Poor draft/flue collar

[j7art2]

I've always had poor draft. I imagine I've got the stacking effect working against me, but you never know. I live in a chalet style house with the furnace in the basement and a 25-30' chimney. Chimney was cleaned, new piping, etc at the beginning of the wood burning season.

Question is, do I NEED a flue collar, and/or will it help with better draft? My piping goes directly into my concrete wall and I've sealed it up with the Rutland 800 degree Latex goop. It's since cracked, and I've been considering ripping it all out and applying some red RTV in it instead or something. I've tried 2 high temperature sealants, and both have cracked and separated at that location. RTV can't crack.

The way my setup is designed, there's no way I can fit a flue collar on there unless I custom cut or fit one, as right above the hole into the concrete, there's a bar that runs into the wall also to secure the piping to the wall.

Worth the time, or just seal with RTV?

 

[brant2000]

When you say the "piping goes directly into the concrete wall", do you have a clay (or other material) thimble? I like to be able to remove mine fairly easily and have given up on trying to use/replace that furnace patch material. Like your's it would always seem to crack and was a PITA. Right or wrong, I now use a piece of thin, flat stove door gasket material that I wrap around the outside of the pipe. I then just force it in to place with a screwdriver. It's worked well for me.

 

[j7art2]

It's kind of a stupid setup. I literally have an 8" hole in my concrete wall for the pipe to go into, and right above it a piece of angle steel that holds the pipe into the hole via coat hanger (from the previous owner)

I've since upgraded to heavy gauge wire. I didn't think about that gasket material though, good idea. I'd likely have to glue mine into place.

One thing I will say though, cause I'm paranoid about leaks is that I've RTV'd each piece of pipe, other than the initial stink from the first few firings, the smell goes away, if you ever go that route.

In the future when I tear it all out to clean it, I'll use a gasket I think. Good idea. It'd take me 2 hours to chip it all out now. Lol

 

[kennyp2339]

800DEG is to low of a temp sealant, do you have a liner that goes to the top of the chimney ?

 

[j7art2]

Yep, clay liner.

The RTV on the pipes is rated for 600. I used different sealant for the wall, and shouldn't I guess. It stunk petty bad the first few firings, but still holds to this day nice and tight, and it's gotten well above that plenty of times.

 

[j7art2]

I should have likely gone straight with RTV to begin with, and should have known better. I assumed a higher rating was better. The first stuff that cracked was rated for 1700 degrees. Ha. Junk.

In other applications, I've used RTV as a direct gasket sealant from the engine block on my 2 stroke air cooled dirt bike exhaust for years with no issues. Probably triple the heat rating there I'd imagine.

 

[bholler]

you need a proper thimble going through to the clay liner and a tight fitting pipe or adapter to slide into it. Then just a little bit of furnace cement will do and it will hold if it is done right