Ch 7 Fuselage Exterior

Before I could sit in the tub all the edges needed trimming. If these were left alone, delamination would be a constant risk apart from all the spikes.

I used a power vibration cutter to about a 0.1″ or so and finished with permagrit rough, then smooth files and finally a bit of 180 grit on the edges. This took a full day.

Yes I did put the tub on the floor and get in it and maybe made an engine noise. I really wanted to try the feel of it with the front seat forward, no cutouts and the slightly thinned out sides.

I really like the seat forwards and the back seat area is much bigger too. I love the slightly wider cockpit area and think I’m OK with no baggage cutouts.

Chapter 7 is finally completed.

All edges need attention

Hand tools

Completed skin

The first pic shows that the LHS is done and peel plied and cloth is being set up and rough trimmed ready to be wetted out on the RHS. This is where the rotisserie is useful. With the room temp being near 30C by the time one side was done I was not concerned about glass falling off although we did check the longeron area a couple of times.

The second pic is with the job done and peel plied. The side I did with help was slightly drier than the side without which was slightly wetter. I think the 3rd ply on the last side done was not as straight as the first when I had help.

Fatigue is a factor in a layup this long and I was stiff and sore for a couple of days afterwards.

The last pic is just of the general work area. There was plenty of room to move around the job which is necessary. I have carpet on the floor and use rubber mats as well to walk on. Both these things make it a lot easier on the body and a nicer work environment. I really like the colour of the foam and epoxy rather than the usual brown of the first systems used on canards. I think these things matter.

LHS done RHS to go…

Finished and very late in the evening

Work area

All the epoxy was done with a 100mm roller which proved MUCH faster than brushes and far more effective in rolling out air and getting the job smooth. Having someone mix the epoxy made a huge difference and my helper was very experienced in this type of work. Doing both sides in a day would not be possible on my own.

The first pic show two plies already wetted out and the third ply a zero degrees being set up. You can see I have tape over the brake area which gets another separate layup later. It was easy to get the cloth on with help. I was not as good on my own later with the other side although these I had cut to rough size earlier which did make it a bit easier. The third pic shows where I made a few marks to help line it up when doing the opposite side. Better to waste cloth than muck about and find yourself short.

The second pic show the 48″ X 3″ upper longeron tapes (plans said 50″ but I’d moved the front seat forward 2″. I don’t think these are necessary because I’m not cutting out the baggage area however advice from a structural engineer who builds canards was to wear the weight of these just-in-case. These were laid up on foil shortest first and lapped over the longerons and sides after the three plies main were wetted out.

It was around 4pm with the second side microed and the cloth placed on it.

Setting the 3rd ply

Continuing with the opposite side

3 ply longeron reinforcement

Glassing the outer skin took 14.3 hours. I had competent help for 8 hours as well. The temperature was 29.2C in the morning and remained in that area for the day. I’ll detail this in a few entries to allow more pictures than usual. I started at 7:15am with the room already pre heated and the epoxy box had been turned on the night before (a cardboard box with a globe in it to keep the glue warm)

With the tub well protected the first side was covered in micro slurry. I used a wide brush to get the micro on and this also helped fill the initial holes a lot faster than a small brush or putting it on lightly. Then a half squeegee was used to remove all the excess and the job was left for about 20 minutes although given only the cells are filled I could have continued.

The next step was to lay out the glass and being the first ply it was OK to take a bit of time to get it right and then do a rough trim. I had drawn line at 30 degrees on the fuselage to help this as well as having a tool that shows 0 and 30 degrees which I use to check the bias of the cloth.

Pne side after micro fill

Laying out cloth side on

Laying out cloth – bottom

Getting the fuselage ready took several days. I sanded the surface smooth to 120 grit and then decided to fill any of the large gaps and dents with very dry micro. While the plans say to do this when you do the layups I find the micro gets diluted by epoxy and sometimes doesn’t fill the dent as intended. I then sanded again after cure and finished off with scotch brite.

I was also thinking ahead that the fuselage layup would be a long one and the less to do on the day the better. I coverd the inside of the tub with plastic and spread this on the floor and used lots of masking tape. The plan being to reduce or eliminate any drips of epoxy where it is unwanted.

I initially cut the glass for the first two plies on one side but it was so difficult to drape the cloth on the fuselage to get it positioned that the next pieces I just made hugely oversized and will have a lot of scraps over. I feel this is worth it rather than risk making distortions in the cloth that are hard to remove.

I also cut peel ply and planned out the 3″ wide strips for the top longeron area on both sides that will be wetted out on foil. I planned peel ply for the entire stake area with a view to fuel resistant epoxy later and probably a very light skin of glass to hold it.

Micro gap fill

Glass cutting

More glass cutting

Now getting closer to doing the exterior of the fuselage. A rotisserie is really useful in turning the fuselage while finishing off the sanding and when it comes to doing the layups.

I had two stands for the ends that another builder had used and I thought might be handy one day. This was long before I thought about building

The simple way for the rear was to just make another firewall piece using the original as a template for the cutouts. Then I put a hole in the center and that end was just about done. I have used a few rivets as shown in the second pic to ensure the rear piece stays put.

The front end was more complex as I didn’t want to put a hole in F22. I just used scrap timber and some large bolts. Its quite strong and the fuse now rotates all the way around.

It’s not perfectly balanced and will need a strut to hold it in each position or it will easily roll around. Which was the idea in the first place.

New firewall blank

Security rivets

F22 front end clamping

This is cutting a 1/16 depression or joggle with a transition to the F22 joggle and the bottom of the fuselage. This was done over a few days.

Its making an allowance for the front wheel gear doors that will come later. Hopefully this joggle will reduce the amount of micro I’ll need later to keep everything flush on the bottom of the plane.

The first photo shows a simple router box that I’ve been using to try and make even depth cuts for the brake area and now these gear doors. Its just a box with a slot in the bottom and still needs to be used carefully but does make it easier to get a consistent depth to a wide area.

I’m using masking tape just out from the transition to try and keep it all tidy as I sand with the used 80 grit.

The third pic shows the finished joggle and how it blends into the joggle for the nose area at F22. I hope it works out and keeps the build looking as neat as possible. These little things may help to reduce a small amount of weight.

Router jig box

Sanding the joggle edges

Gear door joggles

Having a brake from the landing brake…

I’ve made a joggle at the rear of the bottom where there will later be a cover. This will prevent the need for a bump and more micro filler that is needed.

I have done this at F22 as well for the nose join but it wasn’t as tidy as this is. I routed very carefully using a positioned stop to keep the line straight. Then I used masking take to ensure the transition was even. Routing around the cure was tricky. This time I under did it and finished up with files.

1″ joggle routed

Edges smoothed evenly

Completed joggle

The landing brake is coming up soon. I first had another go at the fuselage sides.

They are better than before. Its a little tricky because I’ve make the bottom 2″ thick rather than plans 1.6″ so the templates are only going to be correct at certain places.

While I used the shaping tool I made, some graphite pencil on the templates and then a large sanding board worked well in spot sanding to make things more correct. One issue is sanding the hard longerons and the soft foam at the same time.

Not perfect but now OK to move on. There will be a very small amount of micro required on a few dents after the sides are glassed.

Shaping tool

Template top edges

Template on the bottom

Shaping the top edge of the fuselage. I’d done this a few days ago but not correctly. There is a template in the plans as shown in the first pic. It seemed a lot of curve but I confirmed with another builder…then it was obvious.

Some hours later the front and rear are tapered correctly. I may blend a little more around F28 back towards the pilot otherwise its looking correct. I used several sanding templates as I did on the bottom curve and a plans shape glued and trimmed on a bit of laminex.

Curved template

Top curve

Rear blended to the firewall

Here the top of the longeron in front of F28 need removing. The plans say to also cut out the canard torque tube area. I’ve left this until later and made the cut out a little proud. I’d rather trim it than find I’ve made a hole too big.

As it is I’ll use an offset rather than plans setup in the canard so the hole will just be a circle and not allow for the elispe shape of the plans version of the Roncz. That lets in a lt of cold air!

You can see it cut out in the second shot. Not a big job but it pays to be careful.

Shot three is really just showing that the fuselage is sitting on foam blocks taped to the sawhorses. I’m finding it easy to turn the fuse on my own as its not heavy yet. It is however nice if someone helps. I have been using blocks clamped to the horse to steady the fuselage while I’m sanding.

Canard cutout plans template

Recess completed for now

Sawhorse setup

The first pic is a form I made for sanding the sides. It is just a piece of scrap foam. I drew the profile from the plans sheet of the bottom side view on it and cut it with my jigsaw. Then trued it up a little with files. I’d already made a profile out of laminex for using on the sides so it was pretty easy. Then I glued on a bit of 40 grit sandpaper. Really this was from a belt sander as the backing is really tough and lasts a long time. While I work slowly this only took 20 minutes to make. I’ve ended up making a few of these as sanding tools.

It helped a lot for getting the sides consistent along with the template. You need to go carefully or it will dig into the foam being pretty coarse.

The second shot shows that I’ve plugged the bolt holes for the landing gear brackets with foam and a little micro. I just cut circles out of scrap foam with my router about 2″ deep. Then a touch up by hand. I got a really snug fit in the bolt holes that were preciously cut carefully with the dremel before the bolts went in. Some of my best work and no one will see it once I’ve glassed the outside of the fuselage!

3rd shot is the curved bottom. Remembering that my foam was 2″ not 1.6″ thick I was able to curve it slightly more. Probably no one will see it or notice but I will have a stronger floor for any big passengers!

Sanding form

Side plugs

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