Best way to cut gel coat?
#1
Registered
Thread Starter
Best way to cut gel coat?
I want to install some 3 3/4" stainless cup holders in my dash. Whats the best way to cut through the gel coat without chipping? Are there any good Dremel attachments?
#2
WORD of advise -
Just make DAMN sure that it will fit BEFORE you cut the hole.
I measured twice and cut once and the new radio location still almost didn't fit. It JUST fit.
Just make DAMN sure that it will fit BEFORE you cut the hole.
I measured twice and cut once and the new radio location still almost didn't fit. It JUST fit.
#3
Platinum Member
Platinum Member
A bimetal hole saw will work fine.
Here's the routine:
1) drill a thru hole the same size as the pilot on the hole saw.
2) run the hole saw BACKWARDS to get it started thru the gel without chipping. Once you have cut most of the way thru the gel, before you start cutting glass, change rotation to the normal direction and proceed with normal speed and light pressure.
If you need the far side to remain clean, cut only 2/3 of the way thru, then finish fro the reverse side. If the farside doesn't matter, then go thru from the front - as you get ready to break thru rock the hole sawl fro side to side as it spins.
After you cut, you can lightly clean the gelcoat with a 45 degree chamfer with a sandpaper roll on the Dremel. Usually don't need to, though.
Here's the routine:
1) drill a thru hole the same size as the pilot on the hole saw.
2) run the hole saw BACKWARDS to get it started thru the gel without chipping. Once you have cut most of the way thru the gel, before you start cutting glass, change rotation to the normal direction and proceed with normal speed and light pressure.
If you need the far side to remain clean, cut only 2/3 of the way thru, then finish fro the reverse side. If the farside doesn't matter, then go thru from the front - as you get ready to break thru rock the hole sawl fro side to side as it spins.
After you cut, you can lightly clean the gelcoat with a 45 degree chamfer with a sandpaper roll on the Dremel. Usually don't need to, though.
#5
Registered
Join Date: Oct 2003
Location: Ballston Spa, New York
Posts: 524
Likes: 0
Received 9 Likes
on
7 Posts
The absolute best thing to use on fiberglass is a carbide tipped holesaw. You can pick one up at any plumbing supply house. Lenox makes one in 3 3/4 or 4". The 4" sells for around $55 or so. With carbide you will not get ANY chipping as it enters the fiberglass.
#7
Registered
Join Date: Feb 2002
Location: Melbourne Beach, FL
Posts: 727
Likes: 0
Received 0 Likes
on
0 Posts
I've had great success using a dremel tool with a roto zip bit. I cut out all of my speaker holes, half a dozen gauge holes, and some pop up cleat holes. I usually put the Blue 3M masking tape down as a precaution and you can still see your pencil line through it.
Mark
Mark
#8
Registered
Thread Starter
Thanks for the ideas. It would actually be easier for me to cut the hole from underneath the dash. Otherwise, I have to remove the windshield. Because of this, maybe the dremel would work best.
#10
Charter Member #232
Charter Member
If you can only go from underneith then I would still use the hole saw, but I would use the same method that Mcolist said however I would score the Gell with a razor blade just to the outside of the hole. Then I would not push hard at all and just let the bit do its thing.
Jon
Jon
__________________
Put your best foot forward!
Put your best foot forward!