Best high temp Black sealant.

[tlhfirelion]

Hello. I am finishing my stove install and need some black, high temp caulk/sealant for the single wall interior pipe.
Most of the ones I see on Amazon and the like “only” go to 500 degrees. I’ve had many a fire reach that temp so I’d prefer something a bit more robust. Problem is, I can only find that in red and this isn’t the A team van.
Am I worrying over small potatoes or can someone send a link for what would fit the bill.
Thank you in advance.

 

[bholler]

Hello. I am finishing my stove install and need some black, high temp caulk/sealant for the single wall interior pipe.
Most of the ones I see on Amazon and the like “only” go to 500 degrees. I’ve had many a fire reach that temp so I’d prefer something a bit more robust. Problem is, I can only find that in red and this isn’t the A team van.
Am I worrying over small potatoes or can someone send a link for what would fit the bill.
Thank you in advance.

Why do you feel like you need to seal the joints?

 

[begreen]

Sealant is not used on stove pipe unless this is for a pellet stove with pressurized exhaust.

 

[RockyMtnGriz]

In a perfect world, you wouldn't need sealant, but my world isn't like that. Not to say that it's technically approved, but I've used small amounts of Permatex Ultra Black for this purpose, as well as gasket attachment, gasket enhancement, and window gasket sealing, all with good results. It's rated to 500f intermittent, and that's the temp that it's durable at on an engine (for a very long time). Since my stove pipe usage is normally for about one year, I find it plenty durable. The Ultra series seems to flow/stick, and therefore seal, better than most silicones, which makes it easier to use very little - which is key, and AFTER the pipe is assembled, if you ever want to get it apart again.

If you're worried about combustibility, test it with a propane torch and judge for yourself. Or, there's always the Rutland furnace or gasket cement, rated for 2,000 degrees. I hardly use the Rutland for anything anymore. It's just too permanent, too hard to work with and ugly, and too hard to remove, If you were trying for permanent, though, it would be the first choice.

 

[begreen]

In a perfect world, you wouldn't need sealant, but my world isn't like that. Not to say that it's technically approved, but I've used small amounts of Permatex Ultra Black for this purpose.

Why is your world not like that?

 

[RockyMtnGriz]

Why is your world not like that?

Yours is?? Boy am I jealous!

 

[bholler]

Yours is?? Boy am I jealous!

When it comes to having a fire in your house it should be. There isn't much room for error

 

[begreen]

Yours is?? Boy am I jealous!

Not just mine, but 99.99% of all installs do not need sealant on stove pipe. If it does, something is not right.

 

[bholler]

I do lots of installs and not one woodstove has ever needed sealant

 

[RockyMtnGriz]

Ok, maybe I should explain further. I have a cat stove with a short section of pipe up from the stove to a 45, to a short section of pipe, to another 45, and another short section of pipe, and into a collar to a masonry flue. The draft is marginal for this stove, and I use little dabs of silicone to seal the joints in the areas of the pipe seam, where it doesn't seal very well. With that many joints, all those little seeps of cold air must be too much for it, as It definitely helps this stove. I've used Rutland for that, but found it to be a pain to apply, as well as a pain to remove during cleaning. I like the Permatex much better.

I'm also using it to seal a few similar spots on the pipe to my Kuuma furnace. That thing generates a fine brown flue dust, that can find it's way out of the tiniest gaps in the pipe (those seams again) when the stove isn't burning and the wind is blowing.

Ultra Black hasn't failed me as a door gasket cement, either. It keeps the gasket in place as long as the gasket lasts, and easily peels out of the channel with a putty knife when it's time to replace. It sure beats having to use a chisel to remove the furnace cement.

I'll throw out a crazy one, too. I couldn't get my cat stove door gasket to seal perfectly, no matter what I tried (I even made custom adjustable hinges for the hinge side). With nothing to lose, I decided to try making a rubber embedded rope gasket for it, so I put a new gasket on (again), cranked the door shut for a few days to put a door groove in the new gasket, put a small bead of Ultra Black in the groove with a strip of wax paper on top, and gently shut the door. The next day I had a perfect rubberized seal for my door to shut against, and the door leak was cured. The side benefit is this rubber infused gasket shows signs of wanting to last for a very long time. That was 5 or 6 years ago, and it's still fine.

The application that I thought would be too much for the silicone was the cast iron piece that I replaced the glass in the cat stove with. I put a bead of the silicone on the window gasket when I put it in, since I was desperate to cure the smoke seeps from this stove. I didn't have high hopes, but thought I'd give it a try. The silicone excess exposed to the interior of the firebox has degraded, but the cast iron "window" is still glued to the door after years, and no smoke seeps.

I'll agree, the stuff has a lot of misuses, but it also has a lot of uses.

 

[bholler]

Ok, maybe I should explain further. I have a cat stove with a short section of pipe up from the stove to a 45, to a short section of pipe, to another 45, and another short section of pipe, and into a collar to a masonry flue. The draft is marginal for this stove, and I use little dabs of silicone to seal the joints in the areas of the pipe seam, where it doesn't seal very well. With that many joints, all those little seeps of cold air must be too much for it, as It definitely helps this stove. I've used Rutland for that, but found it to be a pain to apply, as well as a pain to remove during cleaning. I like the Permatex much better.

I'm also using it to seal a few similar spots on the pipe to my Kuuma furnace. That thing generates a fine brown flue dust, that can find it's way out of the tiniest gaps in the pipe (those seams again) when the stove isn't burning and the wind is blowing.

Ultra Black hasn't failed me as a door gasket cement, either. It keeps the gasket in place as long as the gasket lasts, and easily peels out of the channel with a putty knife when it's time to replace. It sure beats having to use a chisel to remove the furnace cement.

I'll throw out a crazy one, too. I couldn't get my cat stove door gasket to seal perfectly, no matter what I tried (I even made custom adjustable hinges for the hinge side). With nothing to lose, I decided to try making a rubber embedded rope gasket for it, so I put a new gasket on (again), cranked the door shut for a few days to put a door groove in the new gasket, put a small bead of Ultra Black in the groove with a strip of wax paper on top, and gently shut the door. The next day I had a perfect rubberized seal for my door to shut against, and the door leak was cured. The side benefit is this rubber infused gasket shows signs of wanting to last for a very long time. That was 5 or 6 years ago, and it's still fine.

The application that I thought would be too much for the silicone was the cast iron piece that I replaced the glass in the cat stove with. I put a bead of the silicone on the window gasket when I put it in, since I was desperate to cure the smoke seeps from this stove. I didn't have high hopes, but thought I'd give it a try. The silicone excess exposed to the interior of the firebox has degraded, but the cast iron "window" is still glued to the door after years, and no smoke seeps.

I'll agree, the stuff has a lot of misuses, but it also has a lot of uses.

If draft is marginal why not address that? What stove is it? What pipe are you using? Cheap pipe can fit poorly

 

[tlhfirelion]

Why do you feel like you need to seal the joints?

seems like best practice to keep the smoke isolated.

 

[tlhfirelion]

In a perfect world, you wouldn't need sealant, but my world isn't like that. Not to say that it's technically approved, but I've used small amounts of Permatex Ultra Black for this purpose, as well as gasket attachment, gasket enhancement, and window gasket sealing, all with good results. It's rated to 500f intermittent, and that's the temp that it's durable at on an engine (for a very long time). Since my stove pipe usage is normally for about one year, I find it plenty durable. The Ultra series seems to flow/stick, and therefore seal, better than most silicones, which makes it easier to use very little - which is key, and AFTER the pipe is assembled, if you ever want to get it apart again.

If you're worried about combustibility, test it with a propane torch and judge for yourself. Or, there's always the Rutland furnace or gasket cement, rated for 2,000 degrees. I hardly use the Rutland for anything anymore. It's just too permanent, too hard to work with and ugly, and too hard to remove, If you were trying for permanent, though, it would be the first choice.

Great reply, I’ll look those products up. Thank you.

 

[tlhfirelion]

When it comes to having a fire in your house it should be. There isn't much room for error

i agree.

 

[begreen]

seems like best practice to keep the smoke isolated.

Smoke should never be leaking from the stovepipe. With proper draft, the flue system is under negative pressure. The smoke is always isolated to the interior of the flue system.

 

[RockyMtnGriz]

If draft is marginal why not address that? What stove is it? What pipe are you using? Cheap pipe can fit poorly

I hate to hijack this thread, as we could have quite a discussion on this stove, I'm sure. It still just sort of works for me, and were it not for a lot of high hurdles, I would have already changed it. I'm still prone to thinking about it, and the cutting torch in the garage, in rapid alternation. It's an Englander 24 ACD. I think if it was sitting under a nice class A chimney, it would be fine. From another old thread:

the 24-fc was a catalytic radient room heater , about 2.5CF firebox, no blower , nor is there an adaptation for one to be added. the unit was built up through 2004. it was rated at up to 1600 sq ft. the unit itself sold new in stores at about $650-$700 (i do not remember actual MSRP but i am close anyway)

if the unit you are looking at does have a blower and header system it is not an fc but an "acd" which is a 2200 sq ft design with the same firebox but an internal header system for the blower. it sold for about $ 800 (ish)

as for the color , the unit has been charcoal gray from 1992 through 2003 with some exceptions we built black ones for lowes with nickle trim for a couple years in the early 80's and we built a "forest green" for Quality farm and fleet in the late 90's

overall it was a decent unit personally i liked the acd better due to the blower but its a solid unit. if you do go with this unit i strongly recommend NOT using the heat reclaimer the unit likes a strong draw and the reclaimer would take away from that IMHO they should never be used on an EPA reburn unit, especially a cat stove.

It's an occasional use and backup stove. I've been chipping at the draft issue for years. I have zero options on the chimney. It's 6" square clay liner in a massive interior masonry that's around 25', starting a few feet above the top of the stove. When I bought the house, it had a loose fitting door for an interior cleanout on the flue (no code inspections here), that I made a sealed bank vault style door for. The round stovepipe was squeezed square, and pushed into the square horizontal masonry flue with some stove gasket stuffed in the corners. I have since fabbed a sealing transition thimble to deal with that.

I have downdraft issues in the prevailing wind, and I made a custom lopsided-opening cap for that. It helped quite a bit. I'm also at 7,000' elevation, which doesn't help with draft. When the wind turns around, and puts my chimney in an updraft, everything works splendidly.

As for the single wall pipe, I don't know what brand it is, it was on the stove when I bought the place. I went from an up and 90 over to the masonry, to a up-45, over, 45, to masonry to try to help the draft. At least that helped with smoke spillage. It's decent heavy gauge pipe, certainly not the super cheap stuff on some other stoves I've used in my life. I've never seen seamed pipe that really seals at the joint where the seam is. When I take that stuff apart to clean it, there's usually a clean streak inside the other pipe from where the air is being sucked in. Usually that doesn't really matter, but I can tell you, in this case, sealing those leaks made a difference.

And, FWIW, this whole mess was installed (for the original homeowner), by a stove retailer: and a local "reputable" mason - with respect to the interior cleanout door, which is marked "exterior use only".