The "men's room" for my shop is out back. The other day I was out back and I noticed a rusted spot, which poked right through when I poked it with my finger.....

I have an over head hood, with about a 3 foot horizontal leg, a 90 degree elbow and a 15 foot up leg, with a cap. The whole chimney is 12 inch heat and air duct.  It has been up around 5 or 6 years.



I bought a new elbow at Home Depot, which was $8.95 and when I pulled the old one out I found that the elbow was half full of soot that had settled in it. I scraped it all out and it really draws now. 

 Hey Jeff,

You can get a cleanout fitting for the chimney. It is basically just a tee with one side capped off. When the flu needs cleaned, you just pull the cap off, and the sediment falls out or can be lightly scrubbed with a chimney brush. Lots of folks use them for their wood stove chimneys where the pipe is exposed. Really simple to keep clean without having to remove any fittings.

 

I have an over head hood, with about a 3 foot horizontal leg, a 90 degree elbow and a 15 foot up leg, with a cap.

You will notice a build up of material in the horizontal portion of the chimney also. Set a time schedule (1 month, 3 months, whatever) to inspect and clean the chimney to keep the air moving properly and reduce the combustible materials that can cause chimney fires.

I just installed a wood stove at my mother-in-law's and the directions recommended inspection every 14 fires (or days of fire) and sweep as necessary. A basic sweeping brush was $12 for the brush (6 inch) and $20 for 18 ft of rod on sale ($35 regular price) The brush can be pulled with rope too. I bought the kit so my brother-in-law can sweep as needed, and have annual inspection and cleaning from the professional.

Phil

There is a difference between solid fuel fires used to heat a house, and a fire in the forge.

Let us start with the house stove and a 4-6-8 inch chimney. A small HOT fire will create little particulate matter and create little creosote. People must keep feeding the fire as a small fire burns out quickly. Instead, they dump a armload of cold, wet, wood (from outside) on the fire and close down the air, sit back and let the fire slow burn for several hours. These chimneys need cleaned early and often.

At the forge the chimney is usually 10-12 inches in diameter for a HOT fire about the size of a melon. There is no damper, or other way, to close the chimney down, and it draws 100 percent of the time at 100 percent of the capability of the draft. As with any fire, the forge chimney will collect particulate matter and will create creosote and should be cleaned as needed.

No two stoves, forges, or chimneys are the same, so YMMV. Extra cleanings and annual inspections are the safe way to go.