Deck core

[Dieselmech]

Hello all!

Is this Ply or Balsa?

Also going off the bottom layer of glass in the images would it be easier to find large sections of rot and delamination by tapping/pushing on the bottom layer of glass? Or on the top once the teak has been removed?

Cheers!

[Chotu]

Hard to say for sure from the picture, but it looks like end grain balsa to me.

It will give slightly if you press on it. From the side. Plywood will give less. There is a softness to balsa from the side.

And yes. Pushing from below you will have a better feel for soft spots. Thought typically it takes your entire weight on one food to really feel anything like that so I wonder how much force you’ll have pushing up.

If you are just happened to look for delamination, from below will definitely be better.

[pcmm]

That is most definitely balsa. If it had been plywood, you would have seen the ply's in that core sample.

[Chotu]

Originally Posted by pcmm

That is most definitely balsa. If it had been plywood, you would have seen the ply's in that core sample.

That’s exactly what’s weird about the picture. Do you see those three layers? It looks exactly like balsa, but it looks like there are three layers.

[rslifkin]

I agree, looks like balsa to me too.

[pcmm]

Originally Posted by Chotu

That’s exactly what’s weird about the picture. Do you see those three layers? It looks exactly like balsa, but it looks like there are three layers.

I think there may be 2 layers of balsa assuming that its not just distortion from the hole saw that was used to cut this plug/sample

[rslifkin]

Originally Posted by Chotu

That’s exactly what’s weird about the picture. Do you see those three layers? It looks exactly like balsa, but it looks like there are three layers.

It looks to me like from the top down, it's some kind of wood, a layer of gelcoat, thick layer of fiberglass, then balsa, then a thin glass skin. The balsa looks like it got chewed up unevenly by the hole saw when this was cut, giving it an inconsistent appearance. One part of it is slightly torn, the bottom bit is cut more smoothly. Could also be 2 layers of balsa in there.

[smj]

Teak on top then a layer of glass then balsa and finally the bottom layer of glass completing the sandwich.
If your removing the teak deck I would think the rot would be caused by the fasteners holding the teak down, so I would think you’d have a greater chance of spotting any delam or soft spots from the top.

[s/v Jedi]

It’s balsa and it seems to be in pristine condition. Stop cutting holes

I think you should tap from above deck to find delamination. With that really thick fiberglass outer skin it isn’t likely to have let water through so I would check mainly around deck fittings and do a “give” test by walking.

Shame that the bottom skin has gelcoat… a visual inspection from below would have worked otherwise.

[Joli]

If you're putting something in the hole, seal the edge of the balsa with epoxy.

[Rumrace]

It’s baltech. I see older grey resin and the decay seems limited to the dark brown layer I hope is not plywood digging in to it likely not the solution. Petrifying the wood may be a solution and a new top coat. The dry wood minwax make a wood penetrator which replaces lost cells with an epoxy like thin liquid.
Certainly a challenge. The balsa looks good by the way.
I saw a large well respected brand blow a chunk of glass off a side and under the hull a bit. Was obviously a factory flaw. You could see glass which never got wet. QC guys cost $$$ and the guys with rollers are often temps.
If the delaminating is in one area then dig. You can even get a rubber mould for just about every non slip.

[Rumrace]

Did you cut a hole through the teak. I’m going to second with Jedi. Stop it!

[goboatingnow]

Originally Posted by Dieselmech

Hello all!

Is this Ply or Balsa?

Also going off the bottom layer of glass in the images would it be easier to find large sections of rot and delamination by tapping/pushing on the bottom layer of glass? Or on the top once the teak has been removed?

Cheers!Attachment 266639Attachment 266640Attachment 266641

It’s definitely end grain balsa

What are you trying to achieve is the sample wet ? ( doesn’t look like it is. )

[Mike OReilly]

Looks to me like a hole cut through a teak deck, (dark wood layer), down through some adhesive and then through a fibreglass layer. Then comes what looks to me like excellent balsa, and finally another thin layer of fibreglass.

It looks fine to me ... except now you have a big hole in your deck .

[s/v Jedi]

Don’t let us discourage you: using thickened epoxy you can do about anything incl. gluing this plug back in. Take a piece of scrap as backer-board, put ductape around it and use hot glue or a couple little dots of ca glue to put it up under the deck covering the hole.

Now mix some epoxy and brush from above to wet out the plug as well as the opening. Add some microfiber thickener to the left over epoxy and coat the side walls, then the side walls of the plug and while checking grain alignment put it back in.

I like to poke around it with a cocktail pick and add epoxy (with the pick) where needed.