Marino iside Seal Issue

[Destination Sea]

Finally Last thursday i tried out the boat . Basically its control when approaching the quay , tried out the auxilliary which proved quite good. It moved the boat faster than with the previous 15 footer due to its deep v. Tried the engine on full throttle for a few seconds to check out the prop.managed to get somewhere to 4300 rev although the boat moved pretty fast. As skip suggested  I changed from a 17 to a 15 inch but will have to try it out . Had some water ingress from the thru hulls which i sealed and tightened the joints one down. However i still noticed water and  after various trails and investigations it resulted from a particular spot on the side close to the transom from where the boat is joint  i.e the side rubber. Went today and sealed up the location. Will have to check it out again and if its ok i can concentrate to rectify the prop selection if required.

[Granitu]

can it cause osmosis if not properly sealed?

(skip enlighten me )

[benri]

@Destination sea.... Isn't your boat brand new? If it still is under warranty before sealing I would have it checked out professionally.

[The_Gaffer]

Destination sea. Make sure the boat is water sealed from the outside and not the inside.  Granitu: water in the hull will definitely cause osmosis.

[skip]

Hmmm I'm guessing here that perhaps the correct way of sealing it would be to remove the white rubber rubbing strip and have that properly sealed. Is that part constantly immersed in water and below the water line? Or does it occasionally dip in?

Osmosis usually affects parts of the hull that are constantly immersed which is why you put the protection below the waterline otherwise we'd all be applying Gelshield or West Systems along the sides as well.

You want to use a sealant that is permanent and suitable for below the waterline as well. Don't just use an ordinary sealer it ideally should be an permanent sealer that is fully waterproof.

Something like 3M 5200 or Sikaflex

3M? Marine Fast Cure 5200 Adhesive Sealant
A faster curing version of 3M? Marine 4200 Adhesive Sealant. The high performance polyurethane becomes tack free in one hour and fully cures in approximately 24 hours. The seal is extremely strong, retains its strength above or below the water line. Stays flexible and allows for structural movement. Has excellent resistance to weathering and salt water.

I have a small tube but sealing from the inside is not an ideal solution as the water will run along the fiberglass seams where the deck and hull join, and then as the others pointed out you might induce osmosis as the fiberglass will become wet and permanently saturated.

[Destination Sea]

The part effected is not constantly immersed in water It is about 1foot above the water line. This only happens when the boat is turning tight and a wave splashes on the side. However I will definetly have it checked later on.

[Moonwalker]

Is the 3M 5200 better than secaflex 291?
I have the rear bracket of my kaptan 15ft always leaking water. It is sealed with secaflex 291 and every time I repair the cracks, it starts leaking again after a while. The silicone either cracks or it forms like boubles that burst and open up a path for water.

[skip]

3M 5200 is a permanent waterproof adhesive sealer. The key however is making sure that the area you are going to seal is dry, if it contains some water could be why it's bubbling.

Sikaflex is similar, can't say which is better or worse.

[Moonwalker]

Will have to clean it all, let it dry and re seal again then. Will use 3M 5200 and let you know the result. Will try to find some time and do it before winter