VC Defiant 1A Lower Fireback source

[peakbagger]

Hi folks, my backup woodstove is a early model VC Defiant that was converted over to the two piece fireback 10 to 12 years ago. The lower fireback failed last year with the apparently inevitable crack after many cords of wood and hard running. I had thought I had a source of a replacement via Chuck at Stove Parts Plus and he was quite helpful in pointing me to another supplier, Cozy Cabins, which up to now has not responded to my e-mails requesting price and availlability. Chuck did mention that he was in the process of getting another foundry to cast older VC parts, but it was a 6 month to 1 year window before this might be in place.

Does anyone have a suggestion on where I might be able to purchase one of these lower fireback sections? There are no local VC dealers and I expect that unless someone has stock I am out of luck with trying to get one from VC.

 

[fbelec]

if you can't find the exact replacement part bring the bad piece down to a metal shop and have them make you up one. i did that with the baffle to my hearthstone 2. it worked perfect and it was 30 dollars cheaper than the stock part plus i would have had to pay for shipping.

good luck

i also use a defiant 1 for my main stove. hellava heater.

 

[Nonprophet]

I got mine from Black Swan--think I paid $110 w/shipping if I remember correctly. http://www.blackswanhome.com/encore-2550.html

Nice people to do business with--I'd buy from them again any time.

NP

 

[fbelec]

here is a link to woodsman

http://www.woodmanspartsplus.com/68/catalogs/Wood-and-Coal-Stoves-Manufacturers-Cross-Reference.html

 

[peakbagger]

Thanks for the suggestions, I have one on order from someone who cllaims they have it in stock.

 

[fraxinus]

In defense of the old Defiants, I've got to say that cracks in the fireback are not inevitable. My original 1 piece back (which was prone to cracks because of its size) was replaced with a 2 piece back in the late 70's; never had a crack after the change to two piece back. The reason cracks appear is almost always failure to vacuum out the fine ash that accumulates between the fireback and the rear casting. The ash blocks air flow and causes overheating. It also prevents the secondary combustion from working as it was designed to do.

 

[fbelec]

In defense of the old Defiants, I've got to say that cracks in the fireback are not inevitable. My original 1 piece back (which was prone to cracks because of its size) was replaced with a 2 piece back in the late 70's; never had a crack after the change to two piece back. The reason cracks appear is almost always failure to vacuum out the fine ash that accumulates between the fireback and the rear casting. The ash blocks air flow and causes overheating. It also prevents the secondary combustion from working as it was designed to do.

my defiant 1 has had a crack in the 1 piece fireback that is about 4 to 5 inchs since i bought this house in 2001. it works fine and has not got any worse. it's a hair line crack. most hair line cracks don't do anything to the way the stoves run. but yes there is always a reason for the crack.

 

[peakbagger]

I have heard the argument that the lack of cleaning behind the fireback (which is a PITA) is the cause of the fireback issues. I have talked to a long term dealer of VC that rebuilds them and he doesnt buy into it and is more the result of running it full bore. I tend to run mine as a series of very hot fires with the damper rod cranked full open, it burns quite efficiently as my chimney has only been cleaned once in 20 years and the one time it was cleaned was out of guilt rather than it really needing it. Nevertheless when I autopsy it, I will check out the ash build up.

 

[fbelec]

it's not a matter of you have a cracked fireback you need to clean. my defiant has it's crack about 6 inches off the bottom of the fire box. when i took the stove apart to rebuild it the first time there was about 1/4 to 1/2 inch of ash behind it. so it wasn't the case there. but it might have been a hot fire because the fireback as slightly bent in that spot. but i don't know how long it's been there because it was like that when i bought the house in 2001. now my other stove is a hearthstone 2. when i bought it, it had a warped baffle and cracked side plate. the side plate in that stove is just like the fireback. the side plate has all kinds of cracks, but is still in one piece so i put it back in. the fireback was in 3 pieces so i had to replace that, and the baffle was severly warped. so i relaced that. behind the side plate and fireback was white powdery ash that had built up all the way from top to bottom it had been there so long that i had to scrap it out. that was why the insides of that stove along with overfiring it was so bad. i had a couple real hot fires in there since. 750 almost 800 degrees for hours, and no damage. i'd say because of the area behind the plates being clean.

 

[fbelec]

hey peak you stove is a defiant 1a right?
do you use it much? how tall is your chimney? does your defiant make a ton of creosote?
does you secondary burner work ok?

sorry for a ton of questions, but i don't ever get a chance to talk to anyone that runs the stove.

 

[fraxinus]

There is a complete rebuild manual for the Defiant 1 and 1a at http://www.vermontcastings.com/catalog/elements/files/2008/2003225/_Rebuild_Defiantpdf. This contains the clearest explanation of the rather rudimentary secondary air tube located between the fireback and rear casting. This "tube" consists of a long piece of metal mesh bedded in furnace cement. In my experience, it does not last very long and I'd venture to say any Defiants more than 5 years past a rebuild no longer have one. (It's very easy to damage it while cleaning this area and it takes major disassembly of the stove to repair/replace it.) The stove works fine without it, but at a considerably less efficient level than with it - you're not really getting the secondary burn the stove was designed to provide.

As for warping and cracking, I'm convinced that ash build up + heat = a cracked fireback. The warping I've seen has almost always resulted from leaving the side loading door open a crack to create a powerful draft for fire starting. This is a useful trick if you're careful about what you're doing, but if done for too long, you'll create a powerful blowtorch effect concentrated on a small area. This leads to inevitable warpage.

In full time heating with an original Defiant (average 8 cords / year), I generally get about four gallons of creosote at the annual cleaning. With green wood, running the stove damped down a great deal because it is too big for the space, you certainly can get a "ton" of creosote.

 

[fbelec]

hey fraxinus
unless it's my computer the link is not working.

what you said about the secondary air tube behind the fireback, thinking about when i had the top off my defiant to clean and rebuild i didn't see that furnace cement tube. maybe i vac it up not knowingly.
i haven't been able to get the secondary to work after that, and i been wondering why and what i did wrong. the guys that did the install 31 years ago didn't do a very good job. i guess back then the lenght of the chimney was measured from the top of the stove putting together the whole length of connector pipe and elbows and chimney. now if i add these up i get 14 feet. the chimney is 11 feet from where the thimble connects to the chimney and up. if i look at the manual that i got from vermont castings i says that i can use a 8 x 12 chimney. here's the kicker and what's wrong. i just got thru rebuilding the top section of my chimney and when i went to put on the top section of clay liner (8 x 12) it was to small. i found out that i have a 8.5 x 13 chimney. so right from the get go it was wrong and the inspection went ok. so back to the secondary i was never able to get the secondary to burn unless it was below 20 degrees out. i thought it was because i had a short chimney. but now between the chimney size length and what you said about the tube it will never work. in your opinion am i right?

 

[fraxinus]

fbelec: I couldn't get the link to work, either. Go to vermontcastings.com, click on support, click on manuals, type in rebuild, hit Go and a link to "Defiant Rebuild Top to Bottom pdf" will appear.

It's entirely possible that you vacuumed up what was left of the tube - I've done it more than once. It can be replaced from the top with the removable plate out, but it's very hard to do a neat or long lasting job. Without the tube, you're not getting secondary burn, but you're still getting the horizontal flame path VC stoves were designed to have. Defiants were rated at 60% efficiency - outstanding for their time.

Not sure I understand your flue size issue. Defiants were designed to vent into 8x8 or 8x12 flues. These are nominal interior dimensions. The larger size you mention seems to be the exterior measurement. In any case, flue size or outside temperature should have no bearing on secondary burn. If you don't have good draft and/or are producing a lot of creosote, something else is wrong.

 

[fbelec]

hi fraxinus
the liner that i put in is marked on the outside of it 8.5x13. the one that didn't fit was marked 8x12. but i do have a good draft. the only time it's ever have a problem is a certain wind direction that i'm not sure which direction but i blows hard and if i am loading the stove and have the door open it comes back at me. other than that it's good even if the stove is cold.

when i read this i bummed out. i guess i'm going to have to pull the top off again. do you know if the screen is regular screen or is there a part that vermont castings sells? when i'm running the stove i usually run it at 500 to 550 on the plate. with out the baffle for the secondary closed. if i run it with the baffle closed it does smoke like crazy, but if i run it straight up at that plate temp it usually doesn't put out that much if at all. if it's cold and i run it 550 to 600, no smoke to speak of.

 

[fbelec]

that 60% eff. rating is that baffle or no baffle

 

[fraxinus]

60% efficiency was right out of the box, or in this case, right off the pallet.