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poul.eriksen · 02-07-2017, 15:47

What is the dark spots on the inside of the hull? Is it normal or is it bad?

(The boat is from 2000 and is made of balsa core sandwich)

Paul L · 02-07-2017, 15:52

Mold or mildew? Does it smell?

CaptJamesCook · 02-07-2017, 16:03

Is it in the fiberglass or is it on the surface? If on the surface try this see if it cleans it...

To kill mold: Use white distilled vinegar and pour it into a spray bottle without watering it down. Spray the vinegar onto the moldy surface and leave it to sit for an hour. Finally, wipe the area clean with water and allow the surface to dry.

If it is under the fiberglass maybe mold in the core?
Someone else may have better answer.

poul.eriksen · 02-07-2017, 23:17

Quote:

Originally Posted by CaptJamesCook

Is it in the fiberglass or is it on the surface? If on the surface try this see if it cleans it...

To kill mold: Use white distilled vinegar and pour it into a spray bottle without watering it down. Spray the vinegar onto the moldy surface and leave it to sit for an hour. Finally, wipe the area clean with water and allow the surface to dry.

If it is under the fiberglass maybe mold in the core?
Someone else may have better answer.

Its not on the surface. It looks like its under the fiberglass, so I can't clean it.

**GordMay** · 03-07-2017, 02:52

Greetings and welcome aboard the CF, poul.

double u · 03-07-2017, 04:19

which boat?

Cadence · 03-07-2017, 09:22

If it surface mold a spray bottle of water with several drops of iodine may do the trick.

uncle stinkybob · 03-07-2017, 09:34

Since it's not surface but under the glass and it's balsa cored my first thought is that the balsa is wet and rotted in those area's.

fatherchronica · 03-07-2017, 10:07

I agree with everyone's favorite uncle. If this is a boat you are buying I would not. If you own it, I would search online for someone who has encountered it, and hopefully had come out ahead. If it were mine and a cheap boat that I could experiment on I think I would cut or drill an exploratory hole to it and see what it is and whether it is through to the gel coat. If it is an expensive boat I would paint the bilges and sell it. But don't spread that information on the internet as it would make me look like a giant douche. I used to renovate hotels, and there are several methods to remediate mold. I suspect that if there is mold that the balsa cores adhesion to the fiberglass is somewhat to totally compromised. If the mold, if it is mold, is confined to the inner surface I think I would drill hundreds of tiny holes to it, kill the mold, inject epoxy into everyhole, fill the holes and paint the bilges. Be forewarned that my opinion is coming from a lifelong glutton for near lost causes that require lots of sweat equity.

Chuck Hawley · 03-07-2017, 10:22

Is it possible that this cored area has some darker balsa and it's not actually saturated? I think that balsa may have enough natural color variations that this is simply darker wood.

At least that would be a better outcome...

Is there any visible damage, like deep scratches, on the hull outside of this area? We had damage from docking near the waterline on our SC 40 and had to have an area of two square feet, or so, replaced due to water intrusion. Not an easy repair job. Remove outer skin, remove core, dry out, replace core, replace outer skin, fair, paint, etc.

Chuck

CaptJamesCook · 03-07-2017, 10:40

What section of the hull is this? Above the waterline below?

I agree drill out a one inch dark spot with hole saw. See what it is

Cheechako · 03-07-2017, 11:10

Just drill a small hole, maybe 3/16" thru the inner wall of fiberglass. Remove the balsa from the drill twists and squeeze it between your thumb and first finger. If wet, water will come out.

hellosailor · 03-07-2017, 11:19

Forget the hole saw, a little finesse is needed.

Hold the middle and trigger finger extended tightly against each other, start tap-tapping on the area. If it makes a different sound, a duller thunk, in the black areas? That's wet core showing mold on the other side.

Next step up is to just take a 1/4" drill bit and drill a hole into those areas. If the core is wet, then wet mush will come out. In which case, you may need to open up and rebuild the entire affected sections. If you're lucky, just sawdust comes out, and a spot of epoxy to refill and seal the hole is all that's needed.

Could be the coring just had some surface mold on it when it was laid up, and it actually dry just ugly.