Vermont castings defiant newbie

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Ksalvojr15

New Member
Oct 26, 2021
2
Southeast PA
Hello all,

I have been using an older Vermont castings defiant for 3 years. I am atleast the 3rd owner, unsure of actual age. Today, during a cleanout for the upcoming season, I noticed a fairly large crack in the firebox, left of the stamped "1975"

The exterior of the stove looks solid. My question.... is it safe to run with an interior crack?

It is not my primary heat source, I use it to hang in the basement and occasionally heat the the house on weekends. Upstairs and basement total about 1800sqft

I am more concerned with the safety of the unit as opposed to getting optimal efficiency of my firewood. I get wood for free, and am more of a hobbyist burner.

Any info or tips would be appreciated. This site has been helpful to me in the past. Thanks!
 

peakbagger

Minister of Fire
Jul 11, 2008
6,797
Northern NH
Yes you can continue to run it with the crack. It will reduce the efficiency to that of an old smoke dragon of similar vintage. At some point the bypass damper may stick but with the crack you need to run it with the bypass open.

If you do want to deal with it, it would be handy to know if there is a seam running left to right under the crack. If so, you can replace the upper fireback. It means tearing the stove down and resealing it. Plan on an 8 hour day start to finish. If there is not a seam left to right and its all one panel it still could be rebuilt but its far more extensive and expensive rebuild. Unless its sentimental, its not worth the fix.
 

stoveliker

Minister of Fire
Nov 17, 2019
2,859
Long Island NY
Make sure you have a working CO alarm; at the end of a fire when the flue cools down, draft can reverse. The crack might provide an easier way for CO to leak out.
 

Ksalvojr15

New Member
Oct 26, 2021
2
Southeast PA
thank you for the reply guys. Definitely gave me some peace of mind. I haven't had time to look for a seam, but I'll keep you posted. A teardown might have to wait until the spring. We'll see if the stove gets more work this winter with the rising oil costs.

I do keep a pretty good eye on my CO alarms. I have one on each level of my house.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,797
Northern NH
BTW, its Defiant "1" is its a one piece back (no seam) , a "1A" if it was converted by the factory or in the field to a two piece back, and "2" if it was built with two piece back. The single piece back cracking was a design flaw made worse by lack of cleaning the space between the back of the stove and the fireback which is a PITA to get to (its in the manual but my guess it rarely got done). The two piece is still a PITA to clean but the seam reduces the cracking but it can still occur just easier to fix. Plan on an extra 1/3 more wood consumption

I found this with quick search
  • Defiant 1 made from 1975- 1980. Model #0019 or 0028
  • Defiant II made from 1980 - 1984. Model #0019 or 0028
 

fbelec

Minister of Fire
Nov 23, 2005
3,176
Massachusetts
i run a old defiant one piece fireback. the crack all started for me when i started using the bypass damper hot air on one side of the fireback and cold air on the other did mine in. if the fireback has a crack you can still use it in updraft mode and it will run like a regular old stove. i have been running with a cracked fireback (huge top to bottom) crack for 4 years no problem. if you try to use the bypass damper some of the smoke goes through the crack and right out and because of the chimney running cooler in the downdraft position you will creosote up your chimney. so with the crack just run it so the damper handle is horizontal. see if you can get photo's of inside the stove.
 

jamesdeano

Member
Nov 16, 2018
2
ca
I was wondering if it looked like this? My question (and mainly to Peekbagger who says its not worth the fix) is, have you ever tried to weld this crack? I know cast iron is next to impossible, but I will try if its possible. And if that doesn't work what about using the same -cement resealer to fill the crack? It works for the other seams. I understand why you say its not worth it though at the costs of new plates. And while I'm bitching about that subject, why in the hell can I buy these firebacks for less than $200 the kit that just has some hardware and cement is $211 more. I wasn't sure if its ok to attach the prices.

IMG_20211116_172113 (1)2.jpg defient7.JPG defient5.JPG defient4.JPG defient3.JPG
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,441
Downeast Maine
I would get a new stove. This is what our Defiant looked like when we moved into our house in 2018. It was a mess and after three weeks of use we moved it into the corner and got a new stove. Those were a smoky three weeks with the thermostat making up its own mind and lots of back puffs. Trying to learn a cracked stove during the windiest time of the year wasn't helpful. It wasn't worth the $700+ to rebuild a stove myself and then put my trust in something I've never done before. I use it as a trap for my air rifles.
 

peakbagger

Minister of Fire
Jul 11, 2008
6,797
Northern NH
I will leave it up to you to decide on buying parts for 40 to 50 year old stove. IMO a weld fix or goop may last a bit but until its replaced, use it like a smoke dragon and forget the secondary combustion. BTW I made that decision 25 years ago to convert it to 1A and then later bought another half fireback. Its been sitting there rarely used since I got my wood boiler running.
 
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fbelec

Minister of Fire
Nov 23, 2005
3,176
Massachusetts
i tried cementing my defiant 1 one piece fireback and it lasted about 3 weeks then it got way bigger and i also kept the passages cleaned. the cement won't stick to the fireback because the crack will move in different ways and the cement will crack again. IMO not worth the money to fix it when you could buy a new different brand stove for a few hundred more
 

SpaceBus

Minister of Fire
Nov 18, 2018
6,441
Downeast Maine
i tried cementing my defiant 1 one piece fireback and it lasted about 3 weeks then it got way bigger and i also kept the passages cleaned. the cement won't stick to the fireback because the crack will move in different ways and the cement will crack again. IMO not worth the money to fix it when you could buy a new different brand stove for a few hundred more
Not only will that new stove be safe and trustworthy, but it will also use a lot less wood than the Defiant.
 
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BrownT10

Member
Jun 1, 2021
136
Massachusetts
I ran a 40 year old Defiant stove for the last 10 years and rebuilt it about 5 years ago. I have since moved on from it, but it was a good stove, but was a smoke dragon. It throws heat like crazy but even the two piece fireback will crack, almost guaranteed. The issue is the ash buildup in the channel behind the fireback that is no easily accessible unless you remove the stove pipe and baffle plate. I thought about rebuilding again but decided on a new stove instead. My 2 cents
 

fbelec

Minister of Fire
Nov 23, 2005
3,176
Massachusetts
i just cleaned out my defiant. it is a pain in the rump. the plate won't come out so i got my shop vac and put on a 1.5 inch hose and adapter from the 2 inch and stuck my hand and arm around it to suck it out and got it that way thru the top 8 inch pipe hole. very dirty job. i wear a long sleave shirt so it gets black and dirty and not me.