Lucky Broken Skeg

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Interesting week with the boat last week. Cleverly forgot to tilt the outdrive up a couple of weeks ago when putting the boat in the backyard. Hooked the sidewalk with the corner of the skeg. Bent the end of it like a banana and broke it off.

DSC04693.jpg


Figured I could straighten the broken piece out and weld it back on. Found out that those people who say trying to straighten a bent skeg will break it are right. The bent piece broke in half when I tried to straighten it with the press.

DSC04694.jpg


Took it out Friday a week ago with the broken skeg, ran for 20 miles. Everything worked great, couldn?t tell a piece of it was missing.

Went out again Saturday a week ago. About halfway through the day, was idling down a narrow part of the river (30-40 feet wide) and there was a huge bump and the back of the boat moved about 5 feet sideways. Must have been a sunken log. River water is like brown paint, can?t see into it at all. Figured it was time to turn around so moved over to the other side of the river. Another big bump and the engine cut off. Chunks of chopped up wood come floating up. Apparently those stainless B3 props (no hubs, solidly mounted to shafts) make good chippers. So I tilt the drive all the way up and idle past it. No bump this time. Put the drive back down, everythings working fine. Kept going, put another 30 miles or so on the boat the rest of the day with no problems. Looked at the props when I pulled it out, no dings or scratches.

Went to put the boat in at the launch the next day, Sunday. Backed it down into the water, went to lower the drive, would only go halfway down, to the very top of the gauge. Cussing to myself, now I have to troubleshoot the freaking trim system! Raised it a couple of times, the third time it went on down, ran it up and down through the drive range a few times, worked fine. Went on out, had a great day on the water.

Went out last Monday evening to take a look and figure out what to do about the skeg. Wasn?t crazy about any of the bolt on stuff. While looking at the skeg I notice a fine crack across the support ear on the gimbal ring. Tilt the drive up and it isn?t a crack, the ear is broken off and hanging by the hydraulic ram pin! Try to lower the drive and the corner of the broken ear hangs it up. Bump it up and down once or twice and the broken piece finally slides by, slips back into position and lets it down. Now I know what was going on with the trim trying to launch Sunday. I figure it broke the ear when I hit the log Saturday afternoon, then ran the rest of the day Saturday and all day Sunday with the broken ear.

DSC04695.jpg


So I order a new gimbal ring. Got a great deal on a ?takeoff? gimbal ring from Imco. Brand new ring they took off a boat to replace with one of their high performance rings. My junk doesn?t classify as ?high performance?, it?s perfectly happy with the stock ring as long as I don?t bounce it off a log.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Lucky Broken Skeg

Pics below show how I spent this past week.

DSC04696.jpg

Ordered a replacement skeg, cut out the piece I needed with some extra ?ears? to give it some extra weld material and better distribute any bending loads (like hitting sidewalks and logs ?..).


DSC04697.jpg

New skeg fit up to drive.


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Bevels on edges.


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Made a plate for the top of the drive so I can run water through the pickup area and the exhaust area of the drive to keep it cool while I?m welding. You can see the water coming out of the overflow hoses on the left and right.


DSC06711.jpg

New skeg lined up and clamped in place. You can see the water from my ?flow through? hoses on the cooling system.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Lucky Broken Skeg

DSC06712.jpg

Ready to start welding.


DSC06720.jpg

Starboard side welded up and ground down flush.


DSC06721.jpg

Port side welded up and ground down flush.

Welded it up with the TIG welder. Drive housing ?torpedo? and seal area never got too warm to touch, probably 120-130 degrees max. Cooling system worked great.

Filled sanding scratches with epoxy filler, repainted per Merc procedure (http://www.mercuryracing.com/techcorners/mercruiserfaqs.php#tech_11). Looks brand new now.

DSC06727.jpg


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Finished everything up Friday afternoon, was out on the water all this past weekend. Great weather, high 70's, low 80's with a little breeze.

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So I figure it was lucky I broke the skeg, not sure how long it would have been before I found the broken gimbal ring if I hadn?t been looking to repair the skeg. Probably would have found it when the whole drive got ripped off the back of the boat and the boat sunk!
 

Adjuster

Petty Officer 1st Class
Joined
Aug 27, 2008
Messages
233
Re: Lucky Broken Skeg

Man I wish you were my neighbor. I would have lots of neighborly projects for you. LOL
 

JustJason

Vice Admiral
Joined
Aug 27, 2007
Messages
5,320
Re: Lucky Broken Skeg

talk about a bad day!!!!!!!!!!!!!!!

Very nice work though!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
70,994
Re: Lucky Broken Skeg

Ayuh,....

Very Impressive....... ;)
 

lkbum

Chief Petty Officer
Joined
Sep 1, 2008
Messages
445
Re: Lucky Broken Skeg

WOW!!! Nice job. I assume you tacked, then filled. Do you think you could have avoided the active cooling you set up if you filled a little at a time?? What alloy filler did you use (in case I ever have this much fun)?
 

BaileysBoat

Senior Chief Petty Officer
Joined
Sep 29, 2008
Messages
716
Re: Lucky Broken Skeg

Very nice 45 Auto. What kind of alloy is used in these lower units. Are they all the same?
 

Dirty Dawg

Petty Officer 2nd Class
Joined
Sep 7, 2008
Messages
172
Re: Lucky Broken Skeg

and may I add, what type of epoxy filler are you referring to with regards to the sanding scratches. Nice!!! Ike
 

Wotknot

Petty Officer 1st Class
Joined
Aug 6, 2002
Messages
310
Re: Lucky Broken Skeg

WOW!!! Nice job. I assume you tacked, then filled. Do you think you could have avoided the active cooling you set up if you filled a little at a time?? What alloy filler did you use (in case I ever have this much fun)?


Either 4043 or 5356 ......... with 5356 being the stronger of the 2.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Lucky Broken Skeg

It was tacked from both sides, then filled working 2 or 3 inch passes from each side. Had to make a second pass on most of it to completely fill it once the entire first pass was done. I used 2 passes (on each side) to fill it once I was a couple of inches from the ends since my TIG maxes out about 1/4" in aluminum. It's at least 1/2" thick in the middle.

Merc advises using 4145 if possible, or 4043 rod as an alternate. I used 4043 since I had 15 pounds of it sitting here.

If I hadn't used the active cooling I'm pretty sure I would have had to pull the lower seal. Merc advises pulling the seals then re-installing the guts to keep everything aligned. I just filled a little at a time near the back even with the active cooling. The bearing carrier and gearcase got warm, but not hot. By the time I could turn it over to do the other side it was cool again. Once I was a couple of inches away from the gearcase it never got warm at all.

The welding went real well, it took twice as long to make the cooling adapter as it did to do all the rest.
 

abj87

Petty Officer 1st Class
Joined
Aug 4, 2008
Messages
354
Re: Lucky Broken Skeg

Nice work on the skeg im even more impressed by the cooling plate you made. Do you have any more pics of the adaptor and the weld maybe?
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Lucky Broken Skeg

Couple more pics for those still interested.

DSC06714.jpg

Welding actually took two days as I cleverly ran out of argon before I could do the final pass on the starboard side. Tip of skeg was 1/8" out of line to port side at this point. Final fill in pass on this side pulled it in perfectly. Amazed myself how dead straight it came out!


DSC06722.jpg

Used PPG aluminum cleaner then aluminum etch, followed by epoxy primer.


DSC06723.jpg

Finish coat was 2 coats of PPG urethane, catalyst, and hardner.
 

chiefalen

Captain
Joined
May 18, 2008
Messages
3,598
Re: Lucky Broken Skeg

Impressive in the least.

Welding is a art.

And you have mastered it.
 

45Auto

Commander
Joined
May 31, 2002
Messages
2,842
Re: Lucky Broken Skeg

Cad model and drawing I made the cooling plate from. The slanted dims in parentheses are the actual measurements off my B3 lower I used to set up the hole pattern:

SS.jpg


dwg.jpg


Couple of pics of the plate for ABJ87. The fwd hose fitting feeds the water pickup port, the aft one feeds the exhaust passage. I had separate valves on each one so I could control the flow individually.

DSC06729.jpg


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Anybody needs to borrow the cooling plate it should fit any Bravo lower. I hope to not have any more use for it for a long time! :)
 

wca_tim

Lieutenant Commander
Joined
May 28, 2007
Messages
1,708
Re: Lucky Broken Skeg

Incredible! Especially for an engineer!!!! :D

I'm thoroughly impressed.... and wish I had that kind of time on my hands!
 

cbavier

Lieutenant
Joined
Apr 8, 2007
Messages
1,363
Re: Lucky Broken Skeg

Great repair job and like others have stated. I wish you were my neighbor. I surely could find something for you to weld.:D
 

Dshow

Petty Officer 1st Class
Joined
Jan 1, 2007
Messages
313
Re: Lucky Broken Skeg

Very nice work! You have to much time on your hands... :)

Looks like you had most of the material on hand... How did this compare expense wise with taking it somewhere or buying a new lower leg?
 
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