Shaping of the Chines 

Chines

The chines form the bottom “corner” of the boat’s sides (where the sides and bottom join up). Simply, the bottom plywood is attached to the chine’s bottom and the plywood sides attach to the chine’s side. The transom is the very back of the hull (stern) and the boat’s engine attaches to it. The chines were made from air dried white oak purchased from Dysons Lumber in St Mary’s county Md. They had some nice 9″ wide 4/4 x 16′ that we planed down to a little thicker than 3/4″. It had some small worm holes so I have to make sure it sealed well when done. Chine: Chine cross section is 2-5/8″ high with a 30-deg bevel, which we retained the 16′ length until we cut to fit. The reason the top of chine is beveled is so rain water doesn’t collect on top of the chine which would lead to rot.


The Chines

Platform 

The skiff is built on a movable platform (layout cart) that was made out of an old wheelchair. We needed to do this so we can roll the skiff in and out of the garage in the event we needed to work on out vehicles, etc. But this rig isn’t a prerequisite, as a couple of saw horses rigged with a couple 2×6’s will work fine. I do think one of the most important considerations is to elevate the skiff so it’s at a comfortable working height, and allowing room for the stem to hang down while working the boat upside down.


Layout Cart (sorry about poor photo quality)

Laying out the Bottom Shape

There are no reference plans, so I suppose this is a “Rack of Eye” build, which is easy because these flat bottom skiffs are pretty straight forward. Laying out the chines appropriately captures the boats bottom shape (breadth plane). The starting point of this layout was determining where the widest part of the bottom will be Looking at some other skiff designs we settled on the “widest point” at 2/3 from the stem.
For this skiff, the bottom length was 13-1/2 ft so we could limit the future side planking to 2-sheets. Try not to confuse bottom length with overall length as the stem is raked at 30-deg (fwd) and the stern is angled at 15-deg (aft), and those angles will result in an increase of overall length (guesstimating 15-1/2′ at this point in the build).

Formal boatbuiling uses 10 Stations to define the lengthwise (longitudinal) positions along the hull. This skiff is less complicated and only uses 4 stations: Stem, 1/3 from stem, and 2/3 from stem, and Stern. So, the general references are as follows:

General Layout References
To lay the boat out easily on our layout cart, we attached 5-ft long 2×4’s laterally (side to side) at the 1/3 station, 2/3 Station and the Stern. These lateral support pieces hold up the chines on a nice flat plane (on this flat bottom boat). To make adjustments to the chine shape (rack of eye) we used small layout-blocks that clamp to the lateral support piece. Later, when we got the right shape, we screwed the blocks into the support pieces. If you’re building the boat with saw horses, you can still easily use this method by setting the horses up at stem, 1/3, 2/3, transom and nail on your 5′ lateral support boards.

Breadth Adjustment Components (2/3 Station shown)


Close up of Components

Planning Out Angles of the Boat’s Sides

We want to have the boat’s sides angled at the stern and 2/3 station at 15-deg, then gradually angled to 0-deg at the stem. The chine is where this is all started and therefore defined as the chine angle. To achieve this chine angle, the layout blocks were give 15-deg angles. The 2/3 station, being widest, was set (with 15-deg blocks) to slightly less than 48″ (measured outside chine to outsidechine). The aft station, being slightly narrow of the widest point was set (with 15-deg blocks) at 41″. I haven’t mentioned but these dimensions should really be set/verified equal distances off the boats centerline (i.e. 48″ wide should be 24″ to port and 24″ to starboard).

Stern And 2/3 Station Set and Looking at Stem

Rough Cutting the Chine to Prepare for the Transom and Stem

Once the stern and 2/3 stations chine angles are set (with layout blocks, etc) we roughly scribed the transom’s angle on the rearward part of the chine (15-deg) and saw that angle on both chines. We then removed the chines off the layout cart and rough cut the stem angle (30-deg) measured 13’6″ from the rearward end.

We reassembled the chines on the cart and loosely tied up the stem end.

Finishing up the Transom

To prepare the chins for the final transom installation, the back ends of the chines needed to be angled properly. We roughly cut the transom angle (rearward angle) at 15-deg, but to have the transom sit flush this cut needs to be “trued “. This is done by putting a scrap board across the back ends of the chines and marking the material that needs to removed (to obtain a flush fit). The truing was done by a orbital sander using 60-grit paper.

Truing Chine to fit Transom

The transom was then temporarily clamped in place and the holes were located and drilled (using taper drill bit with countersink) through the transom and into the chine end grain. The transom was removed after drilling and PL Premium applied on both chine ends. The transom replaced and screwed into place with #10 x 2″ 316SS screws.


Transom Attachment to Chines

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