Cracked Bike Frame Repair

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Did this for a local bike shop... cracked head tube, SUUUPER THIN. Fused the crack with a tig torch then added filler with a 110 mig, ground down the welds 90%. left the weld thick on the back of the steerer where it meets the gusset for a little added stregnth. Let me know what you guys think. before:after:
Reply:I resized the images but theyre still HUGE, sorry about that.
Reply:looks good.  Looks like it a roadbike with a custom paint job.what material was the frame? steel? cromoly?did the crack went under the lugs?
Reply:A  head tube shouldn't be too thin.  Perhaps the thinnest is the problem.Strange crack... for nothing else to be wrong.  Looks like more than half the tube has a crack.I wonder how the heat affected the braze alloy. Were they in a hurry.  Probably should have been sent to the manufacturer of a frame builder.  The lug and head tube should have been replaced.
Reply:Nice fix but I wouldn't ride that frame again.  I agree the head tube should be replaced.  That is a very strange place for a crack to occur.  I have seen pictures of peoples faces when a front wheel failed, Spinergy, and the cost to replace the frame entirely is less than the doc and dental bills to have your face reconstructed.I'm not dumping on you, I assume it was dropped off to be fixed, they weren't asking you to be a bike frame expert.
Reply:looks good to me
Reply:Should be fine as long as your not doing BMX race circuits with that bike! If you are then I would also recommend replacing the partCo-Own CNC shop:Miller :1251 plasma cutter, MaxStar 700 TIG/Stick, & XMT 456 Multiprocess Welder.&  2 Hypertherm HPR260's Plasma CutterSorry I had a bad stroke but now I am back.
Reply:Ok so i got some details... It is a very old Cro-Mo hi-end road bike frame. I dont know who made it but the customer just wanted to give it a second lease on life. I just happened to get referred to the job by a friend of mine. The shop basically called me and said how much to weld this crack, i said 50 bucks, i picked it up and did it in an afternoon. the owner of the shop loved the work.I dont think any braze alloys will be affected greatly or the frame is going to be dangerous to take for a Sunday ride, i have NO CLUE how the crack got there but i am 100% with you guys when you say it is strange especially considering the steer tube was not ovalized... usually when they crack whatever cracked them ovalizes them. I have also never heard of a head tube being replazed? they can do that? again all i know is Downhill race bikes and Dirt Jump Bikes, i have broken 4 frames (one of which was pretty valuable) in my life and all of them were replaced by the MFG
Reply:Oh and when i say that metal was thin it was rediculous... like think automotive sheet metal, i was scared i was gunna blow through.
Reply:Originally Posted by SilveradoI have also never heard of a head tube being replazed? they can do that?
Reply:If the headstock tube was not ovaled, I would have considered using another piece of tubing inside the existing headstock tube and plug weld it in place. A heavier option, but the end result would be stronger than the original.Rex
Reply:Sorry, that frame should be condemned.  It will crack again.  Those thin frames can fail quite suddenly and catastrophically.
Reply:I would not ride it without that tube being replaced and I have fallen on my head once already from a failed  headstock tube. Just takes the right bump and next thing you know you are waking up in some weird place with bright lights.
Reply:Originally Posted by rode2rouenIf the headstock tube was not ovaled, I would have considered using another piece of tubing inside the existing headstock tube and plug weld it in place. A heavier option, but the end result would be stronger than the original.Rex
Reply:Doesn't chromoly suffer heat embrittlement if not treated correctly. This could be the cause of the crack, caused by improper heat treatment during or after the brazing of the original frame. Here is a good forum to go to find out more info::   http://www.bikeforums.net/forumdispl...-Framebuilders