Renew or Reinforce Transom???

John the landlubber

Petty Officer 2nd Class
Joined
May 13, 2005
Messages
146
My transom is probably in need of renewal. My twin skinned dory has had a lot of water in the hull and is about to be fitted with a 140 hp Evinrude V4 from the late 70's/ early 80's. The maximum hp rating for the hull is 140HP. The boat is going to be used for inshore fishing in the North sea (east uk coast). A boat builder told me anything above a 90 he would reinforce the transome cause of the weight/power/vibration. Would this create weak points where the reinforced meets the existing? Is it worth doing? How would you reinforce, extra ply and extra Grp or another means. There are some transom shots on my shareaproject page if it helps. Many thanks
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Renew or Reinforce Transom???

If your hull is rated for 140 hp and there is no rot you should not need any reinforcement. The big if is the question of rot. If there is any rot reinforcement is not the way to go. It will need to be redone.
 

John the landlubber

Petty Officer 2nd Class
Joined
May 13, 2005
Messages
146
Re: Renew or Reinforce Transom???

Am I right in thinking it will only be the rotten wood in the transom that needs to be replaced and does that mean cutting the grp inside the stern vertically on the line of the wood or do I have to cut an inch or two outside that line? (I mean the two vertical lines that can be seen from the outside of the transom) Should I cut out the rear section of the deck before the vertical cuts or doesn't that matter?
 

John the landlubber

Petty Officer 2nd Class
Joined
May 13, 2005
Messages
146
Re: Renew or Reinforce Transom???

Ok, Have just drilled 4 holes on inside of transom. Completely rotten wouldn't you know it, lol!!! How far down the stern am I gonna have to cut? Will I have to cut below the drain plug and self draining outlet? What about these fixings that you can see in my project page either side of the wooded part? Should I remove these as well and fill to ensure they are not the point where the water ingresses? If so do I just brush in epoxy resin or some other method?
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
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7,518
Re: Renew or Reinforce Transom???

Post a link to the page with the photos.

To determine what the fix is you need to determine the extent of the rot. That will tell you what has to be done. Get a hammer and start tapping both on the inside and outside of the transom. Where you get a solid "rap" sound the wood is probably not rotten yet. It the sound is a soft "thunk" then there is rot behind it. You can usually take a crayon or piece of chalk and trace where the rot is.

Most often where the transom is rotton the stringers are gone too.
 

John the landlubber

Petty Officer 2nd Class
Joined
May 13, 2005
Messages
146
Re: Renew or Reinforce Transom???

Thanks solittle, took your advice and got the hammer out. There is a noticeable difference in frequency/solidity between the lower and upper transom. The lower part sounds surprisingly solid, but the closer you get to the top the hollower it sounds. I believe this is probably due to the seam about 1/2" from the top on the outside. If I apply a lot of pressure in that area there is a noticeable joint and there looks to have been some sealant applied here in the past. There shouldn't be a joint there, should there? It should be all one watertight unit, surely. Incidentally, what am I doing wrong with my link to my shareaproject page? When i-boats was in the previous format people could use my link and I didn't have any problems, but the new format seems to have deleted the link. I have gone back in and re-inserted it in my profile and I believe all the options are on. If I click on the link in my profile, it takes me straight to my project page. Any help is gratefully appreciated.
 

Solittle

Fleet Admiral
Joined
Apr 28, 2002
Messages
7,518
Re: Renew or Reinforce Transom???

Can't speak to the shareproject stuff.

As to the rot - The 140 is a powerful engine as you know so I would not recommend any of the "quick fixes". The rot - all of it - has to come out and the only way to do that is to redo the transom. Rot is a fungus and will continue to grow until removed.
 
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