Sand Blasting and Glass Repair

[ryanpratt]

Hello world two questions.

1. I Just got a Zodiac Hurricane 640 and need to clean it all up (Hull) so i can paint it. I was thinking the best thing to do to get rid of all the old oil, bottom paint etc. would be to sand blast the hull. Can I do this? Should i do it? what sand should i use and what pressure?

2. their is a puncture on the bottom of the boat (picture attached) that is about the size of a match book and it goes through 3-4 layers of the glass. what is the best and strongest way for me to fix this.

3. What type of paint should i use?

Thanks again. I would like to start a thread for this project once i start to show the project from start to finish.

[marshmat]

Hi Ryan,

Punctures in fibreglass are typically repaired by cutting back the damaged laminate, layer by layer, leaving the hole with a "stepped" appearance. A patch of fibreglass cloth is cut to the appropriate size for each stepped layer and the patches are laminated in with epoxy.

Regarding sandblasting: It can work, but you'll have to be very careful not to damage the gelcoat or the laminate itself; gelcoat is quite soft and easily damaged. Personally, I'd go with a thorough power-washer job, followed by some quality time with hand-held sanders.

If the boat's going to stay in the water for extended periods, you'll want a good bottom paint system, possibly an osmotic barrier coat as well- ask around the local boatyard to see what's popular on planing hulls in your area. If it's going to be a trailer boat, nothing so expensive is required; a couple of primer coats and a linear polyurethane finish will have it looking factory-fresh.

[TollyWally]

Others may have differing opinions but I'd be more inclined to use a grinder with 60 grit paper, maybe rougher maybe finer depending on how things go. Grind the gelcoat back around the puncture say the diameter of a softball. Fill the hole with some glassbased putty. A few layers of matte, a bit of cloth, all feathered nicely. Some more putty for perfection, nothing to it.

Depending on how aggressive you are with the grinder (less is better) touch up the gelcoat or give it a nice barrier coat of high class epoxy primer and paint combo ( Where is our dearly beloved and long departed transplanted texan when we need him? I miss that guy!) Bottom paint to suit, presto chango happy inflatable. If you limit your beerdrinking ( this is sayig more about me than you) 2 weekends at a moderate pace will do it. You could drag it out as long as you want.... LOL

I see Mat chimed in while I was writing. A shorter version of my post; what he said.

[ryanpratt]

Thanks Matt,

I am looking to paint the entire boat so should i still follow your advice or should i sandblast lightly?