Any experience with putting sawdust fuel through a Harman?

Over the past several years, several times each year, I have had to use-up a very water damaged bag of wood
pellets that has expanded to become saw dust. I open up the damaged bag putting the saw dust into four
5-gallon plastic buckets. Then I let the top few inches of saw dust dry.

I mix the sawdust with good wood pellets to make a pellet mixture of up to 33% fines (sawdust). The pellet mixture
burns fine through a Harman P68, except for bridging in the hopper. There is no point in putting more than
40 to 60 lbs. of the pellet mixture into the hopper. It bridges-up forming a vertical hole down to the trap door
of the auger feed. I have to check the stove every hour or so, using a small broom to break the bridge and
sweep the mixture
towards the auger trap-door, using the small broom to pile-up a new pyramid over the the auger trap door.
More fines, more bridging.

Only about twice in the past five years did the bridging form a hollow cavity above the auger trap door,
causing no more pellet flow and the burn pot fire going out. I get rid of the hollow cavity by either poking
a broom stick down through the pellet mixture, or in the worst case, I scoop-out the pellet mixture to
get down to the auger trap door. Hence, the reason why I only put in to the hopper 40 to 60 lbs. of the pellet
mixture.

I am curious whether anyone has put through a Harman, or any other pellet stove, a nearly 100% fines (sawdust) mixture.

 

I can’t confirm this but my coworker told me his Harman would burn wet sawdust. He got rid of it tho cuz it was too finicky…

 

I have split up the sawdust from damaged pellets and mixed with other bags for the P61a. I don't think I get up to a 33% mixture, but it's not like I measure/weigh them. I do it like I cook, by eye .

I probably hit a max of 15-20% blend. I've never had bridging problems, or any problems doing that.

I don't remember if I've done the same in the P43 - I've probably put a small amount in there too from bags that just had a corner ruined. But since I have to carry the bags upstairs to that stove, it is much more handy to use the P61a.

I personally would not try 100% mixture because I know that my P61a's fines box is always full whenever I clean it. I'd probably be more inclined to try it in the P43 because the fines box rarely has anything in it - even though the stoves burn the same pellets. (the trade off is the igniter are in the P43 fills with ash and I have to clean it on a weekly basis - versus the P61a that can go forever with barely any ash down there.)

 

I am going to experiment for a while to see what percentage of fines will work as well as
a 100% pellet mix. I plan to try 10% fines. I am also making a point to run the hopper
completely empty once about every two weeks, to use up all of the fines that collect at
the bottom of the hopper. From what I can tell, the problems shows-up when too many
fines collect at the bottom of the hopper. Somewhere about 50% to 80% fines at the
bottom of the hopper will stop pellet flow.