Why cement your black stove pipe

joeq wrote:Wow Smitty, I didn't know you could buy 8" flex pipe for stoves. Looks like a handy component when necessary.

That's not flex - it's a solid corrugated 90° elbow made of 304 stainless steel. You couldn't bend this thing if you wanted to.

The first year I bought it, I figured .. IT'S STAINLESS - no need to clean it! Has lots of tiny holes all over it from top to bottom. The acid ate right through in one season .... although not as bad as that black stovepipe - that collapsed into a rusty heap in one summer. At least this one is still usable. Now I remove, clean, & store upstairs every summer. Holes haven't got any bigger.

What!?! Are you telling me my 6" black stove pipe in my foyer behind my stove, is gunna rust out in 1 year? I don't look forward to moving that stove every yr to change it.

I have no idea what Smitty does to his stove pipes.... I've run my black pipe for many years without a single problem to date...

dj

I think I should seal every pipe joint and than install my barometric damper so my draft is cut by 20%.

The last couple times I replaced the pipe on my old stove, I did cement the joints. My chimney doesn't have the greatest draft on warmer days, and I wanted to make sure the chimney draft was pulling air through the stove, not through the leaky joints.

I also disassembled my pipe from the stove and chimney each spring to clean it. it's also important to store it in a dry area. From now on, mine is getting hung up in my garage for the summer.

joeq wrote:What!?! Are you telling me my 6" black stove pipe in my foyer behind my stove, is gunna rust out in 1 year? I don't look forward to moving that stove every yr to change it.

Have you heard of the movie "A river runs through it"? That was filmed in Smittys basement. My black smoke pipe is 10 years old and still in very good conditon. I disconnect it from the boiler and chimney in the spring. Moisture (humidity) and coal ash equal corrrosion. All I do is take it outside and knock on the pipe to remove excess fly ash then store it in my basement.

As i mentioned before, my pipe goes out the back wall behind the stove, and can't be removed w/o moving the stove. If I have to move my stove again, it'll be to replace it with a better one. i just checked my hopper, which I once again let it get too low, and was glowing red hot. and the bottom mouth has distorted to a smaller dimension. such a pain to keep up with. Here's a pic of my set-up.

My DS stove only has two 6" corrugated 90's and then about an 8" straight piece sticking into the thimble. That section has the MPD in it. The joint between the two 90's seems very tight, as is the joint between the second 90 and the straight section.

On my old setup with the Franco, I used the regular black pipe with two tees and one of those four-section "adjustable" 90s. The last couple times I put in new pipe, I cemented all the joints because I was concerned about draft loss. I figured I was already losing enough through my cheap baro damper, tees, and that adjustable 90 piece.

We have a mildly damp basement...no mold or mildew, but enough dampness to soak into any fly ash left in the stove or pipe and cause corrosion. In my early years of burning, I didn't remove the pipe from the thimble over the summer and let me tell you, the humid air, along with outright dampness when it rained, were enough to rot my pipe over the summer. I wised up and started removing the pipe, cleaning it outside, and storing it in a dry place. I also started running a dehumidifier in the basement during the summer months.

Still, even with all that, my pipe wasn't lasting more than 4-5 years at the most. This corrugated stuff looks a bit heaver and, I hope, might last longer with care.

joeq wrote:As i mentioned before, my pipe goes out the back wall behind the stove, and can't be removed w/o moving the stove. If I have to move my stove again, it'll be to replace it with a better one. i just checked my hopper, which I once again let it get too low, and was glowing red hot. and the bottom mouth has distorted to a smaller dimension. such a pain to keep up with. Here's a pic of my set-up.

Hi Joeq,

I recently started a thread for a Surdiac 715 I acquired. Will I be able to burn the Surdiac 715 515?

Does your 513 outlet/flange measure 5.25" inner diameter? Is your reducer pipe mounted on the inner or outer side of the outlet/flange? Do you also burn wood on your 513? May I see how your hopper is setup in your stove? Also can I see a photo of your steel plates that is needed for wood burning?

Mr. extreme, PM sent.

When you (meaning any of you) say that you cemented your stove pipes, what sort of cement is being discussed here?

Larry,

Here's what I use:



Before I found this stuff, I used a whitish cement that came in a caulking tube. It was almost impossible to squeeze out using a caulk gun, and it had a flat, almost plastery finish when it dried. Didn't last worth a toot--I filled a small hole in my old stove's exhaust port with it, and it only held for one season, then fell right out.

My local main-street hardware store guy recommended Imperial cement. It's much easier to work with out of the container, and it has a gritty, real cement (as in concrete) look and feel to it. You can thin it with water if you need to--I thinned it a bit to work it into the stove pipe joints. And it cleans up easy with water. Once it's dry, it's hard, and it sticks. Instructions recommend you dampen the adjoining surface(s) when applying. Patched the same hole in my old stove with this stuff, and it was still rock solid and holding tight after two heating seasons.

More info here: http://www.imperialgroup.ca/stove_maintenanceproducts.cfm?c=325

Black Fur

lsayre wrote:When you (meaning any of you) say that you cemented your stove pipes, what sort of cement is being discussed here?

A simple tube of Rutland's Black furnace cement. It can be found in most hardware stores. It is rated for up to 2000*F,

I've used both of the above.

oros35 wrote:I've used both of the above.

Which did you prefer?