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i dont post on here very often, but i do look on here for help from time to time. you guys are great at giving advice to others. most people of a certain trades dont like to give pointers or help people. i guess for fear of losing there jobs to young bucks or because they learned the hard way and think everyone else should too. anyway i was thinking that it would be nice to have a thread with pointers of how to remedy certain mistakes people make. for instance, ive been tiging for about a year now and think ive gotten pretty good at it(good enuff to charge for my labor). other welders would tell me i'm using too much heat, so i would turn the voltage down. still i would get the same answers, too much heat. then i finally had a guy take some time to tell me how to do it right. i saw him turn up the heat after telling me my work was too hot. he said turn it up and add more filler. so i guess the correct answer would have been turn the heat up, add more filler and move faster. thus less heat into the material. when i was turning the heat down it was making me stay in one spot too long to form a puddle. it made a world of differance in my welds.so what do you guys think. got any pointers for common problems where the explination might cause the newbie to missunderstand what he is supposed to do to correct it.
Reply:Well I'm just a student but here is my tip, it is directed more towards those who are hobby welders because the guys who do it for a living already know this-Fitup, fitup, fitup.The reason I say this is because our teacher has tried to pound this into our heads but some students just don't get it and almost always have poor results. They will try to do an autogeneous lap weld with a 1/16th gap or something like that and they wonder why they burn through. Of course someone who has done it for 20 years will be able to overcome some fitup issues but an inexperienced person like me needs to take the extra time to prep it right, because you will be saving yourself time in the end.
Reply:I think it would be the same dynamic as doing a O/A torch weld on the same work. If you take 15 sec.to get a puddle - too little heat. If you get a puddle in 2 sec. and then 4 inches downstream you are having to move and dip so fast that you cant keep up as fast as the heat is building up - then you started too hot. There will be a just rite heat to gave you a comphortable weld speed for 95 % of thebead. Of coarse the material might suggest adjustment. Might want to err on the hot side for Al.and on the cool side for SS. due to differences in thermal conductivitys. And the better the fitup the easier the weld is to do. If it is tight you can put 100% of your attention into making a perfect bead.I always thought having to keep speeding up( and increasing the dip rate) was a countermeasure for too much heat- but usualy you have to keep going faster and faster and......... and the end of the material is going to be naturaly too hot anyway ...... well you see.I think this is why you gotta have some type of remote current control device. just my thoughts - maybe worth nothing ......TimLast edited by jethro; 03-28-2011 at 12:30 AM. |
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发表于 2021-8-31 23:28:54