Grinding fiberglass

[Rotek]

I am about to start working on my CV16-SS and one of the first things I have to do is to remove the floor and replace the stringers and transom.
In order to do that I have to cut and grind through the fiberglass.

What grits are normally used for grinding?

Has anyone ever used these "Roto-Rasp" on fiberglass?


Thanks

[Glastronjohn18]

I've used 40 and 50 grit because that's what I had available and it worked well. Any thing you use will create lots of dust so be prepared. I tried to do all my grinding outside for that reason. Good luck on your project. To cut the tabbing on the floor I used a multi tool with carbide tip blades. They are more expensive but I found they last 3 or 4 times longer than standard blades. Multi tools create a lot less dust, I've also used a 3 1/2 in. circular saw (Roto-Zip in my case) to cut the floor tabbing. Good luck on your project.

[Plugcheck]

Good time of year to do that work, its hot and dusty and you need to protect your body/skin from all the dust.    There are a lot of choices for abrasives out there.   36 grit disks work well.   Just a suggestion, but i like to leave about half the  glass alongside the stringers, and peanut butter them in place.    Some extra glass alongside and maybe over the top.      I know a few rebuilds that eventually rotted again, maybe consider all composite.

[thedeuceman]

I have never used one, but I suspect they?re not hard enough to last. That glass is really tough on just about anything you used to cut it. After having done a few I think you have to decide what tools to use and how much to remove on a case by case basis seems like they?re all just a little bit different. For most of the rough work I have preferred 36 or 24 flexible discs mostly on the 4 1/2 angle grinder but I use an air grinder for a lot of the tight spots. When I was doing the demo work on our CV 16 V8 (now a half done stalled project) I got some carbide embedded metal discs from Harbor freight that look a lot like the Roto rasp. I used them to grind the glue off the floor from the carpet, they were pretty good for that because when they started to plug up the glue would get hot and it would kind of fling off the disc and then I could also clean them out with a pic if they got really bad. But then I found they also work really good for grinding large amounts of tabbing off, on that project I ground most of it off because it seems like they had done a poor job installing it. I don?t know if it?s good or bad but the thing about the 24 and 36 grit is it makes pretty big debris like long strands. On every project I have done I have use some sort of a dust collector either something I?ve built or in the case of the last one I bought one of these cheapie ones with the bag on top in a bag on bottom. I also wear a Tyvek suit. Make sure and post some pictures as the project progresses.


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[Rotek]

Yeah, I guess the Roto Rasp is not the best idea. I?ll stick with the standard stuff.

I have just bought myself a tyvek suit

I?ll post pics once the real work starts.

[Rotek]

BTW, does anyone have a good advice how to make a cradle?
How should I get the hull cross sections so I can cut the cradle panels to conform to the hull?

[Plugcheck]

Of the two cradles I've made, i just copied the design of my bunk trailers, formed a perimeter, used some plywood in the corners to reinforce, and added some heavy duty caster wheels.

[thedeuceman]

This is the one I?m using for the CV 16 V8 the outer supports are 2x8, the inner supports are a 2 x 8 ripped in half and I just spaced them off of the cross boards so they sat snugly against the outer two sets of lifting strakes


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