2022.11.21 - Transom Inspection

With Naiad de-rigged and ensconced in the Hay Barn, I took a closer look at the leak in the transom in order to determine just what I needed to do in order to repair the leak as permanently as I was able.

Once again Naiad is in the Hay Barn. Doesn't seem like long ago when she was here last but it is nearly a year since she was taken down to West Mersea.

I probably didn't need to level her up athwartship but I did it anyway.

Looking at the place where the water is leaking in from the inside, it looked as though the wood might be a bit soft or, heaven forbid, perhaps a bit rotten. Seeing this on the photo I immediately went out to Naiad and with a sharp pointy thing and poked away at the wood on the inside and was relieved to find that it was quite hard and not soft or rotten. Which makes sense in a way since for the majority of her life she has been spending the on-season on salt water and the off-season in a dry garage which would have been fairly inimicable to rot spores. Then she spent two years or so being rebuilt followed by some time in fresh water and then followed by the last eleven months back in salt water and some of that time drying out on the mud. Nevertheless, the wood in the area of the leak will be pretty well saturated with salt water.

The width of the timber through which the water is leaking is around 2" shown by the black arrow and the water has seeped right through this. You can see from the photo that the timber is made up of around nine of laminations that have been glued together to follow the curve of the hull and I would hazard a guess that the glue line between two or more of the laminations has parted allowing the water to seep in.

Taking a closer look at the outside you can see the white vertical epoxy used to fill in a small hole and at the top of this is the horizontal crack where I think the water is getting in. both to the left and right of this epoxy you can also see two round plugs that I put in to fill the screw holes left when I removed the old bottom rudder fitting and both of these seem to coincide with the glue layer between to of the laminations. This suggests that the screws were inadvertently screwed into exactly the wrong place and over time have forced the glue to fail.

Before I am able to repair this the wood must be dried out. This necessitates the use of a heater since it is now Winter and the temperature is not high enough to dry anything out right now. However, the wood is going to take a very long time to dry unless I strip the paint and glue off first.

It didn't take very long to do this with a heat gun and a scraper.

A closer look shows the split quite clearly now that the antifouling copper epoxy and glass matting have been removed and I noticed that the wood in this area is very wet and easy to damage with the scrapper.

On the inside the top of the veneers is completely dry but in the vicinity of the leak the wood is again easy to damage with a scraper, just like on the outside. However, until the wood is dry there is no point trying to do anything else, like sand it, as that is just going to damage the wood further.

Now that the water-resistant layers have been removed I shall put a small low-powered heater in the lazarette during the day in order to drive the water out of the wood. 

As for repairing the leak I'll use some penetrating epoxy sealer to saturate the wood and inject it into the split initially. Then I'll use epoxy thickened with colloidal silica as a putty and press this into all the remaining gaps with a putty knife. Then the area on the outside will be coated with more epoxy and a wide fiberglass tape applied to the transom over this area and wrapped under the hull with more epoxy used to embed the glass and finally, when all of that is done, the repair will be coated with the copper epoxy antifouling.

We shall see if this fixes the problem.