Cast Aluminium Repair

[Paul.]

A little repair job to a broken aluminium casting on an outboard motor, powder coat removed and vee'd out.


Then clamped to a piece of stainless bar ready for welding


A quick blast with the tig gets it together, its welded both sides, the back is flushed off where the propellor guard bolts on, I'll leave the reinforcement on the top for a bit of extra strength, despite appearing clean it still threw out some contamination when it warmed up.


A coat of black plasticote makes it look better.


This is the prop guard, a bit bent and with a few cracks, not well made either.


This is one of the original manufacturers welds.


The customer supplied a new guard, it took an hour or so of re work to make it fit properly.


They have also had problems with bolts working loose, so its now fitted with cap screws and drilled and wired the heads.


The finished job.

 

[langy]

Neat job Paul

 

[Rrunnach]

When I bought my first engine, Mariner 40HP, anti-cavitation plate had a chunk missing, pretty much similar to what you had. I got a good reduction on price, as repair would be costly, bit of al/al flat bar profiled to in-fill missing chunk, nailed in no time, dressed both sides, then painted, no one would ever know.

That's a real strange prop guard, not seen the likes before. Is it SS and, if so, how to isolate/keep both different materials from making contact with each other??

Tidy repair BTW.

 

[Paul.]

That's a real strange prop guard, not seen the likes before. Is it SS and, if so, how to isolate/keep both different materials from making contact with each other??

Tidy repair BTW.

The jobs for the fire service water rescue unit, apparently the original guard was a plastic of some kind, but was deemed not to be strong enough, my opinion is that the stainless guard is the cause of the problem here, its been dropped or stood on the guard which has permanently distorted and stressed the casting, I've fitted a vinyl gasket between the mating faces, to isolate and hopefully compensate for any misalignment which may occur, I have recommended that they revert to the original plastic prop guard, If they don't I expect to see it in the workshop again.

 

[madkayaker]

Good job typical case of safety guard getting in way and braking things!

 

[Rrunnach]

The jobs for the fire service water rescue unit, apparently the original guard was a plastic of some kind, but was deemed not to be strong enough, my opinion is that the stainless guard is the cause of the problem here, its been dropped or stood on the guard which has permanently distorted and stressed the casting, I've fitted a vinyl gasket between the mating faces, to isolate and hopefully compensate for any misalignment which may occur, I have recommended that they revert to the original plastic prop guard, If they don't I expect to see it in the workshop again.

I'm not surprised cavitation plate snapped, that is one large chunk to be hanging from a 30hp engine, at least with a plastic guard, plastic would give before an expensive and, vital part of engine!

Another point (which you will know) clamp the earth in the wrong place, can melt a few cable windings once arced up!!

 

[brightspark]

cheaper to fix that than knack the propellers every time they go in some shallow waters pulling stiffs out of the river or save a drowning cat

 

[Seano]

Nice neat and tidy job Paul what type of clamps are those you are using in the pics Paul ?

 

[gordon stephenson]

Paul, When you fitted the vinyl gasket did you also sleeve the bolts and also under the washers each side with insulation material,Thats how i used to insulate the end covers from the main bearing housing on big power station generating sets, even had to use 3/4" dia nylon studs sometimes .

 

[Paul.]

Another point (which you will know) clamp the earth in the wrong place, can melt a few cable windings once arced up!!

Yes always very careful on these types of jobs, return lead clamped on right next to the weld,

Nice neat and tidy job Paul what type of clamps are those you are using in the pics Paul ?

Ive had those clamps for over 30 years, haven't seen them sold locally for a while but they are american design and very well made, found them on the web here http://www.destaco.com/squeeze-action-clamps.html

Paul, When you fitted the vinyl gasket did you also sleeve the bolts and also under the washers each side with insulation material,Thats how i used to insulate the end covers from the main bearing housing on big power station generating sets, even had to use 3/4" dia nylon studs sometimes .

Sleeving would have meant enlarging the holes, which may cause problems if its reverted to its original plastic guard, the customers is aware of the potential corrosion problems, and it never gets used in sea water.
The whole motor is a mixture of aluminium and stainless steel parts, it has 1500 hours on it and no signs of any problems so far,

 

[Rrunnach]

cheaper to fix that than knack the propellers every time they go in some shallow waters pulling stiffs out of the river or save a drowning cat

Actually, the opposite, rather replace prop, than having to repair main engine body casting!

 

[Shox Dr]

Nice neat and tidy job Paul what type of clamps are those you are using in the pics Paul ?

Ive had those clamps for over 30 years, haven't seen them sold locally for a while but they are american design and very well made, found them on the web here http://www.destaco.com/squeeze-action-clamps.html

Also known as Toggle Clamps/Pliers, (Destaco) used in the Avo industry. They do come up on UK ebay from time to time, but it's as cheap and faster just to buy some from the states. I do have a linky somewhere to a UK reseller of quirky Avo tools, if I have 5 I'll look

You can fix the Gap/Pressure and it will stay unlike a Irwin g-Clamps.

I bought a few, a while back when I was doing batches of stuff. Handy but really no better than G-Clamps