"It Happened!" Transom has to be replaced! (NOW W/PICS)

[LX Kid]

Found a Pre Alpha MC 1 gimbal housing on eBay for $150 shipped. Didn't realize how hard it would be to find one. On mine the studs had sheared off and all but one wouldn't come out. Still need to find missing studs for new/used one and a transom to housing seal.

 

[LX Kid]

Problem has arisen using two 3/4" plywood sheets. The two sheets together are just too thick to fit into the cut out channel. Decide to get another marine plywoods in 5/8" thickness. Kinda tough finding "anything" plywood right now because Irma blew thru here.

 

[chevymaher]

Found a Pre Alpha MC 1 gimbal housing on eBay for $150 shipped. Didn't realize how hard it would be to find one. On mine the studs had sheared off and all but one wouldn't come out. Still need to find missing studs for new/used one and a transom to housing seal.

But you got one that is the important part congrats.

 

[LX Kid]

No Title

First we tried beveling the plywood perimeter with a belt sander. (I don't think that's a portable hand belt sander he's using! LoL) We then managed a 1/8" vertical side cut on a table saw. It worked but created a problem about putting the outer stern skin back on. The skin would not be flush.

 

[LX Kid]

My new/used gimbal housing arrived by mail. Now I have to find about four missing .mounting studs that go thru the transom. Yesterday I ordered a bellows kit that comes with all three bellows, seals and gaskets. Picked up a 5/8" marine plywood for the transom. As I already explained the 3/4" plywood, we already bought and cut, won't fit into the channel. Right now we have about $1000.00 and a lot of man hours in the project. I'll take couple more pics tonight.

 

[LX Kid]

No Title

Today we put the fiberglass and resin on the inner plywood exterior and cut and sealed the outer plywood pieces. Tomorrow we hope to put the outer plywood on the transom. Plan is to putty up and sandwich the two plywood transom halves together and use 30, 1" stainless steel screws to pull them tightly together. We don't plan on removing the screws as they are SS and they won't rust.

 

[LX Kid]

What a 6 weeks this has been. The three amatuers replacing a I/O transom in a non-traditional manner has been a challenge. Fortunately one of us has had a little fiberglass experience and grabbed this bull by the horns to get-r-done. We have only been able to work from 8-11:30am due to the heat and humidity. None of us old farts want to have a coronary during this project. Tomorrow we will install the outer plywood. Today it took longer than expected to cut and make the two pieces of plywood fit properly. All in all we are proud of what we've done and are very optimistic that everything is going to come out better than what any of us had expected.

 

[LX Kid]

As moderators and the many experienced have indicated that I will probably have more issues than just the transom. They were right! But we three decided to tackle all of them as we really like the sturdy hull that all the Grady White's have. We will have about $1500 in the project and lot's of man hours of our own labor. Taking a long time cause we can only work half days due to heat and humidity while work is being done out doors.

 

[Bayou Dave]

3 workers at 3 1/2 hours per day makes for more than 40 hours per week. It will get done when it gets done and you 3 will be proud parents of a "brand new" boat.

 

[LX Kid]

No Title

Installed outer plywood today. Going to fill gap between two plywood pieces later today so we can re-install the outer skin tomorrow. Used a bunch of screws to pull the inner and outer plywood together tightly while the putty is drying. Decided to remove screws and fill the holes instead of leaving them in. Also glassed in the two new stringers in the engine bay. Will use roven-woven across both stringers and down across hull's bottom and up transom for increased strength.

 

[LX Kid]

Does anyone have any tips on how to push tightly the outer skin to the transom while it dries? Clamps just won't do it. I was thinking of maybe something similar to the way they make cement forms.

 

[JASinIL2006]

I think you were smart to remove the screws.

 

[redneck joe]

deleted

 

[tpenfield]

A lot of folks use the outdrive keyhole to pass a few threaded rods through and in through some 2x lumber spread across the transom width to make essentially a 'big' vise, clamping inside and outside surfaces tight together.

​You can see this method on the many, many transom replacement threads on this forum. Yours being done from the outside is no different in this regard. the common technique should work fine.

I say this assuming that you still have the outer skin of the transom intact and will be re-applying it. (right?)

​The trick will be putting enough thickened resin on the wood to fill any gaps that may exist between the new wood core and the mating surface of the outer transom.

 

[redneck joe]

deleted

 

[JASinIL2006]

The other thing to be concerned about is that you keep the area of the keyhole completely flat so the gimbal housing will fit against the transom properly. If you have any waviness or buckling in the skin as you reapply it, it can be a real pain to smooth out the transom to receive the gimbal housing.

Also, when you slather up the transom skin with thickened resin, be sure to keep your total transom thickness within Mercruiser's specs (2" to 2 1/4", I believe). It would probably be easier to build up a transom that's a bit to thin than to remove material on a too-thick transom.

 

[LX Kid]

Thanks guys for you suggestions! Tomorrow I'll post some pics of the "unusual" way we have decided to pull the skin up tight. We're using putty instead of thickened resin. I'll be sure to take note of the key hole situation concerning the gimbal housing. Thanks

 

[LX Kid]

No Title

The "keyhole" is a separate piece. Had to cut it out of transom to get the Y-tube off gimbal housing. Frozen bolts!

 

[LX Kid]

No Title

Today's work was filling and glassing the gap at the joint and removing all the screws we put in yesterday. Yea, the transom is very strong and solid. Filled all the screw holes with putty. In the morning we'll sand everything in prep for the hull skin. If things go well we'll re-install skin tomorrow.

 

[LX Kid]

No Title

Today's work we had thought we'd get to glassing the skin back on but we had to figure out how to pull it up tight before doing that. So as you can see, from the pic, this is how we think we'll do it. Adding shims behind the lumber boards to pull it tight where needed. On the bottom 2x6 we used lag screws going into the ends of the trailer bunks. Around the perimeter of the skin we are going to use screws to pull the edges tight. The fiberglass will cover all the holes so we are not very concerned about any leakage. As this is a "dry run" we probably won't get around to removing everything to get the puttying done till Sun-Mon time frame.