I found what I believe to be a major structural flaw in the design of Dorado's transom as it applies to my requirements. The transom is made up of 3/8ths-inch plywood, framed with essentially 2x4s on the sides and 2x2s on the bilge and bottom. It has a motor board spanning the top width of the transom consisting of a 5-foot long 2x8 from which to hang an outboard motor. I went and measured my Suzuki 25 hp motor and found that the mounting holes were about 11-inches apart vertically, and the entire mounting bracket is about 16-inches long. So, the motor board will not accommodate my motor.

Note: as I have stated before, my desire is to publish all positive and possibly negative experiences associated with the building of this boat. Just lay it out as it is. I'll be the first to admit that I do not have all the answers, but I will try to find the best solutions to the challenges I come across, both real or perceived. If the designer wishes to comment on any changes I make, I will gladly publish those comments he wants made public on this site as well.

I went to the local lumber yard and found two 10-foot long 2x10s that were grade 2, center cut, Douglas fir. At least I am told they are Douglas fir; I haven't seen the wood called hem fir to know the difference yet. I do know that these were beautiful planks with very strait grain and I kind of got excited just handling them. I am starting to look at wood differently--looking at what can be made from what. Anyway, I am going to cut the planks in half; these are going to form my transom.

I wanted to frame everything in the boat with fir, but when I saw the price of clear fir already dimensioned, over $2 a board-foot for some of the boards I would need, I started looking for alternatives. I bought an edge guide for my skill saw, thinking that I could "rip" the lumber that I needed inexpensively. Those 10-foot planks only cost $8 each. But then I found out that there is a table saw set up at my workplace, so I decided to try it out just for kicks. I LOVE TABLE SAWS. This saw cut through the board easily, and I made a number of framing strips before cutting the big transom pieces. I thought table saws were relatively dustless devices until I saw the floor on the side opposite of where I was standing. There was an 8-foot by 3-foot swath of sawdust extending out from the table saw that was almost 6-inches deep. Obviously ripping the boards includes macerating, shredding, grinding, chewing up and spitting out the 1/8 blade thickness of wood between the boards. Yup, lots of sawdust. What's up with my camera? I have never seen those lines before. Could be lots of sawdust in the air.

Here is something new. The router is mine, a Bosch fixed and plunge base combo kit, but the table belongs to my neighbor Dave. Brand new tables (good ones) cost as much as a router does. Thank goodness for neighbors (with tools). Thanks Dave!

My original plan was to glue three, sized, 10-inch wide boards together edge-to-edge after I had cut a tongue and groove in them, and then laminate the whole thing to the 3/8th-inch plywood transom piece. But I got to thinking that if the planks were to absorb water, they would swell, splitting not only the plywood but probably breaking off the tongues in the grooves as well. I won't show you the results of this experiment, but it actually came out pretty well. However, I have since decided to take a different route.

I have observed that some inflatable boats have 1-inch thick plywood transoms that are rated for up to 50-hp. So, here is what I came up with: a 1/2-inch thick piece of plywood to be laminated to each side of the 3/8th-inch transom piece I have already cut out, bringing the total thickness of the transom to 1 and 3/8ths-inches. The original framing in the plans will stay the same. I may add a smaller piece of plywood to block up the position of the outboard later.

I had found that the weight of the transom as designed weighed about 19-pounds without framing, and if I add another 2x4 so that I could bolt up the bottom of my engine, the total weight would be about 23 pounds. The new design comes in at 34 pounds. The 11 extra pounds of wood gives me a much stronger, cleaner design. My original tongue and groove design would have weighed about 41 pounds. These weights are relative as my bathroom scale is probably off by + or - 6 pounds. If I leave the port-a-potty off the boat, that should compensate for the 11 pound increase in weight. All I have to worry about now are the bears, as they go in the woods, too.

Here you see all three transom pieces at the ready to be laminated. And here is where everything went all wrong. The idea was to paint the epoxy mixture on each inside face, then mix pine flour into the remaining epoxy to a ketchup-like consistency. This light paste would also be spread upon each inside face to fill any voids, and everything would be clamped together.

I massed up 396.5 grams of epoxy to apply to about 2640-inches squared for just two sides (I would glue the transom together in two steps.) I got about 3/5ths done with coating the second face and I ran out of epoxy in the cup. Not only that, but the brush I was using was getting very tacky in the epoxy. I started to become extremely sensitive to the pressing importance of completing...Oh, all right--I panicked. My epoxy apparently was setting faster than I had anticipated. I ran upstairs to try to mix up a small batch of epoxy to apply to the transom before it was too late. In my haste I did not even think about using the scale, I just pumped out 4 strokes of resin to 1 stroke of hardener. I pumped it all into the same container that I had been using just two minutes earlier, even though I had a fresh container right next to the scale. After a quick mixing and subsequent application, I flipped the 3/8ths plywood over onto the 1/2-inch.

Two pieces of transom are laminated, one more to go. They squished around a bit when I clamped them together, but I got them lined up OK. Three pieces done at the same time would have been more than I would want to handle. I lightly clamped the edges and put weights in the middle.

I should always use the scale, even for the hurry-up batches -- it only takes 30 seconds or so extra time. I had never calibrated the pumps, so my concern was whether or not I had the right mixture from pumping the quick batch. After some testing, I found that each pump of resin averaged 30.1 grams and each pump of hardener averaged 28.8 grams, giving me a ratio of 104.5 : 22.01, so what I pumped out yesterday was accurate enough to get the job done.

A word of caution: I don't know if there were fumes coming from the epoxy mixture or if I still had some epoxy on my hands after I washed them, all I know was that shortly after I worked with the stuff my eyes became puffy and irritated as if I were experiencing a strong hay fever reaction. I flushed them with water for 15 minutes and then took an antihistamine to finally get some relief.

A piece of plywood was placed on top of the upright clamps, followed by a mover's pad to seal off he area underneath. The cord you see at the right leads to a small heater. The next day, I laminated on the other piece of 1/2-inch plywood. This time I made up enough epoxy for the whole job, no pine flour in the mixture, though. Instead of the brush, I went back to using a putty knife to spread the goo; it's faster.

By the time I was done, I had a plank that would not break, even if you drove a Mack Truck over it. Though I was proud of my new transom, every time I picked it up, I knew it was heavier than I wanted it to be. I decided to take it in to work and weigh it on a real scale -- 40 pounds -- it was at least 10-pounds over weight, and not in keeping with the lightweight nature of my boat. I decided then and there that I would either have to fix or remake make the transom to be comfortable.

Here you can see the transom; it is a full one and a half inches thick. I am cleaning up the edges with a belt sander. I considered planing a few plys off the face of the transom to lighten it, but it was suggested to me that planning is not the best way to take down plywood. The plys in plywood alternate in direction by 90 degrees for each layer, and planing may tear off a layer that I might want to keep.

I found a company that had a large 36-inch wide drum sander. For $35 they agreed to sand off 2 ¼ plys from each transom face. They would initially use 36 grit sandpaper, followed by 80 grit. I think the final result is fantastic. Not only is the transom smoother, but at just a tad under 1-inch in thickness, it now only weighs 28 pounds.

Let me fast forward a bit here: I cut some good fir to size for the transom's side frames. I then attached the frames to the transom using epoxy and two 3/8th-inch galvanized lag screws with washers per side. I have since learned that putting a bolt through pieces of wood to be joined is a stronger, more desirable method, but these big screws should get the job done. I also added two #10 screws per side to the securing line up. You may recognize this picture from earlier as you can see Bulkhead 4 prominent, with the transom underneath. I plan to "bake" (warm up) everything together.