Can you weld a hole in lower unit casting pocket?

[sabastianunf]

I have a mercruiser 12O sterndrive with a pre alpha outdirve. I think some water must have been trapped in the casting pocket and frozen last winter. at the beginning of this year I saw a small bubble with a crack on the lower unit. It eventually started leaking water and got worse. Can this chip be welded closed without damaging the internal parts. If so where would I find a good person to do this as I do not weld. Thank for the help - I am pretty poor and dont want to shell out $1500 for a new lower unit.

 

[HT32BSX115]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

Howdy,


Most aluminum castings must be completely disassembled to do any welding on them especially if there's a weld needed in an area where oil is coming out. (indicating a rather large crack into the internal area......) It would be reletively easy to weld on the bottom of a skeg or cav-plate etc, since it's thin and fairly far away from the gear housing.

But a crack in the gear housing is totally different. I wouldn't expect it to be repairable at all.

You may be looking at another drive new or otherwise.......


regards,


Rick

 

[Bondo]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

I think it must have fallen out of the stand at the shop but I'm not sure. Anyway it started looking like a little bubble/cracked in the outdrive just above the raw water intake. It wasnt leaking at first but started to leak a little gear oil.

Ayuh,... Got a Picture,..??

Btw,... Brand New lowers are less than 1/2 what you stated.... SEI's...

 

[1fishbone]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

Depending 'where' it's cracked, it might be weldable.

ALL rubber and plastic has to be removed...the whole housing will get hot and ruin/melt anything plastic/rubber.

Call some local marine mechanics, some can weld it, or know a shop that they use that can.
It should be heli-arc or TIG welded.

FYI I've put leg housings in warm water to weld broken anti-cavitation plates.

 

[cr2k]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

It will also depend on the quality of the casting. Some of the old dogs were fairly porous and not weldable.

 

[sabastianunf]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

okay I cleaned and opened things up a lot today and took some pics. Big question is can and how do I repair this? Since it does not seem to affect anything can I fill it with some type of epoxy or something? Open to any suggestions or input.

http://i149.photobucket.com/albums/s53/sabastianunf/12172010006.jpg

http://i149.photobucket.com/albums/s53/sabastianunf/12172010007.jpg

 

[Gary H NC]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

Man! Looks like a rat chewed a hole in it!

Too big to fill with weld unless another piece was cut and fitted over the hole.
What happened to it?

I would find another lower for it...

 

[Fishermark]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

If I'm not mistaken, that area is simply an area for the water to drain back down and out. Not a critical area. I would suggest epoxy and a patch.

 

[sabastianunf]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

must have some mean rats where you are. Scary thing is I dont really know what happened. I wakeboard while my girlfriend drives so she may have hit a crab bouy or log - lost of stuff in the water some days. Was also in the shop at the beginning of the season so may have been dinged there. Just started as a small crack and ding but pushed out - I guess swelled with water. I have noticed more water coming out of the small hole at the bottom.

 

[HT32BSX115]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

Rats?

I guess swelled with water.

If the drive lives where you get freezing temps, the drive probably had some water in there that froze.....(and expanded)






It appears that the hole might be "connected" to the water pickup.

If it is, you might just be able to run it.

Otherwise, you could probably just fill it with marine-tex or other epoxy after you clean it "squeaky-clean".

I don't think I would try to weld it though. It might be hard to control warp in the case etc.....

 

[telstar1]

Re: Can you weld a chip in lower unit?

Re: Can you weld a chip in lower unit?

I think it froze, thats what popped the piece out. I had a similar event years ago, much smaller hole tho, and ran it for several yrs no prob. Try it and youll know. Some epoxy would make it look better.Main thing is no oil coming out.

 

[EddiePetty]

Re: Can you weld a hole in lower unit casting pocket?

...agreeing with the others, it is probably the result of freezing entrapped water in the lower unit, certainly a repair job for JB Weld (after proper preparations and cleaning). Just be certain to 'dam' the void's interior to prevent epoxy from futher clogging the drain hole/passage.

Side Note:
Most of us will advise you that your "WhaleTail" isn't doing your outdrive any good by inducing added stresses.

 

[stonyloam]

Re: Can you weld a hole in lower unit casting pocket?

Here is my two cents worth. I don't think it is freeze damage. If you had water in the oil it would have cracked the gear housing, not up there, besides no oil is leaking out. I believe the only oil up there is the oil in the passage going from the lower to the upper, besides it is not a crack it is a hole. It looks like a casting flaw to me. That sand that you pulled out could have been dislodged during casting and made a thin spot in the case, and over time it just cracked from stress. Is the hole thinner around the edges that the rest of the casting? It doesn't look like there is anything important right there (shine a light in there and take a look, or squirt some water in with a hose and see where it comes out), so I would fill it with something like JB Stik epoxy putty, sand, paint and don't worry about it. That is just me .

 

[sabastianunf]

Re: Can you weld a hole in lower unit casting pocket?

definatley no oil or anything coming out. I believe they used compressed sand lilke material to fill voids/unused space in the cast rather than make it solid metal to save weight and reduce cost. I also think this area doubles as a drainage passage as there is a small weep hole just below the damaged area that leaked more after the cracks formed. It did start as a crack and only opened up as a hole when I removed all the damaged metal. Could have been a thin spot in the metal but this is on a very old outdrive - 1970's - seems like any manufacturing flaw would have showed up much sooner. Foil/whale tail is factory I believe and is needed to help get up on plane - its a very heavy boat with a 120 hp motor - needs all the lift it can get to plane.

 

[Bondo]

Re: Can you weld a hole in lower unit casting pocket?

Foil/whale tail is factory I believe and is needed to help get up on plane -

Ayuh,... Mark nailed it,... It's Freeze damage...

That's the little bitty pocket beside the shiftspool..
If the little drain hole had been cleared, or if the cavity had been cleaned out when the impeller was serviced,...
This never woulda happened...

It can easily be repaired with epoxy, but I'd do it with the lower unit Off, to form the backside of the patch, 'n make Sure it's allowed to drain properly...

Btw,... Whaletails are NOT a factory installation...

 

[sabastianunf]

Re: Can you weld a hole in lower unit casting pocket?

The cavity is packed with a dark sand like substance. - should that be there? should I clear all of this out? Impeller was changed at a reputable shop last spring - suprised they didnt do it. I have changed the impeller before and dont remember seeing anywhere I could clean this out - What should I look for when i drop the lower unit?

 

[Bondo]

Re: Can you weld a hole in lower unit casting pocket?

The cavity is packed with a dark sand like substance. - should that be there?

Nope,... Shouldn't be there,... probably riverbottom or whatever...

Ayuh,... Clean it Out...

Either ya got a lazy Tech, or he's never seen Freezin' weather...
That cavity Has to be able to Drain...

 

[EddiePetty]

Re: Can you weld a hole in lower unit casting pocket?

The cavity is packed with a dark sand like substance. - should that be there?

...take a look at this previous posts and review the replies.

http://forums.iboats.com/showthread.php?t=435368

 

[5150abf]

Re: Can you weld a hole in lower unit casting pocket?

Been welding alumnuim for 26 years and that is totally fixable, any welder with a decent amount of experience should be able to fill that easily.

I have found the key to doing cast is using a really low heat and have it super clean, that is well away from any interals so I woudln't empty the case, the mass of metal and the oil will dissapate the heat pretty quickly.

 

[sabastianunf]

Re: Can you weld a hole in lower unit casting pocket?

wow - i have had this boat for 8 years and never seen water come out that pee hole - but mine is not as big as the one in the other thread. I will Definately clean things out. I live in florida but this year and last year have been the coldest I have seen living here for over 20 years. big thanks to everyone for thier help with this one.