Couple questions about welds....

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Hello, I'm not a professional welder, which is why I am here to ask you all couple questions.Backstory: I built a custom motorcycle frame about 2 years ago.  Modifications to the original frame include fabrication of tube steel for the subframe, and welding on new suspension mounting points.  The frame was built a few years ago, and it was my very first time welding tubular steel, and also my first major project.  The welds look ok to me....not great, but ok.Everything was done on a 110 craftsman welder.  Pretty much everything was fluxcore.....dont know if thats important, although there is some ugly splatter I'd like to clean up.I'm finally getting back to this project, and am almost ready to get the frame powdercoated.  I'm now re-evaluating my welds (2 years later) and am just getting neurotic I guess....lol. Maybe just getting older.  Dont really know, but I just am second guessing myself and wondering if I should be concerned about my old welds.  Not too concerned about subframe, just about the suspension mounts because those are so critical.  Now, the bike was ridden about half a season, and I've looked and I dont see any visual cracks or anything, but I dont really know if that means anything. The suspension mounts were t-welded to the frame.  I welded the inside, and outside of the weld - so in theory it should be strong as hell....if my welds were good Question 1: Is there any way I can test the existing welds to make sure they are safe without destroying them??  As I've become more experienced with welding, I think back on those days and wonder, really, just how good were those welds......  I'd really like to do this without having to destroy and redo all the work that has already been done.Question 2: What if I were to reweld over the existing welds?  I ask this because my cousin (who has fab experience building cars) suggested this. He says if I'm really concerned about it, we can go over them with a 220 mig and really make sure they are strong as hell......Would this be a good idea? Question 3: Most of the subframe welds were ground down (originally wanted it to be all blended in so you couldnt tell where the work was done) but now I'm wondering if there is really enough material there to be strong.  Maybe adding a fresh weld would be a good idea here as well?Any advice would be greatly appreciated!THANKS!PS.  I found my old pics from when I was building it, maybe you can tell me if these welds look alright.  Should I be concerned or am just being over anxious?? (click for big pics)tons more pics available here: http://public.fotki.com/CBRf23/
Reply:No way to really test the weld strength now without destroying the weld or tabs. If you feel uncertain about them then run another bead...escpecially since you already ground down the initial bead.Try using some gas shielded wire instead of flux core if available.
Reply:Thanks slicktoptt, I was planning on using solid wire in a 220 mig if I go over them again. I'll have to talk to my cousin soon and see about getting on this machine.
Reply:When I have a question about a weld I grind it out and re-weld it. I would worry about penetration with a 110 machine And if you grind it out and use a bigger machine with gas O2 incursion will be kept down just better all the way around. BrandonLincoln Tombstone 225 A/C Steel StickerOld Victor O2/Acetylene setupMiller Syncrowave 250 Tig/PC-300 PulserMiller Millermatic 212 Mig HTP Invertatig 201 Giant Teck D50 Plasma cutterLots of HF grinders
Reply:If you aren't happy, start over.   Grind it down and reweld it.  I agree,  use shielding cause to help out.  Better yet,  Tig it.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:cbrl,Looking at those beads, I'd say you really do have a reason to "worry".I wouldn't trust them to ride that bike to the supermarket.Rewelding over a bad bead is not the solution.  Welds need to be ground out and rewelded properly with the right machine, process.  If appearance is important (evidently it is since you mentioned powder coating), I'd recommend hard wire and covering gas or tig.From my experience, if you question whether a weld is "good enough", then it PROBABLY ISN'T.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:There are ways to test welds and determine their integrity(quality).  You'll need to spend some money to do so.  If you don't want to spend the money to have the welds X-rayed, your best bet is to grind them out and re-weld.To assure yourself that your new welds are good, try practicing on some scrap material.  Then make a practice weld on similar materials and then break the welds.  The base metal should fail before the weld metal does.  If the weld breaks in the weld bead, then your process is not good.For such a critical application, you might consider having a professional weld the suspension mounts...Benson's Mobile Welding - Dayton, OH metro area - AWS Certified Welding Inspector
Reply:Thanks for all the replies.I've taken a few welding courses since I built that bike, so I do feel more confident in my abilities (and knowledge) now.   Although I could probably get a more experienced friend to do the work free, or really cheap.Thanks for confirming my suspiscions and for all the advice!