Portuguese Dinghy build - nearly complete.

[capt_nemo]

The FREE Plans for this 7' 6" X 3' 10" Portuguese Style Dinghy caught my eye some time ago on this site http://koti.kapsi.fi/hvartial/dinghy1/simboii.htm

Decided to build it recently out of lightweight 5mm Luan Ply underlayment and mostly Select Pine boards from a local big box hardware store. The boat has fiberglass tape reinforced filleted seams and is epoxy coated with fiberglass cloth reinforcing the outside of the bottom. Interior and exterior received two coats of Interlux Brightsides Polyurethane (different colors of course). The 2 removable scissor-like very tight fitting cross braces for the center thwart and/or longitudinal seat were my own design.

The boat, as built, is a nice easily handled tender for a cruising Trailer Sailor, weighing in at ONLY 49.7 pounds!

It was a fun build, despite the mostly windless hot Florida weather, and kept me busy and out of trouble for a while. Just need to mount the oarlocks for a "complete" boat which are on the way from Duckworks BBS.

The high bow profile showing the exaggerated sheer and rocker.



The interior view with seats removed. A lot easier to sand, paint, and maintain.



The two (2) scissor-like cross braces doing double duty as side strengthening supports and support for seats. They are positioned about ¾" off the bottom to allow water to drain back to the plug in the transom.



The longitudinal seat needed to balance the boat when carrying two (2) passengers.



Close-up of side supports showing permanent side cleats to maintain proper fore and aft position and gunwale bottom edge to firmly wedge downward into a solid fixed position.



capt_nemo

[Pete H]

Lovely job! Well done. Thanks for sharing, please let us know how it goes on the water.

[Greene]

Beautiful!  I also built a Portuguese Dinghy.  Squint The Famous Racing Dinghy.  They are great little rowers, but a bit tender when boarding.  Brenda and I used ours for four seasons and loved it. I added a second set of oar lock mounts so I could reposition the oars for those times I wasn't carrying a passenger.  Being able to do that and center your weight on the lengthwise seat works really well.

Very nice work.


Squint.

[capt_nemo]

Greene,

What length oars did you use?

I'm going to try 7' based on the recommendation of the designer.

capt_nemo

[Greene]

I also took the authors advice and made a set just under 7'.  I found them to be a little too long for rowing and for storage.  I shortened them up so they just fit inside the dinghy lengthwise.  They were perfect for rowing and it was nice to lay them inside the dinghy when we were towing it.  I did use a bungee to strap the oars to the dinghy seats just in case.

About the only thing I would do differently in the dinghy construction is too add a deeper and longer skeg.  When the dinghy is empty the tiny skeg didn't bite into the water allowing it to wander under tow.  I cured most of that issue by cleating the painter up high on the transom which pulled the bow up slightly on the dinghy.  After that she towed as nice as could be.

Mike

[capt_nemo]

Greene,

Thanks for the response.

With handles up in the bow under the breasthook, and blades resting on the bottom under the quarter knees, my 7' oars do fit in the boat. If necessary after sea trials I can shorten them a bit.

capt_nemo

[Greene]

I shortened them enough that they would lie flat on the bench/seat.

Happy rowing!

Mike

[brackish]

Nice job Don.

Curious about the rub rail.  Laminated or solid with a groove?  Did it take the curve or did you have to steam it first?

I'm just about to put mine on the Bateau FS14 I'm building and think I'm going 2 each 1/4" X 1-3/4" pieces on the outside proud of the gunwale by 1/4", then a 1" half round flush with the top both outside and inside with a 1/4" filler strip over the plywood gunwale all laminated.  I've got a big beam of African teak I have to resaw to get all the parts.

Second fairing, got one more to do then prime coat, guide coat, finish fairing and epoxy graphite bottom, then turn it over and work the inside.

[capt_nemo]

brackish,

Found some nice long pieces of precut pine molding in Lowe's Hardware Store. Carefully selected each piece for grain to take the bend of the curve.

On the outside of the hull ply used a 1½" X 3/8" board and on the inside a 1½" X ¼" board. ½" thick boards would not easily take the bend. Total thickness for oarlock screws is approximately 7/8".

The laminations make it light but strong.

capt_nemo

[brackish]

Thanks Capt_Nemo, and you are living proof of what I've always said.  A man cannot have too many clamps.

[capt_nemo]

brackish,

CORRECTION on my previous post. The outer board is, in fact, 1½" X ½" pine! Not the 3/8" as stated. The 1½" X ½" boards that wouldn't make the bend IMHO were the hardwoods available - Poplar and Red Oak. Rest of post is accurate. Sorry if I led you astray.

And, sometimes I wish I had  more clamps. Sometimes had to resort to split rings of 1½" PVC Pipe for clamps just to keep the process moving.

capt_nemo

[Bob23]

Great job, Capt!
  I've had good success using split rings of PVS and ABS pipe. Different sizes for different strength needs.  El cheapo but they work great. 
  I really like this dingy ever since I was beaten badly by Mike Greene at CLR 2013 which i wasn't able to attend. I conceeded my defeat at 2014 and paid my debt to the honorable Capt. Greene with a bottle of Newfys Screetch rum.
  I wonder if this little dink could be sailed? With the hard chine and slightly larger skeg, it could be sailed without a centerboard or leeboard. Or am I reading your mind, capt Nemo?
Bob 23

[capt_nemo]

Bob23,

Yes, I believe the dink could be rigged for sailing.

However, at this time it is not on my to do list.

capt_nemo

[wroundey]

Looks like a great little dingy. I would be interested in seeing some additional detail about the scissor braces

[capt_nemo]

wroundey,

Ask, and you shall receive.

Here is a photo of the pivoting cross brace joint as viewed from the bow. When the second bolt from the right is REMOVED and the bolt on the far right is loosened (by thumbscrew) the  right piece is free to pivot upwards releasing pressure on the bottom of the 2 side braces to which it is attached.




Here is a photo of the two (2) separate braces locked into position. The side braces are wedged under the inside edge of the rub rail and are free to pivot since they are thru bolted to the scissor cross brace at the bottom. When pressed downward into position, the scissor-like cross brace exerts pressure on the 2 pivoting side brace bottoms which is also transmitted to the tops which are wedged under the rub rail edge. The pressure is quite firm and serves to not only add great support to the thin ply sides but also to provide a solid support for the removable top cross pieces that support the seat.



I designed the supports to be removable for 2 important reasons. First, it will not only be much easier to repaint the inside of the dinghy without permanently installed seat, but also the supports with all parts of the mechanism disassembled. Second, it will be much easier to change the seating arrangement if desired.

Hope this helps.

capt_nemo