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Discussion Starter #1
My 66 T120C has had the side stand lug broken off and I want to have it repaired. I got a new cast piece from Baxter as shown in the photo below. It will need to be sliced and welded on. However, the old fitting needs to be removed first. After having the frame media blasted I see what looks like the welds are bronze. Randy at Baxter says the new cast piece is cast steel and the frame is mild steel. I have also attached a photo of what the welds look like for confirmation that this is bronze welded.

If anyone has experience in this subject, I would like to know how to best remove the old lug piece and confirm the best welding method to attach the new one. The frame and new lug are currently at a shop where the owner says he can weld anything. However, he was a bit confused by the yellow and thought maybe it was brazed? I would like to confirm the bronze welding on this frame and also the best suggested method for going forward.
The frame is numbers matching for my engine and as such is not replaceable. That fact did not seem to impress the shop owner but he does have a good reputation. He wont start this for a week so I thought I would do some research............

Thanks.....mike
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I agree with speedrattle - you need to find a more experienced / knowledgeable welder
it would concern me that he does not know how to identify or deal with a brazed joint
 

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You have a few problems you haven't recognized. That piece would be bronze sweated at the factory before the frame tube is in place, not with splitting the lug. For your repair you will have to cut the circle in half, that cast can't be bent open. With that in mind, those two halves of the casting should be MIG or TIG welded to ensure strength. It would seam a waste to try to braze sweat after proper welding of the two halves together. I assume you are not contemplating cutting the frame tube and bending to get the casting on in one piece although a goo frame shop could do it that way. Good luck.
 

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Discussion Starter #6
I understand the original lug was tacked in place and then bronze welded. It will have to be cut off and removed. One part of the question was how to best remove it. As for the new lug, yes, it will be split in two and the seams welded properly. Part two was as to the best method to weld the cast steel to the mild steel. The bronze welding thing has more to do with removing the old one without damaging the frame and to confirm that the factory did bronze weld these originally as I had no idea they were done that way.

I appreciate any and all advice on this......
 

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That is definitely a 'silicon bronze' or 'brazed' joint.
If your other piece is definitely cast 'steel', it can be brazed or tig welded.
If it's cast iron, it can be brazed but not recommended to be tig welded.
Remember also that bronze may be put on steel after being steel welded(tig,stick,mig,etc), but you can't put steel weld on top of bronze.

That bought piece would be steel. That little spring button would snap off easily if it were cast iron.
 

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Most obvious thing is that you need the frame on it's wheels with the engine fitted in order to correctly set the angle of the lug!

I agree that if your welder does not know what a brazed joint looks like you should consider another welder.

For removal ( again your welder should know this ) You can carefully slice the old lug in the same way you plan to do the new one, find and cut through the spot welds and then heat the join with a torch until the braze starts to flow, at that point you should be able to lever the old lug free.

To reattach, since the frame tube will be contaminated from the original brazing that is what I would use. With the bike temporarily built up attach your side stand to the lug and set it in place on the frame, when you have the lean angle right tack it in place with a Mig. Now disassemble the bike, add the other half of the new lug and weld the join having first chamfered the edges of the join. Drill an 8 mm hole through the top of the new lug and out the bottom, into this push a steel pin so it sits just below the surface at either end and weld it in place. Now braze the lug as the factory did.
 

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The kick stand lugs I have seen are a half circle so to speak.They are steel not cast so they are welded. I'm pretty sure the original lugs are malleable iron, aka cast steel that can be welded. It's also not brittle like cast iron...An experienced metal worker should be able to identify the lug metal. I would not use a cast iron kickstand lug..
 

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Discussion Starter #10
Thanks everyone for the replies. We will mark the location and orientation of the original lug before removal and clock the the new one before attaching. The lug angle is ~ 40deg from the the plane of the bottom members so we can check it that way as well. I believe I have an understanding of what needs to be done now. Thanks again.....mike
 

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If you are going to remove the bronze from the frame, first heat it up until brazing flux melts and adheres to the bronze. Otherwise the bronze won't flow.
I usually get the bronze flowing and rake off the joint with a wire brush.
It has to be raked quickly, so an extra hand is helpful.
You won't get it all off that way but you'll get the bulk of it.

Torch requires an oxidizing flame... blue cone, soft flame, not jetting.
 

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Discussion Starter #12
If you are going to remove the bronze from the frame, first heat it up until brazing flux melts and adheres to the bronze. Otherwise the bronze won't flow.
I usually get the bronze flowing and rake off the joint with a wire brush.
It has to be raked quickly, so an extra hand is helpful.
You won't get it all off that way but you'll get the bulk of it.

Torch requires an oxidizing flame... blue cone, soft flame, not jetting.
Thanks for the tips......mike
 
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