Why does nobody talk about the old school brick dust trick for stuck damper plates?

I had a 1920s flue in St. Paul with a damper that wouldn't budge after years of rust. Instead of forcing it and risking a break, I took a handful of the fine soot and brick dust from the cleanout, mixed it with a little 3-in-1 oil to make a gritty paste, and worked it into the hinge. Let it sit for an hour, worked it back and forth, and it freed up completely. Has anyone else tried something like this instead of reaching for the penetrating oil right away?

3 comments

3 Comments

eva_thompson103mo ago

Instead of forcing it" made me realize my usual brute force method was all wrong.

henderson.val3mo ago

My last project needed that brute force push to get past a stubborn bug. Sometimes you just have to muscle through a wall to see what's on the other side. A gentle nudge doesn't always cut it.

the_blair2mo ago

Gotta jump in here and gently nudge you on the soot part, because that's actually not what you think it is. The fine black stuff you're grabbing from the cleanout isn't really soot from burning wood - it's mostly creosote and fly ash, which is way more acidic and can actually eat into cast iron over time if you let it sit. Brick dust is fine, that's a great abrasive, but the creosote is more like a corrosive sludge than a helpful lubricant. I've seen guys mix brick dust with just plain water or a little mineral oil instead, and that seems safer for old dampers that are already fragile. The oil and brick dust combo is solid though, just maybe skip the black sludge from the cleanout and use a fresh batch of dust from a brick you crush yourself. That way you get the grit without the acid attack.