Category: 1930 Dodge Runabout

We have been so busy making progress elsewhere that we have been unable to get back to the 1930 Dodge Runabout 5200 bottom project until yesterday.
As of this mid-afternoon yesterday, John, RJ and I have finished re-sawing and milling FAS grade mahogany planks – 6/4×18”x16.5’ – into a collection of 1/4×6-1/2”x48” bottom planking blanks.
John then began fabricating new bottom planks, one-by-one, since ever one is different from all the others. We find John now having fabricated all of the starboard planks, and, as the clip closes, beginning to seal each of them on all four sides with CPES.
We hope to begin screwing them down, heavily bedded in 3M 5200. In his recent article, “What is a True 5200 Bottom?” (Classic Boating, September/October, 2014), Don Danenberg is blunt about how skimping on 5200 simply translates into fool’s errand now, and troubles lurking on the horizon:
In communication with the two 3M scientists who invented and developed the 5200 product, I was told that one of their first, largest customers was Chris-Craft, who used it to replace the two-part Thiokol they were currently using in the plywood Cavalier and Sea-Skiff divisions. It was apparently tried in the main division of planked boats but added far too much in construction costs to be cost-effective. Higher-end boat builders, like Trumpy
Yacht Company, used it as their standard construction procedure after 1966.
The biggest problem I’ve seen here is inadequate amounts being used. Where I recommend 40 to 60 tubes just for the bottom plank installation, these troubled guys reported they had been billed for 24 tubes. This is simply not enough product to fill all voids. Okay, so you saved a few hundred bucks, but compromised the entire operation?” (p. 24.)
Also following Danenberg, five coats of Interlux 2000E Barrier Coat Primer will be applied once the bottom has been installed and the 5200 has cured, a process that takes 7 days.
Quoting Danenberg again from the same article:
“One of the biggest problems I have seen with short-cut 5200 bottoms is either a total lack of, or inadequate amounts of, Interlux 2000E Barrier Coat Primer. This two-part (thus epoxy) paint is a water barrier coats meant to keep the water from soaking into the bottom planks. It does that with minute platelets in the makeup that vastly slow the movement of water. Unlike hard epoxy laminating glues, it is flexible enough to move with the bottom.” (p. 25.)
Description

Minnow is a 1930 Dodge Bros. 16.5’ runabout who is incredibly original, from her gauges to her quite unique push/pull throttle and Lycoming flathead 4 engine.
Her engine will ride Old Dominion to Robert Henkel Inc. (http://ift.tt/1w7jSRy) in Harsens Island, MI to be completely rebuilt to as close to original as is possible. Given his life-long association with antique and classic wood boats, and especially his well-deserved reputation for delivering work that meets the highest standards of craftsmanship, we are pleased that he agreed to take on this rebuild responsibility.
Our focus for now is the interior of the hull and installing a new 5200 bottom that matches the original planking pattern exactly.
Here we, well John is “tooth-picking” every fastener hole in the bottom framing. Why? Once the Gorilla glue sets, we will cut every tooth pick off flush with the framing using our Multi-master Fein tool, A quick sanding followed by coating with bilge paint fives us a surface into which the new fasteners can bite and hold.
The interior layer of Okoume plywood comes next, the templates for which John fabricated using heavy industrial paper. Once each panel is fitted, its interior face will receive three coats of CPES and two coats of Sandusky Chris-Craft Mahogany bilge paint. The exterior surface will be treated similarly once it is installed.
But all that will be covered in upcoming progress reports. For now enjoy Minnow a’ la porcupine. By the time John finishes, he will have consumed close to 5,000 toothpicks and more than a pint of Gorilla glue.
Thank youu to her Oregon-based owners for entrusting preparing Minnow for next season following languishing on the hard for the last 45+ years!