Jotul F400 Tear Down and Rebuild - What I learned

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ruknight4ever

Member
Nov 27, 2010
8
Maine
Last weekend, I wanted to simply repaint my Jotul F400. I took the stove outside and started to dismantle pieces of it (like the secondary baffle, smoke outlet and top panel). I noticed that the cement holding the rear panel in place was chipped and brittle. I was able to remove all the old cement from the seam and probably could have caulked furnace cement in place. However, I decided to do a complete rebuild. I searched on line for how to do this but was unable to find everything in one place so I decided to write this post.

1. Furnace Cement: After I tore down the stove, I went to my local fireplace store to buy cement to reassemble the sides of the stove to the base. They sold me “Stove and Gasket” cement and not furnace cement. After speaking to the folks at Rutland, the Stove and Gasket cement would have worked fine. However, it’s thinner than furnace cement. My recommendation is to use furnace cement when reassembling the stove.

2. Applying the Cement: The Jotul stove (and I am assuming all others) have a tongue and groove design for the case and sides that need to be cemented together. I filled the entire channel (groove) with cement by using a small putty knife and then installed the mating piece. I lot of cement poured out from the seam, which I believe is a good thing as it should ensure no air bubbles between the mating pieces. If you want to know how much cement to use, err on the side of more than less. It’s easy to clean up afterwards with water and a rag (it’s water soluble). Word of caution: the furnace cement is quite caustic. I did use nitrile gloves during the application but they ripped and my hands paid the price. in hindsight I would have used thicker rubber gloves (like those some would use when washing pots and pans).

3. Bolt Replacement: I was planning to reuse the bolts during reassembly. However, upon closer inspection, the hardware was tired. I couldn’t thread them in by hand, and some were even curved a little bit. I replaced with #2 stainless steel bolts. I could not find flange bolts in M6 1.0 so I used a regular M6 bolt and two washers. I used two slightly different sized washers - one smaller and one slightly (1-2mm?) larger in diameter. The larger diameter washer did two things. First, it increased the strength of the pressure point between the bolt head and the flange. Second, it accommodated for the sizing / shape of combination “U” and “V” shaped flange that the bolts sit on to ensure the washer had pressure on more of the flange. (I know I might not have explained that well - but any Jotul owner who has done a rebuild will know what I mean). I did use anti sieze on each bolt thread during reassembly.

4. Bolt Tightness: From what I read, I knew I didn’t want to over tighten the bolts on reassembly. Unfortunately, I didn’t exactly know what that meant. I know it’s a subjective feel - but couldn’t find a descriptive explanation of what “snug but not over tight” meant. What I decided to do was thread the bolts in my hand until they couldn’t turn anymore, and then I used a 3/8” ratchet, holding the ratchet by the head versus the handle. Using the ratchet in this fashion reduces the torque you can apply during tightening. I tightened each bolt by just using the head of the ratchet until snug. I could have turned each bolt more had I held the handle of the ratchet but that would have, in my opinion, made it too tight.

4. Prep for paint: I used a wire wheel and 220 sandpaper to remove rust and scuff the surface. I also used “Dirtex” in aerosol form to clean the stove of dust prior to painting. I initially wanted to apply the Dirtex to a rag, and then use the moistened rag to clean the stove (to ensure no residue would be left over on the stove). However, I found with the nooks and crannies of the decorative stove design, I needed to apply the Dirtex directly to the stove. To ensure no residue was left over for the repainting, I let 24 hours go by between cleaning and painting.

5. Paint: I bought the Stove Bright paint. The directions call for 2-3 coats with the first coat being a “mist” coat. I did 3 coats - not sure how 2 coats would cover the stove unless you went heavy with the application. I recommend 3 coats and apply each coat thinly. I used 2.5 cans of paint (including painting the inside of the door and the inside of the ash door).

6. Gaskets: I replaced all of the gaskets. However, I was completely unaware that a flat thin gasket sat on top of the left and right side burn plates (I am assuming mine burned away at some point in the past). I only discovered it by I looked at a parts diagram for the stove (see below). My recommendation would be look at the parts diagram during reassembly just to ensure you don’t miss something.



I hope this helps. Definitely welcome any comments or varying opinions on my approach.
 
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EbS-P

Minister of Fire
Jan 19, 2019
2,704
SE North Carolina
Last weekend, I wanted to simply repaint my Jotul F400. I took the stove outside and started to dismantle pieces of it (like the secondary baffle, smoke outlet and top panel). I noticed that the cement holding the rear panel in place was chipped and brittle. I was able to remove all the old cement from the seam and probably could have caulked furnace cement in place. However, I decided to do a complete rebuild. I searched on line for how to do this but was unable to find everything in one place so I decided to write this post.

1. Furnace Cement: After I tore down the stove, I went to my local fireplace store to buy cement to reassemble the sides of the stove to the base. They sold me “Stove and Gasket” cement and not furnace cement. After speaking to the folks at Rutland, the Stove and Gasket cement would have worked fine. However, it’s thinner than furnace cement. My recommendation is to use furnace cement when reassembling the stove.

2. Applying the Cement: The Jotul stove (and I am assuming all others) have a tongue and groove design for the case and sides that need to be cemented together. I filled the entire channel (groove) with cement by using a small putty knife and then installed the mating piece. I lot of cement poured out from the seam, which I believe is a good thing as it should ensure no air bubbles between the mating pieces. If you want to know how much cement to use, err on the side of more than less. It’s easy to clean up afterwards with water and a rag (it’s water soluble). Word of caution: the furnace cement is quite caustic. I did use nitrile gloves during the application but they ripped and my hands paid the price. in hindsight I would have used thicker rubber gloves (like those some would use when washing pots and pans).

3. Bolt Replacement: I was planning to reuse the bolts during reassembly. However, upon closer inspection, the hardware was tired. I couldn’t thread them in by hand, and some were even curved a little bit. I replaced with #2 stainless steel bolts. I could not find flange bolts in M6 1.0 so I used a regular M6 bolt and two washers. I used two slightly different sized washers - one smaller and one slightly (1-2mm?) larger in diameter. The larger diameter washer did two things. First, it increased the strength of the pressure point between the bolt head and the flange. Second, it accommodated for the sizing / shape of combination “U” and “V” shaped flange that the bolts sit on to ensure the washer had pressure on more of the flange. (I know I might not have explained that well - but any Jotul owner who has done a rebuild will know what I mean). I did use anti sieze on each bolt thread during reassembly.

4. Bolt Tightness: From what I read, I knew I didn’t want to over tighten the bolts on reassembly. Unfortunately, I didn’t exactly know what that meant. I know it’s a subjective feel - but couldn’t find a descriptive explanation of what “snug but not over tight” meant. What I decided to do was thread the bolts in my hand until they couldn’t turn anymore, and then I used a 3/8” ratchet, holding the ratchet by the head versus the handle. Using the ratchet in this fashion reduces the torque you can apply during tightening. I tightened each bolt by just using the head of the ratchet until snug. I could have turned each bolt more had I held the handle of the ratchet but that would have, in my opinion, made it too tight.

4. Prep for paint: I used a wire wheel and 220 sandpaper to remove rust and scuff the surface. I also used “Dirtex” in aerosol form to clean the stove of dust prior to painting. I initially wanted to apply the Dirtex to a rag, and then use the moistened rag to clean the stove (to ensure no residue would be left over on the stove). However, I found with the nooks and crannies of the decorative stove design, I needed to apply the Dirtex directly to the stove. To ensure no residue was left over for the repainting, I let 24 hours go by between cleaning and painting.

5. Paint: I bought the Stove Bright paint. The directions call for 2-3 coats with the first coat being a “mist” coat. I did 3 coats - not sure how 2 coats would cover the stove unless you went heavy with the application. I recommend 3 coats and apply each coat thinly. I used 2.5 cans of paint (including painting the inside of the door and the inside of the ash door).

6. Gaskets: I replaced all of the gaskets. However, I was completely unaware that a flat thin gasket sat on top of the left and right side burn plates (I am assuming mine burned away at some point in the past). I only discovered it by I looked at a parts diagram for the stove (see below). My recommendation would be look at the parts diagram during reassembly just to ensure you don’t miss something.



I hope this helps. Definitely welcome any comments or varying opinions on my approach.
Thanks for the write up. I have not seen any tutorials for rebuilding the F400. I’m assuming you didn’t have one to follow either? Is it pretty self explanatory? Pay attention how it came apart and you can figure out how to put it back together.

What color did you paint it? I would be tempted to choose something unique (mine is enamel but I almost bought a project F400 and wanted to paint it something that would stand out a bit)

Evan
 

ruknight4ever

Member
Nov 27, 2010
8
Maine
Thanks for the write up. I have not seen any tutorials for rebuilding the F400. I’m assuming you didn’t have one to follow either? Is it pretty self explanatory? Pay attention how it came apart and you can figure out how to put it back together.

What color did you paint it? I would be tempted to choose something unique (mine is enamel but I almost bought a project F400 and wanted to paint it something that would stand out a bit)

Evan
Hi Evan - I think it’s pretty self explanatory. Unfortunately, I had to figure this out on my own. Someone did a great write up on gasket replacement, but I couldn’t find anything on a rebuild. Like you wrote, watch how you take it apart and reassemble the same way. However, things like how much cement to use or how tight to make the bolts or how much paint does it take are things I couldn’t find definitive answers for - that’s why I wanted to provide the write up.

I chose the same flat black color that the Jotul comes with from the factory. I wanted to use satin black, but the Mrs. thought flat black would look better. I could have seen painting it green or red!
 

vatmark

Burning Hunk
Jan 5, 2017
122
Nebo NC
Do you have a link to the gasket replacement writeup? Also where did you buy replacement gaskets? I have an F500 and a few gaskets look like they need to be replaced. It appears that not all the gaskets are the same size.

Ann
 

peakbagger

Minister of Fire
Jul 11, 2008
7,344
Northern NH
FWIW No matter how long its sits drying, its going to smoke a lot during the first few fires. Many set up a temporary stack in the yard and fire it off outside before bringing it in.
 
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ruknight4ever

Member
Nov 27, 2010
8
Maine
Do you have a link to the gasket replacement writeup? Also where did you buy replacement gaskets? I have an F500 and a few gaskets look like they need to be replaced. It appears that not all the gaskets are the same size.

Ann
Ann,

The link to the F400 gasket rebuild is below. The gaskets are all different sizes. Your Jotul dealer will be able to look up the gasket sizes and lengths. Jotul also sells a gasket replacement kit that includes most, but not all, of the gaskets uses in their various wood stoves. https://www.rockymountainstove.com/jotul-157050-castiron-stove-gasket-kit/

 
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ruknight4ever

Member
Nov 27, 2010
8
Maine
FWIW No matter how long its sits drying, its going to smoke a lot during the first few fires. Many set up a temporary stack in the yard and fire it off outside before bringing it in.
Peakbagger - I thought about doing the first few fires outside. However, the stove is quite heavy and it’s me and my wife that will be moving it. I plan to fire it up after she leaves for work , open all the windows, and pray most of the smell is gone before she gets home. :)
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,868
South Puget Sound, WA
Good write up, thanks for posting. Did you take pictures during the teardown?

When you fire it up, do smaller break-in fires at first. With each new fire, burn hotter until by the third or fourth burn the stovetop temp gets up to 600º. The first couple of fires will not bake in the paint much, but they will drive moisture out of the seam cement. The paint will start baking with the SST > 500º. Put a fan in one window near the stove to exhaust the fumes.

Jotul uses good quality cement on their stoves. They wipe the ooze clean on the exterior but leave it in the interior. In a new stove, you can see the white cement ooze on the interior seams. The closest I have found to this is Hearthstone's stove cement which is sold retail in tubes or tubs.

Tip: Use your cellphone camera to document each step of deconstruction.
 
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ruknight4ever

Member
Nov 27, 2010
8
Maine
Good write up, thanks for posting. Did you take pictures during the teardown?

When you fire it up, do smaller break-in fires at first. With each new fire, burn hotter until by the third or fourth burn the stovetop temp gets up to 600º. The first couple of fires will not bake in the paint much, but they will drive moisture out of the seam cement. The paint will start baking with the SST > 500º. Put a fan in one window near the stove to exhaust the fumes.

Jotul uses good quality cement on their stoves. They wipe the ooze clean on the exterior but leave it in the interior. In a new stove, you can see the white cement ooze on the interior seams. The closest I have found to this is Hearthstone's stove cement which is sold retail in tubes or tubs.

Tip: Use your cellphone camera to document each step of deconstruction.
Begreen,

I agree - I should have taken pictures along the way. Pictures would have done my narrative a world of help in comprehension.

Rutland’s directions for the cement cure seems to be one slow by steadily increasing fire to 500F. Sounds like you are recommending a small kindling fire to start, letting that fire extinguish, restarting a new kindling fire but going a little hotter than the first fire, and then letting that fire extinguish, and continuing that pattern to 500F. What are the benefits of your approach? Doing your approach, can I do all the fires in the same day?

I did leave the cement that oozed to the inside of the firebox in place - I simply pressed it lightly into the interior joint. That’s what I noticed when I dismantled the Jotul.
 

begreen

Mooderator
Staff member
Nov 18, 2005
93,868
South Puget Sound, WA
Yes, I think you could do all fires in a single day.
 

bigealta

Minister of Fire
May 22, 2010
806
Utah, NJ
Nice write up, i was going to do one on how to transport an f400 in a SUV with a dog for a 5 hour drive home!
Might be a good companion to your write up.

Ok so i did it here it is.
 
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