Quadrafire 4100i restoration

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morewoodplease

New Member
Nov 5, 2025
3
Putnam county NY
Hi everyone. I just signed up for hearth.com after lurking for the last few months. I am making this thread to catalogue my Quadrafire 4100i restoration. It's a nice workable stove that I purchased on ebay for $500 recently. I am a new homeowner and am hopeful I can use this stove and my new to me wood splitter to reduce my heating oil expenses and actually be warm this winter.

If this is the wrong area, I can move this to the Quadrafire sub forum, but I believe it's too quiet there given the line is no longer produced by HHT.

The stove is fully dismantled in my garage, and I will be sandblasting and repainting it this weekend.

It has the typical weld cracks on the secondary air manifold, not even as bad as some posts on here given how old the insert is.

Unfortunately the top plate of the stove is warped and shows evidence of overfiring. It has many stress cracks in the area where the flames wrap up over the front air tube. There may have even been a layer of furnace cement up there as well.

!!!

My question: can I fill the cracks with furnace cement, and if necessary, weld an additional plate either on the inside or outside of the top panel to reinforce the area? My mood has been pretty sour since I found out about these cracks given that I am easily $1500 in the hole for my new duravent flue liner and replacement gaskets, baffle board, blanket, and paint.

I am a skilled DIY'er, and to be honest my mind jumped straight to complete replacement of the top plate, but I want warmth NOW and have concluded that that is likely a project for the future if I can avoid it.

So, what say you, how F***ed am I? Can I make this stove work for this season with a half-baked repair? I'm really not interested in buying a new insert.
 

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Hard to really tell from the pictures, but I would personally try to weld that, it helps that I know how to weld and own several welders. In fact one of those cracks looks like it extends from a weld.

Make sure you grind it properly and get the crack out all the way. I’d drill the ends of the cracks with a small drill if you can’t access the backside to make sure you get the crack out.
 
Hard to really tell from the pictures, but I would personally try to weld that, it helps that I know how to weld and own several welders. In fact one of those cracks looks like it extends from a weld.

Make sure you grind it properly and get the crack out all the way. I’d drill the ends of the cracks with a small drill if you can’t access the backside to make sure you get the crack out.
I believe I have enough weld experience to help this thing limp along through at least a season. I have a harbor freight 110v mig and was thinking .035 flux core might do the job for this. I have an argon tank that i bought for doing sheet metal restoration on my 2nd Cummins during COVID, but it seems that this welder might be too weak to get good penetration with solid wire. Considered getting a cheap stick welder to do the task as well.

What do you think? Should I preheat the area to help deal with the carbonization?

Honestly I wouldn't put much work into that. Just weld the Crack on the top and run it.
Should I interpret this as the stove being near the end of its life? Or that the cracking isn’t as big of a deal as I initially thought?

Thanks for the feedback guys.
 
I would grind the crack out into a V-notch, and use the gas shielded solid wire. Do
Multiple passes if needed to fill it.

If it isn’t a cast part, you shouldn’t need to pre-heat. Just keep it clean, and don’t concentrate heat too long in one part of the stove, so you don’t warp it.
 
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I believe I have enough weld experience to help this thing limp along through at least a season. I have a harbor freight 110v mig and was thinking .035 flux core might do the job for this. I have an argon tank that i bought for doing sheet metal restoration on my 2nd Cummins during COVID, but it seems that this welder might be too weak to get good penetration with solid wire. Considered getting a cheap stick welder to do the task as well.

What do you think? Should I preheat the area to help deal with the carbonization?


Should I interpret this as the stove being near the end of its life? Or that the cracking isn’t as big of a deal as I initially thought?

Thanks for the feedback guys.
It has been really abused and is at the end of its life. I would weld the top and run it until you find something better. Do you have the tubes and baffles?
 
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It has been really abused and is at the end of its life. I would weld the top and run it until you find something better. Do you have the tubes and baffles?
Yes, the tubes are there and I purchased a new baffle board and blanket. You can see the parts in the one picture.

Is it a safety hazard? I will likely be burning at least a full load every day.
 
Yes, the tubes are there and I purchased a new baffle board and blanket. You can see the parts in the one picture.

Is it a safety hazard? I will likely be burning at least a full load every day.
The top is yes. Otherwise not really. The welds wont last anyway