Alloy question

What country are you in?

The aluminum solder rods in the US look like they're home-made (they're kinda lumpy) but the rods are flux-core. I dunno how you'd do that cheaply at home. ?

The stuff is all mostly zinc, it's not expensive. That doesn't stop at least one company for vastly overcharging for it however.

Fourney, Muggyweld, HTS-2000 and Dura-Fix are the four most-common US brands. Fourney and Dura-Fix are the cheapest, and local hardware stores often sell them.

You have to play with it to see what it can and can't do. The heat-dissipative nature of aluminum can make it difficult or impossible to do multiple joins close to each other.

For small spot/hole repairs or for "spot welds" in thin aluminum it is great--but for long cracks, long welds or lots of stress, it is not a substitute for true welding.

Australia,my research on another NG suggests Lumiweld. The sticks I have are thin with two smooth sides at right angles and the third side lumpier as if they had been poured into a bit of bent sheet

There likely isn't any real savings to be attained by making your own, even if you had a perfect formula. These rods are a commercial product, available at many hardware retailers and welding suppliers here in the US. Patching old roof flashing, for example, isn't really a good way to repair a leaking roof IMO, but I suppose some would feel a great sense of accomplishment from doing something like that.

The real value is in being able to repair non-ferrous parts instead of buying new parts if/when they're still available. Obviously there isn't much value in repairing mum's pie pans with these rods, but real savings can be realized by repairing machine parts or various fittings which would require parts searches and ordering, or custom assemblies which aren't commonly available.

I've saved many hundreds of dollars worth of aluminum parts with these types of rods, having started using them about 30 years ago.

I've also been able to fabricate a lot of items with stock aluminum shapes which would have needed to have been riveted or screwed together with fasteners. Very handy stuff for fabricating outdoor or boat hardware items.

Some holes can be patched with plastic/epoxy products, but the fix is often inferior to actually making a metal repair.

I've found MAPP gas and a MAPP torch (not an ordinary propane torch) to be much more effective for using these types of rods, since aluminum can dissipate heat fairly rapidly. Actual use requires proper shaping and cleaning of the joint, heating to the correct range, and using a stirring/scratching motion of the rod to keep the oxides afloat and maintaining the proper heat range while adding more rod to fill any voids.. scratching the rod into the workpiece material to attain an alloying of the rod with the workpiece.

I dunno what Doug's seen, but I've never seen the rods with flux core.

I can't help with the composition but do have some lead free low temperature solder for use with pewter that is cast in a similar manner as the alloy isn't ductile enough to be drawn as wire. In my case the solder is D shaped and smooth on one side and slightly rough on the other so I presume it was cast onto a chilling plate with the alloy flowing out of holes in a moving crucible of some sort in a similar manner to the casting of organ tube sheet, see

Repaired the old Springbok Aluminum canoe several times with the alloy rods, and made both canoe carrier for van rooftop and bike carrier for trailer hitch using the stuff - no problems. Also used to repair motorcycle engine side covers etc, and even repaired crankcase of lawn mower engine where con-rod came out through.

I do also have aluminum solder, in wire form, which IS flux cored. I wouldn't use it on anything large, but it is available - and it apparently works. I have about 5 lbs of it - have not used it yet but it was used by NCR (National Cash Register) in production at their Waterloo Ontario plant = where I bought it at a surplus sale a number of years back.

Yep, the stuff is handy, regardless of the cost. A TIG welder would enable one to do equivalent, and likely better or more complex repairs.. but comparing the cost (and maintenance) of a TIG welder (30 years ago when I started using the rods, or today) can't come close to the cost of the rods and some MAPP gas.

As far as I've seen, the rods don't need any special storage protection, and old stuff works as well as new stuff, I generally just keep it in the plastic tube it's sold in until needed. Different brands seem to work just as well as others, IME.

Back when I was boating, I discovered numerous businesses built around prop repair, and apparently they were making money because they'd been in business for years (lots of river boating around here).

Many things just aren't worth the effort of repairing (cheap lawn chairs, for example), but real value can be realized when recovering a damaged expensive part.

My reference to "flux core" was one brand I saw once that looked like a "u" shape of solder that had been pressed closed. I assumed something had been put into the center, but maybe not.

I think I've got Fourney around. It isn't like that, it's just a lumpy stick.

I think Muggyweld sells some really-low-temp stuff, like 300 or 400F? It could have some special uses I guess. I dunno how much it costs, but it might be worth paying for if you needed it.... The typical stuff melts up at 1050F or so IIRC.

DougC wrote: .... The typical stuff melts

I'd say it's closer to 800F, the melting point of zinc.

Bob