The Definitive Frame Welding Thread

[Timeless]

I'd like to create this thread to get your first hand experiences welding the frame of our bikes. Let's hear from people that have done it...what welding machine you used, what settings, what filler rod, how the frame was purged, what work was done...

The idea is to build knowledge to open up new possibilities of customizing or fixing our XB's.

Did you weld something to the frame?

Did you repair a dent?

Lets hear details about it!

 

[Bairframe]

Since nobody has taken the bait yet I'll chime in with my two cents....

The frames on an XB as a general rule should not be welded for multiple reasons. Not to say that it is impossible to do but there are certain processes to do it correctly. The first challenge is that it is an aluminum frame. It is possible to weld aluminum using MIG or even Arc welding but these are crude processes that will yield an inferior weld. The only correct way to weld aluminum is using a TIG welder. Given that the frames are already welded this gives you a clues as to what the material is. 6061 is one of the few acceptable (and readily available) aluminums for structural use and ability to be welded. 4643 is the only acceptable filler rod for heat treating aluminum and this is probably what was used at the factory assuming they used 6061-T6. As a side note for other parts, when welding 6061 for anodizing or color treatment you want to use 5356 filler rod but the problem with using 5356 is that it is not heat treatable.

Here's where the tricky stuff comes in... Heat treating and tempering is most critical when a frame of any sort is made. You could assume that it is 6061-T6 but once you weld it the area around your weld has been returned to the "O" or annealed state and therefore has lost structural integrity. This is not something visible to the eye and has to be tested as to what temper it is. In order to properly temper the frame after welding the ENTIRE frame has to be annealed and then brought up to the correct temper. This can be at temperatures up to 985 degrees fahrenheit (not equipment most people have laying around). This is unless of course the whole frame is already in the annealed state from the factory then the heat area wont change the temper that much but that is highly unlikely since annealed aluminum is very soft and not usually suitable for anything structural as a frame. This presents a problem which is the next concern...

The frame doubles as a gas tank and unless you have a brand new frame there has been gas in it. Welding on a fuel tank is problematic and should not be done by anyone that is not a professional welder. The fuel cavity has to be completely free of fuel (this requires more than just draining the tank) and completely submerged in an oxygen-free environment (do yourself a favor and google welder and fuel tank and see how many deaths you find).

So once you figure out what the material is and the temper and figure out how to drain and submerge the tank while it's welded and heat treated, then you figure out how to properly return the frame to it's original state then you can jump on in and weld away.

If you don't do all this then you run the risk of your frame bending or worse - breaking when it's ridden. Just remember there's a reason they scrap bikes when the frame is damaged...........

 

[firefighter1c57]

hmmmm... what if the frame is 5754? It is made in Italy after all.

What if you have a oven capable of heating it, a TIG hooked to a large tractor trailer of supplied argon, an inspection area that can do a conductivity test of the frame and give you a Rockwell C-scale of the hardness, but, you have no way of controlled quenching the heated part to a set hardness??

 

[Bairframe]

Well I just mentioned that you would have to heat treat rather than going into the whole process. One would assume if you had the furnace then you would have a quench tank. But since you mention it, the proper way to make 6061 that has been hardened previously then welded into 6061-T6 is as follows (based on an air furnace and a water quench tank rather than a salt bath):

Soak the part at 775 degrees fahrenheit for 2-3 hours depending on part size and thickness. Cool at a controlled diminishing rate of 82 degrees per hour down to 500 degrees fahrenheit. Once you get to 500 degrees fahrenheit it can cool uncontrolled to room temperature. The part is now annealed.

Soak the part at 985 degrees fahrenheit for 30 minutes. Note that the 30 minutes starts once the oven and part/s inside have reached the total temperature of 985 degrees (these aren't cookies - this is crucial to achieve the correct hardness). Quench (as quickly and evenly as possible) in an agitated (air bubbles works ok but an agitating water pump is best) water tank where the water temperature is between 86 and 100 degrees fahrenheit. Make sure that the water does not exceed 100 degrees or else you will not have had a proper quench. The part is now in the T4 state.

You now have to artificially age it in order to bring it to the T-6 state. So comes the last soak at 320 degrees fahrenheit for 18 hours. Allow to air cool. The part is now in the T6 state and you are finished.

After this then you can test for rockwell and correct conductivity

As for it being 5754 - it is entirely possible. For that you could use 5754 Mg3 welding rod. You would still have to follow the process for heat treating 5754 (different temperatures and soak times than 6061) up to its proper state which I would assume to be H26. But, like I said to begin with, it's a guessing game unless someone actually knows what the material is. I'm not about to disassemble mine so I can irradiate it and figure out what the material is

 

[bobaganoosh]

I cut a hole in my swing arm and welded this brace in. Just used a arc welder with an aluminum rod

 

[Timeless]

Interesting information thus far.

Bairframe, you bring up numerous excellent points and are spot on with all of your explanations on heat treating/material science. Major props.

At least on my end, I understand completely the limitations of welded aluminum and the necessary post weld processes required to get the material back to temper.

I think it is interesting that there are numerous people that have theories about the frame material...most say 6061-T6 or similar. It would be interesting to confirm or dispute this.


Welding a brace in the swing arm is probably a bit off subject, but never the less close. Plus it looks badass.

 

[Bairframe]

I have the capability to check the material if I can get a sample (at least a 1" x 1" square). So if anyone out there has a piece of a junk frame that they would be willing to part with then lets make it happen....

Timeless - if you have a piece of that swing-arm left and are willing to part with it then let me know. It would be nice to know what these things are made of

 

[Timeless]

I'm in the process of looking for a battered frame to test weld...I would have no problem cutting a piece off it and sending it to you.

I'm afraid I'm not the guy with the cut out swing arm though, bobaganoosh is.

If any one has a beat up frame for cheap we can really get this going.

 

[BuellyBagger]

Bairframe: do u think heat treating would be needed after welding/reattaching "non structural" mounting tabs to the frame. I guess i don't know how far the heat effect zone truely carries on aluminum.

 

[bobaganoosh]

Ill check and see if I still have that peice but I probley threw it out

 

[Bairframe]

do u think heat treating would be needed after welding/reattaching "non structural" mounting tabs to the frame.  I guess i don't know how far the heat effect zone truely carries on aluminum.

That would really depend on the area and thickness of material as to how far it would spread. Aluminum soaks up a lot of heat compared to steel and therefore spreads the heated area out further. If you're talking about small tabs in unloaded areas then you are probably OK doing it. But if you're talking about repairing the areas on the sides of the tank that normally get dented in a crash or somewhere around the head tube then I would not recommend it.

Ill check and see if I still have that peice but I probley threw it out

I'm in the process of looking for a battered frame to test weld...I would have no problem cutting a piece off it and sending it to you.

That would be cool....

 

[bobaganoosh]

Nope I couldn't find the peice I probley threw it out

 

[neomac3444]

Listen to Bairframe he knows what he is talking about! Al is tricky to weld and do what you want with it. This is why a lot of bike builders that are custom guys dont go with it.

Bairframe are you a metallurgist?

 

[Bairframe]

Bairframe are you a metallurgist?

I design and build prototypes for aircraft for a living.

 

[Iamarchangel]

Well, you've left out the most fun part of welding aluminum. Unlike steel, it melts on the inside first. The skin looks solid and then, bloop, you've lost it. There's a certain point when it looks like custard skin and that's your moment.


Proud of being able to flame weld aluminum. Twice.

Go with TIG.

I'm a retired welder. Would I weld a Buell frame? You're joking, right? I'm thinking all sorts of liability issues.

 

[Timeless]

Personally, welding aluminum, I would not consider anything but a TIG machine. But to each their own.

Bairframe, you have offered some great aluminum welding advice thus far. Thanks for your contribution to this thread.

 

[firefighter1c57]

I thought I'd replied to this, but I guess not? Weird things happen from my phone from time to time...

We have the oven to preheat parts to weld them, not really for heat treating. While we have a heat treat section, I don't work there and would have a awful hard time explaining bringing it in.

I'd at one point contemplated welding mounts on the bottom of the frame like the XBRR to attach frame sliders. I'd abandoned the idea due to not being able to discern the XB frame alloy and not being able to discern whether the frame/fuel tank was lined.

 

[Timeless]

firefighter, your concerns have been my own as well and are the basis for starting this thread.

Figuring out the alloy is one problem, but can be resolved, figuring out how to deal with the coating inside the frame is another. Unless it is removed, it will definitely ruin every weld.

 

[Timeless]

Bump for more info =)

 

[firefighter1c57]

Timeless, it can be done. The RR frame they are obviously welded on. The rest of the frame is obviously welded together. I have no doubts it can be safely welded. I just don't know that I can do it.