Clipper's Vera Cruise Build

Clipper's Vera Cruise Build

Sunday, January 12, 2014

Transom Continues Part 2

This week was about assembling the transom. Last week, the parts were cut out and sanded to shape. However, the weather was too cold to do any epoxy work. I did receive the lumber for the chine and sheer members. The wood looks great but the thickness of the chine lumber scared me a bit when I first saw it. I knew conceptually, that the wood was thick. 1 - 1/4" to be precise. I had made cut outs in the transom frame to fit this thickness. But when I saw the wood and realized how thick 1- 1/4 inches really is, I was concerned that I would not be able to bend this wood at the bow frames.

Fortunately, I have access to photos from two other builders of this boat as well as photos from other boats with similar thickness chine members. Seeing that the builders of these boats managed to bend this wood gave me confidence that I would be able to manage as well. Just to clarify, the wood in the above photo will be curved in the short direction as it transitions from the straight sides of the boat to the curved bow. This will be more clear in the future when I actually get to this point in construction. Basically what I will need to do is soften up the fibers in the wood either through steaming or boiling water and then gradually bending the wood to the curvature I need.

When the weather warmed up, I taped off the area on the transom skin that would be receiving epoxy and pre-drilled and countersunk holes in the frame parts for the wood screws. I knew that the actual glue up and assembly process was going to take some time so I wanted to get as much done beforehand as I could. I also wanted to keep most of the epoxy away from the notches since these areas would have been difficult to clean after the epoxy set up.Hence the tape.

The glue up and assembly process followed the same pattern I've used in the past, namely, pre-wet the glue surfaces with un-thickened epoxy, then coat them with thickened epoxy, assemble the parts, add the wood screws to hold everything together, and then wipe off as much excess epoxy as possible.

This process took me a few hours to complete but the results were worth the extra effort. The notches were relatively clean.

Because the transom is mounted at an angle in relation to the boat, the bottom edge of the frame was beveled earlier this year. The plywood skin was purposely cut a bit larger on this same edge so that it could be beveled to match after the epoxy cured. These two following photos show this.

The first shows the parts before clean up. You can see how the skin edge is at a different angle than the frame. The second photo shows that edge after the transom was cleaned up. When the bottom skin is added to the boat, it will lie flat across this area and be attached to the frame members.

I also glued on two gussets to reinforce the corner joints. These were similar to the gussets I applied to the other frames earlier this year.

Cleaning up the glue lines took a few hours, mostly because of having to sand the skin edge to match the frame bevel.

At this point, I started thinking about the remaining work that needed to be done on the transom. The transom needs to have a cut out for the outboard that will eventually mount there. It also needs a motor board to reinforce the mounting area.

I needed to do some research on the mounting requirements of the motor I had in mind. It was here that I realized I was going to have to make some additional changes to the original design of the transom.

When this boat was originally developed in the 1950's, higher horsepower outboard engines were a rarity on small boats. Engines also weighed less. The transom was originally designed to have 3/4 inch skin and a 3/4 inch motor board reinforcement for a smaller motor. The total thickness would have been 1 1/2 inches. However, the motor I intend on user requires a minimum of 2 inches of thickness. This is because it is on the higher end of the horsepower range for this boat. It also weighs significantly more.

Therefore, I am going to add two layers of plywood to the inner surface of the transom. The motor board will still be 3/4 inches thick, but will rest on an additional 3/4" thick piece of plywood that will fill the area between the frames.

I will also be adding mahogany planking to the exterior of the skin which will eventually be finished unpainted to give the back end of the boat an attractive appearance. This planking will be 3/16 inches thick.

Before adding these parts, I need to cut out the middle section to accommodate the outboard. There are certain size requirements for this. A certain width to allow sufficient room for the motor to turn, and a specific height so that the motor is mounted correctly in the vertical direction, Additionally, the internal structure of this area needs to line up with other structural members.

I did some initial laying out of the lines for the cutout, but I need to do some additional research and thinking before making the cut. I don't want to destroy this part.

In order to get the height, I needed to measure a specific distance down from the keel which required me to temporarily remount the transom. I had taken a photo of the method I used to get this vertical dimension, but for some reason, my stupid phone camera didn't actually capture the shot. But basically, the vertical dimension needs to be 20 inches measured perpendicular to the keel. You can just make out the lines of the cut out on the lower edge of the transom in the photo.

Finally, just for the heck of it, I have two photos of the transom mounting showing the keel joint and the knee which mounts on the other side of the keel and reinforces the transom. The knee will be installed later when I install the keel. It will be bolted to the keel and to the transom. The excess material on the keel will be faired away to match the angle of the transom.

So over the next two weeks, I will be verifying the dimensions of the cut out, cutting that piece out, and adding the additional plywood to the transom. The mahogany planking will be applied at a future date. Once the additional plywood has been added, I can then encapsulate the transom for water protection.

That's it for now. I am going to be rather busy this coming week with non boat tasks so I may not get as much done. I will probably wait until I have enough accomplished before posting another blog entry. Take care.

Click Here To Comment:

  1. It's looking great, Carl! I admire your forethought and attention to precision. Using the tape to keep epoxy out of the notches is a great idea. "Some Other Time" is going to be a splendid boat!

  2. Thanks Mike. As I am reading this, I am sitting here sick and your kind words are a bright spot in a challenging day.

    I've been wanting to post another blog article but I have been very busy this week with life. Additionally, I have been having many second and third thoughts on my transom plan so I don't want to make an changes that I cannot undo easily. Kind of analysis paralysis but most of the new information is important and needs to be considered.

    Take care.


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