Area near motor mount/transom delamination and crack.

[Friendliest_catch]

Good evening,

When doing a once over of my 1985 marlin I noticed a delamination point where the stringer motor mount area meets the transom. The wood seemed in solid condition (not rotted) with good color and firmness. I forgot to check the motor mounts for tightness to ensure that the stringers have no rot, but im hoping they're solid. There is no visible movement and the bolts didn't wiggle or move by hand when i checked without a wrench (tomorrow's work).

What's the best way to go about repairing this? Fill with epoxy to soak wood, cut out the delaminated fiber glass, sand around the area and reapply glass with an inch or so overlap?

No issue on the other side. Just that corner piece. Rest of area looks good on all corners.

Photo for reference. Thanks in advanced!

 

[76SeaRay]

If it were me, I would use one of the vibratory tools with the end cutter to trim away some of that fiberglass to see what's underneath. It looks like in the right side of the picture that there was a place where the wood was not covered and therefore would allow water in. You may find rot once you get the delamination portion opened up. You need to make sure there is no rot and if you epoxy that area you will need to make sure the wood is absolutely dry underneath. Best to open it up to see what you have and post a few pictures of the underlying wood. This is just from my experience of finding hidden problems under what appeared to be good surface on my restoration. It can fool you..

 

[todhunter]

Just a guess...but I bet the motor mount is rotten and has sunk, allowing the fiberglass to break because it can't support the weight of the engine by itself. I would drill a core sample of the engine mount and prepare yourself for bad news.

 

[Friendliest_catch]

If it were me, I would use one of the vibratory tools with the end cutter to trim away some of that fiberglass to see what's underneath. It looks like in the right side of the picture that there was a place where the wood was not covered and therefore would allow water in. You may find rot once you get the delamination portion opened up. You need to make sure there is no rot and if you epoxy that area you will need to make sure the wood is absolutely dry underneath. Best to open it up to see what you have and post a few pictures of the underlying wood. This is just from my experience of finding hidden problems under what appeared to be good surface on my restoration. It can fool you..

Awesome. I will take to it this afternoon and see what I find. My plan is to use a Dremel and small chisel to get the old stuff out and off from the area, then I can take some photos and check for moisture. The boat was kept indoors and in a very dry climate so hopefully I'm lucky.

 

[Friendliest_catch]

Just a guess...but I bet the motor mount is rotten and has sunk, allowing the fiberglass to break because it can't support the weight of the engine by itself. I would drill a core sample of the engine mount and prepare yourself for bad news.

I could see that, but that kind of torque from rot should have cause cracks perpendicular to the force right ? And there would be some gap vertically between the crack? When the piece is pushed back to flush it fits with no visible gap indicating it has rotted and is sitting lower...of course il find out in a few hours once I get home and I'm able to drill some holes and check the motor mount bolts.

 

[Friendliest_catch]

Well you called it. It's not looking good at all. The rot stops just forward of the bilge, but aft of the wood you see in place is now in the pile pictured. bought the boat recently and it's not worth enough to do a full rebuild, but I have been looking at the pourable ceramic by Arjay technologies that is used for transforms.

It looks like you can pour that into the fiberglass like a sort of mold and as it fills the cracks and cures it becomes a rigid structural material.

If this boat was rotted all the way to the bow I think I would have thrown the towel in. Photos below..

 

[76SeaRay]

Sorry to hear it. Well they say misery loves company and you will find a lot of company on here including me.. Not sure how far forward my rot goes (haven't pulled up the floor forward yet) but the boat is stripped of everything including the hardtops which had rot also. A lot of work but should be rewarding when its done...

 

[todhunter]

Hate it for you. My brother is planning to use the Arjay stuff on his Glastron CV-19, but he hasn't started on it yet.

 

[Friendliest_catch]

Hate it for you. My brother is planning to use the Arjay stuff on his Glastron CV-19, but he hasn't started on it yet.

Looking into what products are best im between arjay and seacast. Both are solid and have great reviews..seacast unfortunately is across the nation and would cost 250 just to ship it.

 

[Friendliest_catch]

So I found the rot stops at the front of the bilge. The only piece of wood that runs the whole structure is the single 2x6 that runs in the middle of the photo. As you can see the other 3 pieces buddy up to it for the motor but stop at what looks like foam core .

I'm not sure what I want to do. I didn't want to spend all summer on another project. I got this boat with the understanding that it was structually sound /running good.

When I talked to a seacast rep they recommended replacing the entire stringer fore to aft . I have done too many projects lately and don't think I have it in me to tear apart a whole boat when I I've never done so before. The floor and rest of stringer is in good/non rotted condition.

I wonder how practical to drill 12 inch deep holes in the existing stringer and place some kind of rod either steel or composite then use a pourable stringer compound ?

Either way I think I'm stuck pulling the engine at a minimum to get the working space I need.