Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Wednesday, September 26, 2012

Gusset Construction Started

Just a quick update tonight. I've started the process of laying out the gussets and the floor timbers for the frames.

Gussets are 3/8" thick plywood parts that will ultimately be fastened and glued over the joints on the mahogany frame parts. They provide extra strength for these connection points. Plywood is used because it is less likely to split than solid wood. It's cross grain structure is very strong for the amount of thickness.

Two gussets will be applied to each joint (one on the front and one on the back of the frame). They will be fastened with what are called ring nails (sometimes called boat nails ). Essentially ring nails have multiple little ridges around the shank of the nail that prevent the nail from coming out later. In combination with epoxy glue for each gusset, these will be very strong joints.

Floor timbers a made from 3/4" plywood and will connect the bottom joints of the frame pieces (on the frames that consist of two bottom pieces). Their purpose is to provide strength to this joint and serve as a support for the floor (sole) of the boat when it is installed later on. These have to be an exact height so that they line up later when the frames are attached to the building form.

The question might arise why plywood is not used for the frame parts if it is so strong. The problem with plywood frame parts is the edge of the plywood. It has two disadvantages. First it is not a strong connection when parts are screwed or nailed into the edge (solid lumber is however). Secondly, the edge of plywood is harder to seal against water (not impossible, just more difficult to get complete coverage).

By using a combination of solid lumber and plywood, the frame structure can take advantage of the strengths of each type of wood product while minimizing the disadvantages.

Here is an image of the paper patterns used to create the gussets. This process will also be used to create patterns for the floor timbers and repeated for all the other frames. Other frame gussets will be slightly different shapes but will follw a similar pattern of extending 6" over each adjoining frame part.


The next update will continue the discussion of the construction of these pieces. There is an additional photo in the photo gallery showing the gussets laid out on plywood.

Update 5/2/2014 - More in depth explanation of gusset construction

Update 6/10/2015: I've decided to add a small tidbit about the patterns. Because of paper shrinkage, they are a bit smaller than the measured dimensions in the plans. I learned this in October of 2012 (see "Bit Of A Setback To Deal With" in sidebar). I resorted to laying out the measured dimensions on a large layout board and then using that to aid in getting the frame parts correct. Rather than repeat all of that here, it is suggested that you read that posting and subsequent posting to see what I did.

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