The Squirrel and the TSK (Part IV)
Just to be different, this chapter of installing a TSK 30 into a Funky Twinstar fuselage falls into 2 musical segments. Feel free to hum along if you don't know the words.
"A Whale of a Tail to Tell"- thanks to Disney's '20,000 Leagues Under the Sea'
One of the minor
drawbacks of the Twinstar fuse is the lack of a "proper" looking
tail treatment. Due to the fact that lotsa different machines can be installed
in this fuze, I suppose it's not really practical to make a mass-produced
one. Well, luckily for me, a friend down in Christchurch, Colin, is also
putting a set of mechanics into a Twinstar, and since he is a clever chap,
he made a fibreglass tail cover for his set-up. When I found out about this,
I asked nicely and said "Please", and he made one up for me!!!
Then, after fitting the tail stinger, I then tried to solve the next challenge- mounting the vertical stabiliser. After several hours of looking at it, I mounted it at the end of the boom, just at the end of the fibreglass. Boy, was this a mistake!!! Well, if you don't try something- you'll never know. After another couple hours and some $$ spent repairing the boom, I looked again at mounting the stab on the stinger, which was it should have been all along. The two challenges here were to attach the stinger securely to the tail gearbox, and then attaching the vert. stab to the stinger.
After getting out the pencil again, I marked the first of two holes for bolts
to pass through, to attach onto the tail rotor assembly. This required some
packing out, so when the screws are tightened down, they don't pull the stinger
out of line. For this, I used a product that is an epoxy repair system. This
comes in a tube, in extruded form, like putty, You cut off a piece, knead it
to mix it, and shape it to whatever shape you require. It sets very quickly,
so you only have 2 minutes to mix and install. But it cures quickly, and then
can be drilled and sanded.
The final challenge was the two bolts that the stab will be attached to the stinger with. I was able to place these without a problem, and they will even hide the two bolts holding the stinger onto the tail mechanics! This called for a small opening to be cut on the back side of the vert. stab, and some filling around the opening for strength.
Once this part was done, I could finally remove the mechanics from the fuse, and move to the next step- surface preparation.
episode, featuring the Funky Twinstar fuze, is a short but actually kinda
easy one. All you need is:
With the final fit of the mechanics done, they have been removed and the fuze is ready for the surface preparations for painting. As you may remember, I have already given the entire surface a going-over with some #280 wet/dry sand paper, done with the paper dry. Now is the time to do the next step- filling the wee pinholes and mould seams.
At the advice of Bob, my friend from my flying club, I got a spray can of ordinary primer paint from the local hardware store. Using this, I gave the fuze a very light spray. This doesn't need to be heavy- just remember- however the more you spray on, the more you'll have to remove! After a 36hrs to dry, due to kinda rainy day, followed by a nice warm one, I then sanded the fuze again with the #280 paper, but this time wet. This clearly revealed the primer left behind in all the pinholes, etc. It revealed several more spots that I hadn't noticed yet.
I found a product by 3M, Acryl-Red Glazing putty, that is perfect for the job of filling the holes. There is no mixing required, just use it straight out the very large tube. This also comes in a green colour, but you should use a filler that is a different colour than the material you are filling. The cost was very reasonable, too- $18 NZ dollars, for a 1lb 5oz tube. At this rate, I should be able to get 6 or more machines out of this.
Since the areas to be filled are so small, I cut some small pieces of cardboard from a blister pack of some batteries. This was fairly stiff, worked well for spreading the bog, and was free, too!! The spreaders I cut were about 5-10m wide and about 20mm long. Put on the bog in an even thin coat- it'll dry faster that way. Plus everything you put on has to come off- so no need to be too heavy with the bog. After sanding with the #280 paper wet, the areas still requiring more filling were easily seen. After 3 cycles of filling and sanding , the seams and holes are filled very nicely, ready for the next step- a light sanding with some #400 wet/dry. And if I feel keen, maybe a pass with some #600!
The most surprising part about this area of work, was the short amount of time the actual work took. I was able to sit down, and cut back the primer coat in less than an hour- closer to 45 minutes. And the applications and removal of the filler take less time. Due to the drying time required, I found myself walking away from the fuze for an hour at a time, since there was nothing to be done. This was not the difficult, time-consuming chore I thought it would be.
So the next week will see me move to get ready to actually paint the fuze next weekend- if everything goes to plan. Still to do- cut and fit the windscreen, mount the horizontal stabs, and start finalising the decals for the body.
See you guys then!