I'm doing a down-and-dirty job of re-staining my back porch/deck, which hasn't been touched in four years.

The railings are topped by wide flat horizontal boards, one of which has had a heavy object sitting on it. Rainwater has been trapped under this object, and there's now a hole about the size of a ping-pong ball rotted right down into the board (and possibly into the corner upright underneath). The board is still securely fastened to the structure below. All I want to do right now is slow down the rot until my next pass at the deck, when I'll replace the board.

Anyone have an opinion on whether to fill in the rotted-out place with some kind of spackle, and if so, what type to use? Thanks in advance for your advice!

 

It wouldn't be spackle. A wood filler wood work.
Three choices below. All available from the home improvement stores.
PlasticWood.
JB Weld "Kwikwood"
Weldwood water putty.

 

Make sure you remove all of the rotted wood before applying any filler.

 

Okay, thanks! I kind of forgot about wood filler, but thinking about it now, there may even be a container of it in the cellar.

I'm wondering if it's going to cure once I pack that rotten area, because it's a pretty big gap. Even if it doesn't, it ought to keep the water out.

 

Most of those fillers will get like a rock in a day or two. Keep that covered in case of rain.

 

OK, StickShift, thanks! What would you use to do that? I said the gap was the size of a ping-pong ball, but on second thought, it's more golf ball size, and really kind of down in there, and rounded. I don't think I can use a chisel without taking out some of the solid wood around the top of the hole, which would weaken the part of the board where the nails fastening it to the structure are.

It seems like I'd need something like a melon baller with a sharpened rim. If I had shop skills I could make something like that, but I doubt Home Depot carries them!

 

Great, PJmax, good to know it'll set up. I'll definitely keep it covered

 

Bondo works great with wood,

IMO much easier to use, as long as there is a solid bottom so it wont leak out, and no question about the durability!

 

Bondo, huh? Thanks for the idea, I always wanted to use Bondo on something! Maybe I'll add fins to the railings

 

Durham DWP 1 Lb Rock Hard Water Putty

Works great

 

While Durham RockHard Putty works well it is an absolute bear to sand! it pays to apply it neatly or use a softer filler over top of it to dress it off.