Steve Sanford
Well-known member
All~
Here is a new motor board for a friend's Sneakbox. This Sneakbox was built by Red Magnus - the same guy who designed and built the South Bay Scooter. He cut down a sailboat hull.
Red had to experiment with the motor board to get the right elevation. So, a "stealer" was added to the top to increase the height for the 1980s Johnson 9.9. Current owner Steve was concerned about the structural integrity of the add-on - and asked me to make a new one.
The board also needed wedges to increase the effective transom rake. They taper over 9 inches from 1-3/8" at the top to 1/2" at the bottom.
Red added another wedge on the bottom to protect the bottom edge of the transom should in bang on a concrete launch ramp.
I took the photos and lots of measurements and headed north to Pencil Brook Boatworks World Headquarters (my shop.....). Here it is with 2 coats of marine epoxy and one coat of Pettit Shipendec.
Rather than one wedge across the width of the board, I prefer a pair with air space in between to let water get through and away.
Also, I drilled only small (1/8 inch) pilot holes - leaving Steve to bore the full-size ones during installation. I have learned to NOT do certain things when I am 250 miles away from a project. My biggest concern was that I was unsure whether the existing bolts had been installed square to the raked outside of the board OR to the inside of the transom. Steve is a meticulous craftsman (retired aircraft mechanic) and will do it right.
Since the bottom space is only one-half inch, this "hand-hold" is not very useful - but I usually put them on motor boards for when you need to lift the hull. I round over all edges - with a router - for comfort.
These shallow holes are bored with a 1-3/8" Forstner bit on the drill press. Just deep enough to keep the motor from torquing off in a turn, they are located for Steve's particular engine.
NOTE: I used an old piece of treated lumber - a 2x10 I've had kicking around the shop forever. I know it is at least 20 years old. So, it is good and dry AND it's the old CCA. I am not concerned about galvanic corrosion of the mounting bolts because a) the bolts will most likely be hot-dipped galvanized carriage bolts and b) the bolts will be slathered with 3M 5200 when installed - providing an additional chemical barrier.
From what I have read, the newer wood treatments pose a greater galvanic risk to hardware - but stainless steel and hot-dipped galvanized hardware should still give long service. To avoid using treated lumber, one could use other woods - especially traditional species such as White Oak, Douglas Fir, Philippine Mahogany or untreated Southern Yellow Pine.
All the best,
SJS
Here is a new motor board for a friend's Sneakbox. This Sneakbox was built by Red Magnus - the same guy who designed and built the South Bay Scooter. He cut down a sailboat hull.
Red had to experiment with the motor board to get the right elevation. So, a "stealer" was added to the top to increase the height for the 1980s Johnson 9.9. Current owner Steve was concerned about the structural integrity of the add-on - and asked me to make a new one.
The board also needed wedges to increase the effective transom rake. They taper over 9 inches from 1-3/8" at the top to 1/2" at the bottom.
Red added another wedge on the bottom to protect the bottom edge of the transom should in bang on a concrete launch ramp.
I took the photos and lots of measurements and headed north to Pencil Brook Boatworks World Headquarters (my shop.....). Here it is with 2 coats of marine epoxy and one coat of Pettit Shipendec.
Rather than one wedge across the width of the board, I prefer a pair with air space in between to let water get through and away.
Also, I drilled only small (1/8 inch) pilot holes - leaving Steve to bore the full-size ones during installation. I have learned to NOT do certain things when I am 250 miles away from a project. My biggest concern was that I was unsure whether the existing bolts had been installed square to the raked outside of the board OR to the inside of the transom. Steve is a meticulous craftsman (retired aircraft mechanic) and will do it right.
Since the bottom space is only one-half inch, this "hand-hold" is not very useful - but I usually put them on motor boards for when you need to lift the hull. I round over all edges - with a router - for comfort.
These shallow holes are bored with a 1-3/8" Forstner bit on the drill press. Just deep enough to keep the motor from torquing off in a turn, they are located for Steve's particular engine.
NOTE: I used an old piece of treated lumber - a 2x10 I've had kicking around the shop forever. I know it is at least 20 years old. So, it is good and dry AND it's the old CCA. I am not concerned about galvanic corrosion of the mounting bolts because a) the bolts will most likely be hot-dipped galvanized carriage bolts and b) the bolts will be slathered with 3M 5200 when installed - providing an additional chemical barrier.
From what I have read, the newer wood treatments pose a greater galvanic risk to hardware - but stainless steel and hot-dipped galvanized hardware should still give long service. To avoid using treated lumber, one could use other woods - especially traditional species such as White Oak, Douglas Fir, Philippine Mahogany or untreated Southern Yellow Pine.
All the best,
SJS
