Normally I would post this in the Pocketship forum, but it’s been down for awhile. I want to make wood port hole rings for my boat. I’ve found many YouTube videos on how to cut a circle but I’ve not found one on how to cut a ring. Do you make the outer cut of the ring first or the inner cut. And how do you secure the material while cutting it.
My tools include a small router and I can make a jig for cutting circles. I thought about cutting the inner circle first, but that won’t leave alot of material to balance the tool on. ( I’m looking at a ring that is 6” outside diameter and a 5 inch inside diameter.) If I do the outer ring first, then that doesn’t leave alot of material to hold while cutting the inner circle. Suggestions? Or is there a tool I should get to make this easier and safer.
I’d do it with a jig or coping saw, rather than a router, cut outside the line and finish it off with a rasp (round rasp for the inside).
Laszlo
The best tool might be a scroll saw, which can be had for $100 on the cheap end. Probably not worth it for the one job, but if you look at the capabilities and think you might have future uses, might be worth it. You can make a lot of Christmas presents if you have the time, and use up the scraps from your boat kit while doing so. This is how we end up with a garage full of tools.
So probably do as Laszlo suggests. Hard to go too far wrong with hand coping saw (or any hand tools) as you catch the “errors” before they get away from you and ruin the piece.
If you try the router, it can work fine freehand if you have a steady hand. Just screw your piece to a larger piece of scrap wood, with screws outside the outer circumference, with heads flush/below the work surface. Your work piece needs to be large enough perimeter around your circle to provide a good base on all sides of your router so the router stays flat. Clamp down the scrap piece to the work bench. Set the router bit just barely deeper than your work piece. Beware of using wood with significant grain for the scrap base, as that could impact your ability to make a smooth cut as the router bit encounters varying resistance crossing grain boundaries. Cut the inner circle first, then the outer circle. Stay “outside” your lines, then finish with a rasp or sander flush to the line. It should work.
And as Columbo says, “just one more thing…” - Actually 2. You can just leave the inner “donut hole” floating around in the center (after blowing out all the sawdust) after cutting the inner ring when you go to make the outer cut. That will help keep your router flat. And it will probably be easier to make a smooth cut with a larger rather than smaller bit diameter. I’d go for about 3/8 inch and just deal with all the dust. And I’ll now even add a 3rd suggestion - try to set up so you can sit down, lay your forearms on a work surface and use a strong two-handed grip when cutting, that will help keep the router from running away. You’ll be keeping your face close, so wear goggles - set up a good light and maybe have an assistant run a vacuum is an extra benefit so you can see your lines at all times. OK, 4 or 5 more things, as it turned out.
I built some speaker cabinets a few years ago and used a Rotozip with a circle jig to make the baffles. It was the first and last time I used that tool. I forgot I had it until I read this post. I guess I need to build a boat that has some circles in it.