Welding a Rim

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I've got myself a bit of an aluminum project coming up.  I cracked the rear rim on my friend's dirt bike.  I was going to buy him a used rim and lace up a wheel for him.  The rim I was going to buy ended up not having enough spoke holes and all of the spokes on the old rim (which I planned on reusing) were all seized up.  Anyways, I blew the budget on new spokes and now have to repair the old rim.  I plan to weld the crack, which follows the original weld in the rim, but I do not know the alloy of the rim.  Anybody have any insight on the composition of D.I.D. rims for a 1987 Honda CR250?  Which filler I should use?  I've got lots of 4043 laying around, anything else I would have to buy.  I have access to a Miller Dynasty 300 TIG welder for this project, so equipment isn't going to be an issue.  When the rim cracked, every spoke came loose.  I didn't realize the rim was damaged right away and 2 of the spoke holes were worn out by the moving spokes.  I also plan to fill these holes in and re-drill them at their original dimensions.I will try to post some pictures by Tuesday.
Reply:the only thing i can think of is that the rim may be clear annodised after manufacture..and that tells me that it was welded with 5356 in the beginning..so grind off the outside very lightly to get the clear off the weld area...and try to keep the weld as even as possible..after its all done and together again tire and all..get it re-balancedto keep the vibrations down.....zap!I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:It most certainly is anodized, gold that is.  I hope 5356 rod isn't too hard to find.
Reply:it should be just as common as 4043i have repaired cracks and chunks missing from alum. wheelslike Zap said, remove the anodize , and you kinda know the rest  clean clean clean. brush and clean after every pass just dont rush it  take your time and you should be fine
Reply:Originally Posted by 76GMC1500It most certainly is anodized, gold that is.  I hope 5356 rod isn't too hard to find.
Reply:i would look for 1/16 " most welding supply carry  it
Reply:Hey 76GMC1500!One question, Is this motorcycle rim heat treated because if it is, you may have a piece of scrap Aluminum!!! Unless you know exactlythe composition of the alloy, the hardness required whether it's rockwell or brinell, and unless you have access to heat treatment equipment, what procedures were used by the OEM (Original Equipment Manufacturer) then, you may cause more harm than good by welding it back together... You'll certainly be liable if once you perform the initial repair and the rim fails again and the failure is investigated to have occured either at the weld location or adjacent to the weld because, one did not follow proper Post Weld Heat Treatment or PWHT procedures especially if someones get hurt as a result of the rim failing again while riding the motorcycle so, I'd be very careful if I were you!!!   Unless you can get the necessary info required in order to properly repair the rim, I would'nt even attempt to repair it if I were you just on the liability grounds alone!!! If you can contact the OEM and find out the necessary technical info such as the alloy composition, applicable if any - PWHT procedures or heat treatment requirements etc. then you might be able to repair the rim but even then, I would make your friend sign a waiver stating that you do not guarantee the repair, and this way you CYA (Cover Your Anus)!!!   Remember that most of the Aluminum rims whether they are on motorcycles or automobiles are machined from a single Billet of an Aluminum alloy that may or may not have some elements in the composition that can actually be detrimental to welding the alloy and is added in order to help in the process of machining the billet... They are not welded together as some people might like to think so, by adding such localized heat in a certain area of the rim may cause a weakening of that structure or trap residual stresses at that location especially when it involves being subjected repeated dynamic fatigue loads... Somethings gotta give eventually!!! Be VERY CAREFUL and Stay Safe!!! Respectfully,SSBN727 Attached ImagesLast edited by SSBN727; 10-15-2006 at 10:59 PM."Run Silent...  Run Deep!!!
Reply:Originally Posted by SSBN727Hey 76GMC1500!One question, Is this motorcycle rim heat treated because if it is, you may have a piece of scrap Aluminum!!! Unless you know exactlythe composition of the alloy, the hardness required whether it's rockwell or brinell, and unless you have access to heat treatment equipment, what procedures were used by the OEM (Original Equipment Manufacturer) then, you may cause more harm than good by welding it back together... You'll certainly be liable if once you perform the initial repair and the rim fails again and the failure is investigated to have occured either at the weld location or adjacent to the weld because, one did not follow proper Post Weld Heat Treatment or PWHT procedures especially if someones get hurt as a result of the rim failing again while riding the motorcycle so, I'd be very careful if I were you!!!   Unless you can get the necessary info required in order to properly repair the rim, I would'nt even attempt to repair it if I were you just on the liability grounds alone!!! If you can contact the OEM and find out the necessary technical info such as the alloy composition, applicable if any - PWHT procedures or heat treatment requirements etc. then you might be able to repair the rim but even then, I would make your friend sign a waiver stating that you do not guarantee the repair, and this way you CYA (Cover Your Anus)!!!   Remember that most of the Aluminum rims whether they are on motorcycles or automobiles are machined from a single Billet of an Aluminum alloy that may or may not have some elements in the composition that can actually be detrimental to welding the alloy and is added in order to help in the process of machining the billet... They are not welded together as some people might like to think so, by adding such localized heat in a certain area of the rim may cause a weakening of that structure or trap residual stresses at that location especially when it involves being subjected repeated dynamic fatigue loads... Somethings gotta give eventually!!! Be VERY CAREFUL and Stay Safe!!! Respectfully,SSBN727
Reply:Sorry!I thought GMC was talking about something else!!!    Respectfully,SSBN727 Attached Images"Run Silent...  Run Deep!!!
Reply:Originally Posted by SSBN727Sorry!I thought GMC was talking about something else!!!    Respectfully,SSBN727
Reply:Spoked wheels are pretty good about not failing catastrophically.  Even if the rim were to crack completely through, it would stay round enough that you would be able to bring the bike safely to a stop.
Reply:Gold anodized is almost certainly Class-II anodization, true HardAnodization (Class-III) is usually dark olive, dark grey, or blackish.Whatever, you need to grind the weld area(s) clean before welding, and clean well with solvent (acetone) as well.Want the liability in case it fails?  Do the welding.  Don't want the possible legal and financial hassle?  Spend the bucks and buy a replacement rim.  Your choice.6061 looks like it can use either 4043 or 5356 filler, except if you are going to reanodize the wheel.  In that case use 5356, because the 4043 is listed as turning BLACK when anodized.
Reply:Here are some pictures of the damage:Hopefully, I'll have pictures of the repairs tommorow.  I located a 25 lb spool of 1/16" 5356 wire so I'll have plenty to practice with before I do the weld.I don't plan to re-anodize, I just want to match the alloy that is already there to avoid hot short cracking.  The crack is right on top of the old weld.Last edited by 76GMC1500; 10-16-2006 at 08:49 PM.
Reply:Job's done.  It was a little tricky, the wire I was using as filler was very thin and I had to run the welder at 230 amps.  The wire would melt before I could get it near the puddle.  I eventually figured out a techinique and got some good welds.
Reply:nice job! on the inside...dont grind off the weld.. just smoothen it out the best you can while removing as least material as you can..tubes like that...if you dont care about the outside...leave it alone.....zap1I am not completely insane..Some parts are missing Professional Driver on a closed course....Do not attempt.Just because I'm a  dumbass don't mean that you can be too.So DON'T try any of this **** l do at home.
Reply:I'm going to grind it flush where the bead sits, the rest of the weld stays inlcluding the outside.
Reply:The Welds look decent but in my book it does'nt mean a thing especially if the condition of the metal is as bad as it looks in those pics!!! I know that I would'nt ride on one of those if I knew that the inside of the rim looks like it does!!!  Metallurgically speaking, the base metal surrounding the weld looks looks like there's some lamellar peeling or tearing going on there Could it be that its some type of corrosion going on there for a variety of reasons that could be anyone's guess at this point??? Hey what do I know... I'm just an old timer that may need to have his eyes checked out again    However, the welds look good!!! Respectfully,SSBN727Last edited by SSBN727; 10-18-2006 at 11:43 PM."Run Silent...  Run Deep!!!
Reply:That's rim rot.  Moisture gets under the anodizing and rots out the metal underneath it.  None of it is very deep.  I will be removing all of the loose material with a wire wheel this weekend.  The rim is over 1/8th of an inch thick, the deepest rim rot is likely not much more than 1/32nd of an inch.  You'd be hard pressed to find an older inner tube type rim that doesn't show some rot.
Reply:It looks like there are a couple more cracks from that impact to me - at least the start of ones.  I ride dirt bikes and if it were me I'd at the least use penetrant on these spots to check them and repair those too. Attached Images
Reply:None of those are cracks in the metal, that is the anodized coating flaking and peeling off.
Reply:Having bent a number of rims over the years it would be very wierd to damage one side and not the other.  That line on the right is directly across from the crack on the left, JMHO
Reply:if it still apart might be a good time to run a bead on the other sidecouldn t hurt
Reply:Steve has a good point ,and rember aluminum gets more brittle with age.
Reply:ditch the rim, buy a new rim and re-lace the wheel like you know you should...new spokes/nipples and a bit of lok-tite on each nipple, spin the wheel and now you are a rock star....that  rim looks thrashed and trashedOwner - Certified Welding & Fabrication / 22yrs in businessSteamboat Springs, Co(970) 879-5491AWS structural shopHMI 70t iron worker2 field trucks specailizing in structural steel, aluminum and stainless steel
Reply:I'm having a terrible time getting new spokes for this rim, I may have to have a custom set made at $90 before shipping.  My friend and I are trying to do this dirt biking thing low budget because we are still in college.  We do as much as we can for free and have literally haggled for quarters.  Basically, a newer rim is out of the budget right now.  The bike needs a new tire as well, but we'll dumpster dive that one.  It's amazing how spoiled some riders are with tires and how soon they'll throw one away.And Loctite on the nipples?  I'm buying a new set of spokes because I can't get the old ones apart.  The new ones will be getting never-seize.  The spokes on this bike are also straight, there is no hook in the end.  Therefore, if there is any resistance to the nipple turning on the spoke, the spoke will just turn in the hub and there is no way you'll get it loose.76GMC1500,It looks to me like the crack you are repairing is right at the buttweld joint of the rim. It appears to to be too straight accross and nearly perpendicular to the curve of the rim. Has anyone else noticed that?Alohaoldebrush
Reply:well..MY true friends would know none of this would have gotten in this arena..if i was nutty enough to lend one of my cherished D-bikes,i would not want that silver snot on any of my rims..something not right if a borrowed possession comes back in worse condition when lent out..you should have just taken the high road and got your 'friend'(?) a new rim with everything included,then installed it,washed it,lubed it,and changed the oil..just how my circles of beloveds operate in thought patterns of good standing with 1 another..Last edited by Noa'zarc; 11-01-2006 at 12:09 AM.
Reply:odlebrush,  you are correct.  The crack is excactly centered over the original butt weld on the rim.Arcangel, the friend loaning the bike is just as stingy as I am, he understands.  All we want to do is ride together and have some fun.  We broke 2 wheels in 2 weeks.  He disintigrated the wheel bearings in his '02 and I cracked the rim in the '87.  He wanted to weld up the inside of the hub so it would accept a new bearing.  All we want to do is start riding again for the least amount of money.  We may race some har scrambles, too.  The owner of the bike put a sticker on the rear fender that says, "WFO", that is how he expects me to ride the bike.Last edited by 76GMC1500; 11-01-2006 at 03:35 AM.
Reply:well then i'm a big poop stain if this is what is the norm..please acept my humblest oops's..the sticker is a good one!!sounds like a good Drt-biker pal you got there too..may i ask what some of your jump hieghts get too?..never even came close to trash'n a rim on my 500 thus far.
Reply:I don't jump, I trail ride on single track trails.  We run wide open over ruts, rocks, roots, and whatever else gets in our way.
Reply:I'm an ole'fart now, 49, who raced motorcross just about my whole life as a young man. You say your on a budget,,,hmmmm,,,,hospitals aren't cheap either,,,save your money and buy a rim. Good luck,,,,,,
Reply:Well, I gave the rim the beating of its lifetime, today.  It held up fine, but my friend crashed within 20 minutes and we had to go home.  He's fine, just a bruised knee.  He tried to keep up while I endurance tested the rim...
Reply:Did you drill a small hole at the end of the crack to keep the crack from traveling?
Reply:I'm with your GMC... I would of tried the same thing, Glad it worked out for you so far...
Reply:Yes, it was stop drilled.  I put another 5 hours of the hardest riding that bike has ever been through on it yesterday.  The spokes are all still tight.I said I don't jump the bike, but that meant I don't ride track jumps.  I do catch some air on the trails sometimes.  That stuff is probably harder on the bike than track jumps could ever be because I drop from 4-5 feet in the air on to flat ground or into big holes, no ramps.
Reply:Originally Posted by 76GMC1500Yes, it was stop drilled.  I put another 5 hours of the hardest riding that bike has ever been through on it yesterday.  The spokes are all still tight.I said I don't jump the bike, but that meant I don't ride track jumps.  I do catch some air on the trails sometimes.  That stuff is probably harder on the bike than track jumps could ever be because I drop from 4-5 feet in the air on to flat ground or into big holes, no ramps.
Reply:Glad to hear it worked out fine. I love the no frills fixes!!!
Reply:I'm a factory trained Harley mechanic with over 30 years of riding experience in dirt and street.  Ditch the rim (no pun intended, it appears that the ditch already got to it first).Aluminum has a specific heat treat and concentrated heat will soften the metal.  I also worked in a racing shop doing porting and polishing of Top Fuel Dragster aluminum hemi cylinder heads.  When the boys would put too much nitro in the can, I'd spend a day or two putting the heads back together to sell to a po-boy newbe.  Professionals would not use anything critical that had been welded because of the heat treating issue.Hobart 140 Handler w/ gasHyperTherm Powermax 380 Plasmaoxy/acetylene
Reply:Thats because money is of no object to some. Especially a racing team.