Advice Needed on How to Fix Cracked OWB

[dean06919]

During the first year of use, my OWB developed a crack that started from the bottom corners of the door and spread out until it compromised the weld on the water jacket. I had the both cracks welded up and even a plate welded on top of the crack, but the stove cracked again and started to leak water. The cracks were so wide, that once I removed the stoves outer metal, I could see the fire in the fire box.

The stove was made by my neighbor, it uses 3/8" steel and has a water jacket surrounding the back, both sides, top, but there is do water jacket around the bottom or door side. The ash area is about 8" from the bottom of the door to the bottom of the stove. Is the metal around the door flexing because it heats up faster than the other parts of the stove which has water around it? Is the ash area too deep? Any ideas on what is making the stove crack and how to fix it? Any thoughts would greatly be appreciated as I'm not opposed to having the front of the stove cut off and remade.

Hopefully my picture helps to clarify the problem. If the picture is not large enough, I think you can click on it which should bring you to my Picasa account.

Thanks.

 

[pinemartin]

Have your buddy from the next town over stop by this weekend and put a nice vertical 3 pass stick weld on it and you should be good to go.

 

[dean06919]

Next town over? He doesn't know anything about welding. But he does have a brother two towns over....

Heck, if we are going to do this, let's do it right! I want to make my fire box 48" deep and add a water jacket around the bottom and around the door. I'll drop if off tomorrow.

 

[wvlogger]

weld it and forget it

 

[pipehead]

Are you able to drill a small hole where the crack ends, and then weld it (the hole, too)? Drilling a small hole at the end will stop the crack from spreading.

 

[dean06919]

Are you able to drill a small hole where the cracks end, and then weld it (the hole, too)? Drilling a small hole at the end will stop the crack from spreading.

The first time it was fixed, the welder drilled a small hole at the ends of the cracks. Next, he used a grinder to bevel the cracks and then welded it up. Everything was fine until I cleaned out the ashes, shortly afterward the stove cracked again in the same spots, from the corners of the firebox out to the water jacket.

So, he ground down the prior welds, welded the cracks again and placed a patch over the cracks. Everything was fine until I emptied ashes again, then the crack reformed on the right side of the stove, spreading out to the water jacket.

Do OWB's typically have a water jacket surrounding the door side? I think I am having a problem with a deep ash pan (between 8"-10"), no water jacket around the bottom or door side. I think the door side heats up faster than the sides with the water jacket causing the metal to expand, causing a stress fracture. Does this seem plausible? Anyone? Sorry, I'm fairly ignorant when it comes to welding and the properties of metal.

 

[oscar4883]

Was he able to grind the crack from both sides? I'm not very familiar with OWB's and can't tell if that would be possible from the pic. Looks like a nice unit though.

 

[dean06919]

Was he able to grind the crack from both sides? I'm not very familiar with OWB's and can't tell if that would be possible from the pic. Looks like a nice unit though.

No, only from one side. I wonder is that was part of the problem fixing it.

 

[pipehead]

Hello,
Is the welder pre and post heating the welds? Depending on what type of metal it is, pre and post heating are essential to a good weld. It lessens the "shock" to the base metal.

 

[oscar4883]

Sorry for taking so long to reply. I had a long reply typed up last night and then my computer died! LOL Welded a ton of cracks in some brutally vibrating equipment while working in the mining industry. What we always did was apply some pre-heat and weld the crack from both sides if at all possible. Drilling a hole at the termination point of the crack works well. As long as you are sure it is the end of the crack. I would grind it from both sides basically through, and then weld it from each side. The cracks ends should be fairly easy to spot once it is ground and feathered out. Hopefully it can be welded in one pass. If not you will need to feather out the end of the previous weld some. Never bothered with checking pre-heat temps very scientifically. Basically I heat it until I can just touch it for a half a second or so. THe real key seems to be making sure you get the hole crack ground from begining to end. Mind you, I have no science behind any of this really. LOL Just some tips and tricks I picked up from some very good welders I have worked with. If you have, or have access to a welding blanket, it is not a bad idea to throw it over your work area to keep some heat in when you are done. Hope some of this helps.
John

 

[dean06919]

Thanks for the information Oscar, I will put to good use when trying to fix this thing. This is all new to me, I'm very thankful some members took the time to educate me on welding and the properties of metal.