Blisters?? Now a bit confused

[katana750]

I posted this in another area first and was told what has happen weren't blisters. I don't know what it is and probably doesn't really matter. Maybe water was between layers of fiberglass and froze. Its a macgregor and Im not sure how thick the hull is....probably very thin.



I think this is a blister. I have read quite bit about them and understand how it happens but I was a bit shocked at how deep into the fiberglass it went. Easily a quarter inch.

I thought my bottom didn't have any problems. I wanted to store the boat in the water a bit longer term so I thought it was maybe a good idea to remove the ablative paint and then put a water barrier coat on

I pressure washed as much as the ablative paint off as I could. I fair bit of it was already gone. I was working on finding somebody to soda blast the boat to have a perfectly clean bottom. I noticed a fairly large crack. I stuck a screw driver and pried it open and then....ohhh my. Its right by the back bunk and probably eight inches by the time I take the boat off the trailer and grind it all back.

My plan now is not keep the boat in the water this year. Use it as normal. Have it soda blasted when I can. Put it in the garage with heat over winter and fix it next spring. I could always buy a meter and moisture check the hull....but Ive read reason to use a water barrier paint and reasons not to. I would really like to find a place to leave it in the water after it fixed, but not so sure now.

Thoughts?

My question now is epoxy or fiberglass and it is probably smarter to fix it now. Epoxy seems to be the better product but after searching a bit some people seem quite adamant that if you have a polyester product you should stay with it. Eventually I want to find somebody to prep the boat for a water barrier paint by soda blasting it, but the closest people are several hours away (they do travel and will be here sometime) In the mean time I want to patch the boat and use it for the summer. The boat repair kit from west system seems perfect...It might take two kits but I wont have a bunch of material left over.

The other thing I have noiticed is the order in which the mat is layed. There seems to be a great utube video from Boatyardworks. He lays the mat smallest to biggest layers...this makes more sense...but when you see videos for west system they go biggest to smallest. Is it because something is different with epoxy?

Thanks
Dave

 

[Fred Villiard]

The reason to biggest to the smallest, you get the most strength.

When you smooth the lamination to finish you don't cut into the big area, if you have the biggest last you sand it away and all you have left are small islands surounded by resin.

Listen to the experts, West, not the armchair so called experts.

 

[Don S/V ILLusion]

Everyone already told you that isn't a blister. The gel delaminated from the glass. Peel off everything loose surrounding it. The extent of the damage dictates how the repair is done.

Somehow you got way off track here. There is no reglassing, polyester or epoxy required.

 

[katana750]

[quote=Don S/V ILLusion;1114722]Everyone already told you that isn't a blister. The gel delaminated from the glass. Peel off everything loose surrounding it. The extent of the damage dictates how the repair is done.

Somehow you got way off track here. There is no reglassing, polyester or epoxy required.[/quote]

I guess the picture doesn't show it very well, but he gell coat is still very much bonded to the fiberglass. The white line is the gel coat...The picture of it in my hand. The picture of the hull might be miss leading. The de lamination is between the fiberglass layers. I doubt the hull is very thick in the first place.

The piece in my hand:

The gell coat is maybe 32 of an inch thick, then a dark layer...resin?? stuck to that is a woven mat, stuck to that is a chop strand mat.



Thanks

 

[katana750]

The reason to biggest to the smallest, you get the most strength.

When you smooth the lamination to finish you don't cut into the big area, if you have the biggest last you sand it away and all you have left are small islands surounded by resin.

Listen to the experts, West, not the armchair so called experts.

Thanks that explanation makes sense. My thinking was with the big piece on the bottom you only have one fabric layer tied back into the original structure. With the smallest layer first, every layer is tied back to the structure plus each new layer is attached to each other.

I didnt really think about what happens when you sand it smooth.

Its funny after reading all the comments after seeing the west video a bunch a people said it was wrong....some people said it was right. Nobody ever gave a reason. Its nice to get peoples opinions but it does take a while to find which one is correct.

Thanks

 

[Charlie Jones s/v Tehani]

Made my living repairing and building boats for a long time.

As Fred said- largest piece first, always, and for exactly the reason he gave. You get the largest bonding area, layer to layer that way.

 

[katana750]

it makes sense.....now. thank you