motorcycle case repair

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I have a mid 70s honda that I need to do a case repair on. The bike is only going to be used for display but I really dont want to leave this like this. I am fairly competent tig welding sheet aluminum but this will be my first attempt at a cast case repair. I have A donor case to cut the boss off of and graft it on here. I also have another set of scrap cases to practice on. I will be using my miller 250 syncrowave with 100 % argon. I generally follow the 1 amp per thou rule but on this I am really not sure where to start with settings, tungsten, preheating, Etc. Like I said it is only a display bike but I would really like to do it correct. Attached Images
Reply:I would cut the old mount off and stitch a piece of new tubing on. Would come out cleaner with new tube you know the composition of, imo.
Reply:i  had a similiar situation   ,  made a jig to hold  case  and the original  mount position  . then i  cut the mount off ,   took a piece  of round stock   and  milled  the back  side  flat    to fit on case .     glass beaded the case  clean     and mounted in fixture   and   tigged   it up .   no  pre heat   or anything   ,   1/8   green tungsten  .>Innovations are what i leave behind for History
Reply:I would clean it up real good and slide a clean bolt[or a brass or copper rod] back in place and just build it up with weld.Much stronger than you cutting it all away and welding on a piece of tubing. I do alot of this type work and much prefer build up than welding something on.JmoBtw where are you located ?
Reply:Showdog75 has the same answer that I was going to give. Easiest and fastest. Welding a new boss could be tricky because the dynamics involved with shrinkage.Two turn tables and a microphone.
Reply:if you slide anything in to use as a backer use copper my first choiceor brass (rod or tubingDON'T use a steel bolt it will cause prolems if you try to build it up clean clean clean ,, you may have to weld  and reweld after more clean'inidealarc 250/250 ac-dc tigidealarc 250/250 ac-dc tig #2 used for sticklincoln sp100hh125dual arbor grinder polisher30 yrs of hand tools52 pitch blocks 6p-26prake gauge -pitch gaugeG&D prop repair 918-207-6938Hulbert,okla 74441
Reply:Repair cases all the time, only REAL set backs are quality of material the cases are made of......Don't really care for bead blasting unless it's a media other than silica....walnut shells work and DON'T contaminate the  weld.......All depends on how good of a job you want to do.....Even globby  case repairs seem to work.....I find that the cheap jap bikes seem to have the dirtiest  castings.....Use 4043 and make sure you have a weld prep that gets you clean parent metal......Starting with 130 amps will get you there....[ame]http://www.youtube.com/watch?v=_5WTO4oTeiY[/ame]  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:Alrighty then. Sounds like I sould start with 1/8 tungsten, 130 amps and 1/8 filler and brass rod as a plug. I was practicng on a scrap head that  had noticed that it had an occasional green glow around  the weld. Does this indicate mag? I did not think heads were made of mag. Any suggestions on which # filler to use. I do have an identical case that is junk to practice on. Thanx much guys....Steve
Reply:Sorry guys, reread the thread and found 4043
Reply:Just wanted to point out that any type of plug may have to be drilled out when you are done.  I wouldn't use a plug at all.  With TIG, you have enough control to build up the weld where you need it then run a reamer or drill through the hole to clean it up.My name's not Jim....
Reply:i have not a clue what happened here. I cleaned the area to be welded with acetone and stainless brush followed by preheating. I used about 130 amps and tried both 1/8 and 3/32 green tungsten. On the edge was able to get it to lay down but the bead felt rough and sandy. on the back of the case i had really bad results. I am sure this is operator error. As I was sitting here typing this I also realized that the case back was vertical as I was welding. I was almost not gonna post the pics because they were so bad but what the hell Attached ImagesLast edited by benchracer1; 07-02-2011 at 12:06 AM.Reason: add pics
Reply:Have to ask.Do you really weld with that tungsten?
Reply:did not start out like that. I posted that hoping somebody could tell me what caused it to look like that.I also did not mean to post the pictures so big. Thank goodness i had scrap cases to practice on....Steve
Reply:Do you have balance control?Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Is that pure?Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:yes. I had it set to balnced welding
Reply:pure argon
Reply:Take your balance to about 70% straight. That will stop your tungsten from balling back like that and get enough penetration to boil out the crap. Straight argon is perfect. The cast material is saturated with oil and takes a few passes with 4043 to clean up. Some cases just weld like crap. Yours is ultra corroded. You may want to consider breaking into the surface with a dremel. You could then slip a hex head bolt in the hole and weld against that a bit, then twist with a wrench to break it free and weld some more. Works for me anyway.You are on the right track. By the looks of your part, it will work out fine.Good Luck and have fun.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:Aluminum needs to be clean to get good results because what ever is on the surface will be mixed in with the molten metal.......so you need to start with really clean aluminum....I die grind a weld prep on all joints. For build up like your doing the edges need to be sanded or die ground to clean parent metal before you weld.....once you lay down a clean bead you can brush and continue from there.......As far as your tungsten ball as mentioned turn the arc balance toward penetration to keep a tighter ball......I like 130 amps for most 1/8 to 1/4 in. material using the pedal to apply the heat needed......A lot of heat will make your tungsten ball lay over  (3/32  will do this when using too much power)  Miller Dynasty 350Twenty Six HammersThree Crow BarsBig Rock
Reply:What a difference it made breaking the surface. I used 1/8 green tungsten, 130 amps, pure argon and balance at 7. I still have a problem with porosity and the tunsten balling up and turning blue Attached Images
Reply:Looking good on the weld. That is the way old cast looks.Can't help you on your melted back pure tungsten other than that I ditched pure years ago. That tungsten just is balling up too much. Maybe running your balance a bit more towards penetration will help, but I would toss in a 2% thoriated, or 2% lanthanated.Last edited by shovelon; 07-08-2011 at 02:30 PM.Weld like a "WELDOR", not a wel-"DERR" MillerDynasty700DX,Dynasty350DX4ea,Dynasty200DX,Li  ncolnSW200-2ea.,MillerMatic350P,MillerMatic200w/spoolgun,MKCobraMig260,Lincoln SP-170T,PlasmaCam/Hypertherm1250,HFProTig2ea,MigMax1ea.
Reply:thiorated is the red, Correct? Can it be used on aluminum?
Reply:Originally Posted by benchracer1thiorated is the red, Correct? Can it be used on aluminum?
Reply:cool, ill try it
Reply:went ahead and nutted up and welded the cases I am going to use. I am pretty happy with the result. I dont think I would want to go 200 mph with them but as I said earlier it is a display bike. I still have more file work, spotface the ends and maybe a little touch up with the welder. Can Anybody tell me why my pictures are loading so big? Attached ImagesLooks good.