transom repair

martin · #1 03-03-2012, 11:34 PM

Hi I have an 23 i/o was wondering what is the best way to replace transom.. cutting the inner skin or the outer skin.. ? do I need to make a cradle to support the transom and do I need to remove cap... going with a bracket and outboard. with a built in live well in the transom and removable fish box in the floor where the engine was.. thanks Mj

Bushwacker · #2 03-04-2012, 12:32 AM

Don Herman says it's much easier to cut the outer skin, leaving about 3" all the way around as a reference plane for fairing the new skin to.

Entourage · #3 03-04-2012, 09:25 AM

Make sure you do a nice job cutting the outter skin, you should put the old outter skin back when you put everything back together even though your going to need to plug the outdrive hole. Use epoxy to bond the outter skin to the new transom. you will save yourself alot of time and money on fiberglass if you do it this way. I just did mine and i regret i didn't do this.

martin · #4 03-24-2013, 10:11 PM

Okay i just found this post of mine... Entorage. you really think it would be better to just add the old skin and fair it in.. if that is the case. I can start to add the old skin now..it woudl save me a a bunch of epoxy too. I will be installing a twin bracket..

Entourage · #5 03-25-2013, 07:08 AM

I recommend using the outter skin will save you alot of lay up time and money on glass.

martin · #6 03-25-2013, 07:22 AM

Quote:

Originally Posted by Entourage

I recommend using the outter skin will save you alot of lay up time and money on glass.

Man not to mention this glassing of large panels of glass vertically really sucks.. By my self.. I had to lower the bow as far as possible so to get the transom more perpindicular to the ground... I really like repairng from the outside then the inside... I just hate climbing in and out of the boat.. Although it does take more time doing it from the outside...

FishStretcher · #7 03-25-2013, 07:46 AM

I haven't done this, so take it with several grains of salt. But a few things occur to me.
The stringers attach to the inner skin of the transom, so it is by its nature more structural than the outer skin and it seems you might need/ want to add knees to the inner transom. After all, the boats hold together with rotten transom cores, so the real load path has to be thru the inner skin and stringer joints. Which means this will need reinforcement when you put it back together.

The problem of laying up on vertical surfaces is a trick, too. It seems like vacuum with resin infusion is the way to go, but that's pretty exotic for most of us.

<edit> I just noticed you can vacuum bag as you have pics of this in another thread

So if it were me, I would carefully remove the inner transom, add foam cores for knees if you want, and reinstall it. A plus is that with the trailer/bow up, you aren't glassing upside down, and there is no finish sanding. I think if you could use a slow resin, you might be able to do wet layup and then vacuum bag this phase of the install to suck the whole thing together without fasteners. Even shop vac level of vacuum would so for that. You would have to seal the top edge of the transom and drain hole, I think. I would think that leaving the top 3-6" of the inner transom skin intact would help with this.

But all this is just a thought on how to do it in the most general of terms.

bigeasy1 · #8 03-25-2013, 08:45 AM

I have a 74 23 Tsunami I/O, and did my transom from the inside.I know that many do the transom from the outside,but (just my opinion here)I feel the better way is from the inside.You don't compromise the hull ,this way and you don't have to spend hours laying up glass and fairing the outer skin back on.
Overall,it's more work doing it from the inside but I feel It's a stonger repair.

I started by removing the rub rail and the screws,to about midships,then I made a cut on the gunwhales in the center of the opening for the hawse pipes on each side.We could then lift the rear cap off.
Next we cut the inner panel that runs across the stern that has the lip for the engine box on it.
You now have an open access to the transom.I cut back the sringers,and removed the engine beds, and set a blade in the circular saw just deep enought to go thru the inner transom skin,and removed the peat moss core.

I laid up a couple layers of 1708 to the inside of the outer core,then put in the new transom core and followed up with a few more layers of 1708 on the face of the new core extending a good way onto the hull sides.
Another advanage doing it this way is that you already have the transom cutout in the "EXACT! location it was originally.
I used marine plywood for the core,glued together with Epoxy.I used Vinylester,and some polyester to do most of the layup from there on.

Here's a few pics if I can get them to load

martin · #9 03-25-2013, 11:33 AM

I agree with you...

pelican · #10 03-25-2013, 11:41 AM

Quote:

Originally Posted by bigeasy1

I have a 74 23 Tsunami I/O, and did my transom from the inside.I know that many do the transom from the outside,but (just my opinion here)I feel the better way is from the inside.You don't compromise the hull ,this way and you don't have to spend hours laying up glass and fairing the outer skin back on.
Overall,it's more work doing it from the inside but I feel It's a stonger repair.

I started by removing the rub rail and the screws,to about midships,then I made a cut on the gunwhales in the center of the opening for the hawse pipes on each side.We could then lift the rear cap off.
Next we cut the inner panel that runs across the stern that has the lip for the engine box on it.
You now have an open access to the transom.I cut back the sringers,and removed the engine beds, and set a blade in the circular saw just deep enought to go thru the inner transom skin,and removed the peat moss core.

I laid up a couple layers of 1708 to the inside of the outer core,then put in the new transom core and followed up with a few more layers of 1708 on the face of the new core extending a good way onto the hull sides.
Another advanage doing it this way is that you already have the transom cutout in the "EXACT! location it was originally.
I used marine plywood for the core,glued together with Epoxy.I used Vinylester,and some polyester to do most of the layup from there on.

Here's a few pics if I can get them to load

those pictures of the deck,the motor box:

motor box is sitting on starbord ??

that hatch,in front of the box ? doesn't fit flush does it ?

did you replace that deck ?