Welding two different metals together.

[T9 man]

Ok, so I have just bought a new front strut brace made out of a high grade aluminium. It was specially made to be as straight as possible to avoid the Saab bits and pieces. I have an idea about creating an aluminium box section out of a similar flattened tubular aluminium section, then having a stainless steel mesh welded inside the boxed area which will then sport some stainless steel lattice pattern work on top of the mesh

OG, I still intend for you to make me a special one, this is just a T9 "what if" project :bigsmile:

My question is this, can aluminium and two different grades of stainless steel be welded together successfully without distorting the materials? Hope this all makes sense! :blink:

This is the new front strut fitted yesterday:

 

[HDi fun]

I doubt it very much. The melting temperatures will be wildly different. Ask a good expert but my physics is strong enough I think to say that it can't be done.

[If you could make a plate or flange and then bolt the parts together you'd get away with it perhaps?] Ignore this - HDi has re-read the original post and is talking rubbish

You'll also have a potential rust trap by virtue of having dissimilar metals in contact. Electrolytic action could cause serious corrosion. Not good.

 

[T9 man]

Darn, back to the drawing board :sad2: Thanks buddy!

 

[old-git]

Don't weld them together, glue them!

 

[old-git]

I have an idea about creating an aluminium box section out of a similar flattened tubular aluminium section, then having a stainless steel mesh welded inside the boxed area which will then sport some stainless steel lattice pattern work on top of the mesh. Hope this all makes sense! :blink:

Err, not to me Totally confused as to what you are trying to do!

 

[T9 man]

confused myself there as well OG will sort out a sketch to show you!
Glue it you say! :blink:

 

[old-git]

OK, look forward to seeing it

Well, a lot of high spec sports cars are now glued together as this eliminates the distortion caused by welding. Talk to Nick about glues. He gave me some glue a while ago that was used to stick helicopter blades on with! Nick is now using an even better glue.

 

[HDi fun]

That sounds like a sound plan. Modern adhesives are amazing things.

 

[StevieDB9]

you need to be careful when joining dissimilar metals, any moisture will induce corrosion in the more basic metal. I'm guessing this would be particularly the case with aluminium and SS as they're is quite a separation in the galvanic series. Obviously this can be done as loads of cars have aluminium and SS parts but I have no idea what grade of SS is suitable or what protective plating or isolation is involved!

 

[stamford]

you need to be careful when joining dissimilar metals, any moisture will induce corrosion in the more basic metal. I'm guessing this would be particularly the case with aluminium and SS as they're is quite a separation in the galvanic series. Obviously this can be done as loads of cars have aluminium and SS parts but I have no idea what grade of SS is suitable or what protective plating or isolation is involved!

That would be true if living in an area with a high salt content, ie by the seaside. Aluminium and stainless will corrode as they hate each other, been there before in the marine business as I used to design rudder stocks, steering systems and rudder bearings for racing yachts. If the spec aluminium is a structural one then it is probably 2014A, which is not suitable for welding, 6082-T6 is more ideal. There are many grades of stainless steel and not all are rustproof! The grade for open enviroments is 316. Anyhow you can't weld the two you mentioned T9 and as said bond them or use the same material but heat is the issue especially when welding ally, I've made inlet manifolds and it is an art. TIG of stainless is better and neater.

 

[T9 man]

Many thanks for all the help guys, it looks like glue will be the key here on this project. OG - I will ask Nick at Carbon Weezel about his choice of glue that you mentioned earlier.

 

[kain35m]

Just do what I do:

begin welding
melt through
curse
get new part
begin welding
can't melt metal
turn up the heat
melt through
throw part across room
hole in the wall
curse
new part
turn heat down
slowly attempt to weld
metals won't stick
bubbles appear
warping
....curse.....concentrate....slow down
too slow...melt hole
scream
run around house flailing arms and holding part
burn self
drop part
burn hole in carpet
give up