So you need a new floor in your boat, well so did this one. Desperately 🙂
We cut out all the old floor using a rotary hacksaw mounted in a 125mm battery grinder and then used 125mm 80 grit flap disks to remove any remaining lumps & bumps.
A horrible job at the best of times and the dust was unrelenting but we got there in the end.
We then cut out 3 main rafters out of 24mm marine plywood.
The main middle rafter was cut so it fitted the exact shape of the middle hull and was made to fit all the way from stern of the boat to front bow.
This main rafter was then epoxied into position using 2 pack epoxy with thickener powder added.
After forming the curve that was required to match the bow of the boat the left and right center rafters were installed into position and epoxied in
Then came the tricky part.
Fitting the cross sectional ribs into the rafters along the length of the boat.
Prior to fixing the rafters into position we docked out all the rafters with a 6mm deep grove in the position where the ribs were to go, talk about a head f…k but it needed to be done so that we ended up with fully structural floor beam system.
Marking out and cutting the templates for the 12mm ply wood ribs we did with sheets of cardboard along with numbering each template.
Using the same epoxy as we did with the rafters all the ribs were installed
All the ribs were left long so we could plane a 5 degree fall into the center of the boat.
Cut outs were made to enable such things as the stern drain recess along the way.
Each longitudinal pocket is around 1 meter by 450mm
The spacing is not critical but all the center lines of each individual rafter must align.
The side rafters were installed at the same time as the ribs
In all we ended up with some 30 pockets under the floor after all the epoxy went off and the rib profiles were planed to shape.
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Across the floor and 150mm up the hull sides we we applied fiber glass resin and glass sheeting.
we used a 25mm trow away brush to push down the resign soaked cloth to remove any air gaps in the structure.
In the end we applied 4 layers of fiberglass resign and cloth up and over each individual rafter, floor segment and rib pocket making sure we glassed up the hull sides by at least 150mm on each pass.
In the end we achieved a hull structure adhesion across the entire hull that was way beyond required by the orignal boat structure.
Epoxied ribs & rafters
The floor cover plates where now cut to shape. We fiber glassed the undersides of the floor plates prior to fixing them into place.
Prior to fixing the floor plates into place we surveyed all the underlying voids.
From that data we determined the void fill inlet & outlet holes.
On this floor we used 13mm inlet holes and 51mm outlet fill holes.
That worked a treat.
We used a 50mm hole saw to cut the exit holes making sure that we kept the hole off cuts so that when it came to reinstoring the fill & exit holes in the new flooring system life was easy.
Each void we filled with 2 pack industrial expander foam.Wow !
We now had a boat floor that if flooded could remain buoyant on the basis that any given void penetrated did not impact on the buoyancy of any other void.
A nice idea when your in close chasing Snapper close to rocks.
After all the plywood plugs were epoxied back into place and after a quick sand we applied 3 coats of fiberglass and resign.
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As you can see the new floor was awesome
As a direct result of the new floor, the boat is now almost foul proof .
Punching a hole in the bottom of the boat is now not going to result in being sunk due to the bouncy voids in the hull.
Getting in closer on rocky reefs always results in more fish – now hay – how goods that.