# Joining two pieces of aluminium



## The Bear (25 Nov 2013)

Hello all

First up, I know nothing about working with metal, so hopefully you can help

I want to join 2 small pieces of aluminium plate at 90 degrees to each other. Each bit is about 40mm square and about 5 or 6 mm thick. (I've yet to aquire the pieces). Any suggestions as to how? There needs to be a degree of mechanical strength but no severe loading. It is to make a couple of small brackets to lock (and unlock) a very large jig together. 

Can I screw it?
Glue of some sort?
I can't weld (do you even weld aluminium)?

Best way?

Cheers, Mark


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## Graham Orm (25 Nov 2013)

Yes you can. Find a local fabricator and they will weld it for you in 2 minutes.


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## andys wood shed (25 Nov 2013)

Yes you can screw it
Yes you can glue it
Yes you can weld it

Your best bet would be to bend it


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## Jaypee (25 Nov 2013)

As Grayorm suggests, a local fabricator or a company that fabricates in aluminium....they may have some aluminium 40 x 40 angle offcuts in their scrap bin. Good luck.


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## marcros (25 Nov 2013)

ebay- buy a short piece of angle. they will probably cut it for you.


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## The Bear (25 Nov 2013)

Having scoured ebay for aluminium bar and plate I never even thought to look for angle. Quick look now and there are possibly pieces I could use so thanks for that
I still may need to make a joint as well, I'll be back if I need further advice on that later. Thanks to all for now

Mark


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## Lons (25 Nov 2013)

I didn't want to use bolts so I bonded some aluminium angle to a steel gate a number of years ago and it never moved even when the gate slammed. I used sikaflex adhesive thogh I can't remember which grade. If you do buy a tube, it has a short shelf life once opened so it's sometimes best to line up a few jobs  

Bob


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## CHJ (25 Nov 2013)

6mm Alloy plate can be screwed together at right angles relatively easily with 3mm screws, will need mating edge to be finished square for max rigidity.
Take care taping threads and use paraffin or similar for lubricant.

Used to be our standard method of making small bespoke gearboxes for crystal saws and the like. (only we were in the era of 1/4" stock and 6BA etc.)


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## bellringer (26 Nov 2013)

Why not just get a some one to bend it to 90 degrees


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## hazel (26 Nov 2013)

I was also going to suggest getting some angle or finding a way to bend it


also it is possible to weld aluminium  most of the jobs I have had in the past have been welding aluminium


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## mseries (26 Nov 2013)

I must say I did not read into the OPs message that he needs to join his two pieces at the edge of both of them so neither bending nor pre-formed angle would be suitable. No, I pictured an inverted T shape.


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## hazel (26 Nov 2013)

that's not the way I read it, but you may be right... in which case some t-section may do the job?


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## cammy9r (30 Nov 2013)

Perhaps a bit late, however aluminium can be 'welded' at home with a propane or butane torch and some lumiweld rods. I have used them in the past and they work very well. It is really more like soldering the parts together but is actually very strong. There are other brands but I have only used lumiweld. But if you only need a 'L' profile then angle is the way to go as others have said.


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## dickm (30 Nov 2013)

Obviously, commercial extrusions (L, T or whatever) are the way to go here, but interested in the comments about welding aluminium. Have tried it on a couple of occasions, and each time the weld looked OK, but just fell apart after a few weeks. My one-time boss was a senior member of the Welding Institute and told a tale of how they reckoned they had sussed ali welding, and put some of their successful examples on one side for reference. Got them out to show some passing bigwigs a few months later, and they did the same as mine, just fell apart. Mind you, this is going back 40 odd years .

SO, what's the secret for ali welding by incompetents like me?


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## Spindle (30 Nov 2013)

TIG :wink: 

That's how we do it in aviation  

I used to know a guy who could do it with oxy-acetylene - he was really good

Mick


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## hazel (30 Nov 2013)

dickm":2zmet3bf said:


> Obviously, commercial extrusions (L, T or whatever) are the way to go here, but interested in the comments about welding aluminium. Have tried it on a couple of occasions, and each time the weld looked OK, but just fell apart after a few weeks. My one-time boss was a senior member of the Welding Institute and told a tale of how they reckoned they had sussed ali welding, and put some of their successful examples on one side for reference. Got them out to show some passing bigwigs a few months later, and they did the same as mine, just fell apart. Mind you, this is going back 40 odd years .
> 
> SO, what's the secret for ali welding by incompetents like me?




what type of welding have you tried? With aluminium TIG is the best really. I've done a bit of MIG with ali too, but that is a bit too much heat as a rule so you have to use another peice of metal behind it to absorb some of the heat. I've done gas welding on ali once, that was not fun...

I used to have a job welding comercial kitchen equpiment so got fairly good at ali welding lol. Not sure what can tell you though really :/ I hope that they held longer than a few weeks/months though... otherwise there will be a lot of out of use kitchens now


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## marcros (30 Nov 2013)

I was chatting to a fellow forum member davem62 about "welding" aluminium. Whilst not actually welding, he mentioned a product demonstrated at the Harrogate show which I have been looking at online. The web link is here- not sure of availability. 

http://www.rsi-hinderer.de/en/aluagent- ... draht.html


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## dickm (1 Dec 2013)

Strictly, my activities weren't welding, but using a propane torch with those commercially available flux coated rods supposed to work with ali. Trying to repair the front edge of the rotary mower deck, which had come into contact with a brick corner once too often.  . Ended up with reinforcing sheet and rivets, which was not pretty, but safe (-ish)

Haven't got the facilities for Tig; presumably the really neat welds you see on some grain lorry bodies are done with Tig?


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## ss03947 (1 Dec 2013)

Mark, wouldn't 40mm angle not be better than trying to join/weld a piece.?

SS.


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## MMUK (1 Dec 2013)

bellringer":34ra52wk said:


> Why not just get a some one to bend it to 90 degrees




Have you ever tried bending aluminium? One sure way to weaken and fracture it.


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## mind_the_goat (2 Dec 2013)

marcros":31okkef3 said:


> I was chatting to a fellow forum member davem62 about "welding" aluminium. Whilst not actually welding, he mentioned a product demonstrated at the Harrogate show which I have been looking at online. The web link is here- not sure of availability.
> 
> http://www.rsi-hinderer.de/en/aluagent- ... draht.html




I don't think i'd expect much from this sort of joint. Might work with lots of surface preparation and a flux cored aluminium solder, but 'scratching' the surface through the molten solder to pierce the oxide layer? Hit and miss to say the least. Be better off trying an epoxy resin compound to bond the pieces together.


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## SteveF (2 Dec 2013)

why aluminium and not steel ?


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