My wood burning fireplace has a lot of missing mortar between the bricks
right behind where the logs go. I went to Home Depot and they sell fireplace
mortar in a tube (the kind you need to use with a caulking gun). The area
that needs the mortar has a lot of soot around it. Would I need to clean the
soot off before applying this mortar stuff? If so, how does one clean years
of soot? Thanks.

On Mar 27, 6:08 pm, "Remi" wrote:
My wood burning fireplace has a lot of missing mortar between the bricks
right behind where the logs go. I went to Home Depot and they sell fireplace
mortar in a tube (the kind you need to use with a caulking gun). The area
that needs the mortar has a lot of soot around it. Would I need to clean the
soot off before applying this mortar stuff? If so, how does one clean years
of soot? Thanks.

I might be all wrong about this, but given that problem here's a way I
would try: first, wire brush , scrape, whatever to get as much loose
crud off as possible. Then open the damper, bring in the propane tank
and weed burning torch, and slowly, gently, bring the affected areas
up to a temperature that would blue steel nicely. We're assuming that
the firebrick has no hidden crevices exiting to flammable structure,
but it would pay to check. This should work, because carbon deposits
will slowly oxidize somewhere around 800 F IIRC. Following this, the
firebrick mortar should adhere perfectly to the clean area.
For more ideas on cements, mortars, techniques, and such, try
contacting folks who work in ceramics and build kilns for their wares.
HTH

Joe

On Mar 27, 8:02 pm, "Joe" wrote:
On Mar 27, 6:08 pm, "Remi" wrote:

My wood burning fireplace has a lot of missing mortar between the bricks
right behind where the logs go. I went to Home Depot and they sell fireplace
mortar in a tube (the kind you need to use with a caulking gun). The area
that needs the mortar has a lot of soot around it. Would I need to clean the
soot off before applying this mortar stuff? If so, how does one clean years
of soot? Thanks.

I might be all wrong about this, but given that problem here's a way I
would try: first, wire brush , scrape, whatever to get as much loose
crud off as possible. Then open the damper, bring in the propane tank
and weed burning torch, and slowly, gently, bring the affected areas
up to a temperature that would blue steel nicely. We're assuming that
the firebrick has no hidden crevices exiting to flammable structure,
but it would pay to check. This should work, because carbon deposits
will slowly oxidize somewhere around 800 F IIRC. Following this, the
firebrick mortar should adhere perfectly to the clean area.
For more ideas on cements, mortars, techniques, and such, try
contacting folks who work in ceramics and build kilns for their wares.
HTH

Joe

Just scrape it clean and brush off the dust and point the joints with
2 parts sand and 1 part portland cement. Not too much water. Just
enough to make the cement the consistancy of stiff putty. Do not put
a fire in there with severely cracked mortar joints. You don't know
where the smoke will go.

Remi,
I dont throw around the term "have a pro look at it" alot but in this
case your desciption of "a lot of missing mortar" conserns me. If it
is that way in the hearth it is bound to be that way in the chimney
and you need to know if it is. Cracked or missing mortar is a seriouse
problem and can easily lead to a house fire.

If that suggestion doesnt appeal to you wallet but you still like the
fireplace then you are just like me. My fireplace was in bad shape due
to mortar issues, a bad crusty worn & damper, but I still liked the
look of the fireplace. I didnt want to bother with repairs so I bought
a nice candelabra and a chimney balloon. I use the candelabra and
light it up when I want some abmbiance (just like I used the
fireplace. Doing this actually saved money on my gas bill since the
fireplace didnt suck the heat out on my home when i was using it. The
Chimney Balloon helped me seal up the damper nice and tight when i
wasnt using it at all.whick also prevented the den from feeling so
cold in the winter. I know this is a diferent way to look at the issue
with your fireplace, but the best I can offer is waht worked for me.