my woodburner has a 8" pipe for a outlet. can i reduce it to 6" and tye into my chimney? chimney is 8"x12"clay tile. it would consist of 2 elbows and 2 -24"pipes.

It's more of an issue of restricting your stove.

Your flu is adequate, just the tie in is too small. You can try it to see what happens, but I think all that 6" flu pipe is too much of a restriction, and you'll need to enlarge the tie in for 8"

its 8" now. pulled it apart to clean and a elbow broke. no one carry's 8"aroud here anymore. Hence going to 6". the 8x12 liner is about shot also, will probably use a new liner in it.house is 1940ish.

Bad pipe and chimney have burnt down a lot of houses. Think I would make my wallet groan and hire someone. At the very least read everything I could find on proper venting.

Hire a professional.

The safest bet would be to have a new liner installed. Clay liners aren't all that durable IMO and I've installed a lot of them. If your chimney is relatively sound, a metal or a cast in place liner would be the way to go. The metal liner is the cheaper option. Still pricey.

Re line with 5 or 6 in stainless

8" elbows are available all over the place.Get the right part.Dont reduce.And don't buy one,,get two.I keep enough parts on hand to do a total rebuild.Because when you realize a part is bad,,is Sunday or a Holiday when you cant get the part.Thank me later.

X2 what UpstateNY said. I don’t know why you would have trouble finding those parts. Every hardware store around here has a ready supply of stove pipe parts.

I usually look up the manufacturers instructions and follow them when hooking up a chimney to a stove. I have, however, reduced two different 8 inch pipe stoves to 6 inch in the past with no issues. I did it the same as you are considering, an 8 inch opening, reduced to a 6 inch pipe for a short distance into the chimney thimble, which was 6 inch.

its the wrong time of the year to be doing this. everyone that has stove parts have switched over to spring goods. i got one today at the dutchman's store, he had to go into the back room to find one!

Smaller is hotter = clean pipe

For an average wood stove, necking down to 6 from 8 is not an issue. Like stated above, your pipe is deteriorating. If the fitting broke, it is safe to assume that the rest of the pipe is at or near the end of its useful life. a new stack is about 1250 dollars for material. Ive installed a few in the last couple years and they all fell right around that price. Its not a difficult procedure if you know a thing or two about construction, but I would strongly advise to hire a pro if you are not confident in your work. Its not cheap, but far better than what happens when things are not done right.