Hi, my wife has a full carbon Allwave Vanguard Outrigger canoe.

It is only about 12 months old and we have just removed the cover after being stored for the winter to find an extensive 'roughness' on the gel coat - like tiny bubbles, really course to the touch. Also in places, there is visible bubbling, see picture.

She has only over used plain water to clean it (after ever use) and 'Car Plan bumper shine' to polish it, which was recommended by the seller.
It has been stored in a nylon sock and not come into contact with any chemicals. There was no problem when it was last used in October/early November - could frost have damaged it?

Firstly, can you suggest what might have caused the problem, and secondly what products do I need to repair it. I specifically want to know if I need to colour the gel coat (the boat has a multi-colour design!!) or will I be able to just sand away the bubbles and re-coat it with clear gel.


(The darker lines are reflection of trees)

Those don't look like osmosis blisters. Osmosis blisters tend to bubble to the point where they will pop open. And osmosis blisters won't just go away when left to dry out, once it's there it need to be opened up and washed and dried. What you have looks more like some kind of contamination in a painted surface. Either way the only fix is as suggested. Grind or sand them out and either refill the gel coat, or fill/fair and repaint.

Hi drcx, they are popping (see pic) and there is no sign that they are going away, in fact I dont see that they can, they are too big and even if they do the gelcoat where they were will be detached from the carbon.

I think that the fact there is salt water within the bulkheads is the cause as the bubbles are limited to area of the hull and deck above and below the bulkheads - there is no bubbling to the hull below the cockpit.

I cant see any alternative but to sand and refill but do I need to wash out the bulkheads or will allowing them to dry properly (with salt still in) be sufficient. I'm not sure of the best way to ensure the salt is removed other then run fresh water into them for quite a while.