Boat Tarpaulins

[joewalsh]

Need some advise. I am overseas for a 3 year period period , and my boad is layed-up. I covered it with a tarpaulins, thinking it was safe and sound.

Unfortunately, water got inside the tarpaulin and the side of the hull developed Osmosis. I had no idea this could happen
In this case, does the entire hull need treatment or just the affected area? .
Unfortunately I need to put a tarpaulin back on the boat fot 1 more year. Any advise on how best to do this? Should I remove the Stancions or put it over . Any tips to avoid getting water trapped. Or should I leave it exposed?
joeyw

 

[VicS]

That's amazing? Were you using plastic tarps or proper canvas ones?

Whichever pad all projections with old carpet to protect the cover. If you leave the stachions on then protect the cover from chafe at their tops if you remove them you may have to protectct the cover from some of the bases and other projections that are not a problem with the stanchions and guard rails in place. Make sure there are no folds or pockets that can trap water. Perhaps it should only be just large enough to come a few inches below the level of the deck.

I have left mine covered for 2 years on a couple of occasions with no such problems.

 

[Talbot]

If I had needed to leave it for that long I would have had it shrink wrapped.

 

[William_H]

I find your statement that "the side of the hull got osmosis " quite amazing.
Osmosis as I understand it is the seeping of water by capiliary action into the fibreglass or between layers. This tends to happen when the hull is emersed in water and then over a period of time. I would find it surprising that enough water was trapped against the iside of the hull to cause osmosis. So it may have just appeared, but been caused by life in the ocean.
There are many more experts here on this forum but osmosis is treated at the damage site by bursting bubles, cutting away the outer layers and allowing to thoroughly dry before building up the hole up with epoxy and fibreglass. good luck olewill

 

[BrendanS]

I, like you, suspect this was caused by previous use, not by tarps of any type.

 

[dimdav]

what sort of boat is it mate? ie construction material

sounds to me like you could have the same as my current boat, its grp but with a marine ply core, I left it over the winter under tarp and when I went back there were huge bubbles where the paint and first layer of grp had seperated from the ply core and in some cases the ply was rotten through. Still if it is that then no real need to worry as long as you take off all the grp, rotten wood etc and let it dry thoughly. Then what i have done is... epoxy, car repair GRP then finally another epoxy coat back over. The result is a stronger and visually fair repair.

If you are leaving it for another year or so then I would suggest getting some hard wearing tarps but before leaving the boat sit in it when its rainign, see if any water comes in the tarps, if not then strip back all the damp areas and leave open so air can circulate

 

[joewalsh]

My boat is an Oyster 26, which is of a fairly solid construction, I believe. It was amazing to pull back the cover and see 1 patch of Osmosis, 2 feet by 3 with a lot of blisters, on the side of the hull, there is not a single blister below the water-line.

Putting a carpet under the cover is an excellent idea, and would have helped lengthen the life of the cover.

I ordered the Tarpaulin through an advert on PBO, I thought that I had ordered a quality product but it wore quickly and got porous.

If you can recommend a good supplier and type of cover, I should order it would be appreciated.

As the Osmosis is above the water line I am going to do DIY on the bliters for now and hide everything with paint.

Thanks for all the good advise

 

[dimdav]

I found this to be top notch

http://www.tarpaflex.co.uk/acatalog/SUPER_TARPAFLEX_TARPAULINS__MID_GRADE_.html

 

[VicS]

[ QUOTE ]
I ordered the Tarpaulin through an advert on PBO

[/ QUOTE ] If this is one of the woven polyethylene tarps then 3 years is life is rather more than optimistic. I have had less than 3 months service from the lighter ones in the past. I have more recently had better luck with one of the heavier ones covering a small trailer but it is not subject to quite the stresses that a boat cover is. I have not tried the reinforced ones

It will be interesting to know how Sandgrouders "Tarpaflex" ones compare. I notice they also do a reinforced range as well as the "mid grade" in the link.

 

[seaesta]

Why are you covering it up??
I would make sure there is lots of ventilation internally so that any ingress will dry and leave the boat uncovered outside. If you can find an old plane hanger or farmers barn and put it in that then great. Wrapping up a boat seems a very bad idea.
Martin

 

[joewalsh]

The short answer is that my working assumption is that a water proof boat cover would offer some protectect against new osmosis appearing as I won't be in a position to bring the boat indoors until next year.

The patch of osmosis is on the side of the hull hence easily covered. This, is in my logic, was as close to drying it out as I could get.

If this is the wrong thing to do I am open to re-consideration.