Rotting Transom on a 16.5 Tri-Hull

[oldmerc80]

I was in the process of switching my engines on my '62 Larson Tri-Hull 16.5ft. The plywood in between the sheets of fiberglass is rotted out. What should I do? The boat is a two-piece so I might have to use a dremel and cut it in half again and replace the wood. Would it be safe to use a 30hp Johnson on it or would it rip the transom off?

 

[ODDD1]

Re: Rotting Transom on a 16.5 Tri-Hull

Rotten is rotten...fix it or burn it, but dont use it....

 

[singerjr]

Re: Rotting Transom on a 16.5 Tri-Hull

Oldmerc,<br /><br />I personally have never had a rotted out transom. I've had wood problems mostly on wood boats.<br /><br />This is the Engines and Motors section of the board so in case you don't get many responses I wanted to chime in with my concern. You just joined the board so you may not know but rotten wood in transoms is a big topic around here. <br /><br />There is a lot of experience here, you should get plenty of help repairing it if you ask for it in the Boating section of this board.<br /><br />You have a very serious problem that should be addressed before ever taking that boat on the water.<br /><br />

 

[oldmerc80]

Re: Rotting Transom on a 16.5 Tri-Hull

I was looking at some stuff called Seacast. It is a liquid that you pour into your transom and it is supposed to replace the rotted wood. Is this stuff any good?

 

[evin300]

Re: Rotting Transom on a 16.5 Tri-Hull

The seacast idea has been brought up before, no one has ever jumped in and said how great it works.<br /><br />Please allow me to speculate as to why. First of all, it sounds great! I am sure they have sold plenty of this stuff. <br /><br />Now, I am not a engineer, but I will try to put this in my perspective. Picture yourself looking up at the cieling of your bedroom. Above you is a 4 x 12 beam that supports the second floor room above you, most of the beam is water-logged and sagging. The middle of the span is actually rotted, so you support the beam, dig out the rotted material, and fill it with "Seacast", great! now you can sleep peacefully?<br /><br />Problem 1) You have replaced the wood with a different material. Does it have the exact same characteristics as the remaining wood? N......O<br /><br />Ah, but it is stonger and better, good! N...O<br /><br />The big problem here is that you have two dissimliar materials, wherever the two become one, you have a natural stress point, you might as well take a (chainsaw) and cut a line between the two materials, cause that is equal to what you have done.<br /><br />I, for one, would not sleep under this beam!

 

[MercilessMike]

Re: Rotting Transom on a 16.5 Tri-Hull

I would have to disagree, I have used this product with great success, STRONGER then woo, WILL NOT ROT, Ever notice boats are now made of composite materials, not wood any longer? My transomis on a 17ft boat with a 225hp outboard, NO PROBLEMS after 1 year, no cracks no swelling. Just solid<br /><br />If you use seacast you will be amazed at the results. Little more costly than traditional layups, but alot less time and fuss and MESS.

 

[singerjr]

Re: Rotting Transom on a 16.5 Tri-Hull

I've used this type of product under different names for restoration of wood on houses, such as a sill. It is well known in the building trades as a small area cure/stop for rot. If rotted through or the rotten area is large I don't know any quality craftsman that would use this for repairing a large structural area.<br /><br />Another issue, you MUST get the epoxy into the middle of the rotted material, that is accomplished by strategically drilling holes and injecting material with special syringes into the wood, the rotted material must be completely filled. The material I've used expands 10%. In an enclosed transom injecting a large amount of this stuff could possibly crack the fiberglass.<br /><br />I've always understood this is a small area patch not a complete fix for an entire structural component. Another issue with the wood enclosed will you ever know just how good it worked. There is far too much at stake here for a quick easy fix.<br /><br />Just my .02 cents worth, I wish you all the best with your project,<br /><br />

 

[DJ]

Re: Rotting Transom on a 16.5 Tri-Hull

I knew EVIN would get the word "chainsaw" in there somewhere. <br /><br />Go ahead EVIN tell him what he really needs to do.

 

[Hooty]

Re: Rotting Transom on a 16.5 Tri-Hull

Bbrrrraaaaap---bbbrrraaaaaaap--- bbbrrraaaaaap braaaap brrraaaap<br /><br />Go on evin, tell him!<br /><br />c/6<br /><br />Hooty

 

[evin300]

Re: Rotting Transom on a 16.5 Tri-Hull

Ok, guys, I just cant hold out any longer. oldmerc80, I hate to say this, but its time to fire up the ole chainsaw and turn that transom into sawdust. Put her back into the earth where she came from.<br /><br />To Euthanize the transom at this point is your best choice, but you want it to be quick and painless. I suggest a gas or electric chainsaw with at least 14-16" bar.<br /><br />oldmerc80, really I am not kidding! Do a "search" on these boards using the word "chainsaw" to read more. First, check again to see how much damage there really is. Is the whole transom wet? Is there alot of rotting? Some transoms can be re-enforced if the damage is only minimal, Good Luck <br />

 

[evin300]

Re: Rotting Transom on a 16.5 Tri-Hull

djohns19, Hooty and others, I thought I would change my name for a while, just for the sake of change. Evin300 is now known as ChanesawEvin.