Chine notch angles

I'm currently building a Don Hill 17Flyfisher.  I have all the frames completed and about ready to cut the notches for the chine logs.  The plans say to notch the frames parallel to the sides and bottom, and to cut a 25deg bevel on the top and bottom of the chine logs.  Since most of the frame angles are different this will result in gaps at the top of some of the chine logs.

How do you guys cut your chine notches?  Do you cut them parallel to the bottom frame and live with the gap, or do you account for the bevel on the chine?

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Permalink Reply by David Witton on September 3, 2025 at 11:23am

The bottom has rocker, is curved, so the bevel at the bottom of each frame is different, increasing towards the bow and stern. The cut in the side of the frame should be parallel to the bottom of the frame - if so, there will be no gap at the top of the chine log. 

Permalink Reply by Art Page on September 3, 2025 at 12:04pm

Maybe I'm not following, but the plans call for a constant 25deg bevel at the top of the chine.  This implies there is a corresponding constant 25deg bevel at the mating surface on each chine notch, which isn't true.  The end result would be a slight gap on some of the notches.  I believe it's the rib angle (splayed out from vertical) that is different on most of the frames that's the offending culprit, not the rocker angle.

I ended up tracing the outline from a cross-section of the chine log and cutting to those lines, as shown in photo.

Permalink Reply by Bennett Yarbrough on Sunday

That 25 degree bevel on the chine log will allow it to follow the side of the boat. If the sides of a drift boat were vertical then that chine bevel would be 0 or 90 degrees depending on how you look at it. The chine notch bevel is parallel to the bottom. So on frame 5(I think that’s the one with no bevel for the bottom) there’s no bevel for the top of the chine notch. Up on frame nine your bottom and chine log are making a steep uphill sweep. So the notch needs to accommodate that. When the log and frame meet that 25 degree bevel will kick the side panel out at a 25 degree angle the same as the rest of the boat. Hope this helps.

worst case just take some 2x4 and mock it up. It’s easy to visualize once you’ve got something in your hands

edit: I think I see what you’re saying, it seems you’ve some bevels mixed up. You’ve got three going on. The bottom bevel, one side bevel that stays constant(25*) and then the side bevel that accounts for the sides wrapping around the frame. Make a frame 9 and 5 out of scrap and you’ll see what’s going on

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