Large clinker

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scruffy

Member
Hearth Supporter
Oct 24, 2008
35
NH
Anyone really know what causes clinkers?

I didn't attend my stove yesterday as often as usual, I was out side moving snow with the tractor. Came in to find a birds nest size clinker filling the whole burn pot. I was all a glow but all stuck together in one big clump. First time this has happen in such a large mass. Been burning Pennington pellets mixed with Spruce Point.
 
If it's only once don't worry about it but you may need to add a little more air to the mix.
 
mullet said:
If it's only once don't worry about it but you may need to add a little more air to the mix.

I got a couple small "clinker"-type pumice stones about the size of big marbles a few weeks ago, but since I upgraded my firepot on my Astoria, and increased the air, no more problems.
 
My most recent purchase of Penningtons have produced significant clinkers in my Castile burnpot. I have burned them in the past without incident, but my most recent lot of Penningtons produce an almost "lava rock" hard and texture clinker. I'll check the manuf date and post to see if there seems to be any similarities.
 
macman said:
mullet said:
If it's only once don't worry about it but you may need to add a little more air to the mix.

I got a couple small "clinker"-type pumice stones about the size of big marbles a few weeks ago, but since I upgraded my firepot on my Astoria, and increased the air, no more problems.

I got 1 hole drilled and my bit bit the dust LOL. I need to go and get a good bit.
 
mullet said:
macman said:
mullet said:
If it's only once don't worry about it but you may need to add a little more air to the mix.

I got a couple small "clinker"-type pumice stones about the size of big marbles a few weeks ago, but since I upgraded my firepot on my Astoria, and increased the air, no more problems.

I got 1 hole drilled and my bit bit the dust LOL. I need to go and get a good bit.

Mullet, regular steel bits won't last. The firepot is stainless steel, so you need to use Cobalt bits and a little oil during drilling. I started by center punching each location, and then drilled with a 1/16", and then finished w/ 1/8". if you don't use oil, even w/ the cobalt, you'll ruin the bits. I broke a 1/8" one when I dropped the electric drill on the floor (DOH!), but otherwise they are still sharp after all those holes (using the oil).

Finish up by filing the burrs off until no sharp edges.

I got a set at Lowes for about $26.....good to have anyway....they last much longer than standard:

DeWalt
13-Piece Cobalt Drill Bit Set

Item #: 71226 Model: DW1263 Z $24.97 + tax
 
I also had a large clinker problem with the penningtons I purchased at Sams Club in Prescott AZ.

After burning two bags I returned the remainder and picked up some Heaters brand from the Prescott Home Depot. Have not had any clinker problems since.
 
another good idea when drilling steel besides oil, keep the drill speed slow, faster just creates more heat which will take the edge off the bit.
 
Nitch said:
Anyone really know what causes clinkers?

"Clinkers are lumps of silica and other impurities in some pellets that fuse with ashes as the silica melts and cools. Minute amounts of alkaline salts found naturally in some soils can lower the melting point of silica and promote clinker formation."
sound fair... some folks have said that pellets with larger concentrations on bark will form clinkers... maybe the bark has some sand on it when procesed? Don't know.

Last year I used some Fireside Ultras with great success BUT I did have some clinkers when burning them... but I have never had any with the other brands of pellets I've used.
 
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