Soldering Aluminium To Copper

[NeoMorph]

Hi guys,

One of the things I'm working on is building switch guards that seem to be unique to the ATR that I'm building. As I'm building them from scratch it's been a learning process and I've made several very rough versions to see if they work and iron out the kinks.

Here is what the original piece looks like (one of my contacts sent me a real one for free).

[smg id=224][smg id=225]

Now I couldn't get my hands on the metal they used for the frame (really thin and tough steel I think) so I made it out of aluminium and used stiff copper wire to make the cage. Once shaped and attacthed to the base the whole thing is pretty strong. The only problem is soldering the copper wire to the aluminium base. I made a small countersink crater under the frame where the wire comes through and the test version came out OK (a bit rough for a prototype but it did work) but on my production pieces the solder is refusing to stick to the aluminium.

Anyone come across this before in their building? Does anyone have a good idea of getting the solder to stick to the aluminium?

[Garys]

Seen it done by a plumber before but requires alot of heat. The term you want to use for this is Brazing. Not sure of the correct flux to use but Im sure if you do a google search you will be able to find the best flux for the job.

Gary

[jonesthesoftware]

Hi you need Aluminium solder. Another alternative is a product called "Baker's fluid" which you apply  to both surfaces and then use normal solder. BUT  BEWARE bakers' fluid is very dangerous use all precautions as with ACID!. I believe It is a saturated solution of zinc in sulphuric acid. Search for it on the net. Using this you can even solder sheet steel!!!
! Other altermnative is a product called Alumi-weld which needs both surfaces wire brush clean then a propane torch to weld with
hope this helps

[jonesthesoftware]

Hi
just found another product here
http://www.breckocorp.com/gbsazm.htm
regard
geof

[NeoMorph]

Thanks for the information... I never even thought of the problems I have been facing because I've seen it done in the past but that was over 10 years ago. I've been recommended to use this by one of my neighbours who does engineering repairs... It was only after I posted here that I remembered what he does for a living.

http://durafix.co.uk/pages.php?&pID=7

It's expensive but I won't need that much plus it could come in useful for other parts too. Plus it's easy to use. Just need a gas torch (which is what I was using anyway).

[Aerosim Solutions]

Hi, I just thought I would mention if you solder two disimilar metals such as aluminium and copper you will be creating a basic 'battery'! it won't take long for the metals to corrode and eat each other!

Cheers Gwyn

[phil744]

Hi, I just thought I would mention if you solder two disimilar metals such as aluminium and copper you will be creating a basic 'battery'! it won't take long for the metals to corrode and eat each other!

Cheers Gwyn

Gwyn basically took the words out of my mouth, why not just make life easy and make them from brass or just the same material?

[NeoMorph]

Hi, I just thought I would mention if you solder two disimilar metals such as aluminium and copper you will be creating a basic 'battery'! it won't take long for the metals to corrode and eat each other!

Cheers Gwyn

Gwyn basically took the words out of my mouth, why not just make life easy and make them from brass or just the same material?

This was one of the reasons I was asking in the first place. Basically I made the prototype out of what I had to hand. I'll admit that I'm no engineer and the last time I touched physics was at grammar school back in the 70's.

[Garys]

Just to go off subject here for a second but this post brings up another topic that you bought up a little while ago

HOW TO STAY FOCUSED 

Its the small little finishing details like these that can take away from the main building process. Stop it!

[NeoMorph]

I've got to get these replicas made so that Ruscool can redo the layouts so that I can actually use the darn things. I used epoxy on some to see if it works and it did... but that was before I posted here.

Ironically I've made a few of them now out of various materials and if it hadn't been for Gwyn warning me of the potential effect of dissimilar metals (I honestly thought that you needed acid to trigger that tbh) and Phil's idea of making them from brass I would probably be wondering why my replica guards were falling apart some time in the future.

I've actually been doing other things as well for the sim... like doing replica landing light switches that are turning out OK. Then there is the framework for the switch modules I'm using which I've made from scratch. Then there are... well, there are a lot of little things that HAVE worked and I haven't bothered you with. I really should post some pictures just to show how I'm getting on heh.

Guys, I don't mind getting told I'm doing it wrong... you only learn from your mistakes after all (and god, I've made a few here).

Oh and Gary, I've been focusing on this damned guard so much I have the real on sat on my bedside table and I look at it every night and think "HOW THE HELL DO I COPY IT RIGHT!" lol.

[Garys]

Dont worry, Im only joking with you mate.

[phil744]

I've been focusing on this damned guard so much I have the real on sat on my bedside table and I look at it every night and think "HOW THE HELL DO I COPY IT RIGHT!" lol.

Dont worry i have been doing that with the switch that fits that guard now for 2+ years now.

Currently reading HOW TO STAY FOCUSED  thread now because i have gone off on an planetary tangent now

[NeoMorph]

I've been focusing on this damned guard so much I have the real on sat on my bedside table and I look at it every night and think "HOW THE HELL DO I COPY IT RIGHT!" lol.

Dont worry i have been doing that with the switch that fits that guard now for 2+ years now.

Currently reading HOW TO STAY FOCUSED  thread now because i have gone off on an planetary tangent now

So it's not just me then. As they say, "The Devil's in the detail"... or in this case "This detail is a Devil".