Double Hull Dumas Runabout

[Randy1962]

0 miles from you in United States, AL, Birmingham Joined Nov 2021 27 Posts

Help! Double Hull Dumas Runabout I have made a decision that hull imperfections in my first ever build (Dumas Runabout) will require a double hull. For more details, see the link below. https://www.rcgroups.com/forums/show...are-my-options I am well above my experience at this point and will probably have several questions but will start with these. As I see it, the most important edge I need to maintain when placing the first plank is the edge with the sheer since it will not be under the sheer but instead next to it. If I start at the stern and maintain the edge, at some point the plank will rise above the sheer. It doesn’t seem possible to force the plank to maintain the edge using the 1/2 “ kit provided planks. Should I cut this top plank to allow the edge to be maintained? This would of course cause a problem with subsequent planking. If I start at the chine and work my way up, it appears the top plank will not be even with sheer, perhaps 1/8” short.  Do I work up from the bottom or down from the top? As always, I appreciate the help. Signed,  “Confounded in Alabama”

[mtaylor]

Randy, go up to the top of the page (any page) and hover over the "More" link.   A menu will pop up.   Down about half way is topic "Planking Techniques".   Click on it.  There you find several planking tutorials.  Have a look and see if they help.  

[Tim Moore]

Hi Randy. I’ve built similar mahogany runabouts. This is how I would approach this.

ideally, you would remove the side planking and redo it, starting by butting against the bottom planking and going up to the deck. Start at the stern and proceed gluing the planks forward from there. The last few planks will probably not run the full length to the bow, that is normal. Attached is a picture of one of my boats for reference.
if you can’t remove the side planking, you can overplank the same way, starting from the bottom planking and going up. The top edge of the side planking at the deck can be covered with a chrome trim if you can’t get a perfect looking joint, since many of these boats have that detail anyway

Good luck with the repair!
Tim

Edited February 6, 2022 by Tim Moore
Picture

[Randy1962]

Thanks guys.

 

I am about 85% complete with double planking. Things are looking pretty good. No show winner but lots of lessons learned.

 

Tim, your boat is beautiful. What is the finish on it?

[Tim Moore]

The finish process on my Miss Severn was a bit involved. It first had several coats of finish-cure epoxy thinned with xylene to waterproof it as it is fully motorized for performance use in water. Not a suitable process for the dining room. You don’t need that step if it is a display model.

The final finish was achieved by 4 coats of carefully brush applied Helmsman spar varnish, satin, using 400 paper for between coats and then 600 paper after last one. It is then left for at least a week to fully dry and off-gas. This is VERY important. After that it is wet sanded using 600 and 1200 paper. After leaving that to totally dry again for several days, I used a buffing wheel and guitar polish to give a final perfectly smooth mirror like finish. 5 years on it still looks perfect.