Chimney-Cleaning Chemicals

traditional,

I am not familiar with "sticks" to throw in a stove to address creosote build-up. However, I have used "chimney sweep logs" in my fireplace.

These are "logs" made primarily of sawdust and wax, with the chemicals ammonium sulphate, phosphorus pentoxide, and copper sulphate added (according to the MSDS)

Do they really work?

These products work after fashion and are not "new" science. Having spent a considerable portion of my career in fuels tecchnology research, I remember a text that I once read that gave the chemical compositions of such materials, mechanisms, etc. I will try to locate the name of the text and post it.

Do they work? In my experience, not if you already have build-up issues...

I've used wood stoves small & large, fireplace inserts, as well as open fireplaces through the years...

These products do work at a minimum, only if the right treatment is first applied..

I got years ago, a couple of chimney brishes of different sizes - you start with the smaller to knock off the larger build-up & then you finish the job with the larger brush to clean the 4 corners (if you have a block chimney design)..

The larger hardware stores sell the fiberglass rods that can be extended or not...

Clean the bugger first - then using some of these products will help as you burn, but eventually you will have to give the cleaning another go - to be safe in your home

Be careful with the chemicals as some of them will be high corrosive (salts) and will corrode metal parts in the chimney like damper hinges, flanges, etc.

Much better to use chimney brushes as mentioned before to remove substantial build ups and once the chimney is clean, make a point to run the fire "hot" with excess oxygen once a day to keep the creosote at bay.

We used to do this when I was living in New England and using an air-tight Vermont Castings woodstove for supplemental heat. We would run the stove with a good load of wood on the "up-draft" setting and let the stove pipe temp run in the 900-1000F range for a good 5-10 minutes. You could hear the crinkling of the creosote in the metal pipe. !!!! Make sure the chimney is clean enough before you start doing this or you WILL have a chimney fire !!!

Doing this routinely would result in "puffy" flat black creosote in the chimney rather than the hard, shiny, black slag that accumulates when wood stoves are run on a low heat habitually. Annual cleanings became perfunctory at that point and really just served to inspect the chimney liner, etc.

The high heat also "dries" the creosote and the delta-T and its subsequent expansion and contraction helps "flake" off the deposits.

Good luck !!

Sir Robin,

I received similar advice from the mason who built my chimney, which was brick with a terra-cotta liner. He also said that while the flare-off was in progress was a good time to check for chimney integrity, gaps and cracks etc. I never had to any chimney cleaning beyond this.

LG_DAVE

Thanks for all the thoughts on burning wood .

I try to maintain about 300 degrees in the stove I've noticed if the glass gets blackened it's an indication to burn hotter .

I have a very tall chimney and have had some creosote buildup in the past I leave a chain suspended by a 1/8" cable and tie it off if I ever need it it's ready to go ,and it works great.

I was simply curious about the composition of chemicals that aledge to prevent buildup but I think the advise that it may cause deterioration to metal components is a good reason to avoid them.