welding lower unit
 

hey
i have a lower unit from a 225 yamaha that has a crack in the housing in the exhaust tunnel,can this be welded if yes what kind off welding rods should i use ? material type?

I would tig weld if I was going to do it, you can control your heat better and it will look much nicer

Be careful gear lube could catch fire

I would not use the aluminum arc rod on that. It burns very hot and is kinda uncontrollable when welding something thin like that. Better off with a tig in this case...

I am a skilled trades tool & die welder for GM. If you need to ask what type of rod to use...you should not be attempting this. Take my advice sir, you can and probably will, do alot more damage to the unit. This will then double the cost to have it done correctly. Please have a knowledgeable welder look at it for you. Over the years, I have had many items brought to me that someone "attempted" to repair. In almost every case, they made the object wayyyyy worse than it was to begin with. Be smart...and know your limitations. :drink:

Even with a tig, you're going to put a lot of heat into this and the whole casting will twist. Maybe not perceptable, but enough to throw off machining tolerances. I'd seek out a new/used lower unit

thanks for the reply´s
i have a friend who is a tig welder who will do the job,but since i am not native english speaker i don´t know the tech name of the alu alloy ? that he should weld it with ?
do you have some kind of specs?
thanks again

Almost looks like its been "fixed" before. Alot of pinholes in the paint....

I do and have done alot of aluminum welding in my time. You must take out the internals first, bead blast not sand blast all the paint off a least 6 inches around the crack, it will be alot bigger then its showing also, then the outdrives are a poured casting and they are full of pits and holes, very pour castings all the time hard to weld and look good. pre heat is a key to stop warping also. It can be done but only tig!!! dan my 2 pennys

This is easier, has a warranty, and more reliable than welding that..........

http://www.sterndrive.cc/mm5/merchan...amahaLowerUnit

thanks little d
that was what i was looking fore..

rchevelle i just want to give it a try before spending the 800us plus shipment to europe

Little d are you still around ?
we welded a skeg on the rh motor with succes but this one causes us some headace every time we finnish the weld it cracks down the middle or just on the side of it......
we have tried with drilling holes making V shapes, welding backwards ect...
I guess we don´t have the pre-heat and cool off correct ?
how would you pre heat and at what temp..

all idea´s welcome
we weld with helium/argon mix and tried with pure alu and mixed "rods"

thx

just got back to the comp, been really busy. i know the last couple i did they also cracked in the middle. i think the cold or contamnents blow threw when cooling, argon mixed is good, i use my tourches to heat. grind the middle back out the perheat and do it again. i grind mine back out with carbit tip hand dremils not sanding wheels the check and see if it has welded through then cross weld it again. hope it goes well dan