I stripped a table that sat in the south sun for many years, it had faded drastically. Stain soaked in evenly and all look good. Applied varithane on the piece and all looked well after application but hours later multiple bubbles formed. I scratched finish and reapplied coat. Again once finished looked good but hours later bubbles again. I did this repeatedly (even changed cans of varithane). No success, resulted in stripping piece again. During stripping wood fibres started to come off in patches (once looking it was in the places that most of the bubbles formed). What is happening and what can I do to condition the wood so it will not bubble. I am going to have to do a major sand to get some of the missing fibre marks removed but do not want to strip again. Again this piece sat in south window for atleast 50 years.