cavitation

[firekindler]

I have a Fisher Papa Bear - when I open the draft knobs in the morning after being shut all night, and load the stove, it often if not usually cavitates. Why is this and how can it be prevented? On the advice of one of the members here, I've adopted the habit of only cracking the knobs slightly until the stovepipe heats up. Then I open up all the way until the stove itself gets up to temperature. But the cavitation happens regardless.
Thanks!

 

[bholler]

I have a Fisher Papa Bear - when I open the draft knobs in the morning after being shut all night, and load the stove, it often if not usually cavitates. Why is this and how can it be prevented? On the advice of one of the members here, I've adopted the habit of only cracking the knobs slightly until the stovepipe heats up. Then I open up all the way until the stove itself gets up to temperature. But the cavitation happens regardless.
Thanks!

It isn't cavitation it is back puffing. It happens when the firebox fills with smoke then ignites. What moisture content is your wood at? Have you tried opening the air more instead of less?

 

[coaly]

It isn't cavitation it is back puffing. It happens when the firebox fills with smoke then ignites. What moisture content is your wood at? Have you tried opening the air more instead of less?

I suppose a Fisher Smoke Pump could cavitate. But I don’t think there’s a fix for it.

 

[firekindler]

It isn't cavitation it is back puffing. It happens when the firebox fills with smoke then ignites. What moisture content is your wood at? Have you tried opening the air more instead of less?

My wood is well seasoned. When I open the draft knobs all the way it gets more severe.

 

[bholler]

My wood is well seasoned. When I open the draft knobs all the way it gets more severe.

What moisture content is your wood at?

What is your chimney setup like?

 

[sneefy]

In order for a stove to cavitate the moisture content would need to be quite high. 😉

 

[Eightball1313]

my old kodiak stove does it too, ive found over the years that the best way to avoid it is to start the fire, with the air control knobs all the way open let the door cracked for 10 minutes or so while the stove pipe heats up to 400 or so degrees, then close the air knobs down to the like 3/4 or 1/2 open ish and close the door, idk why but that seems to work.

It always seemed like if i closed the doors right away with the air knobs wide open it would start going crazy right away, but if you close em down a little and then close the doors and contunally close them down to like 1/4 open then it doesnt do it.

 

[stoveliker]

Cavitation is an imploding gas bubble in a liquid. This is back puffing as bholler said.

This happens when a fuel rich gas mixture is present in the stove. Insufficient draft or wet wood can cause this (because of incomplete combustion leading to half burned gases in the firebox). Opening the air allows in oxygen, leading to an explosive mixture.

Bholler's questions need answers before a path forward can be outlined.