Welding cast aluminum

[skipmac]

The mulitistep pulley attached to the crankshaft that drives the alternator and water pump">raw water pump is damaged. Has a small chip on the outer edge of the pulley where the belt rides. Pulley is cast aluminum which research and a couple of welders say is repairable.

BUT, showed it to a guy that does welding and fabrication at the local boat yard, he looked carefully and said welding wouldn't work. Said the aluminum has absorbed salt and based on previous experience, the weld won't hold. Even grinding back to what looks like clean, bright metal he said the welds fail.

Have to say I had a similar experience powder coating the old cast aluminum port light frames. Most had minor fish eyes and similar imperfections. Asked the guy that did the work and he said it almost always happens with boat parts.

Found a replacement pulley from Westerbeke for $462.00. For a PULLEY????? That's why I will never, never, never buy a Westerbeke product again.

Considering JB Weld Steel to see if that will hold. Any other ideas or suggestions? Or should I try another welder?

[Reefmagnet]

If it's a high magnesium alloy (like you'd find on a motorcycle engine component), it could be a problem. If it's a silicon casting alloy then it should be a cinch. The metal does need to be clean. Any corrosion will cause issues with welding. Perhaps consider brazing with a high silicon filler and flux rather than fusion welding. This can be done with oxy-acetylene or TIG.


At the end of the day, if it's throwaway anyway there's no harm in giving it a try.

[Pauls]

Grind back to fully clean metal. Preheat the part. Immediately after welding put the part back in the oven, or wrap it in a good insulating blanket and let it cool slowly.

Cast aluminum is weldable. Cracking can be handled by preheat and slow post weld cooling.

[OldGreyB]

[QUOTE=skipmac;3527961]The mulitistep pulley attached to the crankshaft that drives the alternator and raw water pump is damaged.

Found a replacement pulley from Westerbeke for $462.00. For a PULLEY????? That's why I will never, never, never buy a Westerbeke product again.

/QUOTE]

So a quick google research of industrial sites shows an Aluminum 2A V Belt Pulley 3-1/2" Double Groove A Section 1" Bore, 1/4" Keyway retails around a $30 Australian. I imagine even cheaper in Florida.

So find your local industrial pully supplier for a suitable sized diameter and number of groove replacement. If need be, take it to your local machine shop. They can modify the bore or mill the keyway to suit your application. You will be $$ ahead and have a new part.

[Manateeman]

Cast aluminum is a toss up. People who TIG aluminum know most of the tricks but we have run into stuff which we have given up on . ..we would get a machine shop to adapt a stock one as suggested above.
The manatee crew

[skipmac]

Adding photos to clarify the situation. Note, this is all one single casting.

The ID of the center hole is 2/18". The OD of the smaller part of the puller is 5 1/4", the larger 8 1/4".

Also note several holes through the body that mounts it to the rest of the system.

I looked for industrial pulleys but everything I found in that size was a spoke design, not a solid body so would not mount to the engine. I even considered buying two pulleys, a smaller and a larger and stacking them up to get the two different diameter grooves but again the size killed that option.

Unless someone can direct me to a better source of industrial pulleys IE large, solid body designs, I'm stuck with repair or replacement of this one. Or a new engine.

[thinwater]

Which engine? Could it be one of the Kubuto tractor engines with a Westerbeke badge?

[Manateeman]

Thinwater has a great eye. Maybe it is Kubota . A propeller shop might be able to make two pieces work. Call Tyler Dominic in Brunswick GA.
The manatee crew.

[skipmac]

Originally Posted by thinwater

Which engine? Could it be one of the Kubuto tractor engines with a Westerbeke badge?

Engine is a 1984 Westerbeke W58 which I figured out after much searching, is a Perkins 4.154 block. This I believe is a Mitsubishi block.

All the basic bits from Perkins are exactly the same but a fraction of the price charged by Westerbeke. Example, the block water pump $270 from Westerbeke, $90 from a Perkins tractor shop. Identical except for the color of the paint. That by the way is just the impeller section. It's a two piece pump. If you replace the larger casting that mounts to the block that's over $700 from Westerbeke.

BUT, so far I can't find a Perkins pulley that matches. Westerbeke did all the marinization including the intake and exhaust manifolds, raw water pump, heat exchangers and of course the pulleys as far as I can tell. They even changed the starter but I have to admit, for the better.

The Perkins starter mounts to the front of the bell housing so the starter is under the block and a bear to access. Westerbeke mounts the starter from the transmission side making for much easier access but it also spins in the reverse of the Perkins so you have to buy a Westerbeke specific starter.

I have a spare engine I purchased from a repower after that engine locked up so have a spare pulley but it's in worse shape than the original. I'm going to try JB Weld Steel and give it a go and if that doesn't work try the welding before springing for $462 for a new pulley.

[skipmac]

Originally Posted by Manateeman

Thinwater has a great eye. Maybe it is Kubota . A propeller shop might be able to make two pieces work. Call Tyler Dominic in Brunswick GA.
The manatee crew.

Thanks. If plan A and plan B don't work I'll make Tyler plan C. New pulley is down around plan W.