Any ideas as to why? And what can be done to fix the problem?

Thanks
Barney