| I began recording a construction Journal after I had already completed a
good portion of the Hull. At this point the hull has been cut epoxies and skinned with 1/8
plywood. |
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| This is a top view of the Hull |
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| This shows the overlaps of the skin to the attach strips for the skirt |
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| Front view showing the taper of the hull, and the overlap at the nose of
the skirt attach strip. |
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| A good picture showing the different layers of attach strips and 1/8 skin. |
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| I am now starting to form the bottom portion of the craft. The lines that
you see here are for the skid plate mounting pads. This guide will be used to form the 2
inch foam and 1/8 inch skid plate. |
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| This is the rear of the craft, you can see that the guide ends 12 inches
from the stern of the craft, These measurements were made with square, measuring 15 inch
for inner line and 8 inch for outer line |
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| Here we have placed the foam on half of the craft, you can see that the
guide is completely covered. A couple of long screws were used to secure the foam in place
and the outer edge of the craft was cut using a hot wire. The plywood that is laying on
top was cut using the guide that was drawn on the bottom of the craft. |
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| Foam is cut and placed on the other side of the craft, again a couple of
screws were used to hold it in place for hot wiring. You can also see that the inner edge
of the left side has been cut to match the skid plate pad, This was done using a jig saw. |
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| The outer edge is completed, it is not important to do a perfect job at
this because it will be hot-wired again later. |
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| This is a picture from the rear of the craft showing the inner edge cut.
All pieces will be epoxied and vacuum bagged next. |
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| I am marking the rear of the craft for the rear skirt attach strip |
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| In this picture you can see that I used a router to cut to the 3/8 inch
depth in the foam. A Router is the correct tool for this, does a very good job |
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| close up |
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| The rear attach piece is then inlaid into the foam using epoxy |
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| All pieces of the skid plate base were epoxied and placed into position, I
used a few screws to hold it all in place while it sets in the vacuum bag. |
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| Description of what you see here is: 1)Everything is placed into a large
plastic envelope, then sealed with caulking and duct tape.
2) the hull is covered with a layer of blankets so that the suction can breath, then a
50 foot garden hose is coiled around the surface. This garden hose has holes drilled in it
so that it provides a uniform suction, Then another layer of blankets are placed on top of
the hose.
3) The hose is attached to a vacuum and voila you are compressing 13.5 feet of boat
uniformly.
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| Here you can see the vacuum bag compressing, notice the bulge were the
garden hose is |
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| The hose is attached to the vacuum |
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| A close up of a axle boot used to seal the hose to the vacuum. A shop vac
works ok but if I did it again I would use a converted fridge compressor. |
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| When the Hull comes out of the bag, approx. 10 hours. The actual skid
plate will be attached. The skid plate is 1 X 3/4 by approx. 15 feet. It curves to follow
the shape of the skid plate. So how do you bend 15 feet of wood. This is what we came up
with a "Steam pipe" it worked great. This picture shows the wood placed into a 2
inch pipe |
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| The pipe was placed between two stands at approx. 20 degree slope, so that
the steam, when condensed will flow back into the steam pot.The steam pot is an old 5
gallon paint tin and is heated by a tiger torch. The wood |
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| This picture shows the steam pipe in action. The wood was steamed for 2
hrs and placed into a jig. |
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| Step one of the jig. I used the skid plate base and traced the outer edge
onto the work bench. You can see that there is a slightly different bend on each side of
the hovercraft. |
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| This is the first piece of wood in the jig. This stuff bent really easy.
Make the bend while the wood is hot. Let it cool for a day before you remove it from the
jig. I used spruce for this, I may bend some oak (tighter grain, actually about the same
weight) just to see if it turns out even better. |
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| This is a picture of both pieces of wood in the jig, the jig is nothing
more than some deck screws and some wooden blocks |
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| Well the Hull is out of the bag and the epoxy has set. Time to Hot Wire |
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| We start at the back and cut the angle in the foam using the side attach
strip and the skid plate as a guide |
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| The Hot Wire will do a rough job because it is going through some large
amounts of epoxy in places. This angle will be sanded down later |
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| First side complete, 20 minutes work. Trick here is to go slow and
apply constant even pressure and allow the wire to cut the material. |
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| This is the Hot Wire Bow that I made. It can be adjusted to make a 5 foot
cut or a small cut like we just made, 1.5 feet. The Wire is Mig welding wire, This wire
holds up to the heat but will stretch and break once in a while. You can use NiCr wire if
you like. The power source is unregulated 12volt 2amp from a battery charger,if you are
cutting a wider section lets say 5 feet wide, just move the amp up to 4 or 6 amps.There
are many Hot Wire plans on the web, I looked at a lot of these, If you are uncomfortable
with electronics, transformers etc. This method is simple and effective. |
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| A close up of the rough cut. |
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| I finished sanding the Hull and flipped it over, this is a picture of the
sanded taper, you will notice that some areas I cut too deep with the hot wire, these will
be repaired with 2 part foam. |
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| This view shows the back of the craft, I continued the angled taper around
the back of the craft, this was not on the plans |
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| This picture shows the cut away at the front of the craft, this is to
prevent plow in
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| The skid plates were attached using a mixture of epoxy and fiberglass
fibers. I used a few dowels to position the skid plate were it should be. |
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| This picture shows the skid plate in place before I cut the end to fit. |
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| Attached to the skid plate I will be using a plastic cover that will take
most of the abuse. The plastic I used is from the inside of Semi Trailers it is used as a
skid plate on the walls to protect them from forklifts etc. |
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| I attached the plastic to the skid plate using #8 3/4 inch screws, then I
flushed the plastic to the skid plate using a router. |
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| Skid plate complete |
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| Side view, You can also notice in this picture that I have started
fiberglassing the outer attach strip. I am using 4 inch strips of 4 oz cloth.
This completes the Hull section. |
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