What Type of Pipe for Chimney?

[WaWaZat]

Well my 20lb 7" steel pipe chimney mounted to a fabricated steel mount didn't work. I used this because I acquired the pipe for free. One of the 2 threaded sleeves that was cast into the refectory dome is starting to pull & crumble the casting around it. So I need to find a lighter alternative.

The attached pictures show what I have now. How critical is the type of vent pipe that I use in a small dome (inside dims: 28" dia x 12.5" h, 11" landing). The front of the pipe sits back 2 inches from the front of that 11" landing. Can I use some 2' ducting from Home Depot mounted to my steel plate? ...or I may go as far as to fabricate something from flashing & a pipe collar to save even more weight. I'm not sure what kind of heat the pipe will have to withstand. I plan on painting whatever I use with black BBQ grill paint. A big concern is cost.

[WaWaZat]

Re: What Type of Pipe for Chimney?

Would standard galvanized vent pipe from a Home Center work? It sure is light enough & inexpensive. I can't find any specs on a heat limit for this stuff... nor do I know what temperatures the top, front of the landing of my small oven will reach.

[mfiore]

Re: What Type of Pipe for Chimney?

I believe most people use a double lined, insulated vent pipe rather than single cylinder.

[WaWaZat]

Re: What Type of Pipe for Chimney?

I believe most people use a double lined, insulated vent pipe rather than single cylinder.

I suppose that would keep someone from burning themselves if they touched it. My oven is up high enough where I'm not too concerned with that.

Anyone know how galvanized vent would hold up to the weather if I painted it w/Rustoleum High-Temp?

[david s]

Re: What Type of Pipe for Chimney?

Most people go for stainless steel. Galvanized steel will probably have to be replaced down the track. I had a pot bellied stove years ago and I installed a galvanized steel flue pipe. It lasted 12 months.

[blacknoir]

Re: What Type of Pipe for Chimney?

Go with a clay flue liner!! There are tons of pics and tips on using one.

[dmun]

Re: What Type of Pipe for Chimney?

I don't see any reason you can't use what you have. 20 pounds? That's lighter than the flue tile that's standard. I think your problem is the expansion differential between your casting and your metal plate. Could you just slather it on with heat stop, or your mortar of choice? or if you bolt it down, just do so loosely, so there is some wiggle room for expansion.

Your heavy steel pipe is going to be much more durable than that galvanized sheetmetal crud.

[meterchimney]

Re: What Type of Pipe for Chimney?

Would standard galvanized vent pipe from a Home Center work? It sure is light enough & inexpensive. I can't find any specs on a heat limit for this stuff... nor do I know what temperatures the top, front of the landing of my small oven will reach.

[brickie in oz]

Re: What Type of Pipe for Chimney?

The acids in the flue gasses will destroy gal flue in no time, better off with ss.

[WaWaZat]

Re: What Type of Pipe for Chimney?

I ended up going with a double walled pipe that my local HVAC guy mounted on a custom duct that I bolted to the top of the oven. I supplied him with a template for the mounting surface and he did the rest for $45. The pipe is about 18" tall and I put a home center cap on top to keep water and animals out. I believe the pipe is galvanized. I did doubled walled to keep the temps down on the outside of the pipe to prevent the paint from flaking. I painted it with a Rustoleum flat black... I believe it was recommended by Rustoleum that I use a latex over galvanized. It's been 2 1/2 yrs and pipe and paint are in excellent condition!... in the Chicago weather and using the oven 1-2 times/month.