Grinding & Sanding

[Pake]

I am grinding/sanding to prep for glassing. There are many gel-coated areas. These surfaces are a bit rough. How far down must I go? I will be sanding with 60 grit.

See this link for pictures: http://s291.photobucket.com/albums/ll310/Mapawaf/

Thanks.

Pake

 

[erikgreen]

Re: Grinding & Sanding

Until you reach glass/material that is not discolored by water or dirt, is clean of glue and paint, and has no loose, unbedded glass fibers sticking out of it.

 

[gcboat]

Re: Grinding & Sanding

Just need to get the surfaces rough enough so the new material will have something to "bite" into. I'd be a little leery of that 60# paper, thinking something like 80# should be plenty. My $.02

 

[TheWoodCrafter]

Re: Grinding & Sanding

I'm using 40 grit on my gel coat to remove crazing. Gel coat is very thick compared to paint. Now I'm grinding through it to the glass to get rid of the crazing. The color goes from white to gray when to gel is gone.
If you don't have any crazing I would think 80 to 100 Grit on a sander not a grinder would be plenty to smooth things out.

 

[oops!]

Re: Grinding & Sanding

sorry bud.....thats a lot of pics......

each repair is different.....crazing fixed one way.....new glass application another way........gell coat repair another way....

each repair uses a different sanding/ grinding grit/tecnique

what exactally are you tring to repair?

 

[Coors]

Re: Grinding & Sanding

Before you go further, dig out the rotten transom, and assesss the damage there.

 

[Pake]

Re: Grinding & Sanding

The transom wood is out. I will be sanding to the glass and installing new marine plywood. I gotta tell ya, the "professional" transom install had many unbonded spots. I was quite amazed at that. It was also only 1 1/2" thick on the bottom 1/2, even though there is plenty of room for it to be 1 1/2" throughout.

 

[Coors]

Re: Grinding & Sanding

Ya might search Seacast in here-Gary is expert.