These ended up being quite easy to form. After clikoing a piece of Plexiglas to the inside rail (rising to 1" above the existing rail), a lay up of 6 layers of 6oz glass across the rail and up the plexi. Since these rails have a lot of weight applied to them in the process of getting into and out of the aircraft we figured that this kind of strength would be necessary.

When cured, blind fasteners were added to attach the new glass rails to the steel ones using machine screws. Once the inside angles were done, an outer mould was built from plexi and oak

When cured, blind fasteners were added to attach the new glass rails to the steel ones using AN3 bolts. Once the inside angles were done, an outer mould was built from plexi and oak.

(they are hard to handle, and never stay where you put them), so for the next steps a vacuum bagging system was built. This works better since it applies even pressure everywhere, giving a nice consistent material thickness, and when using peel ply, and an absorbent fabric excess resin is removed. Ours was built out of a little airbrush compressor, a 5-gallon pail with lid, and a switch.

The compressor was hooked up from the inlet side to the pail, and then from the pail to the vacuum bag. By putting the switch against the side of the pail it was set up so that the compressor would run until the pail would begin to implode, opening the switch and shutting the compressor down. This would regulate the system to approx. 4-5 inches of vacuum, which seemed to work reasonably well. We tried to increase the vacuum even more, but unsuccessfully as the 5 gallon pail ended up being about 2 inches thick. Later we tried using a piece of 6" ABS pipe, with a vacuum regulator and managed then to get up to ~20 inches of vacuum.

The compressor would run a bit hot after a while so a fan was added to keep the temperatures down, since a part would be in the bag for 12 hours or more usually. Boxes were added around the compressor to keep it in one place, as otherwise it would go for a walk around the plant floor it vibrated so much.

The vacuum bagger complete, the new nose profile was laid up, and placed into the bag. This seemed to give much better results, as there were no problems with the glass lifting away in the corners of the mould where considerable problems had been experienced before.

After the part had cured in the mould we were at a bit of a loss as how to remove it from the bag without leaving bits of plastic all over the part. Then the answer occurred to us. If vacuum got it in, air pressure could get it out. A couple of PSI of pressure back into the bag succeeded in slowly peeling the bag off the part without any tears in the bag or leaving any plastic attached to the parts that we had moulded.

Now that the part was cured and out of the mould, a few hours were spent trimming the excess cloth off and fixing the few defects (pinholes and a few small voids in corners). Then the part was glued onto the fuselage side rails (with a couple of layers of glass on the inside to reinforce it).

To date this part of the structure has proven itself strong enough to move the aircraft by pulling on it without any problem.

To prevent the turtle deck from moving around, we then made locator pins out of 1/4" steel rod and added holes to match on the fuselage side rail.

About 2 to 3" was cut off of the fuselage side rails and grafted onto the turtle deck to make a place to glue these locator pins into.

A friend around this time chose to tell us that if you increase the temperature that you are working at you could accelerate the curing of the epoxy considerably. This proved to be a real time saver when bonding pieces together and filling pinholes as we could accomplish more in a day. An electric forced air heater and a plastic "tent" is a lifetime saver.

With the rear limits of the canopy frame now defined (and locked into a stable position), we were ready to get onto the hardest part of the job, the canopy frame itself.

After a couple of days to allow the resin to cure (we used a mix that had an 8-12h+ working time at 20C, and a 72h+ curing time to make sure that we had lots of time, and we needed all of it) the frame was popped out of the moulds to see what we had ended up with.

Once out the canopy frame turned out to be structurally strong enough (I could barely bend any part if it, it was stronger way beyond what we expected).

There was a "little bit" of flashing around the edges, and a little bit of time with a die grinder with a cut off wheel made short work of that problem.

If you have noticed the different colour of the frame compared to the previous parts fabricated, this is due to our finding out that pigments for epoxy resin exist. We used a white pigment for all parts from the canopy frame on to reduce the amount and effort required in priming/painting to get a nice white colour when everything was done.

After cleaning up all the edges, and filling any defects in the frame all was ready for the next step: the latch.

Latching posts were then fabricated out of ½" steel rod as per Figure 4, latch slides out of .050" and ¼" ID tube like Figure 5, and a latch rod out of ¼" rod like Figure 6.

Assembly of the latching system was pretty easy; two holes 0.189" were drilled through the closed canopy frame and through the fuselage steel tube side rails. We then removed the fibreglass side rails and enlarged the holes through them and the

canopy frame to ½".

.With the posts loosely screwed to the side rails, and the slides laid onto the canopy frame I then installed the latch rod. With everything aligned and in place we then bonded the slides to the canopy frame.

Note: After a couple of years use, I have decided to change the latch rod. Depending of temperature the system described works from easily (when cold) to very difficult (when hot) due to the varying expansion of all components with temperature, and the flex that the latch rod demonstrates when any amount of force is applied to it to overcome slight misalignments. This coming winter I plan on replacing the rod with 2 lever driven rods that will be easier to operate.

With the latching system complete it was time to start

the cosmetic work… Like all the covers over the edges of the canopy frame. These were made by filling all the edges with foam and then sanding to the desired shape (a nice arc). We then laid up 2 layers of 4 or 6 oz cloth with a black pigment added to the resin on top of the foam. Because a mould was not used we ended up with a nice low gloss textured surface that does not cause much reflection in the canopy.

Now that the canopy frame was complete except for the installation of the plexi, we decided that we should try to post cure the resin for maximum strength. This requires heating the parts to >50 degrees C, with the parts either in the moulds, or on the plane installed in their final resting places so that no deformities would be added during the post curing process.

As I work for a company designing large power supplies this did not’t seem to be a big problem. My laboratory was almost big enough to roll the fuselage in, and I had plenty of power supplies that I figured could use a good "heat run". We rolled the ’14 into the room, hooked up the power supplies with big heaters as loads (all in the room), closed up the doors as much as possible and went home for the rest of the weekend. My temperature logger recorded the highest temp as being 45-50 degrees C, so we were close.

This was the scariest portion of the whole project. Time wise the canopy installation only took 1 day (say 10 or 12 hours, we were very cautious), but it had the potential of being the most expensive mistake in the project. As such we enlisted the help of a fellow club member Jock Proudfoot who has done this a number of times helping other home builders

The first step was to determine which portion of the canopy we were going to use. This step would determine the profile of the new canopy. A great amount of time was spent sliding the canopy blank fore and aft trying to find the most pleasing profile

After marking off the canopy with a removable marker the cutting began. We tended to be very conservative, removing 1/8" to 1/4" at a time, and then checking the fit of the canopy on the frame after each cut. A ¼" die grinder with a 3"X1/8" wheel was used to make all cuts. To prevent damage (scuffing/scratching) to the plexi from the "band" clamps we put a layer of masking tape on the canopy before clamping.

When we had achieved an acceptable fit it was time to attach the canopy to the frame. We put down a layer of cabosil and epoxy on the frame, and put canopy on top. We used "band" type clamps (otherwise known as ratchet tie downs) to hold the canopy down. We had problems holding the canopy to the side rails, so we made up large "C" clamps out of scrap 2X4’s to hold the plexi in place with foam blocks to prevent damage.

Once the canopy was strapped into place, we added brass wood screws to act as a "rip stop" attachment in addition to the glue bond.

After all of this it was time to clean up and see how much of the plexi we would be throwing away.

As can be seen there was a considerable amount of scrap (and the photo doesn't show any saw dust!).

The next day when we came in, removed all the clamps, and removed the canopy from the fuselage.

We then masked off the plexi so that when filling the gaps between the plexi/frame joint we would not get epoxy onto the Plexiglas

After filling/sanding was complete the masking was replaced and we then painted the frame.

Alex and I made a change to the basic HP14 canopy profile during this process.

I am 5’6" tall, and Alex is 6’ + something, so fitting both of us in the cockpit requires some work beyond just changing the rudder pedals. Alex ends up slouching right down, and even then ends up with very little headroom to the canopy, so it was decided that the new profile would give more headroom.

We ended up adding about 2 ½" more headroom at the rear of the canopy frame. With the plexi curved in the way that it is, this give I would estimate at least 3" more headroom above the pilot's head and this makes the cockpit much roomier than it used to be. The headroom is so much that I have not hit my head on the canopy since the change (even when flying on the ridge in Pennsylvania).

It also might make in flight rudder pedal adjustment possible, with a very flexible pilot.

With the canopy complete it was time to start on the last piece of the puzzle. Blue foam was used again to give rough shape to the turtle deck, coated with epoxy for protection. We then got out a can of every bodyworker’s favorite. Bondo.

This was to be the most expensive plug built for the project as 27Kg (about 60 lbs) of body filler ended up being used on the turtle deck plug. This part of the project seemed like it would never end. Add some body filler, wait for it to cure, and then sand most of it off. It seemed to take a couple of weeks of building up the plug and fiddling with it until an acceptable shape was achieved.

Laying up the actual turtle deck brought to notice a new problem. The wooden frame we added kept puncturing the bag when vacuum bagging (we didn't know about mastic or extending mould edges at this time).

We ended up using a shop vacuum to do the job (low pressure, but very high volume) which gave better than

nothing results (it generated about 2-4 inches of vacuum).

Once the turtle deck was out of the mould the next task was to attach it to the front edge that was previously built.

We again rigged the HP to make sure that everything

was fitted correctly. The two pieces were tack glued initially, and then we took everything apart and laid a couple of layers of glass across the joint on the backside.

Now, because the canopy sides had flared out we stripped the hull sides to bare metal, and then built the sides back up to match the canopy profile.

From this point the rest of the job was finishing work: filling, sanding, and painting (and lots of all 3).