I purchased a 1990 PII without a motor and knowing it was it rough shape. I was going to have some glass work done and fix scatches with Marine-tex. We lifted the boat off the trailer the other day and under the bunks were round blisters in the gel. Is this going to be a total, sand down and re-gelcoat project. Or can I run the Marine-tex down the blisters and seal it off good enough. The boat is white if that matters.
What has happened is a process called Osmosis.
This happens a lot on boats that are kept in the water, one of the reasons they paint the bottom with copper based sealing paints on water kept boats to prevent this..
This is the reason on bass boats you only see it on the hull, where it sits on the wet, carpeted bunks.
Does not happen too often on bass boats.
Gelcoat is water resistant, but not totally " waterproof ".
If viewed under a high powered magnifier, you would see microscopic pores in the gelcoat, similar to pores in your skin.
These pores, depending on the quality of the polyester or vinylester resins used in the manufacturing process can actually let some water vapor pass thru over time.
Sometimes the water vapor is able to permeate the gelcoat thru these pores, and over time enough water vapor will cause blisters to form on the gelcoat.
The blisters will hold water, and like a blister on your finger , will pop over time.
When this happens, the gelcoat layer will start to peel, exposing the glass mat/resin ( the actual hull structure ) to the water......this is where the real problem can develop. If the mat/resin had any breaks in it , it too can absorb water, only the glass mat will act as a sponge and hold the water.......this will lead to the hull delaminating over time if not fixed properly.
Most never know it is happening cause we rarely ever look at the hull that sits on the bunk boards.
Not too much you can do to prevent it from happening, other than jacking the boat up a little off the trailer and putting a coat of some type of polymer sealer like Pro -Tec on the hull to seal the pores in the gelcoat.
Marine-Tex will work , it is totally waterproof.
But, it will only be good as the prep work you do to clean out each blister and make sure the glass laminate is not wet, or damaged. If it is , all the damaged parts will need to be removed and the glass totally dry before you apply the Marine -Tex.
Good luck with your repairs.
Thank you for your help.
We had a discussion (the people who would help) and decided we are going to sell it to someone with more skills than we have.
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