best tool for cutting holes in boat

[Jarod]

Hi There

I have an e27 and will be enlarging the opening in my head to accept a slightly larger lewmar replacement portlight for my 70's vintage leaker. I want to buy a tool that will have other uses on the boat as well. My first thought was a jigsaw, but you cant really get a jigsaw into tight places for cutting. I also considered a new dremel....does anyone know if it will cut through say some 1/4inch fiberglass with a 1/2inch plywood backing??? or through the cabin fiberglass for my portlight opening.. i like the idea of the dremel because i can get into tighter spots with it and of course its myriad of other uses....but i am not sure how effective they are for cutting....any good suggestions...thanks all

jarod

 

[SAILSHIGH]

Rotozip

May I suggest a Rotozip. They have really added great tools to this basic cutting device. I just used it to cut through concrete with ease. Tight spaces no problem.

Good Luck!

 

[Loren Beach]

Holes....

I have used a compact auto-scroll sabre saw for this type of work for many years. On the boat this means drilling a pilot hole and then sawing from the outside of the cabin or cockpit, where there is more room. Be sure to put a layer of blue tape or taped-on cardboard tight around the cutout you are creating -- this prevents having the base of the vibrating tool "write" on the finished gel coat or paint.

I always make a precise paper pattern first of the "cutout." Once that is marked (and checked numerous times...) then I make holes and noise. Double check on the inside with your cutout pattern to forstall having to dope-slap your forehead after you have accidently sawed into something you should not have.


A "Dremel" (or any of the competing brands of small die grinders is good for getting that last eigth of an inch you find out that you have to remove. I use their small sanding drum with it.
I have a Roto-Zip also, but it can be too agressive for trying to do precision work when free-handing. Don't ask me how I know this...

Best of luck,
Loren

PS: the newer versions of these little sabre saws have a dust port that fits small vacuum hoses - this is a Very Good Idea.

 

[Chris Miller]

trim cutter...

could also use a trim cutter- like a very small router. First with a rabbeting bit to enlarge your opening, then with a pattern cutting straight bit to finish it up. small footprint/very nice lines. wear hearing protection in tight spaces.
Just thinking out loud...
Chris

 

[Geoff Johnson]

Last summer I had to cut a 6 inch hole in the deck of my Laser to install a port in order to access the interior for repair work. I used my (old model) Dremel with a spiral cut blade (like the Roto-Zip, only smaller) and the circle cutter you can get for the Dremel. The deck was a 1/2 inch sandwich of fiberglass and coring. The process was very easy and the Dremel cut a perfect hole.

I would not recommend the the router/trimmer. I have a lot of experience with it from my cabin sole project. It is a powerful and potentially dangerous tool and should be used on with a well-clamped guide, never freehand.

 

[Martin King]

Probably the cleanest way to do it is with a laminate trim router
and a template-if you have the room on the cabin side to use
a template. If you just need to enlarge the existing hole say by
1/4 ", I like a die grinder equipped with a sanding spindle and
some 80 grit.

Martin

 

[Geoff Johnson]

Martin makes a good point. If there is already a hole, you won't be able to use a circle cutter without covering the hole in some way. However, a small router, with a template and pilot bit will work if you have the room and some way to clamp on the template.

 

[Emerald]

i like the idea of the dremel because i can get into tighter spots with it and of course its myriad of other uses....but i am not sure how effective they are for cutting....any good suggestions...thanks all

jarod

Hi,


I'd put the Dremel into the "light finishing work only" catagory. If you have small pieces which need precise work, they're good. If you have real material to go through, you'll find it is too slow and will not last as long as you like.


Geoff - surprised you had good success for such a large hole and thick material with a Dremel. How old is yours? Mine is/was about 6 years old and is a "pro" for whatever that is worth. I never found it up to the task you describe. For the big holes, I find a nice hole saw on a heavy duty drill my favorite (granted the initial buy of a 6" blade and mandrels is expensive and sometimes hard to find that large).


Just my .02 worth, based on one dead Dremel on the bench after way too few hours of actual use.

 

[Martin King]

I'd agree that the Dremel is really for light duty work and not
suited to grinding glass. If you're just reaming out a little bigger
opening, the die grinder with sanding spindle offers good control
and fast results. If you get an assortment of different diameter
spindles, you can easily match the radii in the corners. If you are
not familiar with routers and templates, this would be the safest
course to take. I used this method to correct the sloppy
openings on my own boat. On every port 1 or more fasteners
were missing the cabinside altogether and I ended up reglassing
all the openings to fix that.

Martin

 

[Geoff Johnson]

Yeah, what's with the portlight openings? Ericson must have used the new hires for that job.

Anyway David, I used the standard issue Dremel (old model). I might have taken a few years off it, but the spiral blade doesn't seem to take much power. The fiberglass trashed the blade, but it certainly was much cheaper than buying a hole saw that size.

 

[Emerald]

Hi Geoff,

Sounds like the Dremel did what you needed, and totally understand the economy if you don't already have a collection of hole saws going.

I've been forced to come clean by another Ericson owner on the board that at least one of my larger saws and mandrels in my collection came as a thank you gift for having said friend buy the critter so I could go make a bunch of holes in his hull one Saturday morning a year or so ago, and upon completion of the task, I believe I told him that part of the job was free, but fixing the new holes was quite costly

For the record, I had to buy a larger one recently - ouch, but at least I already had that mandrel

.

 

[Geoff Johnson]

I once cut a 4 inch hole in a boat using one of those cutters with arms and cutting blades on the end and which are supposed to be used only in a drill press. I guess you can use anything as long as you're not too particular about how many fingers you take home.