Yes I am a novice that needs help I built a picture frame with purpleheart wood. put 2 coats of tounge oil on and followed with 3 coats of helmsman spar urethane spray. looked great I then decided to apply one more coat and in process oversprayed corner. Now I can see a faint outline of where my mistake happend. Now to the question the can says if I can’t recoat in 1 and half hr’s to wait 72 hrs and sand and recoat. Don’t understand why does anyone think it would be a problem to go ahead now after 12 hrs to sand and recoat to even it out?
Discussion Forum
Get It All!
UNLIMITED Membership is like taking a master class in woodworking for less than $10 a month.
Start Your Free TrialCategories
Discussion Forum
Digital Plans Library
Member exclusive! – Plans for everyone – from beginners to experts – right at your fingertips.
Highlights
-
Shape Your Skills
when you sign up for our emails
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply. -
Shop Talk Live Podcast -
Our favorite articles and videos -
E-Learning Courses from Fine Woodworking
-
-
Replies
Polyurethane varnish have problems with adhesion and have a narrow recoat window where coats will bond together. Past that window they have to be able to mechanically bond by having the lower coat abraded by sanding to give tooth for the finish to adhere. The problem is that spar urethane is a quite soft finish and isn't likely by be ready to sand for the 72 hours specified. If it won't sand to powder it isn't ready, and after twelve hours I doubt it would. If you try sanding too early to you will likely clog sand paper, and possibly disturb under layers that are still very soft,
Some other questionsdo come to mind. First, is what kind of Tung Oil--by brand name? Many of the tung oil finish products on the market aren't tung oil, and that affects how they should be treated. Secondly, why Spar Urethane. That's a finish designed for exterior use--albeit in areas shaded from the sun. Interior varnishes are quite a bit more durable for your furniture type applications, though picture frames don't really stress the protective capabilities of finishes,
This forum post is now archived. Commenting has been disabled