Bonding brass shim to aluminium

[Jayville]

Hi all.   Has any one tried bonding brass shim to aluminium...l like building small oscillators and aluminium against aluminium is a no go...where I live brass is hard to get and if I want it sent to me the cost is quite high...I have tried bonding 1mm brass shim to 10mm aluminium flat bar but it peels away with a bit of effort...I have roughed up both each material and have tried the 2 pack adhesive that is used to stick cars together these days but to no avail..perhaps I am going down the wrong track but I like experimenting..all advice would be appreciated     Clem

[derekwarner]

Clem.....just about any thermal bonding [of metals] by fusion can be achieved by controlled processes in controlled atmospheres 

common yellow brass with a MP of ~~930C to aluminium with the MP of~~460 C
common yellow gold with a MP of ~~1060C to the same aluminium with the MP of~~460 C

These are not gluing processes, but thermally fused over the entire surface areas of each of the two metals, so the physical bond between the dissimilar metals can only attain the mechanical strength of the less noble metal ...which in the case here is the aluminium

The down side here is that you nor I can achieve such processes in our garage workshop...so the cost of purchasing brass metal stock could be considered less costly than home made apothogree  type experiments ..... Derek

 

[Jayville]

Derek...thanks for the reply.i have worked in stainless steel industry all my life, and even when I was an apprentice.. Which is a long time ago we used to use cad plate which a sheet of  2 mm 316 ss bonded to a 10mm sheet of black mild steel ..it was easy to cut ..we would cut the ms side with oxy and the ss would cut like butter ..this is were I thought about bonding brass to ally..back to drawing board.i am getting boat over to Melbourne in new year so I will have to stock up with brass...it is lovely stuff to work with...cheers clem

[Noitoen]

If you make little grooves/deep markings on both metals and use high temperature epoxy it will stick together. You have to cure the epoxy under a little pressure and with heat, usually a little higher than the working temperature.

[Ian S C]

It is possible to use soft solder on aluminium.  Scrape the surface to be soldered to get rid of the oxide film, and immediately cover with clean oil(this keeps the air away from the metal), using a big soldering iron, the one I use is about 30 mm sq x 90 mm long copper part, or the 175 Watt electric iron, put that on the aluminium through the oil and heat the metal, rub the iron firmly across the surface and add the solder.  Wipe the excess oil off, place the tinned brass on the solder surface of the aluminium and heat with the iron until the two parts are sweated together, hold the parts together until cool, that's it.
Learned to do that soldering earth straps to aluminium radio chassis.
Ian S C

[gbritnell]

I don't know where you're located but you might look into having either the cylinder or the standard anodized. This will give a hard surface to the part.
gbritnell

[Jayville]

Thanks all for your help..I think I will take gbritnells advice and try anodising ....cheers clem