Finishing is finishing me off
I'll begin by apologizing for the long post. This is actually the short version.
Iím having a finishing problem that I just canít seem to solve. I asked some questions about finishing a walnut coffee table last fall. Shortly after those postings I developed a severe case of Sciatica and was operated on in February. Itís been a long recovery but Iím finally back in the shop and trying to finish the coffee table top that I built last year.
My question, now in desperation, is how to proceed. In the two pictures you can see the unevenness of the finish when viewed under a raking light along the grain then the beautiful appearance when viewed under normal light across the grain.
Iím using Zar poly cut 50/50 with mineral spirits. I donít know if thatís the right thing to do since Iím in Florida and the temp in my garage is mid to high 80ís when I apply the finish in the AM and it hit 90+ in the afternoon. Iím cutting it to make it a wiping poly and so that it dries faster and collects less dust. On the other hand I want to give it enough time to level and pop any bubbles. I donít know if thatís the right way to do it.
Due to too many attempts to mention, Iíll just go over the last one which leads to the pictures. The Poly skinned over in the can even though I was using Bloxygen. I punched through the skin and ran a spoonful through cheese cloth. I then cut it with mineral spirits and applied it with a lambís wool applicator that I wrapped in a lint free paper towel to keep the wool from shedding into the finish. I ended up with a lot, and I mean a lot, of tiny nubs all over the table. I tried to take them down by using a 3M ďBetween CoatsĒ finishing pad with my ROS. It wasnít doing a great job so I used some 800 grit sandpaper which I believe is about the same grit as the sanding pad. Anyway, the result is what you see in the pictures. It is smooth as a babyís butt, but doesnít look good in a raking light. I did order a new can of Zar poly which will arrive next week.
Back to my question, how to proceed.
Do I need to do more sanding to the table top or will the next couple of coats of poly eliminate the blotches? Iím afraid to sand too much because, even with a high grit, I can sand down to the bare wood. I had 5 thinned coats on it before I started with the scotch brite pad and sandpaper.
Am I using the right ration of poly to mineral spirits based on the temperature? Should I be using more or less mineral spirits?
Am I applying the poly the best way? The paper towel around the lambís wool pad has made for a smoother application than a just a paper towel or a cloth.
So far, Iíve been playing around with this for a month, trying different approaches and Iíve already sanded back down to the bare wood and started over. Any suggestions will be gratefully accepted since this finishing job has me just about finished.
If you have an open mind, youíll generally find that youíll learn the most from the people who say the things you least want to hear.