What kind of metal?

[nathan13]

I have a 1957 Mercury Mark 55E outboard motor and the lower unit the prop section has a crack in the fin area. I was wanting to possibly get a weld job done to it, but I don't know what it's made of , cast iron or aluminum. Any takers?

 

[racerone]

????????------------------Aluminum

 

[Chinewalker]

The lower unit housing is cast aluminum. All of the inside bits - shafts, gears, bearings, are steel.

 

[Scott Danforth]

its an aluminum alloy. which alloy is anyones guess.

 

[gm280]

In answering your initial question, you can have the cracked area welded IF you take it apart. I had a new anti cavitation fin section welded onto an OB and after dressing it up and painting, I can't even tell where the welded part was welded on now. So your answer is "YES" you can have it welded. But the welder needs everything removed from the cracked area so that the heat won't melt or distort things... Lots of folks have that done!

 

[quicktach]

Make sure it's spotless clean and degreased before taking it to the welder.

 

[nathan13]

Thank you all for the help.