Ch 5 Fuselage Sides

The RHS lower triangular longerons were very similar to gluing the left side. I was even more careful to get the excess glue wiped up. Flox is very hard when it sets! The clamps were all lined with PVC tape so released easily.

The nails were removed after curing by heating them first with a soldering iron… then they just slide right out.

RHS clamp setup

Easy clamping

Nail removal

Spent some time setting up the gluing procedure for the lower triangular longeron. As well as a dry clamping session I pre drilled the 2mm holes for nails that assist getting things in place per plans.

After removing the local peel ply and sanding all surfaces I used pure epoxy with a brush and then wet flox to join. The clamps also clamped onto the sides of the workbench. The hardest part was getting all the excess off otherwise a very easy job after all that prep work.

Set up lower longerons

Clamping LHS lower longerons

LHS lower done

Spent some time making lower longeron clamps. These take the triangular shape and make them into a square for clamping. A difficult job then becomes easy.

Carefully cut the lower longerons so they are easier to bend when they go on the sides. Plans have just the rear cuts, I also made a few incisions in the front section so that the timber will have less ‘tension’ in it when fitted.

Cutting out clamps

Longeron clamps

Bend cuts

Make the small spruce LWX and LWX pieces for the spar area.

While sizes for the ends are given, they need to be certain angles 35 and 45degrees to fit together. The 2″ piece I laminated per plans from 1″ sections.

I made the LWY a touch short so added another piece and cut them down. See the first pic. Not a lot of wood in this airplane.

Following the plans position for LWY and the sheet plan you end up with 0.2″ differences. I’ve deferred gluing these in until discussing with other builders. The spar box cutout MUST be big enough so this will drive the measurements.

Laminating LWY

Spruce pieces for the spar box area

Plans wrong again

Top Longerons

0/4/12 Floxed Sitka Spruce longeron to the RHS. Both sides were trimmed back to the foam edges. Peel ply is then removed and the contact surfaces lightly sanded. The longeron is a datum point so especially needs to be straight. A very light coast of pure epoxy followed by wet flox to both mating sides. Multiple clamps are used and a big cleanup of all excess flox.

11/4/12 Did the LHS top longeron. Same process. The two stiffeners called out for p5-2 are omitted in my build as I will not be cutting out the sides for baggage so these are unnecessary.

Small Longerons 9″ long need to be 2″ high. 1″ pieces are laminated together for this.

RHS Straight Top Longeron

Clamping LHS

Making LWY

LHS Fuselage two ply of UNI Layup. First micro the foam. Then let it settle a little and roll out the two pieces of cloth. Spend some time positioning and getting the fibers straight and at 30 degrees. This always takes a while but is easy to pull the glass around because its still dry.

The wet to out and leave it very slightly wet. Do the second ply again without wetting out. A little harder to get straight as some of wet glass begins to come through the new ply. The fuel gauge area and particularly the window and elbow room cutout is hard to get sitting down without air bubbles.

It looks great with 2 ply on but peel ply is necessary and it takes a bit more epoxy to wet out. The whole thing took about 6 hours with the LHS taking 7 hours. It just takes a while. Then there is prep before and clean up afterwards.

Glass lined up

2 plies done

Peel plied

Cutting the glass for the LHS fuselage inside layup.

This needs two plys and two pices per ply of UND cloth. It requires a 30 degree bias and I layed it out on the fuselage foam sides, got the weave angle correct then taped the edges and cut. The pieces are carefully labeled with one long and one short piece and alternated long and short so the two plys are not the same. The bias goes in opposing directions for each layup as well.

I also made up a written job/layup schedule and wrote how far from each edge each pice of cloth began so I could get them positioned more easily once the layup began.

This prep work takes a couple of hours for such big pieces which then need to carefully rolled up so they unroll where I want them and then covered awaiting layup day.

Carefully rolling out the glass

Ensuring the 30 degree angle

Tape with labels

First Micro slurry the entire side. Takes a while as most of the micro is scrapped off. Just enough left to fill the foam and give the glass a bed.

Then very carefully laying out the glass with the bias at 30 degrees and all the fibres very straight. This takes quite a while.

Once straight and everything lined up I begin wetting out.

Ready for micro

Glass layed out, fibers correct

Wetting things out

This took 7 hours from start to finish…just the layup part. Quite a big job.
Two pieces make 30 degrees one way then the next ply is 30 degrees the opposite. Then peel ply is added for where there will be tapes and joins.

Second ply

Second ply laying on the first

Side layup 2 plies done

Finished sanding and preparing the sides for glassing. Final smoothing of depressionedges and sanding along with all the necessary lines for peel ply. I also marked out 30 degree angles for the two ply of UND.

Could be anything

Fuel gauge depressions

Fuselage inside ready for glass

Preparing UND glass for the fuselage inside. Two pieces required at a 30 degree angle. Took quite a while to lay it out at the right angle, cut to size and tape the edges, then roll it up for tomorrow. 2 Plies (four pieces were required)

Hey…thats me

Rounded the edges of the front window and depression for the pilot. The UND needs a reasonable outside curve to roll around.

Finished the sight gauge depressions making a gradual ramp. The design here should prevent any problems with the passenger nudging the gauge and the angle should make them easy for me so see from the from seat when I turn around.