Posted: 10/6/2004 5:57:35 PM EDT
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Ok, I've got a bolt that's snapped off in a cast aluminum (I think) engine casing. There's not enough left on top to thread a nut on, but enough to weld one to the 'stub'... The problem is that I don' t have a proper welder, and don't want to buy one just to weld one nut to one bolt... Now, I assume that an arc-welder would work for this sort of situation... Since this is basically a high-amperage DC current run thru an electrode (the arc welders I've seen consist of 2 cables with jumper-type ends, and a welding rod/electrode), would a car battery & heavy jumper cables work in this situation? |
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Pay someone to TIG weld a nut to the stub. The car battery thing only works on TV. You will probably ruin a good battery and screw up your part. You can not controll the amperage on the car battery. That means that your 750 cold cranking amps will be running through the rod when you should only be using about 115-125. Don't do it. |
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We are talking about a 20yo 5mm bolt shaft. It is located on the head of a motorcycle, and cannot be drilled out without pulling the head due to clearance... There is enough of a stub sticking out that it rises to the top of a standard nut (1/4" or less), but it is snapped at an angle, so no dice on the visegrips... Paying a welder means renting a trailer + paying the shop fee... I was under the impression that the batt I have would only supply 40-60A... All I know about welding is that an arc-welder would allow me to stick a 5/32 or so rod in there, strike it against the bolt, and I should end up with a bolt fused to the stub... I don't think there's enough clearance for a wire-feed device, either... |
| Is it on the head or on the cylinder? If you cant get a drill to it you will have trouble getting a TIG welding to it too. I don't know any responsible welder that will even try it with a gas tank that close to it. If I wasn't down with this FU back you could pull the head, I'd let you ship it to me and I'd do it for bragging rights. If it aint worth the $50 or less to fix it right then why bother at all? |
| Sounds like your best bet is to pull the head and drill the bolt then ez-out it. Even if you welded it, may go bad and you weld the bolt to the head. IMO, even if you do hit it just right, I don't think it'd handle the tourue of you tring to get it out and snap it again. |
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I dont think theres a cheap way around this. I think you going to have to do this the hard way and pull the head off drill out the bolt and retap it. Chances are the second you strike an arc (using any process) on that bolt and try to fuse somthing to it your going to destroy the hardness of the remaining bolt and the affected area around the head. leading to even more headaches down the road An arc welder wont work for you, the process is not precise enough for the job. Kinda like using a machete for plastic surgery DONT DO IT!!!!!! tig (heliarc) would prob work but id still be worried about taking out the temper of bolt and head. |
The gas tank is off the bike, so that's a non-issue... It's not worth $50, I just don't want a slow, seeping oil leak dripping on the fins & smoking after I seal it back up... It's not worth tearing the motor down (which requires disconnecting the shaft drive, pulling the motor, and then pulling the head) and buying a new head gasket (the 20yo original won't be re-usable) just to get this one bolt out of 20-or-so out... The valve cover is off, and if I can just get a bolt attached to the stub it will turn right out (just overtorqued, not frozen)... |
I agree with this, although TIG (GTAW) is not going to be any different. You're still creating a temperature that is so far above and beyond the melting range of aluminum, that it's going to wreak havoc on the head. Do ourself a favor and disassemble... |
No, I am not shooting up a perfectly good, running bike... If all else fails, I'll use hi-temp gasket-maker & just seal it up as best I can... I'd rather do it 'right' though, which means that bolt comes out... |
All I know is I welded a box end wrench to a fire wall one time trying to remove the POS + cable nut off a battery post. It stuck on there pretty good  GM |
I apologize my poor vision caused me to mistake your Firebird Emblem for a Dodge Emblem...  I need to go put my glasses on now.MT |
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NO, NO, NO, NO, NO, NO! Don't throw the baby out with the bath water. Take your time and remove the screw properly. What ever it takes. Stand on your head, remove whatever to gain access. Welding anything is NOT the answer. All I did was weld this week and I have been welding a LOOOOONg time. Use a reverse drill, use an easy out, use Liquid Wrench and TAKE YOUR TIME. You will have a more harmonious outcome. Alphabet soup online welding instructors. Gee fucking whiz. You need someone like ME to fix this for you if you can't do it yourself. No slight here, experience may be what you need to save your motor. Believe me there is no fifty cent fix to your dollar problem. If the only way is to pull the head, suck it up and pull the head. Sometimes it is the shortest path to getting finished to merely get started. |
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Broken Stud Puller: www.thetoolwarehouse.net/shop/AP-7413.html www.thetoolwarehouse.net/shop/TTW364.html#257Metric. Railgun.... |
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if its only overtorqued, why dont you try some jb weld to attach the stub. try to get some pb blaster or similar into the threads over a day or so and see what happens. eta:
i'm not sure this is fair. there are some extremely accomplished welders on this board...and in this thread. |
(no pun)
| drill it out with a drill bit that is smaller than the originail and tap it to make it turn right to lossen instead of left to lossen and place a right hand threaded bolt of the same thread and insert and it will back out once the new bolt bottoms out . just did this to my motor when the easy out wouldnt work |
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What Sparsky said. But I would check around and see if there are some acid solutions that will attack the steel and not aluminum/ Otherwise the variations on drilling and scew removers seems the way to go. If you can get into there with a dremel you may be able to get some kind of bit stuck in there ala screw remover. Soak the the snot out of it with penetrating oil. |
Your probably right. What do I know about welding? |
Ding-ding-ding. Ladies and gentlemen, we have a winner. You can use a screwdriver socket, and plenty of PB Blaster or similar (what we used to call "Indian Creeping Oil" when I was a kid.  )
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| The drill it out and use an ectracting tool would be the proper way IMO. But in your situation I would try the chisel & hammer method (wecsog impact) with maybe a little heat on the bolt first. If that didn't work I would weld a nut on it with whatever I could find for a welder. |