Upgrade from 9" to 12" MFD Garmin1243xsv

[Westerly Fluke Guy]

I am under the impression that the gloss black dashboard on my 21SE is an acrylic material.
I am going to have to cut to open the hole up to accept the 12" unit.
What have you guys used to cut the dash plate?
Any problem encountered such as cracking or chipping?
With past projects I have incrementally used drills 1/64 at a time to not crack similar acrylic materials.

 

[warthog5]

Surface gets taped....Layout on tape...Cut with a jigsaw.. Ultra fine Bimetal blade 18TPI. Drilling holes for screws.....Here where you need a drill size checker...use it to check the screw size to drill bit size. You need to go with a looser hole than norm...This is because the material is so hard it will crack. you want the screw to still grip, but not bite hard. one size less than if the screw fell in the hold. Usually its 2 sizes less. And sneak up on turning the screws in...Do it by hand so you can feel whats going on. Use the screw like a tap...in and out to cut the threads.

 

[Westerly Fluke Guy]

Surface gets taped....Layout on tape...Cut with a jigsaw.. Ultra fine Bimetal blade 18TPI. Drilling holes for screws.....Here where you need a drill size checker...use it to check the screw size to drill bit size. You need to go with a looser hole than norm...This is because the material is so hard it will crack. you want the screw to still grip, but not bite hard. one size less than if the screw fell in the hold. Usually its 2 sizes less. And sneak up on turning the screws in...Do it by hand so you can feel whats going on. Use the screw like a tap...in and out to cut the threads.

Thx.

 

[Westerly Fluke Guy]

Surface gets taped....Layout on tape...Cut with a jigsaw.. Ultra fine Bimetal blade 18TPI. Drilling holes for screws.....Here where you need a drill size checker...use it to check the screw size to drill bit size. You need to go with a looser hole than norm...This is because the material is so hard it will crack. you want the screw to still grip, but not bite hard. one size less than if the screw fell in the hold. Usually its 2 sizes less. And sneak up on turning the screws in...Do it by hand so you can feel whats going on. Use the screw like a tap...in and out to cut the threads.

That layout template requires the use of a 9/16 drill bit on the corners of the opening. That's a crazy big hole to be drilling through that acrylic without cracking and tearing it up even if its brought up one drill size at a time.. I think I'll possibly drill much smaller take it all the way up there to the prescribed radius with a milder cutter like a Dremel or die grinder.

Have any of you guys had a problem with the black dash material?