HobbyKing.com New Products Flash Sale
Reply
Thread Tools
Old Mar 17, 2011, 12:53 AM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
Build Log
Dumas SK Daddle Too .15 Nitro

This is a build thread of the #1402 SK Daddle Too kit by Dumas Products. I purchased the kit and basic driveline from fellow RCGroups member fly2mike and started gluing almost one year ago. This is my first wood boat kit. I decided before starting anything that an air-cooled nitro rc boat would be really cool and simple so that's what I did. Here's some progress from frame work through initial primer coat.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Sign up now
to remove ads between posts
Old Mar 17, 2011, 01:16 AM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
The SK Daddle Too kit contains several types of hobby grade wood that is roughly diecut. The frames, sheers, stringers, keel, rear deck, and transom are mahogany plywood. The bottoms and sides are birch plywood and the top deck is beautiful mahogany plank. I used Mercury M100XF high performance CA on every joint and it worked very well. It's the best CA I've ever used hands down. Here's my boat last April with chines installed and ready for sheeting.
av8rga is offline Find More Posts by av8rga
Last edited by av8rga; Mar 17, 2011 at 01:26 AM.
Reply With Quote
Old Mar 17, 2011, 06:00 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
3/16" strut template drilled and bottom sheeting installed.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 06:34 PM
"Unnecessary Necessity"
coriolan's Avatar
Canada, QC, Quebec City
Joined Sep 2006
5,917 Posts
Its Ok to use CA to assemble a boat but you better double-up all your joints with epoxy,there is lot of vibrations in an IC boat and CA is brittle. You'll need some kind of sealant anyway for the wood inside and epoxy is best to resist fuel and give all your joints some resilience. Epoxy resin is a bit expensive but you can use regular (slow)epoxy glue and brush the inside, epoxy glue can be thinned with alcool to brush on with a cheap brush and the alcool evaporate quickly. What kind of engine you plan on using?
coriolan is offline Find More Posts by coriolan
Reply With Quote
Old Mar 17, 2011, 06:39 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
Bottom and sides installed. The motor mounts are also installed here and flotation.

SK Daddle boats have a unique rounded transom. I love the look. It took me many hours and lots of patience to get the plywood sides formed and glued without splitting. The first step was to soak the plywood with warm water. Next I wrapped the wet wood around large and small spray cans using rubber bands. Cool thing about rubber bands - you can adjust the "tension" of each band as the shaping occurs being careful not to over stress the wood. I had to repeat this several times until the wood would hold form, wetting and drying each time. Once shaped and dry it was easy to glue in place using again more rubber bands, a CA extension tip, and kicker.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 08:58 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
Next steps were sanding the sides flush with sheers, installing and sanding the deck stringer, sealing the bow area, and installing the mahogany deck and deck sides. For watertight sealing and strength of framework and compartments, I use thinned 30 minute epoxy brushed and blotted, or hard card scraped both with heat. Senior modelers taught me a long time ago you must build true, strong, and LIGHT. She looks rough in these pictures but the sanding and shaping, mainly the rear deck area has not been done yet. Taking any wood boat from this stage to final clear coat is where the magic is.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 09:06 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
The exit hole for 3/16 flex drive is cut and trial fitting done of engine, pipe, drive strut,fuel tank, and rudder. I have made it adaptable to any small block nitro engine including water cooled if need be.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 09:45 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
August 2010 and finally got the rear deck area squared away. What a pain but I'm happy with the results. The radio hatch fits nice and flush and should seal up watertight.

Lots of time sanding with 150 grit on bars, sticks, rods, you name it! Light epoxy microballon filler and more sanding... I've learned you can never have enough sanding tools building wood models.

After the 150 grit sanding was complete, I applied a light coat of epoxy finish resin. I use the method of applying, spreading, heating, and scraping the excess off. I scrape with window tint "hard cards" but it's similar to a yellow Bondo card - kinda stiff yet still molds to a curve. What's left is a thin hard resin coat with very little weight gain. The first coat was basically sanded away with 220 grit, then two more light coats, lightly sanding between. I'm leaving the deck area clear(natural) and the hull bright red.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 10:26 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
I've chosen Top Flite's line of LustreKote spray for this boat. I've had great results with my airplane projects and nothing beats a rattle can for convenience. BUT - The stuff doesn't apply well in temps under 70 degrees F (what paint does?). So my winter was a waiting game especially considering we had record snow and low temps in Atlanta. I'm working on my wife for a heated paint booth....

Alas with some recent warmer temps and some final 600 grit wet sanding, I've started to prime. This is two lights coats applied. LustreKote is very forgiving especially the primers. After five minutes it's dry to touch and will not run if you load it on.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 17, 2011, 10:33 PM
Taking care of the pond.
MILLERTIME's Avatar
United States, CA, Sanger
Joined Apr 2004
7,377 Posts
I'm watching.
MILLERTIME is online now Find More Posts by MILLERTIME
Reply With Quote
Old Mar 17, 2011, 11:21 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
The engine I'll be installing is a Traxxas TRX Pro 15. I had two of these brand new from T-Maxx upgrades. This engine isn't the best in class but it runs well, true ABC BB type, and I had it in inventory already. Since this engine is air-cooled, it won't require hull speed to provide water circulation. My goal is to have a very low idle in the water. I've installed a MIP3073 heavy flywheel to help with that. If I get high temperatures, I'll add some water cooling tubes and plumbing, or just swap the engine.

The standard nitro small block pilot shaft is 5mm, so this coupler is unique going from 5mm to 3/16 cable although I think big brushless marine motors run 5mm standard now

I'll be running the stock header and exhaust. If need be, I'll go to a .15 tuned pipe. There's several options by Mac Products.

Here's some trial fit photos of the engine, flex shaft, strut and prop. That's a 3/16 plastic sport prop by Dumas. Still looking for a good metal prop.
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 18, 2011, 12:02 AM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
Here's the flex shaft installed, filled, and primed. Thanks to RC Groups, I learned the proper way to bend larger brass tubing. It involves heat treating the bend area, or "annealing" the brass and letting it cool slowly. I used a Bernzomatic torch which resulted in melting and a hole - first attempt... Second time, I dimmed my shop lights so I could see how hot the brass was glowing. It would be easier with a smaller hobby torch and knowing what temperature the brass you're working with anneals at.

Next, I sealed one end of the tube with tape and filled it with sifted play sand. This prevents kinks and flattening of the tube while bending. Using a simple plywood guide, the tube bent very easily and is still soft enough to bend a bit more for perfect alignment. Some Brasso cleaner and it looks like new brass again!
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 18, 2011, 12:32 AM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
The radio hatch is all done except for clear coat. I use Bob Dively liquid mask film for all my paint work. It's always pulls clean and i've used it on all types of surfaces and paints. Great stuff especially for NITRO tribal flames!

And here's a quick picture of the mahogany deck on the bow.

Next is to paint the hull. Then clear coat the decking, hatch and hull, and final installation of radio, engine, and drive. Hopefully be done by April, one year since starting this build!
av8rga is offline Find More Posts by av8rga
Reply With Quote
Old Mar 18, 2011, 02:51 PM
Registered User
Amp Abuser's Avatar
Joined Dec 2007
1,462 Posts
Great job on the build! It looks lke your Dumas prop will be to shallow for submerged running a small portion of the upward swinging blade is going to breath and cause cavitation or some loss in thrust. If a surface prop is used it will be set too deep and will try to climb up on the prop hub and bury the nose. Also no flywheel weight so the only no load weight on the engine is just the drive line. You can stretch your piston rod in a sec or snap it if ran wide open too long without load. If the Dumas props rotating top blade is at least 1/4 in under the bottom of the hull / to back of transom at speed you may be ok.
Amp Abuser is offline Find More Posts by Amp Abuser
Reply With Quote
Old Mar 18, 2011, 05:25 PM
Registered User
av8rga's Avatar
United States, GA, Cumming
Joined Mar 2006
55 Posts
Quote:
Originally Posted by Amp Abuser View Post
Great job on the build! It looks lke your Dumas prop will be to shallow for submerged running a small portion of the upward swinging blade is going to breath and cause cavitation or some loss in thrust. If a surface prop is used it will be set too deep and will try to climb up on the prop hub and bury the nose. Also no flywheel weight so the only no load weight on the engine is just the drive line. You can stretch your piston rod in a sec or snap it if ran wide open too long without load. If the Dumas props rotating top blade is at least 1/4 in under the bottom of the hull / to back of transom at speed you may be ok.
Thanks! and thanks for the advice. That makes sense. Right now the tip of the prop is just in line with the bottom on the transom but I can go lower if I need to. I planned on having to adjust lots of things once I run it. Luckily the strut is fully adjustable and the tube is soft enough to bend more.

The rudder is about three inches long and seems deep for this size boat. What affect would shortening it do and should I wait tilll I run it first?
av8rga is offline Find More Posts by av8rga
Reply With Quote
Reply


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion Dumas SK Daddle Brushless Motor Bob SF Racing Boats - Electric 35 Dec 26, 2011 08:17 PM
Discussion Dumas 36'' SK Daddle jbl302 Scale Boats 2 Dec 09, 2011 10:56 AM
dumas half-pint and sk-daddle jr. Kloud Dock Talk 4 Dec 02, 2008 01:24 PM
Discussion Outboard Sk Daddle Too? mistel Dock Talk 2 Nov 11, 2007 09:47 PM
Discussion 7.5cc Dumas SK Daddle 4Sale Fatdog Racing Boats - Internal Combustion 1 Feb 20, 2006 07:13 AM