Cutting the slots out of the Revell 1/72 U-Boat ?

I sanded mine from the inside until you can see the holes. Then just punch them out and clean them up. Most people use a dremel set on a low speed with the same idea. But before you open them all up, you should determine which boat you want and find out what the patterns of the flood holes were. You may have to fill some in or resize them. Not all flood hole patterns were the same. I would strongly suggest you contact Dougie Martindale. He has a lot of info on this and other subjects concerning specific boats. He just posted some very good info on the different types of exhaust patterns and flood patterns at Ship Chat.

Here's a link to a post he just made on flood hole patterns. If his name is highlighted at the top, you can e-mail him about anything specific. I've gotten lots of info from him myself. Good guy.

http://www.clubhyper.com/forums/shipchatframe.htm

Good luck!

Jess

I'm still a bit rusty (read: haven't built a model in about 17 years) and was afraid to grind away the inside right up to the point where I could see the exterior(afraid of working the plastic after it was already that thin).

Using a drill approximately the same diameter as the flood hole I drilled out one end of each flood hole then gound one long trench along the inside using the drilled hole as a depth gauge.

Once I was close to the the thickness I wanted it was really easy to remove the rest of the flood hole by drilling the other end then scraping/filing the insides. I also used a bullet nosed stone to slowly grind away from inside if I found the finished flood hole edge was still a bit too thick.

For myself the piece of mind of being able to see how deep the trench was allowed me to be a bit more aggressive in grinding the trench. For myself the drilled ends looked nice and uniform.