Need advise: Cutting the cabin trunk to install new Signet displays

[Gint]

Hi Guys and Girls,

I just ordered new Signet (SL250) displays to replace my old broken displays. The new ones come with a "soap dish" inlay so that the displays sit flush with the cabin trunk. I need to cut the old small circular hole (used for just the wires) into a large square hole for the soap dish. I was thinking about taping the section and using my Dremel with the bit shown below. Is this the best approach? ( Image link: https://ibb.co/7JztfXK )

[waughoo]

That bit is going to make a rather messy hole.  I would recommend a cut off wheel or even a jig saw.  You have a lot of material to get rid of.

[Gint]

That bit is going to make a rather messy hole.  I would recommend a cut off wheel or even a jig saw.  You have a lot of material to get rid of.

Ah, good idea! I have a small grinder on the boat. Perfect!

[waughoo]

I am also curious to know if that "bucket" can be left off thus allowing for surface mount.  Might be worth checking into.  I hate cutting MORE holes if I can avoid it.

[KWKloeber]

Ive used a roto zip to cut such holes and it worked well just going slow and steady staying on the line. Ifvi did it again I'd duct tape a straight edge to the fiberglass for a perfectly straight cut.

A 1/16" angle grinder blade will work.

I've also used a Dremel for such cuts but put a roto zip bit in it. That works very well instead of a Dremel bit.

[Ron Hill]

Gint : I'd use a saber saw or your Dremel Tool with a saw bit.  The Dremel will give you a finer cut.  If you use a saber saw or a "jig saw" be sure to use a "down" cutting blade!! 

A few thoughts

[Noah]

And if saber saw it will have to be a very long blade too. I would use an oscillating tool.

[Gint]

I am also dreading cutting a bigger hole in my boat, but the original screens where mounted externally and they stick right into your neck and back when you're resting against the cabin. Thanks for the advice, I have a few days to think about it... to cut or not to cut. I'll keep you posted on the outcome. 

[Phil Spicer]

Have you thought about covering the holes with a thin piece of teak? Mount things back by the wheel? Another option.