Welding aluminium ( or even aluminum )

[lw395]

I've tried various miracle aluminium 'welding' products over the years with mixed success.
Lumiweld was one of my better experiences.
I think, technically the join can be viewed as a weld, because the rod effectively dissolves the metal of the work into an alloy, a bit like solvent welding plastic.

These things have their uses, depends on what the problem is, but if epoxy won't do it, I would tend to be looking for a craftsman with the right tools.

 

[JSYmartini]

Actually I would call it Brazing due to the higher working temperature ~400°C against 200~250°C for common lead/tin or lead free soldering -but what do I know?

"The distinction between soldering and brazing is based on the melting temperature of the filler alloy. A temperature of 450 °C is usually used as a practical delineating point between soldering and brazing . Soft soldering can be done with a heated iron whereas the other methods require a higher temperature torch or furnace to melt the filler metal."

 

[CreakyDecks]

I remember seeing a TV programme showing some craftsmen (only appropriate word) making a D type Jaguar replica in exactly the same way as they were originally built. They were making this amazingly streamlined car bodywork mainly by rolling flat aluminium sheets and gas welding. More skills we've lost forever!

 

[DownWest]

I remember seeing a TV programme showing some craftsmen (only appropriate word) making a D type Jaguar replica in exactly the same way as they were originally built. They were making this amazingly streamlined car bodywork mainly by rolling flat aluminium sheets and gas welding. More skills we've lost forever!

Still done by a few. But TIG is a sort of more sophisticated gas welding. The wheeling of ally to make bodies is very much still practised, and by young enthusiasts rather than old codgers.

This question comes up occasionally over on the mig welding forum. Unsurprisingly, they don't think much of the stuff.

 

[CreakyDecks]

I don't know about "more sophisticated", certainly more expensive. I've tried all the welding techniques and TIG was my favourite when we had a big BOC Transtig set at work.
When I tried it I found TIG welding aluminium hard enough without the extra problems that gas welding panel distortion must have given the "old codgers", so I have to take my hat off to them.

 

[C08]

Apology for the thread drift to the OP.
I am thinking of getting some cast aluminiun alloy davits with brackets for horizontal mounting and having brackets welded to bolt them vertically as well to compensate for a rather thin horizontal mounting area. Is it possible to weld cast alloy?

 

[30boat]

Apology for the thread drift to the OP.
I am thinking of getting some cast aluminiun alloy davits with brackets for horizontal mounting and having brackets welded to bolt them vertically as well to compensate for a rather thin horizontal mounting area. Is it possible to weld cast alloy?

Yes it is .Engine castings are routinely welded.I don't know anything about metalurgy but there may be alloys that are more suitable than others.

 

[Lakesailor]

See my earlier post #17. Gearbox bellhousings are cast.

 

[cliff]

"A temperature of 450 °C is usually used as a practical delineating point between soldering and brazing ."

And where pray tell did you find that little snippit - curious as for the past 35 years the delineating point has (in my field at least) been~250°c although there is also the issue of the mechanism of the bond and the extent of micro alloying and formation of intermetallic phases along the bond zone. The easiest way was lead or lead free tin solders were used for low temp soldering <250°C while use of brass, bronze, Ally and silver alloy fillers was classed as brazing where the temp was lower than the melting point (or liquidus temp) of the base metal.

 

[noelex]

Make sure its a marine grade aluminium.