Sandblast the bottom?

dopierce · Post by **dopierce** » Wed May 18, 2005 4:36 pm

I need to strip 20 years of bottom paint off my 7.9 and am considering sandlasting. Has anyone have any experience with this?
Dave

Jeff Bonvallet · Post by **Jeff Bonvallet** » Wed May 18, 2005 5:07 pm

Several people at our club sandblasted thier bottoms a couple of years ago. Everything went great until they tried to repaint. None of the bottom paints used would stick. After some research they discovered that they had used a silica sand that coated the fibreglass with some sort of silicone residue. A great deal of effort was then put into cleaning this off before they could paint. Apparently there is a type of sand that can be used that won't leave this residue. Do your home work!

Post by **Tom Elsen** » Wed May 18, 2005 6:26 pm

Dave

I can't agree more with Jeff's point of 'Do your homework'. Talk to a LOT of other racers who have had it done by that (specific) person, not just the yard.

There are many different media including various sand(s), soda and micro-beads. So you've got to get that part right. But from there, operator skill is everything. And a bad job will completely screw up your boat.

dopierce · Post by **dopierce** » Wed May 18, 2005 6:46 pm

Thank guys, good insight, I'll do my homework!
Dave

Stef · Post by **Stef** » Wed May 18, 2005 7:56 pm

After some extensive research I found the media of choice for removing bottom paint is walnut shells. If this is not available a plastic bead can be used.

Rudeman · Post by **Rudeman** » Wed May 18, 2005 9:26 pm

Having run a performance sailing bus for over a decade where we experimented with most everything I would vey strongly advise against sandblasting period.

Chemical paint strippers and sanding afterwards is the best methods to remove old paint.

It is also the most safe.

Coldduck · Post by **Coldduck** » Wed May 25, 2005 9:32 am

I refinished my bottom 2 years ago. The bottom was sand blasted and I repaired a number of blisters and defects. Prior to barrier coating I longboarded the hull and used Interprotect 2000E.

My bottom was primed with VC Tar which virtually eliminated the possibility of sanding. The VC Tar clogged the paper almost instantly. The sand blasting was done by a knowledgable yard and when they finished the surface was rough but they did not cause damage to the gel coat.

I have not had any issues with adhesion. My boat is sailed in fresh water so I use VC-17m which is very smooth and fast.

Good Luck

S2 7.9 Meter Class Association

Sandblast the bottom?

Sandblast the bottom?

Sand Blasting