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Hello yall. I had a job to weld a seat post onto a motorcycle frame for my Uncle. Well he had one of his freinds come to tack weld the seat for him to measure and mock up the seat. I was not there at the time. The seat is mild steel as so is the frame. Well i guess this person doesnt know what tack weld is. He laid a full bead around the seat and also used the wrong gas mixture.I went to there house yesterday and inspected there equipment and noticed that he used straight 100% argon. Not 75%argon and 25% co2. I am postive that straight argon is used for mig only when welding aluminum and SS steel and non ferrous metals.My uncle is now scared of the weld now after i told him that his freind used the wrong gas mixture. The seat looks to be secured. Well he wanted me to go over the welds with my tig welder. I told him I wasnt sure about it because i am not sure if it is okay to weld ontop of somthing that was already welded with a differnt process. If anything, Ill have him grind off the welds. Should he just leave this weld on his seat? Our should i reweld it for him? He is worried about it, but the seat looks to be secured to me. If I do reweld it in the GTAW process should i use a 316l stainless steel rod?, An old timer told me to use a stainless rod.Thanks
Reply:if your gonna tig it anyway...grind off the weld and start new...stainless rod? use 70-s and you'll be fine...zap!
Reply:Was the weld an obvious bad weld? One you just don't feel good about? If so redo it it by all means. A bad weld is a bad weld regardless of what, if any, sheilding gas was used. I wouldn't redo it based solely on the use of straight argon tho. Here's an excerpt from a tutorial: " The use of pure argon to weld steel usually results in undercutting, poor bead contour, and the penetration is somewhat shallow."Heck I can do all that with even with the right stuff.
Reply:I have welded (mig and tig) mild steel with straight argon without ever a problem. However, if confidence is the problem, you may have no other choice but to re-weld.Smithboy...if it ain't broke, you ain't tryin'.
Reply:Yeah the above posts are all correct. IF you feel its a bad weld, grind it out andreplace it. If not what the heck. As far as welding over a previous process, ie someone lays a mig and then you weld tig over it. NO problem. There are some exceptions, but they are very particular and more so in the coded world. Generally, you can lay anything ontop of anything...an example is combo hand welders...you weld tig root with 7018 fill and cap. Now, the exception to this is if youve got a bad weld, dont weld over it. not because you are using a differnt propcess. Because you wont burn out the impurities or discontinuities, therefore you will have good weld over bad weld...equals still a bad weld. Grind it out and make it right. I can do thjis mig on stick, stick on mig, mig on tig, tig on mig, stick on tig, tig on stick. Of course you would personally never see me do most of these combos. Ive only ever done stick on tig. But again thats just cause for me tig root 7018 fill and cap is the only time I bother using two seperate machines. Anyway, if it appears good, leave it. If it were frame Id not say this..its seat. If it has undercut, poor appearnace whatever, grind it out good, and layin a good weld.Good luckIF it Catches...Let it Burn
Reply:If you are pretty sure the wled is fairly strong, but just ugly, clean it up, and go over the weld with the tiggy to give it a better appearance. I have to do this sometimes with mig welds that are good, but just too friggin' ugly to stomach. They come out looking much better, and I don't have to grind out 100% and start over. Most times, I don't need to add any fill, just move the mess around to a better place.
Reply:Make your uncle happy, clean it out and reweld it, ER70S-2 filler, carbon steel, if not, as long you ride and own this bike, you will always feel it was never done right! NO Stainless Steel Filler.MigAluminum - 75% Argon 25% Helium or 100% Argon (I prefer the first mix, try it you'll love it)Stainless - Tri mix or Ar/CO2 |
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发表于 2021-9-1 00:16:59