The Shipyard ( Dry Dock ): Builds & Questions > Pleasure boats, Sports, Race, Power and Leisure Boats:
Building a Dumas Chris Craft Runabout kit
SailorGreg:
I recently purchased this kit from a fellow Mayhemer (thanks Mark) who had decided he was never going to get around to putting it together. It is a few years old, and I don’t know how it compares with the kit you buy today, so some of my comments as we go through the build might not apply to a modern kit. (But of course they might!)
I plan to build this pretty much out of the box, although there are a few mods I hope to make as I go along. I have read a lot of build threads elsewhere of this type of boat, although they are few and far between here on MBM. My only previous significant model boat building has been my steam launch (http://www.modelboatmayhem.co.uk/forum/index.php/topic,41151.0.html) and I have never built a model boat kit before, so this is going to be an interesting ride. If there is anyone out there who has experience of Dumas kits, please feel free to chip in. O0
Having sorted through the box of bits (all present and correct), the first step is to produce a building board. Mine is from 20mm MDF and is marked out as instructed in the Dumas instructions.
Well, that was easy. Next is separating the diecut frame and keel parts from the plywood sheets. I have to say I have seen better quality ply in my time, and I picked up a few splinters during this process (including one down a finger nail – ouch! >:-o ) Other than that the pieces came out pretty easily with a sharp scalpel, although at this stage some are pretty fragile as I found out. Still, nothing a drop of CA can’t fix.
I also came across a potential issue with the frames. I put two marks on each of the frame position lines to allow me to get the frame central (something the Dumas instructions don’t suggest) and then found when I put the frames to these marks that the keel slot was off-centre.
You can see that the corners of the frame are on the pencil marks each side but the centre line is not in the centre of the slot. All the frames that slot on to the keel had a similar offset. The keel was also a loose fit in the slot, so some of the apparent offset could be lost by pushing the keel to one side of the slot. After thinking about this, I decided to press on and align the keel and frames as best I could within my marks and trust that the hull fairing would even out any discrepancies. I should point out to those unfamiliar with Dumas kits that the central keel only covers the forward half of thr boat. The rear half centreline is defined by a "butterfly keel" which is basically two flat strips of wood fixed over the aft frames. The keel you see in the next few pictures is only half the length of the finished boat. All will become clear later! :-))
The keel is a double thickness of ply. I glued the port and starboard halves of the keel together with a simple jig to make sure the edges were exactly aligned as I clamped the two halves together – just a few strips CA’ed onto a firm base.
At the next stage of erecting the keel and first 6 frames I did favour getting the keel along the centre line over getting the frames exactly centred. It remains to be seen if I regret this in the future! Actually once the frames and keel were glued together and to the building board, there didn’t seem to be any huge discrepancies (but then I don’t know at this stage what is significant and what isn’t! :embarrassed:
Well, that’s it for the moment. I am already a little more advanced than this, so the next few posts will catch up to where I am. I've just realised I haven't posted any piccies of the kit contents, which seems to be a favoured starting point. I'll see what I can do on that front for the next post.
Greg
Capt Podge:
Hello Greg,
Those frames look awfully fragile at the moment, should become more rigid as you progress though and things tighten up.
Never built one of those myself but still find it an interesting subject O0
Looking forward to your progress :-))
Regards,
Ray.
Martin (Admin):
Nice start Greg! :-))
Vintage:
--- Quote from: SailorGreg on January 25, 2014, 10:22:02 pm ---I recently purchased this kit from a fellow Mayhemer (thanks Mark) who had decided he was never going to get around to putting it together.
--- End quote ---
Good luck with it Greg - I've too many projects and I'll be interested to see the progress.
Thoroughly enjoyed your steam launch build - I've been inspired to get on with my MHB Topaz...
Mark
SailorGreg:
First, as promised, a couple of piccies of the box and its contents.
At the top are the vacuum moulded seats – I will probably use these initially but I rather fancy some vinyl (or even real leather) ones, so will keep copies of all the cockpit pieces to allow me to make replacements sometime later. Under these is a bundle of mahogany planks which will form the outer planking of the hull and deck. The cardboard tube contains styrene strips which will be the caulking between the deck planks. Under the tube are some mahogany sheets for sheer planks and other trim pieces. In the box proper are other wood sheets, mainly birch ply, to build the internal structure. By the time I took the photo the sheets of nasty ply for the frames had already gone to be used. The small box on the left contains a piece of plastic for the windscreen, the rudder, propeller, dowel for flagstaffs and a few other bits and bobs. A prop shaft is also provided but I plan to fit a replacement with a metric thread (as I also plan to replace the propeller). In the middle is a plastic bag of chromed fittings. These are of rather average quality and I suspect will be the cause of great indecision when the time comes to fit them – use, modify or replace? On the right are the “decorations” – name, home port and self adhesive flags
OK, on to the real business. The next step is to erect the rest of the frames along with the sheers and chines, which lock everything together. All these parts have to be slotted together and put in place before anything is glued, so having a third (and fourth) hand is a distinct advantage. O0 Unfortunately I am not so blessed, so I just cursed, swore, picked everything of the floor a few times, and eventually got to this stage.
All the joints now get a drop of CA and a squirt of kicker, as do the legs of the frames where they rest on the building board. Everything then becomes a lot more solid. :-))
Next come some stringers and for some reason those supplied were a little short.
You can see the cutout in frame 2 where the stringers should reach, but they don’t. :o Not to worry, I made up replacements from some Douglas fir I had and pressed on. Next problem – one of my replacements was too short but I didn’t find out until I had started gluing it in place. :embarrassed: (The first person to say “measure twice, cut once” can leave now!) Rather than rip out the glued joints, which I thought might damage the fragile frames, I CA-tacked a second piece of wood alongside the stringer, tacked this to a large block which I braced against the frames then planed a scarph joint in situ. I popped the two pieces apart, turned one round and glued them together – instant longer stringer! Here’s the joint being cut.
Having got over that little wrinkle, the other bits and pieces needed before planking begins were added. The next picture shows the curved transom piece and the end of the “butterfly keel”.
and then the balsa blocks that form the bow. Here they are with shaping underway -
and finished –
Next was a bit of fairing and I made up a board for the larger, flatter areas (80 grit as you can see).
I made sure all edges had been touched with the abrasive and that the bevel formed along the edge of the chine was even all around, then stopped. Next was the first planks, and here they are.
Next time will be the first layer of planking and separating from the building board, Can’t wait to see her right way up!
Greg
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