RUST!

[recppd]

Here's the deal...

The weather here in MA has turned a bit chilly lately so I decided to clean out the stove and get her ready for the Fall. This is the third season with my Jotul Kennebec insert and I am anticipating my first burn! Anyways, I was in a cleaning mood today so I opened up the doors to check the inside and what I discovered was pretty disappointing! I immediately noticed surface rust everywhere from where the door gasket met the face, inward. Surface rust I can deal with, but the interior was a different story. I started poking around with the vaccum and big chunks of rust started dropping off! What immediately concerned me was the amount of rust. Is this normal? I didn't notice any of this last season. I removed the cast iron "re-burn" plate that sits between the burn chamber and the flue pipe and it was coated with caked-on rust. Big chunks were easily flaked off! What I did notice was that the base cast-iron seemed to be intact, or at least it appeared that way. What I'm concerned with is the cause of this rust. I'm guessing it was caused by trapped humidity from the summer months.

So here's are some questions...

Should I bother to clean and paint over the external surface rust? Do cast iron stoves normally rust like this? Should I be leaving the doors slightly ajar during the off-season? How about putting a container of moisture absorbing pellets inside during the summer?

Any suggestions are appreciated.

Thanks.

 

[elkimmeg]

I would expect that from a zolzang stove, but a Jotul? Does not sound right to me. Hopefully MSG, a Jotul dealer, can better answer if this is normal and Jotul warranty policy if it is covered

Take pictures and save some of the flaking rust in a dated and labled ziplocked bag

 

[Roospike]

Hummm , It does sound odd for cast ... but i have not see an issue like this before . for the summer months you can put news paper in your wood stove to help keep out moisture . News paper in a stored cooler , a fridge or freezer is common for storage and down time to keep out mold , moisture and musty smell .......... I'm sure it would work in a wood stove .

 

[MountainStoveGuy]

I would expect that from a zolzang stove, but a Jotul? Does not sound right to me. Hopefully MSG, a Jotul dealer, can better answer if this is normal and Jotul warranty policy if it is covered

Take pictures and save some of the flaking rust in a dated and labled ziplocked bag

No, i basicly live in a desert. Nothing rusts here. I dont think it would be normal, but logicly thinking, cast iron is cast iron, to a point. it rusts do to moisture. I would think it would be local conditions causing the rust. I wouldnt think a defect in workmanship is causing the rust. Surface rust is normal on any painted stove or insert. Flaking isnt. Is it possible that you have a chimney leak somewhere? Im not dissmissing jotul responsibility here, but to me it seems like a local problem. Thats my first impression. I would think a bag of silica in the summer would be a good idea, you guys get as much rain in a day then we do in a year.

 

[Todd]

I don't think this is normal. Contact your dealer and explain your situation. Do you have a chimney cap to keep the rain out?

 

[BrotherBart]

Ok I will stick my neck out here. That isn't rust. To much of it in too many places. It sounds like you burned some wet wood late in the season. When I have done that flakey crud collects inside the stove and above the baffle. Sitting there in contact with steel long enough in a humid environment makes it look like rust but it is just plain old creosote. Surface rust happens under it and it flakes off the stove surfaces.

What does the chimney look like?

And as to cast iron rusting, from previous posts here it seems that the firebox in the Jotul inserts are steel, not cast.

 

[begreen]

Here's the deal...

The weather here in MA has turned a bit chilly lately so I decided to clean out the stove and get her ready for the Fall. This is the third season with my Jotul Kennebec insert and I am anticipating my first burn! Anyways, I was in a cleaning mood today so I opened up the doors to check the inside and what I discovered was pretty disappointing! I immediately noticed surface rust everywhere from where the door gasket met the face, inward. Surface rust I can deal with, but the interior was a different story. I started poking around with the vaccum and big chunks of rust started dropping off! What immediately concerned me was the amount of rust. Is this normal? I didn't notice any of this last season. I removed the cast iron "re-burn" plate that sits between the burn chamber and the flue pipe and it was coated with caked-on rust. Big chunks were easily flaked off! What I did notice was that the base cast-iron seemed to be intact, or at least it appeared that way. What I'm concerned with is the cause of this rust. I'm guessing it was caused by trapped humidity from the summer months.

So here's are some questions...

Should I bother to clean and paint over the external surface rust? Do cast iron stoves normally rust like this? Should I be leaving the doors slightly ajar during the off-season? How about putting a container of moisture absorbing pellets inside during the summer?

Any suggestions are appreciated.

Thanks.

No stoves don't normally rust like this. Did you get a lot of water coming down the stack during the monsoon summer and not notice it?

 

[K31Scout]

Maybe one of those plug in dehumidifer rods that go in gun safes would help during the summer. We get humid here and I may do that next summer.

 

[thechimneysweep]

Sounds like you might be experiencing what we call "shaling." The metal inner firebox parts turn orange, and start flaking off. When we see this, the cause is usually salt or other chemicals in the wood. Are you burning mill ends or scrap lumber of any kind? Do you add any "Soot Remover" chemicals to your fire? Some contain rock salt.

 

[recppd]

Thanks for the replies!

Here's some answers to some of the questions posted...

1. I burned Home Fire Prest Logs exclusively last season. No cordwood at all! They were expensive, but burned great and yielded very little ash. They do form "clinkers" in the bottom of the stove (looks like lava rock), so maybe some of that formed on top of the baffle plate? Those not familiar with these can see the specs at www.homefirelogs.com. I'm going back to cordwood this year as the Home Fire logs are too expensive in this part of the country ($418 per pallet).

2. The chimney is lined with a 6-in. stainless liner and capped at the top. The only way rain could get in is with a strong side wind. My guess is that the rust is from the humidity trapped inside the firebox. My Jotul Kennebec has a 3" air intake duct that is connected to an outside vent. I didn't close the vent this summer, so I'm wondering if the normal air flow during those months allowed humid air to be trapped inside. Just a thought...

3. "Shaling" - very possible! I'll have to open up the shopvac and check the contents more closely. I don't add any type of "soot remover".

I wish I knew how to post pics to make things easier....

Thanks again.

 

[babalu87]

I out one of those do not eat bags that come with electronics in my stove after the season ending cleaning.
I think I will continue with that practice.

The bag I have isnt the ordinary one , it came with a big piece of equipment at work.

 

[MountainStoveGuy]

if you want to email them to me you can, i will post them. Its not hard. just reduce the photo to a max 250kb and hit the "post reply" button, and attach.

 

[recppd]

I out one of those do not eat bags that come with electronics in my stove after the season ending cleaning.
I think I will continue with that practice.

The bag I have isnt the ordinary one , it came with a big piece of equipment at work.

I gotta tell ya, you totally lost me with this one...

 

[Shane]

I think he's talking about that silicate crap that they put in jerky to absorb the moisture. Only alot bigger.

 

[minesmoria]

I am on coastal bc where the logs are made, i asked them were they their logs come from.

Some of it comes down the coast towed in log booms in the ocean, and others logs from up country


The salt eats away at the stove.

 

[webbie]

Is the firebox in Jotul inserts 100% cast? I know there are sometimes steel inserts.....but probably not the firebox.

It would be a real rarity for cast to rust out - consider what it goes through in and on your car engine! In fact, I have almost NEVER seen a piece of thick (newer stoves) cast iron rust out. I have seen it powder from coal and excess heat.

But assuming you don't see warpage, etc....my first guess is something harmless - like excess furnace cement....sometimes there can be lots of this. Or, perhaps some parts are steel like baffles or tubes?

I guess we have to watch out for the salt in those logs also! But, again, I would take a wire brush to the insides and study closer to see if cast is really flaking.

 

[recppd]

Okay, upon closer inspection I have come to the following conclusions...

There is definately some surface rust visible, but nothing serious. The "chunks" that I took for rust appear to be a hard, black/rust colored substance that I'm assuming is the bi-product of burning the compressed logs. My theory now is that the same "clinker" material that formed in the bottom of the stove also attached itself in lesser quantities to the rest of the firebox/baffle plate. During the normal burning season I would have never noticed it. But now that it's had a chance to dry out, swell with the humidity, and loosen itself - well, I guess I mistook it for heavy rust. If you held it in your hands you'd say the same thing. But breaking it apart you'd find that it's charcoal black inside. Very heavy and feels metalic, but apparently not rust. But it fooled me...

I guess all I have to figure out now is if it's worth cleaning off the external firebox rust and painting it? If I do, would I use a straight flat black stove paint, or does Jotul have it's own color?

Thanks again for the replies...

 

[MountainStoveGuy]

Stove Bright Flat black will do it! Glad you figured it out.

 

[HarryBack]

I am told I frequently have a firm grasp for the obvious.....has anyone tried, after cleaning the stove int he spring when you are done burning, spraying WD40, or Mystery Oil inside their unit to act as a buffer between the humid air and the steel? Works well in my pellet stove.

 

[webbie]

That's too obvious - we should do that on our bikes, too! That's exactly why we don't do it.....heck, most people don't even clean the ash out at the end of the winter