Welding Aluminum!

Discussion in 'Whizzer Motorized Bicycles' started by go-rebels, Jan 26, 2009.

  1. go-rebels

    go-rebels Member

    I had a bit of a mishap where my Whizzer took a soft fall on some grass and broke the clutch lever near the pivot point. I ordered another lever through Mike at Simpson Motorbikes (thanks Mike!) but being a fix-it guy, I needed to try a repair.

    Now this isn't easy. Welding cast aluminum is generally very difficult for seasoned welders, and this was tough due to its small size and no convenient way to fixture the two broken parts through the welding process.

    I've had some success with Durafix aluminum welding rods (http://www.durafix.com/) but I've often had a problem getting sufficient penetration into the base metal. The rod has the one advantage that it is generally stronger than the base metal, so if a section thins out, I might still be OK.

    The piece I attempted to weld to the handle was only about the size of a nickel, as the level broke next to the pivot point where the cross section reduces in size. I chamfered the break area on both parts and set the parts on a large vise positioning them using magnets and various loose spacers. In my first attempt I used propane gas but I couldn't seem to get the weld rod to flow onto the base metal. I changed to hotter MAPP gas and got the rod to flow nicely on both sided. A little filing and I was ready to go.

    I put the handle on the bike and squeezed the clutch. So far so good! Then I pushed the lever down and snapped it off at the repair joint. Hmmm...

    Years ago I went to a "tool" trade show and picked up a Henrob welding torch (http://www.cut-like-plasma.com/) to do some light sheetmetal repair. This is the finest steel welding torch I've ever seen using acetelyne + oxygen gas! If you do any light gage welding, you certainly need to look at this torch head. In summary, it provides a very hot, small flame through different nozzles (tips) allowing welding of sub-1mm sheet. If the joint allows, no weld rod is needed, but if there are gaps, then copper coated steel rod can be used as filler. Anyway, I tried the smallest tip on the aluminum castings, quickly remelting what I put on earlier and got excellent penetration into the base metal. The key is keeping the tip moving, else you'll make an aluminum puddle through the entire thickness of the part. Some filing, sanding and re-drilling of the pivot hole and I was riding again!

    Durafix Welding Rod and the Henrob Welder = SUCCESS


    A boring Henrob youtube video: http://www.youtube.com/watch?v=6v1WJ6uPsaQ

  2. Mountainman

    Mountainman Active Member

    oh yes -- welding that aluminum -- takes more of a welder than I was

    my buddy made custom wheel chairs
    he knowing that I had done some welding asked me to help out a little
    man that was (for me anyway) some hard touchy welding
    after a few hours of popping through that thin stuff -- I had had enough !!!

    I only know one welder today who I would trust to weld a brake handle
    that's one out of 20

    Mountainman -- stick to welding 1" thich steel plate !!!

    much better yet -- ride that motor bike thing !!!
    Last edited: Jan 26, 2009
  3. arceeguy

    arceeguy Active Member

    Welding cast aluminum with a torch? You definitely have some mad welding skills! I sometimes have trouble welding 14 ga. mild steel with a MIG setup. :dunce: As far as welding with an oxy torch, well, I've only used mine to cut or to loosen rusty nuts and bolts. :goofy: :D
  4. go-rebels

    go-rebels Member

    The Henrob welder is the ticket here! I've been able to fill some pretty big gaps in steel using their copper plated steel welding rod and the right tip. It's really quite amazing what a little practice will do.

    I don't trust my skills welding a "brake" lever, but the clutch lever won't kill me should it fail.

    I'll post a pic of the final weld after I remove it from the bike and file it a bit. Its sticks a little in the pivot opening as I didn't work down the thickness quite enough.

    And this was my 1st attempt on such a little cast aluminum part. The Henrob gun is really quite amazing!
  5. KilroyCD

    KilroyCD Active Member

    Wow, I'm very impressed. If I had tried what you did, I'd have a puddle of molten metal on the bench in front of me. :grin5:
  6. n8ygn

    n8ygn Member

    (Henrob) not so much the rod.

    YOu guys should listen the henrob torch is amazing, I have been using for years. Cutting, welding, brazing what ever and use 1/3 the gas and o2, but it still takes a crazy man to trust his life on a brake grip and his welding skills. The sudden stops hurt, and also the ones where you slide and slide and slide!!!!! Dane
  7. Henrob Torch

    Hi guys, I first saw this torch "gun" at an antique car and motorcycle swap meet. It was 450.00 I think, a lot of money for me then (and now the way things are). It was very late in the year, and I told wifey, THAT is my Christmas present! I slipped away form our "spot" several times and watched the guy weld. NOW don't get me wrong, I knew, that he knew, exactly how to work that thing, BUT, he could do things my Victor 100 set, and my ex-military Marquette set could NOT do!

    Well, 3 or more demos later I was hooked, I watched the DVD a bunch of times, even duplicated it! I still cannot do everything he did, BUT it is very efficient, and capable of less (to none at all) warping, and uses VERY little fuel.

    I do need to watch the video again soon, as you do use it a little differently than I did my Victor.

    It is now called Cobra 2000, and is exactly the same as the Henrob.

  8. yes I have one & yes it is great..... I love it for what it is..... but when ever I need it it is always a set up from being what I need & have to swap tips around

    I have 2 torch outfits 1 set up with the henrob the other with a regular torch & for a quick cutting a couple rusted bolts or a quick spot weld I grab the regular torch but for laying a decent weld on thin metal the henrob is the way to go it will also weld nice thick metal too I used a ratchet strap to pull my bushhog back together after I split it down middle nearly 2 feet & welded a piece of 1/2" plate steel across & flowed it into the base metal & it has held for years now.

    oh & yes I would trust my work to weld a brake lever I have been welding for over 30 years & everyone that has seen me weld has offered me a job I started with mapp gas when I was 10 & a friends arc welder & at one time I made my living clipping cars that was all MIG welding though.

    I was at a custom restoration shop 2 years ago for a seminar thgay was putting on for rebabbitting engines & they had a Henrob & the shop owner had seen the show but he wasnt good with it & I told him it took practice & I had him welding nice with it within 3 days...

    there are some high temp soldering rods out there for aluminum which do good but I wouldnt trust personally on a brake but would for a clutch do a search for muggyweld it is a start until you can weld aluminum.

    I know 1 guy that makes his living repairing broken aluminum motorcycle cases whew. too much for me he has a small machine shop in a storage building in his back yard & his work is top rate. he is the best aluminum welder I ever met in my life. I am just good with aluminum & excellent with steel.

  9. RdKryton

    RdKryton Active Member

    My welding could only be described as melding. Ray Charles could do a better job...
  10. Baverian

    Baverian Member

    good old days.....Huh

    Back in the 60's I apprenticed in germany and I can remember the Meister showing us how to gas weld aluminium . He welded or more or less added material to the valve cover sealing surface on a VW head(BTW the head was on a bench).He used a powder or some sort or flux that pooled at the corect temp to add rod . The trick thou is you must use dark purple lenses in your welding gogles to see the pooling take place.
  11. Turtle Tedd

    Turtle Tedd Member

    aluminium welding is best done with T.I.G... when you light it up with a tig unit you will be able to tell if you can weld it or need to toss it....Cast alumn.can be a combo of anything...you can melt a lot of magic rod on a bad part but it will break if put under stressy..you can get away with gas if your just doing a surface build-up like a valve cover or side cover if it is not going to take much stress from a nearby fastner
    Last edited: Jul 14, 2009
  12. machiasmort

    machiasmort Active Member

    I can't mig weld to save my life but am pretty proficient with gas and arc. The trick I use for gas is to get the stick close to where your heating your base metal. The stick will always melt first, then you know the base metal is about to start flowing! By the way that torch seems like a quailty product!
  13. Turtle Tedd

    Turtle Tedd Member

    MACH numbe one rule with welding anything with any process is to heat the base metal (part) first ..when it begins to melt only then add the fiiler rod. .the main secret to welding is to watch it melt ,watch the puddle,focus on the puddle add the rod athe the right instant and move the puddel while adding the rod (filler material)..without putting to much heat into the area...all welding is a practiced technique except maybee for MIG witch is pretty easy to master..BUT there are also many gas brazing techniques that are used for welding light gauge bike frame parts,but these parts must be designed for this type of welding. 50 percent of welding sucess is determined by the design of the joint and what type of stress it is giong to take, the grade of the metals used and the preperation of,,,if this is not done right the best welder cannot make it right...never use a MIG welder without a gas hookup...you must have gas..period..with any type of wire,including flux core
    Last edited: Jul 15, 2009
  14. Happy Valley

    Happy Valley Active Member

    Huge difference between billet aluminum and aluminum tubing, and all aluminum tubing is not the same, using the right filler alloy is important.
    Problems can occur maintaining the structural integrity with the precarious configuration of a lightweight bicycle frame under load and applying heat with welding can mean some method of relieving stress, heat treating or aging. TIG is best for aluminum tubes.
  15. machiasmort

    machiasmort Active Member

    As subject matter of the thread would suggest Welding is the fusion of metals not the brazing. My reply was inorder to help the less welding knowledgable out there. By applying heat to the work piece and not having an idea how hot it's getting, you'll have a puddle alright!

    Aluminum by property has a great deal of heat transfer. Applying heat to the workpiece and filler(usually thinner) rod at the same time, gives you an idea of how hot the workpiece is getting before you make a puddle out of it! When you see the rod starting to melt you know to be on point and ready to pull back on the heat.

    There are different grades (alloy's) of rod you can use, the less tin, usually the lower melting point. It's nearly impossible to use a heat dam when welding aluminum because of the fast heat transfer. There's alot more to welding it than penetration, like the flux your rod contains or you apply! Penetration is not a problem with gas welding so long as you see your base metal melt, then it's all in flux and matching your alloy and filler!

    Fluxing or flux included on your filler rod(gas welding) substitutes for added gas in mig and tig welding. In mig and tig the gas creates a "shield" to push away impurities from our air. Welding is actually a chemical reaction but I won't get into it too much. When you heat metal, it takes different chemical compositions depending on environment and ammount of heat.
    Last edited: Jul 15, 2009
  16. Waterfowl

    Waterfowl MBc-Sponsor

    This guy knows what he's talking about.
  17. machiasmort

    machiasmort Active Member

    No doubt TT knows what he's talking about, I just seen Killroy's earlier comment about having a giant puddle.. Sounds like me when I first started out... Gas welding, to me came real easy. I'll be the first to admit, I'm not good at mig, at all...

    Here's a great site, I'm sure will keep you up. The second one is the sites Home page, on frame welding. You guy's are gonna love this!
  18. Turtle Tedd

    Turtle Tedd Member

    tig welding....must use the proper rod. none contain flux.
  19. Waterfowl

    Waterfowl MBc-Sponsor

    I can't tell if you are joking about those sites or not. I hope you are not being serious.
  20. Turtle Tedd

    Turtle Tedd Member

    no offence mashiasmort but the above mentioned sights should be blocked .....concerning all parts that have anything to do with motorcycles or bicycles that are made of aluminum....Gas welding-s offNO..flux core of any kind-NO...aluminum welding rods are 36inches long and come it straight tubes,,this is for tig...alumin mig rods is called wire,comes in rolls,,never has a flux core...There is a lot of BS welding info out there at gun shows boat and car shows.trade shows etc...every bodys a welder...guess I shut up before I **** anyone off because I do not know anything about these HT motors or these motorized bikes..dont type to well either