Transom Strength

Questions about boat repairs with our resins and fiberglass: hull patches, transoms and stringers, foam, rot etc.
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anonymous

Transom Strength

Post by anonymous » Fri May 11, 2007 1:57 pm

I am in the process of rebuilding my Transom on my 16' Bass Boat. I tore out the old rotten transom and am now ready to put in a new one. I am planning on using Ply wrapped in Fiberglass, completely sealed. Then fiberglass it into place.

My concern is will the motor when remounted just rip the transom right off?

I will post some pics tomorrow, but basically the total back end of the boat was rotten. From the deck up from the left side of the boat to the right.

The floor and stringers are in great condition, only the transom was rotten. I was able to leave the Skin on the back of the boat, but there is little or no support to mount the new transom to, so I think once I put the new transom in and fiberglass it to the skin and put it all back together again that the motor will rip it off.

I was thinking of putting some kind of Angle Supports from the floor to the transom, but ??????

Even if I was just replacing 2 feet of the transom, how will it hold and not rip off? I dont understand.....

What are your thoughts.?



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Re: Transom Strength

Post by jacquesmm » Fri May 11, 2007 2:05 pm

sunkShips wrote: My concern is will the motor when remounted just rip the transom right off?
Don't worry, our transoms stay with the boats. :D

The good news is that your stringers and sole are good. Post the pictures and Joel will respond. We will tell you how to weld that transom to the stringers, side, sole, motorwell, deck to get it all as one very solid piece, stringer than before.
See the pictures of the Aquasport rebuild, it shows how we do it. Also see this:
http://bateau2.com/content/view/75/28/
Jacques Mertens - Designer
http://bateau.com

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ks8
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Post by ks8 » Fri May 11, 2007 3:17 pm

Pictures are very important. I think many of us look forward to seeing them, and the final results of the repair. :)

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Post by crasea » Fri May 11, 2007 4:05 pm

My project turned out to be a bit more than just the transom but that is a part of it. Mine is an I/O but I think there will be similarities and maybe this link can provide some help. I'm starting to build the transom this weekend.

forum/viewtopic.php?t=13273

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Post by jacquesmm » Fri May 11, 2007 4:53 pm

Outboards and stern drive work the same way with the load of the engine transmitted to the transom.
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http://bateau.com

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sunkShips
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Added Pictures

Post by sunkShips » Mon May 14, 2007 9:29 am

Here are Pictures of my Boat. I am now a Member and not posting as a Guest.

--------
You will notice the expanding foam in the pics. I used that to fill some holes in the plywood edge that was left. I piped in the foam then today leveled it off and fiberglassed over it. I wanted to have a tight smooth edge to sit the new ply on.

My bigest concern/question is : with no angle suport or support on the sides how will the motor not just rip off the transom? Is fiberglass that string to hold from the bottom and edges of the boat?

Image
Image
Image
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Image

Here is a simple drawing of the shape of the "hole" in the transom. The rotted ply that I removed is in that random shape. and about 2 inches thick. the Left side of the transom the wood rotted all the way to the Left side of the boat.

Image
Last edited by sunkShips on Tue May 29, 2007 12:27 pm, edited 7 times in total.

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Post by MadRus » Mon May 14, 2007 9:43 am

I think you'd do yourself a huge service by reading a few of the tutorials in that section of this website, and especially that refurb thread by Shine. Fiberglass and epoxy is definately strong enough, but it's not going to be one piece, it will be several laminations, and you may need to add some supporting structure, but yes, fiberglass and epoxy will do the job.

Also read about mixing thixotropic fillers into the epoxy, much stronger than filling your plywood edges with foam, which has vitually no compression strength. Seriously, do some more reading and get familiar with the process and you'll be in much better shape in the end. Keep going though, you'll get it done.

I just reread this and it sounds like I'm being a jerk, but I'm not trying to be, I just believe a lot of questions are answered the hard way, by digging deeper into the process. And the way I built my first boat was to read everything I could and imagined myself performing each task and if I couldn't imagine it I'd keep digging.

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Re: Added Pictures

Post by tech_support » Mon May 14, 2007 9:51 am

Im not sure why the foam was used :?: Would have been better to use thickened epoxy putty. Now the new core will be bonded to the glass you put in over that foam. The glass bond to that type of foam is very poor - the foam is now a weak a link

I would remove the foam, fill the cavity with epoxy putty, then bed the new core into place with epoxy glue.

joel

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Foam Weak Link

Post by sunkShips » Mon May 14, 2007 11:56 am

I figured that might be an issue, it is just filling in mionor gaps its not really structural. When you say epoxy putty are you referring to Resin and Wood Flour that I keept hearing about?

and Epoxy Glue? sorry new to all of this, but I do want to do it right and make it lat for a good while.

Thank you....

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Re: Foam Weak Link

Post by tech_support » Mon May 14, 2007 12:05 pm

sunkShips wrote:I figured that might be an issue, it is just filling in mionor gaps its not really structural.
From the pictures, I cant see how its not structural.
sunkShips wrote:When you say epoxy putty are you referring to Resin and Wood Flour that I keept hearing about?

and Epoxy Glue? sorry new to all of this, but I do want to do it right and make it lat for a good while.
Thank you....
Yes, epoxy putty would be thickened epoxy with wood flour, same thing with epoxy glue. Epoxy glue is usually a little thinner (less wood flour mixed in)

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