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I've been lurking for quite a while and finally registered. trying to learn how to handle metal for obvious reasons. Read - Newbie but am OK with a stick and 7018 if I could just get the amps right. I've done a few projects, small welding table, flat dump bed for my truck, work on the wood splitter, etc. anyway.....I have a wood boiler that apparently I over fired and caused a bit of warpage. I need to straighten the face so the door seals properly and re-weld the factory seam. You can see from the pics that there is a slight bit of warpage (My guess is 1/8" tops). You can also see from inside the firebox the metal has shrunk and pulled a factory weld apart. the gap is wider toward the inside of the fire box. And there is a 1" vertical piece that split next to the factory seam that needs to be welded. The factory seam is about 4" long. None of the repairs are on the water jacket but it is close quarters. The 4" seam can be welded from the outside of the unit but I will need to get on my back and lay in the unit for the 1" vertical piece.My plan is to use a portapower jack to apply outward pressure where the gap is widest while heating the face in an upside down "V" shape. My plan is to keep the pressure on while letting it air cool. If I can get it straightened out then I'll clean up the old weld and lay a new bead.the opening of the door to firebox is about 20".Questions: Is this the correct approach for this repair? Or should I reheat the inside (in a "V" fashion) where the metal has shrunk while applying the pressure?How big an area should my "V" be? to straighten the warpage?any other comments or considerations?? thanksPictures to follow....Ice
Reply:Here is pic of the whole unit for size perspective.
Reply:and another showing the firebox size. It's about 40" deep by 26" high by 22" wide.
Reply:My biggest concern is getting the flange straight so the door seals. the metal is mild steel at 3/16".Ice
Reply:I think your plan sounds great. Putting a portapower in there to get it moving is exactly what I would do. I would try to be careful with the torch as to not cause more damage, bending. I would also think it would be wise to grind that whole area around the welds clean, then carefully air-arc or grind a nice deep groove in those welds. Personally I would then weld a pass with 5P+ (6010) then clean those passes with a grinder and a wire wheel or carbide burr bit. After that I would take my time and weld her up with (7018 3/32) filling it up with stringers. Once I was satisfied with that repair I would then re-fit the door to the (new) opening. You may have to bend,cut,heat,re-weld but you can make it seal nice and tight again. Good luck man!
Reply:grind out old weld press out bevel weld release should be good to goHigh Octane Welding
Reply:The back of the fire box is the water jacket. I don't want to push too hard to straighten the front. the front is multiple pieces welded into an assembly (a lot sturdier than the back). The back of the firebox (my brace for the portapower) is just a 3/16" plate. Thats why I'm thinking about heating it up with a "little" pressure on it and get it to move a bit before welding together. But, I'm am timid about applying too much heat or heating the wrong area and warping the shat out of it, ending up worse than it is now. It is warped inward, should I apply heat to the face (door side) or the back side to get it to move back to its original position? Some threads on here talk about just using heat without a press/clamp/jack to "relax" the metal back to its original shape.Ice
Reply:Here is a good video to start with: Mr. Shrink(One of my favorites)Dave J.Beware of false knowledge; it is more dangerous than ignorance. ~George Bernard Shaw~ Syncro 350Invertec v250-sThermal Arc 161 and 300MM210DialarcTried being normal once, didn't take....I think it was a Tuesday.
Reply:You need to grind out the weld first for clearance. After that it won't take much effort at all to straighten. If you're worried about pressing against the water jacket. Then don't. Use a chunk of tube or beam to bridge the door opening and use a C clamp to pull the frame straight.My name's not Jim....
Reply:3/16" isn't that big.. how much of a gap should I have before rewelding? Just don't have alot of experience. Also there is a bead on both sides of where it separated. I can't get "behind" I can only face weld. should I lay a piece of backing in there or grind it all out and bridge it? is that an option?Ice
Reply:Nice video thanks for that MNDave. I'm going to put a clamp on it like you suggest Boostin and see what it does. busy tomorrow may happen on sunday. I'll report back. How much to grind out?????Ice
Reply:Just enough to get any weld metal out of there. When that thing was built, there was a nice clean edge on the material where the joint is. If you leave jagged edges, they will butt into each other when you try to pull it straight. I like to grind welds down flush and then run a thin cut off wheel through the crack. If you want to bevel the joint, you can then follow the crack with a thicker grinding wheel. Only grind part way into the material.My name's not Jim....
Reply:OK now I have a plan or two i'll give a try this weekend when I find the time. what about amperage? stick welding with 3/32" 7018Ice
Reply:Biggest issue I see is that you are going to have to weld this vertical up if things are positioned like I think they are. ( i doubt this is practical to turn up on end so you can weld it flat) You don't sound very experienced, so my guess is you are going to have a tough time doing a good job welding vertical up. Most guys I know with limited skills usually want to run too cold and make a mess of it.You should probably get yourself a bunch of pieces the same thickness and prep them similar to how this is going to be welded and practice a bunch 1st. Most students when they get to doing open root bevel joints like you are going to have to do, have issues getting their root pass to burn all the way thru. Most tend to be scared they'll blow big holes in the sides, so they keep the puddle too far up on the side walls and don't break down the root. You'll know right away if you are going to have this issue when you run your practice pieces. If you flip them over and can still see the original edges of your cut/grind marks, you'll need more work.These practice runs will also tell you what settings work best for you. Go as hot as you can and still control the puddle. If you are having issues dripping ( and I'm betting you will) that's not usually do to running too hot. It's because you aren't reading the puddle and you are spending too much time in the center and need to hold the sides longer.Vertical up usually separates those who can, from those who can't weld. It's usually the position most of the students have the most difficulty with. If you can find someone who can do this well to help coach you it would be a big help, that or have them do the welds.Me I'd probably run the root with 6010/11 and then weld it out with 7018..No government ever voluntarily reduces itself in size. Government programs, once launched, never disappear. Actually, a government bureau is the nearest thing to eternal life we'll ever see on this earth! Ronald Reagan
Reply:For perspective, another pic. this shows the door and the crack on the top of the opening. Vertical Up?? or overhead?? DSW - Yes I am timid about doing this weld. It has 1900 gallons of water in it so it has to stay as is. I have put the portapower on it and pressure will take out the warping on the face (to get a good seal on the door) but the gap toward the firebox is still bigger than gap toward the door. Also I can only grind away the bottom part of the old weld. It is welded on the back side too (not going to be able to get at it to prep). I asked the question before... can I just cut out about half an inch and lay another piece in there to bridge the gap? basically two parallel lap welds. Today I ground away the bottom part to get a better look at it. I didn't bevel it out or gap it yet. ???? Eventually I'll have to pull the trigger or put the gun away. Thanks for all the comments guys.
Reply:Update...Got it fixed. Hired a pro who got it done in about an hour. pics will follow when I get them.Would like to thank all that gave advice. I need to practice practice and then practice some more. I'm a pilot who wants to learn how to weld.......Ice
Reply:How did the pro go about fixing it?My name's not Jim.... |
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发表于 2021-8-31 22:44:18