I’ve got a knot-hole in one of my fascia boards and I’d like to “fill-it-in” with something (then paint over it). I’d rather not replace the entire fascia if I don’t have to. Can you recommend something to “patch” the hole?
Regretfully, I don’t have a photo here at work today, but the hole is about the size/shape of a chicken egg, and it’s maybe ½” deep; it’s not all the way through the board. There’s a little bit of wood left back there for “support”.
Bondo actually works pretty well for exteriors that get painted. That deep of hole may take several built up layers to fill. Also if you haven’t used it before it sets up fairly quickly.
Do not use Bondo. It will harden too quickly and is impossible to smooth out. Finish sanding is a pain.
I use JB Weld’s wood filler. Two part putty. Good working time (just don’t make a big ball at once, exothermic reaction), smooths easily with a wet finger or joint knife. (You can even fake a grain if you want.) Final sanding is simple.
Just about any filler will do. Bondo shouldn’t harden up too fast to fill and smooth a hole like that, but just mix any glue with some sawdust and fill the hole, or use any kind of wood filler. Painting over it will seal it well enough to last decades. If the wood around it shows grain, after the filler sets take a knife and cut some grain lines into it, once painted over no one will notice.
Durham’s Rock Hard Water putty. It comes as a powder you mix with water. Work time is relatively short, but it doesn’t shrink as badly as other fillers, sands well and takes paint well. Bonus, it lasts forever in the tin and you don’t end up throwing away a lump of dried out filler a year from now.
Word. I have used that to close up a seam on the underside of eaves. It’s great general purpose filler. And yes, it lasts, I’ve had only three containers over the past 30 years, used each one up, sometimes didn’t open the can for years at a time. I must have thrown away at least 30 half full containers of other fillers in that time.
The Durham’s Putty may be a better choice than Bondo. Using Bondo as a wood filler presents two materials that expand and contract at differents rates meaning an increased probability the overlapping paint will crack in the near future.
That was actually my first choice. I love this stuff, but I’ve not used it in an exterior application like this. Then i read this on the back of the can: …Durham’s will absorb moisture, like from underneath porch flors [sic] or decks, condensation within walls, and humid environments like showers or bathtub enclosures, which will prevent Durham’s from completely drying or adhering.
I assume that once i fill and paint, I should have sealed any moisture out. However, that knothole has a small hole in the bottom which would “open” to the attic. Maybe i should hit that small hole with some latex caulk to “seal” it before trowelling in the Durham’s.