Sandblasting and Gelcoat

[Jim]

Is sandblasting to remove bottom paint harmfull to your gelcoat?

 

[Mike Ross]

Yes, according to my yard

I just talked to the service manager at my marina about sandblasting. Its the cheapest way to go - their price was $13/ft. But he said every boat runs the high risk of having air pockets opened up in the gel coat. He said it doesn't matter how old the boat is or the condition of the gel coat, it jut happens during sandblasting. Any air pockets would have to be ground out and then filled. He said he usually warns people to expect between $1500 and $2000 worth of repair costs after the sandblasting.He highly recommended just having it sanded down to the gel coat. This was also in the $1500-$2000 range.I decided to do it myself using peel away. It took 2 people 2 full days to apply and remove the paint, then it took me almost 2 more days worth of sanding to remove the old primer and get down to gel coat.hope this helps,Mike

 

[Don]

Mike: re peel away

Why did you have to sand off the primer? Wouldn't that have come off with peel away too?I ask becuase I'm getting ready to do that job soon on my 37. What size boat do you have that took 2 days/2 people?

 

[Mike Ross]

Hunter 34

Don,My boat is an '86 Hunter 34.I'm assuming what I sanded off was a primer. After using the Peel-away, and scraping off the many layers of botton paint, there was a thin, greenish yellow layer underneath that. It was only removed by the peel-away in a very few spots. The green 'primer' was a very thin layer. Some of it came of by cleaning with a scrubber. I knew I had to sand the hull with 80 Grit before applying the barrier coat, so I just sanded it all off. It came off very easy, leaving a nice clean white gelcoat underneath.Hope this helps,Mikeps: I posted earlier asking for advice as to what the green layer was, the only response was that it probably was a primer.