I am going to add a front access door to my center console to access my trolling motor batteries. Any suggestions on the best cutting method, or particle blade, or saw type. I know when I cut holes for rod holders, the best way I found was to start off cutting in reverse.
Right now I plan to tape it, and cut through the tape using a jig saw. Any suggestions would be appreciated.
A jig saw or recipricating saw will work, but I’ve found that the gelcoat can chip easier. If you have a die grinder with a cutoff wheel you can make a nice cut if you take your time. Wear a dust mask though, you’ll get a lot more dust than with a saw. Probably would’nt be a bad idea to wear one while using the saw.
Bob Van Gundy
Marine Designs,Inc.
Custom Aluminum Fabrication
803-727-4069
If you use the jig saw I suggest you use a metal cutting blade as they don’t have a lot of set which might cause tear-out or even better would be to grind away the set in the blade .
Tooth set is the side-to-side bending of saw teeth. Tooth set is used to widen the cut and prevent pinching of the saw blade . The more tooth set the wider and rougher the cut .
I use a Bosch jig saw and have no problems cutting thru glass. Bosch offers a laminate blade that only cuts on the down stroke to prevent chipping, I usually just use one of the finer teeth blades
Fine tooth jig saw blade as spareparts suggested, also helps to put some tape down where you will be cutting, mark cut line on tape and cut thru tape as well, helps to avoid chipping.
Russ B. Formerly known here as “Top2Bottom1”
www.joinrfa.org
God is great, Beer is good, People are crazy
You may not have one but, a Rotozip spiral cut saw works really well on fiberglass. I used one when I redid my console gauge panel and it cut very cleanly.
Mandopickr,
Like the others here said, a high-RPM jigsaw with a good blade will work, and I imagine that most fiberglass shops probably use either that or a 4" grinder. However, I want to tell you about something that has worked even better for me as an amateur on cuts where I had to have near-perfect results in “nervous areas”. I don’t know if you’re going to do enough cutting in the future to justify buying a $100 tool for this, but if you are, here’s something for you to strongly consider. On the last couple Fountains we had, I really wanted to make sure I got ultra-clean cuts as I was cutting in cosmeticly important areas, so I used a high-RPM pneumatic reciprocating saw, like the one pictured below, to cut out large sections of gelcoated fiberglass, and I didn’t get any chips whatsoever. I’ve also used it to make precision, cosmetic cuts in carbon fiber with excellent results. I got a nice, perfectly clean, very thin, accurate cut line every time–laser-like. Very happy with this tool. If there is any complaint, it’s that it can be a little slow on thicker panels.
As you can see in the link, it cycles at 10,000 RPM (SPM), while most jigsaws are anywhere from 500-2500. Its extra high RPM/SPM gives it the clean cut, and it’s compact so you can cut in tight places and funky angles–which are not uncommon when mounting flush-mounting big screens and stuff like that. I’ve used this to cut flat areas of gelcoated fiberglass anywhere from 1/4" to over 1" thick (with foam core–not solid 1" glass). The blade (at least on mine) also starts and stops instantly, with no speed-up/slow-down time (i.e., it is instantly at top RPM when you hit the button), unlike a jigsaw or other electric tool. I think that helps, too.
Either way, take your time and don’t force the blade. Watch out near the end of a thin panel cut with jigsaws or this tool (or any reciprocating tool) because one side (the cut-out part) won’t have much structure left to support it, and if you don’t do it right, it will start moving, vi
If the corner radius is large enough I’d use a hole saw to cut all four corners. Then, cut the straight shorts as described above… just thinkin’ out loud.
17’ Henry O Hornet
26’ Palmer Scott
how bout a dremel tool?
Thanks all, I have a rotozip, but I have a tough time freehanding straight lines with it (if I go this way, I’ll mount a guide). But first I’m going to check into gotcha’s pneumatic reciprocating saw. If my compressor will handle it, I can justify that expense with other applications. And I like the hole saw for the corners.
Thanks again.
quote:
Originally posted by crnawolfmanhow bout a dremel tool?
I use a Dremel w/ “router attachment” for all holes I cut into boats. Never screwed one up…yet! I’ve done speakers, stereo, cup holders and a solar fan so far!
‘05 Wellcraft 232 Coastal rockin’ a Yammie F225
‘00 Aqua Force Flats 15 w/ Yammie F25
"Kiss my ass, I bought a boat; I’m goin’ out to sea." (Jimmy Buffett covering Lovett)
the roto zip is the most useless tool I’ve ever owned, once you try a Bosch jigsaw, you’ll never use anything else, I also have one of those high rpm saws, nothing cuts like a Bosch saw
So, you don’t like your Rotozip?
Mando:
I have used almost all of those listed above, most commonly use a jig saw with a metal cutting blade and set on a low bite setting. Lee’s saw is also know as an air body saw used for cutting sheet metal on cars. I bought a cheap chineese one for around $30 bucks from Harbor Freight when I was restoring my jeep. While I have never used it on fiberglass I can see how it would work great, as Lee said the RPMs are much higher and I know for a fact it cuts sheet metal cleaner than a jigsaw. Thanks for the input Lee, glad to know I got another use for a tool I already have in the garage.
Glad to be of help, Contender. A jigsaw would be my second choice, but it still won’t get into the tight places and angles that these neat little saws will. BTW, I saw one of those Chinese ones on sale in the paper for $10! LOL. Harbor Frieght is a trip. Not sure what the RPM’s are on the $10 one, but it sounds like the one you bought worked out well. I actually enjoy using this little saw. Just makes you want to cut something. 
Gotcha Covered,
Lee Strickland
Strickland Marine Insurance Agency, Inc.
https://stricklandmarine.net
843-795-1000 / 800-446-1862