[Gonzowerke]

Newbie here, looking for info on gas torch use for mating tubing with bronze filler rod. This board does seem to be TIG/MIG/Stick centric, but I know someone out there has experience outside those methods.

Is this the right place to ask my questions?


Thanks

[Braehill]

I haven't brazed (Bronze welding, so to speak) for about 30 years , but when I did I just used an Oxy/Act torch with a welding/brazing tip. If your looking for specific recommendations on models you'll have to wait for someone who does it still. These folks are sure to chime soon. Most people who do this are very fond of the process.

In brazing, only the filler metal is melted and it uses a capillary action like solder to bond the 2 (sometimes dissimilar) metals together, that's why it's not a weld in the true sense of the word.

Len

[Mike]

Welcome to the forum.

[Gonzowerke]

Thanks for the welcome!
I know it's not really welding, but I always hear it called that. Before I ask away, let me tell you what I want to do.

I am building a 1978 Honda CB750K. I want to convert the swingarm from twin shock to monoshock. I was considering using Bronze welding to add the bracing and shock mounts on the swing arm and frame. I then got the idea that, since it looks so cool when you are done, of just clearcoating the swingarm so you can see the bronze fillets. I then got the bright idea to strip the frame, and just go over the existing welds with a skin of bronze to make it match the swingarm and just clearcoating it as well. So my two questions are this,

1. Will it be strong enough?
2. Will I be weakening the existing welds by heating them up and coating them with bronze?

I know that companies like Harris in the UK make frames with bronze, and the Ariel Atom is also assembled with Bronze, so I should be okay, providing I do it correctly.

[coldman]

I have done alot of braze welding for decades now. I can tell you braze welding is surprisingly strong, but here is the caution:
I have no doubt that there are factories that produce braze welded frames, but their materials and brazed joints are designed for purpose to cope with the many types expected forces with safety. Your existing frame is designed for the same but with fusion welding. Unless you are an engineer that can certify the safety of swapping weld methods, you may be taking a detour to boot hill sometime soon.
Coating an existing fusion weld with bronze should not weaken the weld as long as you don't force cool the weld (quenching) otherwise its back to boot hill again.

[noddybrian]

As previously stated - brazing can be a strong & appropriate joint method if done well - but as far as I know ( in the UK ) it cannot be used for any part of a vehicle considered to be load bearing unless you can prove it was originally made using this method - you may get away with it if the MOT tester does'nt see it but it's an instant failure normally - some older bike frames were brazed - but I think for appearance & simplicity I would Tig weld the frame.

[gocirino]

I do a lot of silicone bronze mig and tig. When I have done motorcycles for people that wanted that bronze look, I would just weld with ER70 and go over it with silicone bronze. Works great!