Replacing Transom

[Trouthunter]

I am replacing my Transom on my StarCraft Islander 26 with coosboard does anyone know if it is glued to the transom or is it just bolted to it only. This boat is also having the engine replaced with a 5.7 liter engine & a new floor replaced with non-wood. Thanks for all help

 

Edited December 10, 2019 by Trouthunter
correction

[whaler1]

Sounds like a big job. Considering replacing the floor in our boat. Please keep us posted as to how it goes and what was entailed. Good luck.


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[Ready or Knot]

I have replaced a couple of transoms in aluminum boats and the ones we did were just through bolted to stringers and supporting structures. I know nothing about the material you are talking about but make damn sure that it is ok to use against bare aluminum and will not corrode it. Dont be afraid to use plywood again , after all it has lasted over 20 yrs. This is not a small job but is quite doable. The floor in my experience is harder as most go under sides and fasteners can be hard to get to. Good time to replace all fuel lines and vents also. Good luck. These are great boats that a guy can pull and trailer around !

[Sk8man]

For folks unfamiliar with it this may answer some questions:

http://coosacomposites.com/technical-data/faqs

 

[sstout]

When I replaced the transom in my starcraft it was only bolted in. Remove the old screws on the splashwell (it's an outboard), remove the ones threw the transom and the old rotten one slid right out. I then pieced that together to make a template for the new one. Granted my starcraft is only 16ft, so alot smaller.

 

That coosboard looks interesting. Post some pics of how it's coming along.

[Jack]

Looking at the pictures of coosboard on their website I notice in marine applications it is glassed in place with resin/epoxy and some cloth. That process makes the board very rigid. On an aluminium boat you can only bolt the board to the transom . Will it be rigid enough to support the engine if not encased in resin/epoxy and cloth ?

Good luck!

[Trouthunter]

2 hours ago, Jack said:

Looking at the pictures of coosboard on their website I notice in marine applications it is glassed in place with resin/epoxy and some cloth. That process makes the board very rigid. On an aluminium boat you can only bolt the board to the transom . Will it be rigid enough to support the engine if not encased in resin/epoxy and cloth ?

Good luck!

The boat has a I/O so that is not a problem

[Bozeman Bob]

7 hours ago, Trouthunter said:

The boat has a I/O so that is not a problem

 I also wondered, but not about the weight capacity  . There must be a load of some sort on the out drive.The pushing and or torque action of the prop comes to mind. Is the structural strength of Coosaboard the same relative to the thickness as plywood ? Didn't actually see that in there write up.  Plywood glued together with each sheet going in a opposite direction adds to the structural strength of it. Not sure if Coosa  has that property.  As mentioned the plywood worked for 20 years and that probably wasn't coated with a resin to make it more waterproof . Might want to research that ,anyway good luck !!

[sstout]

I second that. When I did my transom and then my floor, I used marine grade plywood. Then I soaked it in 3 coats front, back, and sides with penetrating epoxy from totalboat. In the case of the transom both sheets were coated, then glued together to get the thickness, then the edges touched up with more epoxy. I could only imagine how long that coated marine ply will last. Probably longer than anyone will have the boat, even after me. 

[rolmops]

On 12/9/2019 at 6:22 PM, Trouthunter said:

I am replacing my Transom on my StarCraft Islander 26 with coosboard does anyone know if it is glued to the transom or is it just bolted to it only. This boat is also having the engine replaced with a 5.7 liter engine & a new floor replaced with non-wood. Thanks for all help

 

It is only bolted on if it is the original one.

When you remove the old engine, it will give you a chance to check the wood that is inside the lengthwise aluminum stringers. It will help you very much if you first remove the engine in addition to the gear box.

In addition , I very much suggest that you use a cherry picker with chain or straps going to the far port and starboard ends of the transom with big eye bolts screwed in the top of the transom. That way, you can keep the pulling pressure up while nudging the edges up and out

[Knotlost Charters]

I did my 26 footer 2 years ago, no its not glued only fasteners.  You will need to cut the corners of the transom, as on the top its welded. Its not a big deal it can be re welded or riveted back together.   When its all off spend some serous time cleaning the transom skin on the inside. I found many corrosion pin holes, I welded or replaced skin where needed. I also coated the inside of my skin with the epoxy that's for tinny boats cant think of the name but its for filling holes and creating a no corrosion surface. I have had marine plywood coated with epoxy rot to hell in 10 years, I would not have though it so but it did and it wasn't in bad conditions either. It shocked me but it did. I replace my tansom with an all aluminum 2 X 2 tube and 1/4 inch plate. It works flawless and I had a bunch of Nancy's tell me the world was going to stop spinning if I did.  Flexing can be an issue of concern and dont dismiss it, when your done and you take it out to sea test it (I know you will of course, will very carefully)  run a few strings across the back on the outside, you can duct tape them and watch them as you accelerate to make sure your not getting excessive flexing. You have to have a way to check and make sure the transom isn't moving much. If you have a lot of flexing back to the drawing board. That's why I went the way I did. 

[dbitting]

On 12/10/2019 at 9:40 AM, Sk8man said:

For folks unfamiliar with it this may answer some questions:

http://coosacomposites.com/technical-data/faqs

 

If i'm not mistaken you can send them a template of you transom and they will cut a panel for you