Wed Jul 4, 2001

8 hours

Pictured  top right - Cutting out the foam skid risers

Pictured 2nd right - I used the 1/8 ply skid base plates as a guide.  I marked a line on either side for a reference when I epoxy later. 

Pictured 3rd right - Cut out complete.  I used a large handsaw to cut the straight cuts in the foam and a keyhole saw to make the curved cuts.   I used a Dewalt random orbital sander and a piece of 2x4 with sandpaper to smooth out the inside curve.  I am not worried about the outer edge because I will be hot wiring it off at an angle.

Pictured 4th right - View from front of the completed risers with plywood base resting on top.

Note - I deviated from the plans slightly.  The inner edge of the foam riser should have 1/2" clearance from the base ply to the edge.  I made it flush.  I also won't have 1/2" clearance on the outer edge as I am hotwiring the angle using the skid base ply and outer skirt attach strip as a guide.

Wed Jul 4, 2001

cont...

It's in the bag.  Again.  Very hot today around 26 - 30 C.

Pictured top right - Here is my trusted assistant, and really the brains behind the whole operation, my 1 year old daughter Kaylee.

Pictured 2nd right - I am attaching the foam risers, rear inner skirt attach strip and 1/8 ply skid base in one step.  I worked pretty fast and developed a good sweat.  You can see where the hose enters the bag.  Out of view to the right is the vacuum pump sucking 17" Hg.

Pictured 3rd right - I ran the hose inside the risers and about 3.5  feet up the outer perimeter on each side.  The hose has two 1/8" holes in it about every 1.5 inches. 

Pictured 4th right - A close up of how the hose is run along the sides.

Thu Jul 5, 2001

After 17 hours I shut off the vacuum pump and removed the hull from the bag.  I am very pleased with the results.  There was a little epoxy sepage from the seams that I needed to file off on the aft inner skirt attact strip but other than that great!

Pictured top right - Bottom of hull with foam risers and 1/8 skid base ply attached.  I need to slope the foam so it  tapers from the skirt attach strip up to the outer edge of the 1/8 skid base ply.  A fellow hovercrafter is coming over with his hot wire rig (much better than mine) and we are going to try hot wiring the slope.  This will be done by keeping the wire at a 90 degree angle to the outer skirt attach strips.  I will use the outer skid base ply edge and outer skirt attach strips as a guide.  I am not sure how well this is going to work but its worth a try.  This isn't quite how the plans show the edge constructed.  It is close the way the 13P hull appears in the UH General Hovercraft Construction Video.  I like my way better as I will end up with a smooth transition from outer skirt attach strip to skid base ply.

Pictured middle right - Rear of craft with inner aft skirt attach strip inset to be flush with hull.

Pictured bottom right - I had such strong vacuum that the hose slightly indented the foam. 

Fri Jul 6, 2001

4 hours

Today I a friend, Wayne, came over and hot wired around the craft.

Picture top right - Wayne is running the hot wire bow down the craft using the skid base ply and outer skirt attach strip as a guide.  This worked really well.

Picture 2nd right - This is Wayne's hot wire control panel.

Picture 3rd right - The bow left a nice rough cut.  It did a pretty good job eating through some heavy epoxy.

Picture 4th right - I don't see this on the plans but I am tapering the rear of the craft.

Picture 5th right - I used an orbital sander and a flat hand sander to smooth out the sides of the craft.

Picture 6th right - This picture illustrates how the foam is tapered at the back of the craft.

Fri Jul 6, 2001

Cont...

Today I also put together a quick jig for cutting the duct forming discs.

Pictured top right - I took some angle aluminum and mounted it to my Dad's router (sorry Dad).  I will be able to use it to cut perfectly round forming discs for the duct.  I was going to use my jigsaw but this will work much better.

Pictured bottom right - Close up of how the jig mounts to the router.  The router had a plastic bottom that was held on by three screws.  I removed the bottom and drilled holes in the angle aluminum so the screws would be more or less flush with the angle aluminum.

Fri Jul 6, 2001

Wayne took me out and we went hovering on his Scat 2.  This was my  first time ever on a hovercraft.  It was a blast.  This was defiantely incentive to get my 13P up and running by the end of the summer. 

The river is the North Saskatchewan and it flows down the middle of our city Edmonton.  It is a beautiful river that flows to us from the Rocky Mountains.  This year there was some water quality tests done and it is safe to swim in.  It is also safe to eat the fish from the river but they recommend that consumption be limited to 1 fish per week because of high mercury.  This is where I plan to do the majority of my hovering. 

Sat Jul 7, 2001

4 hours

Today I went and picked up 4 sheets of 4x8' 7/16" OSB particle board.  They were $10.90CAN per sheet.  I only needed 3 sheets but bought 4 for fudge factor. 

Pictured top right - Two lift fan forming discs stacked on top of each other.  They are 26 1/4" diameter exactly.  I used the router jig I built yesterday to cut the discs.  It worked really well.

Pictured 2nd right - I cut the two discs out of one 4x8 sheet.

Pictured 3rd right - I used the  random orbital sander to sand the flat edge around the perimeter.

Pictured 4th right - here is the lift fan sitting on top of the duct forming discs.  There will be about 1/8" or less space between the fan blade edge and the duct wall (the less the better).

I need to get some ratcheting tie down straps to hold the plywood around the discs.  I am going to use some 2x4's inside the discs to hold them apart.  I will probably drill a 1" hole in the center of the discs and use the 1" steel shaft to align the discs.

Sat Jul 7, 2001

Cont...

Pictured top right - I used 2x4's to act as spaces between the discs.  I used a drill press with 1" bit to drill a hole it the center of the center 2x4.  I screwed the 2x4's to the lift duct forming discs.

Pictured 2nd right - illustrates how the two discs will be mated together.

Pictured 3rd right - I used the 1" steel shaft too hold the two disc assemblies together.  I then used several 3 1/2" screws to join the two halves together.

Pictured 4th right - I bought two ratcheting tie down straps.  I wanted to see how hard it would be to wrap the ply around the disc.  I went against the grain so the ply was resistant to bending.  I was able to completely wrap the ply around the disc using one ratcheting tie down.  The plywood overlapped on itself.  This is a good sign.  I believe I need to join two pieces of ply together with epoxy and fiberglass and then wrap the ply, with the grain favouring bending, around the disc.  The grain would be parallel to the steel shaft in picture 3rd right.  For the test wrap pictured here the grain was at a 90 degree angle to the shaft.

Sun Jul 8, 2001

1 hour

I was out at the lake today hence the 1 hour construction effort.  I did manage to cut the lift duct ply and fiberglass it together.

Picture top right - Two 48" x 20" 1/8" ply sheets butted together.  I used plastic wrap and a 1/8 ply sheet under the seam.  Epoxy doesn't stick to plastic wrap.

Pictured 2nd right - I used 6oz fiberglas cloth about 4" wide to join the seam

Pictured 3rd right - I covered the epoxied seam with plastic then added a 1/8 ply sheet to the top of it.  I weighted it down with my lift duct disc formers among other things. 

Tomorrow I will cut and wrape this ply around the lift duct forming discs.

Mon Jul 9, 2001

8 hours

Wow.... what a crappy day... I failed miserably at the lift duct. I actually had it almost right the first time but perfection got the best of me and I had to wrap it again... sanded off too much... crap... ok start over this time with two pieces of wood unjoined by fiberglass and epoxy.... almost got it.. sanded off too much.... CRAP.

I am epoxying two new pieces together and will start over again tomorrow... things should go a little better as I have the procedure down a little better. I tried using the brad nailer... it really made a mess of things. The ratcheting tie down straps work really well. I think I will try tomorrow just ratcheting and then fiberglassing the one joint

Tomorrow is a new day...

Tue Jul 10, 2001

5 hours

Today is going great.  I just finished the lift duct.  Marked a line 5.5" from the edge of the inside duct and ran it ~82 3/4".  I am using this as a guide to keep the disc in the right place when I wrap the plywood. I also marked two lines on the outside of the duct ply that mark the outer edges of the disc formers.  I am going to use these lines to brad nail in place.  I wrapped the ply around the discs and ratcheted tight. I marked the ply where it overlapped.  I removed the straps and cut the ply on the line.  Incredibly when I wrapped the ply around the discs again it was a perfect fit.  I mean perfect.  Luck is with me today.  I don't know where she was yesterday.

I highly recommend ratcheting tie down straps for this.  They work great.

Pictured top right -  The ply wrapped around the forming discs. 

Pictured bottom right - the ratcheting tie down straps hold the ply tight.  I bought some 5/8" brad nails and I will use them to secure the ply to the disc.

Tue Jul 10, 2001

Cont...

Pictured top right - I cut two pieces of 1/8 ply to cover the back of the skid risers.  This is not on the plans.  I believe it is a good idea to protect the foam from chipping away.  And the weight it will add is negligible.

Pictured 2nd right - This 1/8 ply piece will be epoxyied into position and then fiblerglassed around the edges.

Pictured 3rd right - This is the inner skirt attach strip/ landing skid.  I needed to find a good method to bend it to the curved shape of the bow.  I am using a 3.5" long 1/4" diameter wood dowel.  The skid is 1" high that leaves 2.5" of dowel that gets sunk into the hull through the skid plate.

Pictured 4th right - I drilled two dowel holes and sunk them into the hull to hold the skid.  I did a test bend and I was able to bend the skid to almost the right shape with the two dowels.  I may need to epoxy a section of the skid at the time making the bend over a few days. 

Tue Jul 10, 2001

Cont..

Pictured top right - I epoxied the ratcheting straps to the 1/8 ply duct.  My reasoning is that it will strengthen the duct and allow me to use less if any brad nails.  I didn't wreck the ratcheting part of the strap.  I just need to buy new straps and I can use these ratchets again.

Pictured 2nd right - I epoxied the joining seam.  I used 1" 6oz fiberglass cloth.  I used the table with plastic underneath to hold and shape the duct.  I only used a 1" strip to avoid getting a flat spot.

To finish the duct I will epoxy 6oz fiber glass strips on either side of the straps and in between them.  Once this is complete I will release the pressure on the straps and see how well the duct holds to the ply discs.  I can always re tighten the straps if it doesn't and throw in a few brad nails around the circumference of the duct former discs.

Wed Jul 11, 2001

Its been 17 hours since I coated the straps and joined the seam.  I went out to the garage to take a look.  I couldn't be happier.  The seams are holding the natural curve of the duct perfectly.  I couldn't resist the urge to loosen one of the ratchet straps.  The strap loosened easily.  The straps bonded well to the outside of the duct.  I am very pleased with the results.  I will add 3 more strips of fiberglass to the outside of the duct. I think I will be able to complete the duct without brad nailing the duct foming disc to the ply.

Pictured top right - I used a broom handle, chair, table and some quick clamps to hold the cylinder so I could easily lay fiberglass cloth around the outside.  The broom handle went through the 1" hole in the duct forming dics.

Pictured 2nd right - The disc has two strips of 4" wide 6oz fiberglass on it now.  I flipped it around after epoxying one side.  

Pictured 3rd right - I used the left over epoxy to bond the 1/8 ply riser backs to each skid riser end.  I used T-pushpins to hold the ply on the foam.

Up next I will remove the ratcheting clamps from the sides and lay a 2" fiberglass ring between the two straps.

I am thinking of putting a web cam in my garage to capture the most up to date images of my progress.  It would be set to update every 10 seconds and would be a great way to watch me work live.  If I can find some really long USB extension cables I will move my quick cam into the garage.  My office is 25' away as the cable lies...