Cutting Hole in Hatch

[OrangeCrush]

Has anyone successful cut a hole in a plexiglass hatch? I want to install a Vetus UFO2 passive vent to improve ventilation in my forward cabin. The installation calls for a 85mm cutout, and I would guess that my hatch plexiglass is about 1/4” thick. I wrote to Vetus and they recommended I employ a “professional hatch repair service” but I don’t think they have those in Brooklyn!

Has anyone successfully cut a hole in a plexiglass hatch? I’m gonna get some scrap plexiglass and try a few things out. They sell an adjustable carbide tipped hole cutter for about $7 that might do the trick, or maybe a regular hole saw. A 85mm Forstner bit isn’t cheap but could be worth it if it’s definitely the best tool for the job.

Any tips or relevant experiences are greatly appreciated, thanks in advance.

[Pete17C]

Regular hole saw should work, just go slow and keep it straight/plumb. You don't want it to bind (might cause the plexiglass to crack) or get too hot.

[MikeFergie]

I just drilled a hole through 2 of my Lewmar hatches with a normal steel drill bit and my battery operated drill with no issues. Those glued on handles fell off so I needed to screw them tight

[gabilo]

Sure it works ... as Pete17C said... get a hole saw and drill it ... remember to drill from BOTH sides as the plexiglass is brittle and will otherwise leave an ugly edge.

[Jim Cate]

IIRC, kerosene is a good lubricant for cutting acrylic plastics. Use of such will help keep the temperature down at the cutting face.

Jim

[pilott]

And it would be a good idea to polish any cut edges with sandpaper, and to round off the edges somewhat.
Any tiny cracks or sharp edges can act as stress concentrators, and may initiate cracks in future

[a64pilot]

If you ever have to cut plexiglass for whatever reason a dremel with the cloth wheel and just polishing compound can polish the edges and make them clear and smooth as opposed to rough and white.

[Uncle Bob]

Originally Posted by OrangeCrush

Has anyone successful cut a hole in a plexiglass hatch? I want to install a Vetus UFO2 passive vent to improve ventilation in my forward cabin. The installation calls for a 85mm cutout, and I would guess that my hatch plexiglass is about 1/4” thick. I wrote to Vetus and they recommended I employ a “professional hatch repair service” but I don’t think they have those in Brooklyn!

Has anyone successfully cut a hole in a plexiglass hatch? I’m gonna get some scrap plexiglass and try a few things out. They sell an adjustable carbide tipped hole cutter for about $7 that might do the trick, or maybe a regular hole saw. A 85mm Forstner bit isn’t cheap but could be worth it if it’s definitely the best tool for the job.

Any tips or relevant experiences are greatly appreciated, thanks in advance.

Hi, I had the same query and took the hatch to a supplier of acrylic material, his response was, " oh ffs give me the thing" and in no time he had cut the hole with a battery drill mounted holesaw cutting from both sides to prevent exit damage, handed me the hatch, smiled and suggested that I f off before he charged me. Took all of a couple of minutes.

[sy_gilana]

I use a jigsaw with a metal blade, on the slowest setting, and keep it cool and lubed with soapy water.

[rsn48]

no time he had cut the hole with a battery drill mounted holesaw cutting from both sides to prevent exit damage, handed me the hatch, smiled and suggested that I f off before he charged me.

Seems to me you owe some one a beer or two.

[RaymondR]

I have found that large hole saws tend to pull off centre and drill a largish hole if a hand drill is being used. Consequently I generally hole saw a hole in plywood in a drill press then clamp the plywood down onto the work piece to act as a centering guide when using a hand drill with largish hole saws. Good firm guidance is critical when drilling brittle stuff like perspex. Lubing with kerosene from a spray bottle helps.

[Rchido]

I went to a machine shop and, after marking the center, the cut the hole for me.

[NorthCoastJoe]

Use a hole saw going slow, best if you can do in in a drill press with a block of wood backing it up. I do this often and have no problems.

[wayne.b]

Originally Posted by OrangeCrush

Has anyone successful cut a hole in a plexiglass hatch? I want to install a Vetus UFO2 passive vent to improve ventilation in my forward cabin. The installation calls for a 85mm cutout, and I would guess that my hatch plexiglass is about 1/4” thick. I wrote to Vetus and they recommended I employ a “professional hatch repair service” but I don’t think they have those in Brooklyn!

Has anyone successfully cut a hole in a plexiglass hatch? I’m gonna get some scrap plexiglass and try a few things out. They sell an adjustable carbide tipped hole cutter for about $7 that might do the trick, or maybe a regular hole saw. A 85mm Forstner bit isn’t cheap but could be worth it if it’s definitely the best tool for the job.

Any tips or relevant experiences are greatly appreciated, thanks in advance.

===



A hole saw is the right tool for the job. Under no circumstance would I recommend the carbide tipped fly cutter that you described. You will need a drill motor with a lot of power, preferably with a side mounted gripping handle. I used a hole saw to successfully mount six Nicro solar vents in a similar project.

[jhulmer]

Originally Posted by gabilo

Sure it works ... as Pete17C said... get a hole saw and drill it ... remember to drill from BOTH sides as the plexiglass is brittle and will otherwise leave an ugly edge.

Originally Posted by Jim Cate

IIRC, kerosene is a good lubricant for cutting acrylic plastics. Use of such will help keep the temperature down at the cutting face.

Jim

These are my answers also.



I have installed vents in my plexi on my previous boat. I used water but I'm sure Kerosene would lubricate better.



Cutting halfway through from the bottom with a regular holesaw and finish from the top reduces the breakout.