Soldering/welding alumin(i)um ?

[John Candy]

I wonder whether anyone here has tried this?

It claims to weld aluminium at low temperatures with a normal butane/propane torch, flowing into the joint like solder.

The rods are widely available (search "Saker Solution welding rods") and here is just an example supplier and it includes a couple of short video clips.

https://www.warmday.co.uk/collections/tools/products/solution-welding-flux-cored-rods?variant=31117399064681

For many years I have had a coil of Carrs aluminium solder but it requires Carrs "grey" flux which is now unobtainable. I understood that joints made with it would oxidize/degrade very quickly unless a protective coating was immediately applied. There are other fluxes available but I have never bothered.

I wonder if this method is any more resistant to degradation?

If it works, I think it may be  useful for welding up lightweight carriage underframes, etc. from ali angle.

John.

[IanT]

Some years ago (probably quite a few now - they do slip past) a friend and I watched a demo (at an ME show) of aluminium soldering. The Demonstrator made it look remarkably easy and as my friend's son had a (cast) part that needed repairing, he brought a kit. He practiced on some scrap ali first but wasn't happy with the results, so ended up using an epoxy resin for the repair.

It could be that 'newer' solders (and fluxes) have made this easier but I suspect that (as with welding) it probably also needs a high degree of skill & knowledge too - perhaps coupled to having the right grade of aluminium alloy to solder.

As an aside I was reading a very long series of posts (on Model Engine Maker) yesterday - following the construction of a very impressive model stationary engine. There was much discussion about the builders use of JB Weld to fabricate large steel assemblies, as well as assembling the (pressure holding) pipework. The builder was very confident that JBW was perfectly safe in most circumstances but built some test parts to demonstrate this. He tested them for water tightness at 300psi and the joints all held. I was impressed but also a little surprised. I'm certainly not suggesting changing from silver soldering (for our applications) but clearly modern two-part expoxies are very capable. I think I would probably explore their use with aluminium frames before trying the soldering route.

However, the only real way to find out - is to suck it and see John   :-)

Heads Down and Stay Safe everyone

Regards,

IanT

[John Candy]

Regarding JB Weld, I have been using that for at least 25 years and it is really strong.
Biggest job I have used it on was a cast iron Victorian lamp standard which stood in our hotel car park in the Lake District. Our builder managed to decapitate the heavy lantern and fractured the collar which attached it to the post. I repaired that with JB Weld and it was still standing when we sold the hotel, ten years later.
More recently, a car developed a leak in the radiator core and was booked to go in for replacement on 30th March .... the day the garage closed for several months lockdown! I drained and dried the area involved and forced a large blob of JB Weld into the affected area. Since then the car has covered a few hundred miles without any loss of coolant. Saved nearly 300GBP!
A pack of the aluminium weld rods costs around 10GBP, so I will probably give it a trial run on some ali angle, etc.
Regards,
John.

[John Branch]

I note that the JBW website lists a large range of products.  Are the ones we are talking about here the 2-part  epoxies, either in syringe or tube, or the putty?

Not having seen the range before, they do look as if they could find many uses in the workshop.  A good reliable glue is not to be sniffed at, I am told.

John

[AshleyW]

i often watch keith appleton on you tube, he works at steam workshop, so of his working at the steam workshop videos use and mention JB weld, so as they are a trusted seller and have a high turnover of products, i suppose Keith would not mention the product unless he was a strong believer in it.

[dajo]

This is simply a repeat story, I suppose; but it may be of interest.  I had to decide between glue and welding for the railway in the image.  Welding meant buying a welder and learning how to use it; I chose JBWeld two part epoxy with some trepidation.  Joints in the railway modules are mainly aluminium to wood, some  metal to metal.  Joints in the module supports, the pieces that with tubes on the sides, separate items that stack, are totally aluminium to aluminium.  The carts are all nuts and bolts, no glue.  JBWeld has exceeded my expectations.  I have had a couple of joint breakages caused by human "helpers" being rough enough to bend the metal as well.  Here is a record of one breakage and repair that boosted my opinion of the glue, although the joints are mainly aluminium to wood: http://ngdr.net/Manifold/PortableRailway/TechnicalDetails/DamageAndRepair/Top.html
dajo

[John Candy]

I note that the JBW website lists a large range of products.  Are the ones we are talking about here the 2-part  epoxies, either in syringe or tube, or the putty?

John,
This is the type I have used for at least 25 years.
It is super-strong and has a shelf-life of 25 years.
The photo is of my second tube which is now about 16 years old and was last used just a few weeks ago.
Regards,
John.

[IanT]

I note that the JBW website lists a large range of products.  Are the ones we are talking about here the 2-part  epoxies, either in syringe or tube, or the putty?

John

There are now different versions of JBW John (fast setting, high temperature etc)- but the kind I was referring to is the original (slow set) two part epoxy. I've seen a number of folk comment on Forums and in articles that (as a general rule) the fast setting versions of epoxies (including JBW and Araldite) are not quite as strong as the slower setting versions which normally take at least 24 hours to cure.

This can be a real nuisance sometimes as things can wander. I've repaired a fan motor this evening by making a new brass bush (with grub-screw) to replace the original broken plastic hub. I've joined them with Araldite but had to use a drill stub-end to keep the parts aligned until sufficiently set - then try to pull it out after a couple of hours before the drill got glued in too. Hopefully it's still aligned but I'll give it a day or so before fitting it back. It's from my fan-heater, which started making a real racket - but it's too cold in the workshop without it.

Regards,

IanT

[John Branch]

Thanks for all the responses.  It seems to me that the choice between fast and slow setting depends mainly on the application, but that the product itself does "What it says on the Tin".

I'll give it a go when I next want to join things that I do not want to separate, ever.

John

[753]

John
What is not working when using good old-fashioned solder, a joint well made with good penetration will be strong enough for our needs, after all a model wagon in a train is hardly under great stress!
If it ain’t broke don’t fix it.

Mike