Building the Glen-L HOT ROD - Cavitation Plates Page
 
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We fabricated an alignment jig made from 3/4" plywood scraps and hose clamps to mark location of turnbuckle mounting holes on the 7/8" OD control shaft. (28-APR-2012)

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Double faced carpet tape was used to temporarily hold the cavitation plate male bosses while fitting.  Mounting holes will be drilled after the control shaft has been machined.

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Hole centerlines were marked with a die grinder cutoff wheel.  Parts were reassembled and measurements were double checked before sending the control shaft out for spot facing and drilling. (29-APR-2012)

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Once we got the control rod back from the machine shop, the turnbucles were trial fitted. (28-MAY-2012)

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Now to cut the foot pedal control rod, thread the end to accept the clevis end and mark the control rod for the 1/4" wide keyway.

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The cavitation plate is fastened to the transom with 5/16" x 3-1/2" stainless steel button head machine bolts.  Every second bolt hole was overbored to 1/2" and filled with an epoxy and West System 403 filler. (26-JUL-2012)

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A 1/4" hole was bored slightly above the bolt hole.  The thickened epoxy slurry was loaded into a syringe and pumped into the bolt hole.  Once cured, the cavitation plate was reinstalled, a 5/16" drill bit was used to locate the mounting holes. 

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A 9/32" pilot hole was bored followed by a 5/16" tap to thread the bolt hole.  (29-JUL-2012)

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The threaded bolt hole is less likely to leak than an unthreaded hole.  Several wraps of teflon plumber's tape or thread sealant is all that is required to seal the threads.  If needed, parts can be easily removed in the future.

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To ensure that the cavitation plates were installed flush to the bottom of the hull, we used a length of 1/4" steel plate supported by two hydraulic jacks.

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Time to get the transom ready for final paint.  Sanding with an inline air file with 180 grit sandpaper was followed up with block sanding using a long, hard rubber sanding block. (01-AUG-2012)

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Paint prep included a wipedown with Final Wash wax, grease and silicone remover followed up with DuPont Plas-Stick 2319S Plastic Surface Cleaner.  The substrate was tacked with a 2K tack cloth before applying three medium coats of DuPont 4004S Ultra Productive 2K Urethane Primer-Filler.  The panel was block sanded with 400 dry and 600 wet sandpaper, prepped as mentionned previously and base coated with Limco Urethane white. 

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An hour later, we topcoated the white base coat with single stage Sherwin Williams Genesis GC 3.5 VOC Acrylic PolyurethaneThe color was custom mixed Corvette Yellow.   (03-AUG-2012)

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Masking tape was removed four hours later.

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Unfortunately the topsides won't be painted this year.  It's time to get the boat back in the water and see how the cavitation plates will affect the handling.

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Opening for the thru hull fitting is to the left of exhaust pipe hole.  This should place the thru hull roughly 1" above the waterline. (11-AUG-2012)

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We used a hole saw and a sabre saw equipped with a metal cutting blade to cut through the stainless steel transom support.

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Here are the cast aluminum oval thru hull and related components.  We cut a custom gasket for the thru hull flange which will be bedded in Permatex "The Right Stuff" gasket sealant.

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Here's the finished product.

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Here's the view from inside the boat.

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It's a very tight fit, but there's just enough room for the thru hull fitting and cavitation plate pedal control rod. (18-AUG-2012)

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The thru hull retainer thickness had to be reduced 3/4" to compensate for the 3-1/2" thick transom.

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We built custom pillow blocks from 1" x 2" aluminum bar stock.

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The bar stock was notched to fit over the steel angle iron frame clips.  We bored a 3/4" diameter hole through the bar stock and loctited a 1/2" ID x 3/4" OD bronze bushing.

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To gain enough clearance for the foot pedal rod, the starboard side fuel tank cradle was modified to shift the fuel tank over 1-1/2".

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The large spring ensures that the control handle returns to the neutral position e.g. cavitation plates flush with the hull bottom.

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While we were at it, we fabricated a new gas pedal and mounted it on the 7/8" diameter shaft that was supplied with the Glenwood cavitation plate foot control kit.

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Here's an excerpt from the Glenwood Marine Catalog explaining how the cavitation plate override system works :

"On high speed boats, quick accurate setting of the cavitation plate is desirable for safety and best performance.  Using a combination Foot Control and Control Handle with an Override Assembly makes such adjustment quick and positive.  Usually the cavitation plates are set by the hand control to the desired pitch.  However, when quick acceleration is desired, or when the bow of the boat needs to be brought down instantly, the foot control can be depressed to override the hand control.  When the foot control is released, the cavitation plate will will return to its initial pre-set pitch."

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The boat is finally back on its trailer.  We've affixed the Transport Canada Capacity Label to the upper starboard corner of the transom.  Click the photo for a higher resolution 2272 x 1704 image. (21-AUG-2012)

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We are now known as Kane Custom Boats Ltd..  Our Transport Canada assigned Boat Manufacturer Identification Code is YPB.  The capacity label was issued after a marine survey was performed to ensure that the boat conforms to Canadian boat construction standards.  The boat can now be sold to the general public.

 

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Revised 24-AUG-2012

Building the Glen-L Hot Rod : www.kanecustomboats.com