Cutting scuppers (aka machining slots into noodles)

[Charles G. Clark, Jr.]

Oh wise counselors,
I have two 18 1/2 foot, 3/4 x 3/4 inch noodles to cut scuppers into. The problem that I have is in determining how to cut the scuppers across something that is that long, skinny, and wiggly.

My plan is to cut them on my router table using the miter guage slot with a miter guage to push the noodles through the bit. I will support the ends of the noodles to minimize the amount of flex. I have thought about using a 1/4" upspiral bit to cut out the waste using multiple passes.

I have already marked out the part of the inwale that will not have scuppers--the tapered areas at the front and back and the three seat locations.

What do you think? How do you guys cut the scuppers when you start with solid material?

Thanks.
Chuck

[canoeblderinmt]

Chuck,
Try a search on "Scuppers". There have been lots of posts showing very ingenious ways of cutting solid scuppers. John Michne's excellent site also has some good detailed instructions. Good luck and post us some pics, OK?

Greg

[Tim Eastman]

I've got my bettin' money on John's technique.

Chris and I are catching up on things to do during the winter and Gunnels fits right into that category. Check out John's site!

All the usual disclaimers apply - no connections to John etc. Offer good while supplies last and your mileage may vary.

http://www.michneboat.com/Gunwales.htm

[ealger]

http://s12.photobucket.com/albums/a237/ealger/Scuppers/

MLCS now offers a spiral carbide cutter with a pilot bearing that would work better than the straight bit shown in my pictures.
Ed..

PS: What ever method you decide to use, practice on some scrap first! Some inwale material has a nasty habit of splintering.

[Patricks Dad]

PS: What ever method you decide to use, practice on some scrap first! Some inwale material has a nasty habit of splintering.

Well said. But use the same material for your practice. When we did our inwales (cherry), I spent hours practicing on some scrap maple that I had in the garage. It was incredibly difficult to scupper consistently. I finally just held my breath and went at the real stuff and had no problems doing all the scuppers without incident. I was sure I was going to mess it up (I couldn't do 5 scuppers in a row with the maple).

good luck!

[Charles G. Clark, Jr.]

All,
When I made my Wee Lassie II, I tried, unsuccessfully, to make my scuppers on the router table. In the linked picture, I tried the top sketch and the grab of the router bit was too strong for me to comfortable trying to hold things in place. I gave up in favor of cutting semicircles with the drill press.

I am trying the approach depicted in the lower figure this time. I believe there will be less grab running the smaller bit through the width of the inwale.

I will test on scrap material before committing to the real inwales.

Routing Scuppers

[Fred G]

I was very satisfied with roughing out with band saw, then finishing with spindle sander. I used oak. The router did not seem to work very well on the oak. I'm sure cherry would have been ok with the router.

[Tom in MN]

Have you thought about cutting a whole bunch of small rectangular blocks out of the same wood and gluing them on to your gunnels with gorilla glue or epoxy. Use a spacer block to space them and tape to hold them in place. It will require some sanding and clean up but much easier than cutting them. You can also do this when you attach the gunnels, add a block with some glue, and screw through the block when you screw on the gunnel using a block of wood as a spacer.

If you insist on cutting them. I would make a sled about six inches wide almost as long as the gunnel, with wood runners in the miter gauge slot. Place a block of wood on the sled the length of your scuppers. Then run the sled, with your gunnel on it, just into the table saw dado blade, or router bit on your router table and pull it back. Then move the gunnel, seating the newly cut space over the block and cut the next one. The same way you would make a box joint with a box joint jig. Search the web if you are not familiar with this technique.

Do you have a plunge router? You could make a sled that holds the gunnels that has wood blocks spaced evenly on the sled. Set your router against the first block, plunge and route until you hit the second block. Pick up the router, move to the other side of the block, plunge and route until you hit the next block, and so until they are all cut. Of course you will have to do some lay out and set up to get the right spacing, depth, etc.but once it is done, cutting the scuppers will take about 5 minutes.

There you have it, three different methods for making scuppers.

[Oshan OkaPini]

Maybe this has been gone over before, but you gotta solve the problem with what tools you have.

I started by tapering the gunwales to the shape that I wanted and then taped the inner (hull) sides of an inner and an outer gunwale together. I measured and marked the location of the supper slots in each taped pair. I then clamped a forstner bit in the drill press and centering the drill on the joint between the two pieces, drilled each end of the slot. I then set the table saw to the same depth as the radius of the forstner and removed the material between the drilled holes. Some judicious sanding cleaned everything up and on the hull they went.

Just another way to skin that cat.

Cheers

Norman in MS

[Kurt Loup]

Here is a link to some pictures of how I cut my scuppers with a template and a router with a guide bushing. The scuppers were cut prior to ripping the inwale from a board. Disregard the bottom photo on the page. http://www.loup-garou.net/random

Kurt

[Charles G. Clark, Jr.]

What a great idea! I hadn't thought about curring the scuppers BEFORE slicing off the inwale. I will put that in my "bag of knowledge" for next time.

I cut my scuppers this weekend using the router technique I described earlier--with one modification. In practice, I found I got better results using a 1/2 inch mortise bit in place of the upcut sprial bit.

What I like about your approach that I didn't get with mine is the rounded profile of the scupper. With my apporach, I get a square corner in the scupper.

Do you think that I can use this as an excuse with my wife for building another canoe? :twisted evil

[Jeff in Farmington, MI]

Another easy method to cut the scuppers is to pass the inwale laterally over a "dish cutter" bit in a router table. The dish cutter has a rounded edge and a flat bottom. The flat bottom of the bit cuts the inside surface of the scupper, while the rounded edge cuts the radius in the corner of the scupper.
I purchased my dish cutter bit from Grizzly.com.

1) Mark the start and finish points of all the scuppers on one of the inwales.
2) Line up both inwales side by side on the router table. Support the long lengths with saw horses or something.
3) Clamp the inwales to each other with the intended hull-sides flat against the router table. Use two clamps so that you can move them along the length of the inwales one at a time while keeping the inwales aligned.
4) Make successive overlapping passes over the dish cutter bit until the length of the scupper is cut.
5) All that is left is to break the edges over and sand smooth.

This process worked very well for me. No jigs or fixtures required, and both inwales are identical because the scuppers were cut at the same time. I thought it might be difficult to move these 18 foot long "noodles" over the router, but it wasn't a problem.
Tip: Cut the ends of each scupper after most of the material has been removed. That way, your last pass just cleans up the radius corner.

Jeff