Are these "blisters" normal ? Hearthstone Castleton

[Evermal]

Hi everyone ! I'm new to the forum and new to everything wood stove related , so any help will be really appreciated !

I just got my hearthstone installed , and did 3 small break-in fires. I used a few pieces of kindling following the instructions on the manual. Then I tried a bigger burn (about 3.5 hours) , using kindling again and 3 small pieces of cord wood. I did left the front door open for some minutes , to get the cord wood ignited , but short after that I heard some hissing coming from the top of the stove so I closed the front door and decreased the air flow. Overall I think I didn't reach very high temperatures as the catalyst probe barely entered the active range.

Once I was done I noticed something like blisters inside the firebox , on what I believe to be the refractory cement. Is this a signal of over fire ? Is it damaged ? Or this is somewhat normal ?

Thanks for your time !

 

[stoveliker]

I think your bricks were not dried out enough yet. I.e. more small to medium fires needed. Then dialing down the fire produced smoke that absorbed in the moisture, creating creosote that you see.

 

[Highbeam]

What you’re dealing with here is the soapstone “mud” that hearthstone uses to seal between the stones in addition to the splines. When the stones are assembled this mud spooges out just like bricks in a wall. Easy and necessary to clean on the polished outside of the stove but on the inside they just wipe it around. That thin layer pops off but the seal is still good.

Don’t worry about it.

 

[begreen]

These blisters will pop under greater heat in the firebox. You may see some black liquid under the back of the stove with the first hot fire. That too will go away after a hot fire or two.

 

[Evermal]

Thank you so much for the help! I was worried I did something wrong

 

[BigJ273]

Very interesting. Never seen that before.