My rain barrel won't swell.

July 19, 2006 3:46 PM

Any idea why my wooden rain barrel won't swell when filled with water like it did last year?

Last year I put it out in June and one rain it filled up, swelled, and held for the rest of the summer. I didn't have a spigot on it so I siphoned the water out.

This year I didn't get the spigot installed until July 15th. So I tried to fill it with water from the hose and it just wouldn't go. I tried filling it for 24 hours. I tried soaking down from the outside.

Any ideas?

The metal braces seem to be in the same place they were last year (I can tell from the discoloration of the wood).

posted by cda to Home & Garden (10 answers total)

So the water is leaking out?

Maybe the wood just got so dried out and old that it can't physically absorb water how it used it.
posted by bangitliketmac at 4:08 PM on July 19, 2006

Did it shrink back to its original size after you siphoned the water out?
posted by clockzero at 4:27 PM on July 19, 2006

I wonder if a little soap wouldn't help the water soak in.
posted by Good Brain at 5:32 PM on July 19, 2006

Not to derail but what's the significance of the swelling? Why is this desirable?
posted by stupidsexyFlanders at 5:53 PM on July 19, 2006

Barrels leak until the wooden staves soak up water, expand and are pressed tightly together.
posted by joegester at 5:57 PM on July 19, 2006

Response by poster: It is leaking, I should have said that.

Yes, I'm afraid it just got too dried out.

It didn't shrink when I siphoned it, I never siphoned out all the water (left 1/4th).

(And thanks for filling in joegester)
posted by cda at 6:05 PM on July 19, 2006

Perhaps try filling it with very warm or even hot water.
posted by clockzero at 6:27 PM on July 19, 2006

Boatbuilder chiming in:

Was last year the first time you used it? Perhaps the wood has been compression set.

"A particularly critical situation develops when wood is restrained from swelling (...) If swelling is restrained, the effect is that of compressing the wood. However, the elastic limit strain is less than 1% (...) Therefore, compression set may develop. Upon redrying, the piece "unloads" itself by shrinking to a smaller than original diameter, thus loosening the joint."
-Understanding Wood, Bruce Hoadley

Anyways, what happens is the wood fibers crush when they're restrained, and then on the next moisture cycle don't expand as much as they did previously. This, along with normal moisture fluctuations and the fact that it's an easy way to fit them, is the reason wooden axe handles have wedges in them. So that you can tighten them. If the staves were dry and fitted too tightly when the barrel was build, this may be the cause. They crushed one another.

The only other thing that I can think of is to look at the staves for checks (little cracks, they tend to open up at the ends and around knots). Sometimes when wood dries unevenly this will happen, and if they occur around a hard irregular surface like a knot they might not close up when the staves swell again.
posted by vonliebig at 7:54 PM on July 19, 2006

A clarification - If it has been compression set: If you look around the metal bands and there's a little play or a groove in the wood you may be able to wedge it out. Work alternating sides like you do when you tighten the lug nuts on a tire. If there is no play the stakes may have unloaded and warped while they were loose, then swelled up again and now the edges of the stakes aren't in contact the full length, but the parts that are tight are taking up all the slack in the bands.
posted by vonliebig at 8:07 PM on July 19, 2006

Response by poster: Last year was the first year that I used it. Before that it held wine according to the label.

The gaps between the slats looks very evenly spaced. And the same all around the barrel.

I thought about trying to adjust the metal bands but it's not apparent to me how to do it.

Here is a picture.

I think I'll start by tapping the top two down and the bottom two up.
posted by cda at 5:58 AM on July 20, 2006