Diesel Duck 382

Diesel Duck 382
Diesel Duck 382 with the "get home" steadying sails up.

Monday, January 30, 2017

Rocket Science

If you are a woodworker....check that, if you've ever assembled a piece of knock down furniture from a big box store you are familiar with assembly instructions.  Step 1: locate included hardware, Step 2: snap part QQ into ZZ and on and on.  While this, no doubt, can sometimes be confusing at the very least you know there is an orderly process to the assembly of whatever you are building.  It's the same for woodworking when you buy a set of plans or read them from a magazine.  The only difference being that you have to make part QQ and ZZ first.

Boat building is so much different.  When you buy a set of boat plans you get several plan sheets with various descriptions and measurements.  No step 1, no start here, you are on your own, so to speak, to figure it out.  I'm not complaining, I'm typing with a smile because that is the beauty of boat building. I'm proud of the things I've built in wood.  Let's be honest though, anyone with the $10,000 worth of tools should be able to build a damn nice end table.  The skill, if any, is the fact that most of the things I've built were my own design inspired by another piece.

I have new found respect and admiration for amateur and professional boat builders alike.  It's an impressive skill to be able to just build a boat, let alone design one.  As a first timer it is both disconcerting and exciting to attempt such a project knowing what I now know.  I've been reviewing my plan sheet in CAD form for quite some time but the scope of this project really hit home when Mr. Buehler sent some of the final plan sheets in paper.

I used some Larch off-cuts that were not good enough to use for the boat and made them into 2-by stock.  Using those along with some scrap T-111 that use to be my fantasy draft board, I made up a platform for a bulletin board.  I bought some 12" x 12" cork tile squares off of Amazon ($5 for four of them) and attached them to the T-111 with double sided tape and construction staples. I then put up the first four plan sheets.  It is definitely easier to review them in this format versus the Ipad.

With my paper plans hung prominently in the boat shed I got to work lofting the transom and bow.  I began by disassembling the long narrow loft floor that I used for the keel.  I spun 3 of the sheets of OSB 90 degrees and secured them to the cradle.  This gave me a lofting platform that was 12' wide by 8' tall.  Using the same process I used for the keel, the work went quickly.  The only difference this time was that I had enough room to use a real baseline so I didn't have to do any additional math.

The dark spots are drops of water from the condensation dripping from the inside of the roof.

I snapped chalk lines at each station

Once I had the lofting, I went ahead and made my patterns for the transom being sure to note the rabbet on each station.  Another tip if you are attempting something similar; make your marks in pencil first before committing to ink!

I am still without a loft floor big enough to do the entire transom.  You can see in the picture above the transom is cut off where the OSB ends at around 8 feet.  The patterns were secured with glue and construction staples.

Next up was the bow.  I didn't make any patterns for this lofting as I don't see a need.  Of course that may change in the future when I get to assembly.  If needed, I will unroll the lofting and make any required patterns.  I really only did the bow lofting to see what it looks like full scale.  I can say without reservation that this boat is huge.  You can read all you want, but until you see things full scale it's difficult to comprehend. It was awesome to stand up the transom pattern when it was done to see just how big it was.  The bow was drawn on the same paper and you can see from the pictures where the two loftings overlap.

Before I got started in the boat shed, I started a fire in the fireplace in the shop.  I wanted to work on the shaft log and do a glue up with the resorcinol. This adhesive requires a  minimum air and material temperature of 55 degrees.  By the time I got done lofting the shop was at a very comfortable 74 degrees.

If you read about resorcinol glue you start to get the impression that it takes a rocket scientist to work with the stuff.  However after one successful glue up I can report that it is not that difficult.  It surely requires careful measurement and I used a postal scale to ensure accuracy.  I used Aerodux 185 resorcinol that I purchased from Amazon for $120 dollars a gallon.  Quite expensive, but since the shaft log will live it's entire life submerged, I believe it is the only adhesive up to the job.  Resorcinol is still the only adhesive rated completely water proof and the only structural adhesive recognized by Lloyd's of London.  Boat builders have been using resorcinol for more than 70 years to ensure a permanent bond.  Epoxy, for all it's positives, cannot boast that kind of performance. Epoxy will definitely have a place in the keel and the rest of the boat, but this job called for the best.  For more information I recommend reading Larry Pardey's book, "classic boat construction" for all the details on epoxy and resorcinol in boat construction.

After carefully measuring the resin and hardener by weight I mixed them thoroughly.  Once mixed the glue had the consistency of cake batter.  I spread a relatively thick layer on the face of the prepared stock that was clean and free of dust and contaminants. I then laid the mating piece on top and clamped them together with several clamps.  Resorcinol requires high clamping pressure and the directions give measurements in newtons of force required.  I have no idea how many newtons I was exerting but I made the clamps extremely tight.  I had even glue squeeze out around the entire piece so I believe the joint is well filled.  Resorcinol and epoxy differ in this respect where epoxy only requires moderate clamping pressure.

In the temperature I was working in, I had plenty of open time to get the glue up done.  If I was working in the middle of summer I would need to move faster.  The beauty of Aerodux 185 versus traditional resorcinol is the fact that you can work with it in temperatures down to 55 degrees and it has modest gap filling abilities.  Resorcinol is hard to find and I was only able to locate a couple different brands on 3 websites.  Amazon was the cheapest with the best shipping costs.

I checked on the glue up the next day and it appeared to have set up solidly.  I broke off a piece of the squeeze out and submerged it in a glass of water for 24 hours.  When I checked on it the next day it was just as solid as when it went in so I believe I mixed it correctly.

Next weekend I plan to glue up the other half of the shaft log and get to work on assembling some of the other keel components.

I started a Facebook page for the Sea Dreamer Project in order to get pictures and progress reports up in real time.  Please check it out here: Sea Dreamer on Facebook

As always, thanks for reading and if you have questions or comments please don't hesitate to contact us.  We very much appreciate all the advice, ideas and encouragement.


  1. Hi Scott, first bit of wood together, exciting. How did you prep wood before gluing with resorcinol, did you just put thru thicknesser and call it done or more? Did you tooth surface first?


  2. Hi Andrew, These were stock 2x8's so relatively freshly machined and smooth. Epoxy likes a little space in the joint or tooth on the face but resorcinol likes it tight and smooth so I didn't run it through the planer again or sand it.