Expert's Corner — uv
TIP: UV Varnishes Only Give So-So Protection
damage damages finish finishing flexner object panel slow sunlight the finishing store ultra-violet light uv uv-resistant varnishes woodfinishing woods woodworking z-spar
Normally, I use the accompanying photo to show that mass-marketed varnishes sold in home centers and most paint stores for exterior finishing don’t contain any more UV resistance than common interior varnishes. But the panel also shows that even the much more expensive varnishes sold in marinas still aren’t perfect at resisting UV light. I stained the panel with red dye (because red dye fades faster than most other colors) and coated the panel with five coats of four different varnishes. From left to right, a popular boat varnish from a marina, two common varnishes sold in home centers for...