CONTINUOUSWAVE

Q1: what is the recommended method to replace a transom drain when the surrounding wood appears soft and rotten?

Q2: should I scrape out the old wood and fill with epoxy?



BACKSTORY
On my 1983 13-foot hull I am going to replace the drain tubes (as part of the process of installing a new engine).

After pulling out the drain tubes, I noticed the wood inside [the hull] looks rotted and soft, as seen in Figure 1. The wood looks great up top in the outboard engine mounting holes.

Is that a photo of wood or is it the drain tube? It looks very dirty inside but that is not unusual for a drain tube.

That is the wood in the photo. I’ve removed the brass drain tube. The indent on the bottom was caused by me while I was removing the old tube.

It’s definitely rough and dirty.

Q3: how much wood should be removed and replaced with epoxy?

Q4: Or should I just install a new tube?

The drain seen in Figure 1 appears to me to have been modified from the original. It looks like it has a section of plastic pipe inserted. You can see a distinct change in material between the hull gelcoat and the drain tube. Or perhaps what appears is just some old sealant.

Typically a hull drain would not be drilled through the transom area with embedded wood reinforcement.

Q5: are you certain that the hull material surrounding this drain is wood?

Also, replacement of drain tubes is a topic in the Frequently Asked Questions answers. See the answer at:

Q12: How Are brass drain tubes replaced?
https://continuouswave.com/whaler/reference/FAQ/#Q12

If the drain is actually drilled through wood, and the wood is rotting, you should use a rot-stopping treatment like GET-ROT to stabilize the wood. Then you could enlarge the hole slightly, and coat the wood interior with epoxy. Then re-drill the hole to the proper size to fit the replacement brass drain tube. Don't seal the entire tube in place with sealant. Don't use a super-adhesive sealant like 3M4200 or 3M5200. Just use a marine caulk at the ends of the flared tube if you don't get a good seal with the rubber O-rings.

"GIT" ROT
https://defender.com/en_us/boatlife-git-rot-wood-repair

Really appreciate the help.

According to this diagram, the drain tube is installed through wood on my 1983 13’ Whaler.

https://continuouswave.com/whaler/reference/13/graphics/13Wood.gif

That’s just some leftover sealant around the entrance to the tube. I will check out Git Rot and follow your advice on enlarging the hole slightly and adding some epoxy. Thanks!

In order to use GIT ROT or any other penetrating epoxy, the wood must be dry. You will need to thoroughly dry out the drain passage through the transom wood before applying a penetrating epoxy to soak into the wood.