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Digger6135
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If you use Lumiweld rods they can be joined.
Digger6135
Digger6135
As you say can't weld ally or it's alloys to magnesium or mag alloys without the result being a brittle mess
While those zinc based self fluxing solders may physically work it's not recommended for similar reasons... brittle intermetallics making the joint next to useless and/or severe galvanic corrosion issues. FWIW durafix (different brand name for the same ZnAlCu solder as lumiweld, SIF555 and a bunch of others) categorically state "do not use on magnesium"
While those zinc based self fluxing solders may physically work it's not recommended for similar reasons... brittle intermetallics making the joint next to useless and/or severe galvanic corrosion issues. FWIW durafix (different brand name for the same ZnAlCu solder as lumiweld, SIF555 and a bunch of others) categorically state "do not use on magnesium"
langy
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Not successfully
Mmm Ok... Just as I thought then really.. Just have to think of another way of doing it then.. I should be able to bolt a plate through it somehow instead...
Thanks eveyone...
Screwdriver
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I hope it is. I'm going to TIG some 4043 to a so called "magnesium" engine cover. My understanding is that a typical "magnesium" casting is going to be something like 3-5% magnesium and welding will dilute the alloy at the interface.
In my case, there's a small cover which blanks off the crankcase breather and it has been down the road, scraped, cracked through and punctured. The weld is hopefully going to seal it without it needing to be a structurally or mechanically sound. So long as it doesn't fall off...
If it doesn't work, I'll grind it off and bung it up with JB Weld.
S.
In my case, there's a small cover which blanks off the crankcase breather and it has been down the road, scraped, cracked through and punctured. The weld is hopefully going to seal it without it needing to be a structurally or mechanically sound. So long as it doesn't fall off...
If it doesn't work, I'll grind it off and bung it up with JB Weld.
S.
Mag valve covers are relatively common... Mercedes, BMW and some Mitsubishis are three off the top of my head and the list of mundane stuff with mag valve covers and other castings is waaaaay longer. Same deal with many motorbike engine & clutch covers, most manufacturers have used mag at some point
A drop of vinegar will tell you if the cover is magnesium or not, the acetic acid in it will react with mag and fizz/bubble away as the reaction produces hydrogen. If it's ally, even a AlMg alloy, the vinegar will just sit there doing nothing
If the cover is mag then 4043 or any other aluminium filler WILL result in a brittle mess that'll probably crack all by itself and give you a bigger problem to fix
A drop of vinegar will tell you if the cover is magnesium or not, the acetic acid in it will react with mag and fizz/bubble away as the reaction produces hydrogen. If it's ally, even a AlMg alloy, the vinegar will just sit there doing nothing
If the cover is mag then 4043 or any other aluminium filler WILL result in a brittle mess that'll probably crack all by itself and give you a bigger problem to fix
Screwdriver
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Yes my bad. If it is magnesium then it's 6% aluminium etc. From here: http://www.archivesmse.org/vol28_6/2865.pdf
I will test it and the chances are the best bet will be JB Weld after all. Sadly I can't risk a test on this irreplaceable cover!
I will test it and the chances are the best bet will be JB Weld after all. Sadly I can't risk a test on this irreplaceable cover!
Screwdriver
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I can tell you a little story though. Many years ago (!) I was working for the Ministry of Defence, during the Falklands. The biggest problem in those days was the Exocet missile which would skim the surface of the sea at Mach 1 giving you only seconds to detect it and shoot it down. It would penetrate six inches of steel armour plating at anything up to sixty degrees before it would even think about exploding. As often as not, the device would make a bee line for the central control where all the electronic noise was coming from.
We digress. Back in the day, we were building destroyers with an impressive amount of so called top-weight. Towering super structures built way above the height of the hull for no other reason than that it made the ships look impressively evil!
Unfortunately, the only way to have such an impressive, top heavy look is to use a lot of lightweight magnesium alloy and it is true: it will burn. Later designs reduce the bulk of the superstructure...
S.
We digress. Back in the day, we were building destroyers with an impressive amount of so called top-weight. Towering super structures built way above the height of the hull for no other reason than that it made the ships look impressively evil!
Unfortunately, the only way to have such an impressive, top heavy look is to use a lot of lightweight magnesium alloy and it is true: it will burn. Later designs reduce the bulk of the superstructure...
S.
langy
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Why not tig it with magnesium rods ? It welds just like aluminium but you need to not overheat it.
^^ That's what i'd do. Mag filler wire is 'kin spendy but is available in small packs of 12 which is a bit more palatable ££ wise. I would offer to sell you a stick or two but this
recently turned up and the last thing i want to do is sell some wire and then run out part way through a job
recently turned up and the last thing i want to do is sell some wire and then run out part way through a job
Screwdriver
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No rush. Let me know if you have any left over when you're done.
Cheers
Cheers
I can tell you a little story though. Many years ago (!) I was working for the Ministry of Defence, during the Falklands. The biggest problem in those days was the Exocet missile which would skim the surface of the sea at Mach 1 giving you only seconds to detect it and shoot it down. It would penetrate six inches of steel armour plating at anything up to sixty degrees before it would even think about exploding. As often as not, the device would make a bee line for the central control where all the electronic noise was coming from.
We digress. Back in the day, we were building destroyers with an impressive amount of so called top-weight. Towering super structures built way above the height of the hull for no other reason than that it made the ships look impressively evil!
Unfortunately, the only way to have such an impressive, top heavy look is to use a lot of lightweight magnesium alloy and it is true: it will burn. Later designs reduce the bulk of the superstructure...
S.
Were they Magnesium Alloy or Aluminium Alloy...
Its possible to bond Aluminium to Steel and produce a bimetal plate so the top can be welded to Ally and the bottom to the steel.
penfold
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What's with the picture of a Town class cruiser? The warcanoes with the aluminium superstructure were the type 21s, although aluminium cladding and lining was blamed for higher casualties on type 42s and LSLs as well.I can tell you a little story though. Many years ago (!) I was working for the Ministry of Defence, during the Falklands. The biggest problem in those days was the Exocet missile which would skim the surface of the sea at Mach 1 giving you only seconds to detect it and shoot it down. It would penetrate six inches of steel armour plating at anything up to sixty degrees before it would even think about exploding. As often as not, the device would make a bee line for the central control where all the electronic noise was coming from.
We digress. Back in the day, we were building destroyers with an impressive amount of so called top-weight. Towering super structures built way above the height of the hull for no other reason than that it made the ships look impressively evil!
Unfortunately, the only way to have such an impressive, top heavy look is to use a lot of lightweight magnesium alloy and it is true: it will burn. Later designs reduce the bulk of the superstructure...
S.
Screwdriver
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Sorry, googled a picture of the Sheffield and didn't really look at it!
Fixed!
Fixed!
HMS Sheffield definitely was Aluminium superstructure. Obviously very famous around these parts (Sheffield). The previous one had loads of stainless and was nicknamed the Shiny Sheff
The exocet set fir to the Aluminium which will burn in the right conditions (windy)
The exocet set fir to the Aluminium which will burn in the right conditions (windy)
daleyd
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Sheffield was not made of aluminium, none of the type 42s were, the only sizeable British ships to be made with aluminium in any large quantities were the type 21s.
Yes youre right..............from wikipedia
The sinking of Sheffield is sometimes blamed on a superstructure made wholly or partially from aluminium, the melting point and ignition temperature of which are significantly lower than those of steel. However, this is incorrect as Sheffield's superstructure was made entirely of steel.[15] The confusion is related to the US and British Navies abandoning aluminium after several fires in the 1970s involving ships that had aluminium superstructures. The sinking of the Type 21 frigatesAntelope and Ardent, both of which had aluminium superstructures, probably also had an effect on this belief though these cases are again incorrect and the presence of aluminium had nothing to do with their loss
Its always been said around here that it was the Aluminium that caused the fire. Im surprised.
The sinking of Sheffield is sometimes blamed on a superstructure made wholly or partially from aluminium, the melting point and ignition temperature of which are significantly lower than those of steel. However, this is incorrect as Sheffield's superstructure was made entirely of steel.[15] The confusion is related to the US and British Navies abandoning aluminium after several fires in the 1970s involving ships that had aluminium superstructures. The sinking of the Type 21 frigatesAntelope and Ardent, both of which had aluminium superstructures, probably also had an effect on this belief though these cases are again incorrect and the presence of aluminium had nothing to do with their loss
Its always been said around here that it was the Aluminium that caused the fire. Im surprised.
daleyd
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Yeah it was a very common misconception for some reason - I think it was actually published in the press and so it kind of stuck. The type 21s were as far as I know the only British ones - there was an instance of a (peacetime) fire on one of those when they were new and firefighting was hampered because of ladders and suchlike buckling.
