Central Boiler Cast iron Door has cracked. Need some help.

[muddstopper]

I have repaired lots of cast using regular mig wire. The trick is preheat and not trying to weld up the entire cast in one pass. I normally take a propane weed burner and try to get as much area around the crack up to around 600f. I'll weld about a inch, after Vee'ing out the crack, and let the temps stabilize as the welded area will get much hotter than the preheated area. I also us a small hammer and ping the fresh weld. Once temps stabilize, I will weld another inch, rinse and repeat until the crack is welded. Also drill a small 1/8 hole where the crack ends, this relieves stress. On old cast iron pots, I will sand the weld smooth and take a piece of coarse sandpaper and hammer to restore that rough texture. Just lay the sandpaper with the coarse side down and start pecking on it with the hammer. Emphasis on peck, not beat the snot out of it.

 

[babybart]

I have been following the thread and I am curious. I get why Kevin is disappointed by them not honoring the Lifetime Warranty and not wanting to spend the money for a new door. I am just not sure, since I am by no means an expert, that it would not just be a savings in the long run to get the new door. The welding process to be done right seems long and then he has a repaired door that cracked in the first place, albeit after 17 years. Possibly a manufacturer, after constant warranty issues and then some R&D figured a plate door was the better design and in an indirect way pushing him in that direction. I would be pissed if they did not honor the lifetime warranty as well but he only has 3 options; weld cracked door and hope it lasts another 17 years, buy a new door from manufacturer that hopefully is a better design and guaranteed, or replace entire system because he does not want to deal with that brand anymore. I agree that $300 after 17 years is not bad, I also agree he should not have to pay that in the first place but...

 

[panolo]

May be talking apples and oranges here. The Classic stoves are not catalytic and I have no forced air. Just a simple temp. controlled damper. Not as efficeint as newer stuff but less maintenance.

I had to stop by my dealer yesterday for a part and looked at the inside of a classic door. It's the same plate steel that is on my edge.

 

[Marshy]

Probably cracked because of thermal cycles. Every time you open the door its subjected to cold air. I dont think it would matter how you burn the boiler. Maybe it would help to crack the door for a few minutes or more to let it cool slowly before you swing it wide open... yeah I know that doesn't help your current situation, sorry.

I wonder if you could buy some cast-able fire ceramic and make a box over the inside of the door and cast a 2-3" layer over the door... after you attempt to weld it I guess.

 

[Mike Van]

Just my 2 cents - I wouldn't spend over 300 on a door for a 17 year old boiler, the days have to me numbered on that unit. Try to weld it, nothing to lose. JB weld also makes a thermal high heat product, years ago I used their regular stuff to fix a cracked block on a Briggs.

 

[muddstopper]

https://www.bing.com/videos/search?...eo&qpvt=lock+stitch+cast+iron+video&FORM=VDRE

 

[panolo]

Just my 2 cents - I wouldn't spend over 300 on a door for a 17 year old boiler, the days have to me numbered on that unit. Try to weld it, nothing to lose. JB weld also makes a thermal high heat product, years ago I used their regular stuff to fix a cracked block on a Briggs.

Very valid point. But I am guessing that because it's Kevin's you can probably eat out of it. If you have followed some of his build threads he is meticulous.

 

[Deleted member 117362]

Very valid point. But I am guessing that because it's Kevin's you can probably eat out of it. If you have followed some of his build threads he is meticulous.

Agree, like his truck. He probably is unable to sleep at night, knowing it has a crack. I get it.

 

[panolo]

Or his cabin thread. One of my personal favorites of any message board post I have ever read.

 

[Mike Van]

Matters not who owns it, rust never sleeps...........................

 

[Kevin in Ohio]

https://www.bing.com/videos/search?q=lock+stitch+cast+iron+video&qpvt=lock+stitch+cast+iron+video&view=detail&mid=22FD25B635257F03FEAE22FD25B635257F03FEAE&&FORM=VRDGAR&ru=/videos/search?q=lock+stitch+cast+iron+video&qpvt=lock+stitch+cast+iron+video&FORM=VDRE

Have you used them? I can make the hardened drill guide so I may try that sometime.

 

[Kevin in Ohio]

Very valid point. But I am guessing that because it's Kevin's you can probably eat out of it. If you have followed some of his build threads he is meticulous.

I clean it out at the beginning of the season and use dry wood and follow instructions. I don't use Ashtrol because I didn't see any difference.

 

[Kevin in Ohio]

Agree, like his truck. He probably is unable to sleep at night, knowing it has a crack. I get it.

My daily driver has never been washed. LOL I keep the nice stuff nice though. It's just I'd expect a stove to have a longer life expectancy than an asphalt shingle roof.

 

[Kevin in Ohio]

Matters not who owns it, rust never sleeps...........................

That's why I got the stainless version....

 

[muddstopper]

Have you used them? I can make the hardened drill guide so I may try that sometime.

I have never seen anybody use them. But if you make the hardened guide, I want one

 

[ATpro]

Drill the end of the crack so it will stop the crack, V out the crack a little, use a nickel-type electrode (nickle rod) that is made for welding cast iron. Pre-heat and weld a little at the time to control heat. Ping the metal around the weld a little to re-leave stress, preheat and weld again. Do this till you finish the weld then you can grind the weld flat. If you don't need to grind the weld it is better to leave like it is. Welded cast iron car and tractor blocks this way in the past along with cast iron fire grates and they held up well. On thick pieces of cast iron I actually drill along the crack about every 1/4 inch and drill the hole the size of the welding rod that I use for the repair. I knock the flux off and cut the rod and drive them in the hole that I drill and grind them off even with the surface then V them like I did the crack. This creates a stitch affect when I weld the crack.

 

[Kevin in Ohio]

I have never seen anybody use them. But if you make the hardened guide, I want one

What drill size you want and with what spacing?

 

[hoskvarna]

You've Mig welded cast iron? What wire?

I have mig welded lots of cast
As has been stated heat very well before welding but just as important is cool down. The weld and cast cool at different rates.
I migged the bottom of a diff housing on a tractor. V it out welded then took a big pan of coals and put on floor jack and raised up to housing. Left it to cool until I could feel no heat on the pan. Still holding.
I would take door off,v out well but not so deep that you will blow thru. Heat,weld and dump lots of hot coals over the whole surface of door as deep as you can get them and leave it for days until it is ambiant temp.
My 2 cents [emoji3061]


Sent from Hoskey Hills

 

[muddstopper]

What drill size you want and with what spacing?

well, I don't know, I suspect one would need to find out what size those little plugs are and spacing would be needed to be so that when you go back over with the second stitch the little plugs would over lap. I have heard/read a lot of good things about this type of fix, but I don't know anybody that has bought the tools to do it with.

Did a little search. Drill is wire size #29, thread dia, is .234. They make the stitch pins for cast or aluminum, which would be handy. I couldn't find a price for just the pins, or the complete kit either, but they do come in different lengths for different thickness of metal so that's a plus.

 

[Kevin in Ohio]

well, I don't know, I suspect one would need to find out what size those little plugs are and spacing would be needed to be so that when you go back over with the second stitch the little plugs would over lap. I have heard/read a lot of good things about this type of fix, but I don't know anybody that has bought the tools to do it with.

Did a little search. Drill is wire size #29, thread dia, is .234. They make the stitch pins for cast or aluminum, which would be handy. I couldn't find a price for just the pins, or the complete kit either, but they do come in different lengths for different thickness of metal so that's a plus.

In watching the video, Why can't you just use standard bolts? (grade 3 or less) Cut them off. Do you think they are really soft? I'm assuming the shoulder is for twisting off the driver head but do you think it is for a seal as well? You tap all the way and add locktight so the threads should seal. What are your thoughts? Zipping them off with a die grinder and cut off wheel shouldn't be that bad. Just depends on the cost of their plugs I guess. I hadn't considered buying their plugs is why I ask.