sealing fibreglass?

[mitchellbj]

just bought a fibreglass tinny and the bung hole is through the transom and you can feel just bare timber in the middle it feels wet but it has been raining and there has been water through it. it doesnt feel like its rotted but how could i seal it up im thinking drilling it out for a bigger bung then sealing it some how any ideas?

[Rip it up]

Yes job Mitch.

Let's get a few questions out of the way.

Does it have a false floor? Eg. Two bungs or just one.
And can you access the area inside the boat.

The simple test for solid timber is a spike test. Grab a small screw driver and stab it into that "wet" timber. A solid transom will not be able to scrap at the timber. Wet will be a mushy dark deposit left on the screw driver.

If it's only wet from rain. Then your winning.

Remove the affected bung and clear away any old silicon/sika.

Get it bone dry. Tip it up for a few days. Then go nose down while working on it. Use hair dryers or a pedestal fan pointed at for 24hrs etc.

If it has no false floor a bigger bung is a good idea. Stop the small items from blocking the drain.

I would attack the timber with a die grinder to open it up. Because often the bottom of the bung is close to the hull. And you want to open up the area above to make room for bigger bung.

With the opening a snug fit for your bigger bung, and you have access to the area inside the boat, I would create a tapered funnel effect inside. \_/

Then grab some epoxy resin preferably or flowcoat if you only have access that. And paint the exposed timber. Remembering that this might affect the tight fit of your bung in the hole.

Alway use sika flex below the waterline. And your good to go.

Think about the old bolt holes too. An oversized hole and epoxy is a good measure to stop the rot later.


Damo's dodgy boat building factory.

[odes20]

Yes job Mitch.

Let's get a few questions out of the way.

Does it have a false floor? Eg. Two bungs or just one.
And can you access the area inside the boat.

The simple test for solid timber is a spike test. Grab a small screw driver and stab it into that "wet" timber. A solid transom will not be able to scrap at the timber. Wet will be a mushy dark deposit left on the screw driver.

If it's only wet from rain. Then your winning.

Remove the affected bung and clear away any old silicon/sika.

Get it bone dry. Tip it up for a few days. Then go nose down while working on it. Use hair dryers or a pedestal fan pointed at for 24hrs etc.

If it has no false floor a bigger bung is a good idea. Stop the small items from blocking the drain.

I would attack the timber with a die grinder to open it up. Because often the bottom of the bung is close to the hull. And you want to open up the area above to make room for bigger bung.

With the opening a snug fit for your bigger bung, and you have access to the area inside the boat, I would create a tapered funnel effect inside. \_/

Then grab some epoxy resin preferably or flowcoat if you only have access that. And paint the exposed timber. Remembering that this might affect the tight fit of your bung in the hole.

Alway use sika flex below the waterline. And your good to go.

Think about the old bolt holes too. An oversized hole and epoxy is a good measure to stop the rot later.


Damo's dodgy boat building factory.

Aahh! All good except the end.! Dont use flow coat at all, it will just crack off after time. Its not designed to be a finish over wood. Yes use epoxy or Polyester resin, BUT! Use matting as well!!! Just straight epoxy is nowhere near as reliable as laying some woven roving or simalar to give it strength. if you do this you will have a completely reliable oucome for your efforts. No disrespect Damo.

[Rip it up]

Fair call odes. The cracking effect of flowcoat is a problem. The fibre addition is a fair call. With that sort of work on the bung area from the inside, it will save the transom for a lifetime.


Damo's dodgy boat building factory.