Harman P68 carbon build up

[MarkDon]

Hello folks, I've been a lurker on this site but here is my first post. Please bear with me. I have owned my harman P68 for about 6 years now and routinely burn 5 tons of pellets per season. I use lignetics. Over the years I have replaced the auger, combustion blower and fiddled with things to make my stove run nice. I have always been happy with the stove performance and heat output. On to my question. Last two years I have been dealing with carbon build up in the burn pot and also on the flame guide. Normally, I chisel this carbon out each time I clean the stove (per ton) with no ill effects. Last week I hit my breaking point and need help. On a particularly cold night the carbon build up actually made the flame guide push up out of position which scared the wife and I. How can I stop this carbon build up? I have replaced the flame guide with no help, I run the stove in room temp and am very happy with the temp and stove usage of pellets. I get about a ton burned before my ash pan is full. I also keep all my pellets in the basement from the summer when I buy them untill I use them. Thanks for all ideas and help. Mark

 

[Bioburner]

Sometimes its the fuel.

 

[SidecarFlip]

This might help and again, it might not... While I don't have a Harman I get hard carbon buildup in my burnpot, takes about a week to 10 days of hard running (it's been pretty continuous hard running lately), anyway, the hard carbon builds up on the pot on the backside and starts impeding the rotation of the agitator rod, the fingers hit the carbon buildup and it causes the pot to literally try to jump up out of it's mount plus it makes a loud banging noise, very disconcerting to say the least.

What I do, is I have 2 pots in rotation. One pot is in the stove and the other (along with it's agitator rod) is soaking in a pail of water. When the pot in the stove gets the carbon built up to the point where it starts banging, the stove gets shut down, pot pulled, ashes and clinkers dumped (I burn a corn/pellet mix) and the fouled pot goes in the bucket and the one thats been soaking comes out.

Here's the neat part. The pot thats been soaking, all the hard carbon literally falls off and any stubborn spots just need a gentle prod with a putty knife to remove. I then have a completely clean pot, carbon free, smooth as a baby's butt....

What I'm suggesting in as much as you have 2 flame guides is soak one in a bucket of water while using the other and alternate weekly, No chiseling the carbon and you'll have a clean runway for your fuel to move on. No 'speed bumps' and no moving flame guide.

 

[MarkDon]

Thanks for the idea with the flame guide as I do have two of those to rotate out. That alone will probably be a big help. However, my burn pot looks to be bolted in place and attaches directly to the auger tube and does not look like it is easy to take out and replace on a regular basis so I still need help to eliminate the build up in the pot. Thanks, Mark

 

[3650]

welcome to the work of daily pot scraping.

 

[SidecarFlip]

I think BioBurmer puts graphite in his pellets, you mught want to PM him, he's a moderator on here....

 

[Tonyray]

Hello folks, I've been a lurker on this site but here is my first post. Please bear with me. I have owned my harman P68 for about 6 years now and routinely burn 5 tons of pellets per season. I use lignetics. Over the years I have replaced the auger, combustion blower and fiddled with things to make my stove run nice. I have always been happy with the stove performance and heat output. On to my question. Last two years I have been dealing with carbon build up in the burn pot and also on the flame guide. Normally, I chisel this carbon out each time I clean the stove (per ton) with no ill effects. Last week I hit my breaking point and need help. On a particularly cold night the carbon build up actually made the flame guide push up out of position which scared the wife and I. How can I stop this carbon build up? I have replaced the flame guide with no help, I run the stove in room temp and am very happy with the temp and stove usage of pellets. I get about a ton burned before my ash pan is full. I also keep all my pellets in the basement from the summer when I buy them untill I use them. Thanks for all ideas and help. Mark

I have the P61A Which has either the same size burnpot as the 68 or pretty close.
that said, I never had any carbon at all on the Flame guide....just ash...
Even when burning Stove chows from Home depot which are hot but Ash city...
also burned some Lignetics..
Are you burning room/auto exclusivly?

 

[MarkDon]

Yes, room temp, auto is all I ever use and it has really been burning this year with the cold. It very rarely burns at a low setting for long. I do scrape the ash out of the burn pot every time I add pellets. I just don't scrape way down into the pellets that are still burning. Just enough to keep the first few rows of air holes clean

 

[gfreek]

I pull away the ash on the burn pot and use the Harman tool with the pointed end and scrape under the pellets in the burn pot and the side edges quickly. Daily

 

[Bioburner]

I think BioBurmer puts graphite in his pellets, you mught want to PM him, he's a moderator on here....

The graphite was mixed into a couple cups of pellets and run through the auger to help rid the stove of auger squeal. I rub graphite powder into various pot parts on a Bixby and worked ok on a Quad Santa Fe pot to keep from having build up of carbon. First year I had the PC45 I was having carbon sticking speed bump issues whatever and those pellets where just plain nasty. Last couple years not having those issues.

 

[alternativeheat]

I pull away the ash on the burn pot and use the Harman tool with the pointed end and scrape under the pellets in the burn pot and the side edges quickly. Daily

To me this is the answer with a lot of brands of pellets. Some others don't leave the carbon to begin with. But ya, just scrape the pot, it only takes a couple of minutes. Typically there will be a hump of carbon under the burning pellets and one on each side plate of the burn pot. generally the Harman tool will get it out. On occasion I have used a screw driver. But just scrape right under the coals you can feel the ridge line and break it loose. Wear gloves, no need to shut the stove down and you get it before there is a huge buildup !

 

[Tar34]

The answer to my carbon buildup was the serendipitous discovery that if I mix corn with pellets, it virtually eliminates carbon buildup. The stove burns much cleaner as well. My mixture is 2 parts pellet to 1 part corn or 40lbs pellet to aprx 20lbs corn. I mix by volume. I have no carbon buildup. Never have to scrape pot.

 

[alternativeheat]

The answer to my carbon buildup was the serendipitous discovery that if I mix corn with pellets, it virtually eliminates carbon buildup. The stove burns much cleaner as well. My mixture is 2 parts pellet to 1 part corn or 40lbs pellet to aprx 20lbs corn. I mix by volume. I have no carbon buildup. Never have to scrape pot.

Feed store here gets $11.49 for a 50 lb bag of corn.

 

[Bioburner]

Feed store here gets $11.49 for a 50 lb bag of corn.

Talk about some markup. Fridays buy price at the local elevator was $3.45

 

[alternativeheat]

Talk about some markup. Fridays buy price at the local elevator was $3.45

I said thank you very much and hung up the phone. I thought if it was a bit less expensive than pellets I might try mixing the two in the P61. On receiving the quote over the phone at first I was speechless. The girl was proud to announce they had it whole kernel, cracked or crushed.

 

[bogieb]

I said thank you very much and hung up the phone. I thought if it was a bit less expensive than pellets I might try mixing the two in the P61. On receiving the quote over the phone at first I was speechless. The girl was proud to announce they had it whole kernel, cracked or crushed.

Yeah, I've done a search on "local" (southern half of NH) suppliers of burning corn, and it either as expensive, or more expensive than pellets that I can get fairly locally - unless I want to go to CT. I've wanted to experiment, but not if it would cost me more in initial cost, and in transport.

 

[alternativeheat]

Yeah, I've done a search on "local" (southern half of NH) suppliers of burning corn, and it either as expensive, or more expensive than pellets that I can get fairly locally - unless I want to go to CT. I've wanted to experiment, but not if it would cost me more in initial cost, and in transport.

A guy in RI. sells it bulk not sure for how much. I think I'm done with the corn idea for up here in the NE !

Some guy over in the NEPA Crossroads forums says he burns rice coal in his P61, fwiw. Claims no issues, claims it's the same auger and feed system as the Harman's coal stoker had. Again, fwiw . I'm not advocating anything just passing on the info.

 

[bogieb]

A guy in RI. sells it bulk not sure for how much. I think I'm done with the corn idea for up here in the NE !

Some guy over in the NEPA forums says he burns rice coal in his P61 fwiw. Claims no issues, claims it's the same auger and feed system as the Harman's coal stoker had. Again, fwiw . I'm not advocating anything just passing on the info.

It is something like $225/ton - one bag!!, a ton of 40 lb bags is $325.

 

[alternativeheat]

It is something like $225/ton - one bag!!, a ton of 40 lb bags is $325.

What is ? Corn or Rice Coal ?

 

[Tar34]

I'm paying $6.00 for 50 lb or 1bushel. Less f course if I buy in bulk.

 

[mikesj]

I burn mostly Lignetics- on ton number six for this season. I usually do a light scraping at least once a day. I probably do a heavy duty scraping every other day or so. I just wait for the stove to cool down a little and I use a 1 inch masonry chisel as a scraper. The edge on it and its heft seem to break off the larger chunks of carbon pretty well. If I notice carbon build up on the sides I scrape there too.

All in all, I spend about a minute every other day.

 

[Don2222]

The best way to fight the carbon buildup is by using the Selkirk DT venting that warms and dries the air going into the burnpot. Also makes the stove 10% more efficient. IMHO not the cheapest solution but the best solution!

 

[SidecarFlip]

Talk about some markup. Fridays buy price at the local elevator was $3.45

We are in the wrong business Bio.... I need to hook up my grain trailer to the barnyard buick and head to New England. You handle the bag end out the glory hole, I'll handle the hydraulics and we can retire on a 42 foot trailer load....

$3.48 / bu / 14% yesterday, 50 bucks delivery, minimum 500 bushel.

$11.49 / 50 is unbelieveable markup.

 

[SidecarFlip]

A guy in RI. sells it bulk not sure for how much. I think I'm done with the corn idea for up here in the NE !

Some guy over in the NEPA Crossroads forums says he burns rice coal in his P61, fwiw. Claims no issues, claims it's the same auger and feed system as the Harman's coal stoker had. Again, fwiw . I'm not advocating anything just passing on the info.

Far as I can see, the mechanics are the same but is the venting up to a coal fire? Not sure about that.

 

[SidecarFlip]

The best way to fight the carbon buildup is by using the Selkirk DT venting that warms and dries the air going into the burnpot. Also makes the stove 10% more efficient. IMHO not the cheapest solution but the best solution!

I'll take the low road on that. I'd think just the opposite would be true, colder denser air should provide more oxygen that hotter air, but what so I know.