Frame welding

[Oltcit]

There is a Swedish product made for the aerospace industry that you can sometimes find at Vintage or Classic Motorcycle shows for welding aluminium using a butane gas torch.It consists of a small roll of special aluminium wire which you apply and scrape with a screwdriver, it flows a bit like solder. The demonstration samples withstand people trying to break the joints, the original metal breaking before the weld.
The split in your frame looks like a stress fracture, have you been riding in too high a gear?
As other posts have mentioned your frame may be beyond it though.

Yes, I have heard about that has torch thing, but I cant belive this will be enough strong. I dont know, what do you mean too high gear?
I am still looking for a welder, which is not too far.

 

[Illaveago]

I noticed that the split was on the chain side of the frame and thought that the torque/ twisting action might have caused it to fracture, along with all of the vibration from modern rough road surfaces.
Riding in too high a gear, what I mean by that is large front chain ring to small rear sprocket. So if using that set up you decide to climb a hill you will find it harder to push the pedals round rather than making it easier by dropping down a few years on the rear wheel. If on the other hand you decided that you were not going to be beaten and continue in a high gear it would put more strain and flex through the frame which I assume might have led to the split.
That is only my theory, as other posts have mentioned it could have been poor heat treatment.

 

[Ajax Bay]

You seem not to want to hear this @Oltcit but I'll reiterate: you're flogging a dead frame/horse - rid yourself of the chimera of a 'good as new welded' frame.

There is very little chance that the job will be successful.

(@Yellow Saddle later suggests that you could wrap the whole chainstay in carbon fibre - you'd have to clean that part of the frame first.

Get a new one, remove, CLEAN and use all your 'parts' to build up a 'new' bike, and enjoy riding it, confident that it will not let you down. Why are you having trouble finding somewhere/one which/who will weld your aluminium frame (and getting little help here)? Because people recognise it's not worth doing. Getting a new frame would probably end up costing less, and it'll maybe come with a warranty, which any weld won't.

 

[Drago]

I'd take a hacksaw to it to make sure no one else can ride it, then take it up the dump. Welding it will simply weaken the frame without the heat treating and finishing process afterwards, which will difficult to reproduce and expensive.

 

[fossyant]

It's a cheap bike, bin the frame.

 

[Tom B]

Whats the frame make/model?

 

[Oltcit]

Whats the frame make/model?

Carrera Crossfire

Obviously doesnt worth to fix it. But I love this bike and that is why i wanted to do.
All right, I throw out the frame.

 

[si_c]

Carrera Crossfire

Obviously doesnt worth to fix it. But I love this bike and that is why i wanted to do.
All right, I throw out the frame.

If you're going to drop the frame, worth looking at are the likes of Planet X, you could pick up a new frame at a reasonable price, which you can just put your current components on.

http://www.planetx.co.uk/i/q/FRPXRT58AFS/planet-x-rt-58-alloy-road-frameset

Is kind of what I'm thinking, although they do the kaffenback 2 steel frame for about £200, which I'd guess is not that much more than the cost of getting someone in London to weld it.

http://www.planetx.co.uk/i/q/FRPXKBD2/planet-x-kaffenback-2-frameset

 

[winjim]

Or just buy a NOS crossfire frame off ebay for about 60 quid...

Ebay seller piper1967 has some in.