Had to pick between a poly brush and a steel brush on a tricky flue today

I was working on a 70-year-old terra cotta flue liner this morning and the soot was really caked on. I usually grab my 8-inch poly brush for most jobs but the guy I was helping swore by his steel wire brush for old buildup. I went with the steel brush on his advice and honestly it worked great for the heavy stuff but I switched to the poly for the final pass to avoid scratching the liner too bad. Does anyone have a go-to brush for old flues like this or do you just play it by ear?

2 comments

2 Comments

elizabethhart21d ago

I remember back in 1985 when I was learning the trade from an old timer who swore by nothing but steel wire brushes on anything older than 40 years. He said poly brushes just slide over the hard crust without digging in. I've stuck with that mindset and never had a problem with scratching terra cotta as long as you keep the brush moving and don't bear down too hard. That said, I know some folks who ruined a liner once with a steel brush by getting too aggressive on a soft spot. So it really depends on how much crust you're dealing with and how careful you are. I'm not sold on poly brushes for the final pass because I've seen them leave a thin layer of dust that can bake right back on with the next fire.

richard11021d ago

Oh man that reminds me of a time I was cleaning a flue and my helper dropped his steel brush down the chimney. Took us an hour to fish it out with a magnet on a rope. Do you ever have to watch out for loose tools getting stuck in tricky liners?