I just applied Helmsman exterior OIL BASE gloss poly to the top of a 2'X6' work bench top.
I have used this same can of finish full strength on the legs and cross stiles, 3 coats, last 3 days no problems other than some dripping.
Today I raised the grain on the top with a damp (not soaking wet) rag with water on it and did the final sanding.
3 hours later I applied the poly.
I thinned the poly with some paint thinner and it flowed on way better than full strength.
10 minutes after application I started seeing a kind of bubbling on the surface forming as I watched (NOT AIR BUBBLES)
I tried to smooth it with the brush and it actually continued and got a little worse.
After 20 minutes I started wiping it with an old t-shirt and think I got it looking ok, but it took much wiping.
I dumped the thinned poly back into the half can of finish.
1) What the heck is going on here?
2) Do I dare use the finish for a second coat tomorrow or get a fresh can and use it unthinned?
The only thing I did different on the top compared to the legs was raise the grain and thin the poly with paint thinner.
I am pretty experienced and never had this problem before.
Thanks, ron