Cement coming off?

I have a Hearthstone Mansfield and my burn times have been going down hill for a while. When I looked in the stove I could see the cement on the joints was missing in quite a few areas, so I picked up some Rutland stove cement, cleaned the stove with a wire brush, and went to town re-sealing the joints.
I thought I did a good job, guess not. Most of what I put on has come off after about a month of burning.

I followed the directions on the tub of cement. Does anyone have any tips, or maybe a better brand of cement, they would like to share with me? I need to sort this out as I'm burning too much wood and the stove doesn't want to get above 425 degrees.

Thanks guys.

Only a wild guess, but maybe Woodstock's cement would work well if it is soapstone you are cementing? They have ground soapstone in their cement, I think. Maybe they'll sell you some..likely.

Hearthstone has the same cement that has stone in it. You can get a temporary fix with rutland but since soapstone expands at a different rate you will not get a permanent bond as you would with a cement made of soapstone.

Wow....didn't know that, or even think of it I guess. I'll go out and see what I can find tomorrow.

thanks guys.

I wouldn't expect to find soapstone cement at the local hardware store. Really, even rutalnd is becoming rare as people seem to be sissys and using their thermostats for heat.

According to the professionals, experts, and manufacturer the cement on the inside of a hearthstone is just extra that spooged out during assembly and was not completely wiped off. The seal between the stones is done with a steel spline within a gasket sock that is slid well into each stone into grooves cut into the stones. Like a tongue and groove floor but all stones are grooved and the tongue is a strip of steel.

The cement is not what seals the stove. That's what they told me anyway. Tom Oyen seems to be well educated about this.

My dealer told me the splines didn't extend to the end of each stone, and the cement was the only thing sealing the stove in those "corners". Not sure if he's right or not, but I can see daylight in a couple areas where the corners of four stones meet.

Daylight! That's not good at all.

are the gaskets ok....dollar bill test?

With a paintbrush and water try to get the area clean of dust and wet...maybe that will help the cement bond better.

The gaskets are good, and I did clean the stove and get the stones damp.

I'm going to call the Hearthstone dealer and see if they have the right cement on the shelf.

I have some cement coming out, and also picked up a outside air kit and ceramic baffle the other day. Once everything comes in I'll dig into the stove.
In the short term, I've placed a magnet over one of the secondary intakes on the bottom of the stove. I also put a paperclip in one of the flaps on the primary air control, to close it right off when the control is closed. Not exactly the right way to fix things but the stove is putting out way more heat and burning a lot less wood.