Week 235 - Long Range Fuel tank and cowling Part 9

Hours to date: 2204.25

Well my big news is that I have given up my day job. 

So I am now working full time on the Twister.

This should mean that I will stick to my earlier timings of - ready for paint by May and ready for flight by July.

So as you will see below things are moving on quite well.

I've probably overbuilt the long range tank a bit - I think it could take a 50 cal bullet and still stay intact :). There will be no need for the internal baffle as it is plenty rigid enough and being on the center line of the aircraft any sloshing of the fuel will not affect stability anyway. I used 4 layers of 450 gsm carbon but I think 3 layers would have been enough - especially with the overlap in the corners. I found the 450 gsm carbon to really need a lot of resin to wet it out properly - I've only used 200 gsm carbon previously.

It was a real pain to get the tank to release - it took me hours with the plastic wedges and a rubber hammer. Finally got it released and realised that it does not come out of the space very easily so a few tweaks to the shape at the back will be in order. I should have built out from the sides of the baggage area at the back to allow for easier installation and removal. I may redo this area as a fix.


I've flipped the plane over and am now working on the lower half of the mold. I had to do a few repairs to the plug as there was a bit of damage caused by the wooden struts and hot glue (these were used to hold the parting boards in place). I just used filler and sanded down using progressively finer grades of sandpaper and then gave it a wax - it feels smooth and uniform enough. So much for the wax stopping the hot glue from sticking - maybe I was a bit rough getting the parting boards off?

Hopefully the lower mold will be finished and we can start laying up a part in it by the end of next week.

Baggage area all taped up with duct tape before laying up the long range tank

I made patterns for each side to make things easier

I did the back and bottom first then each side at a time.

On it's side for the long range tank layup of the right hand side panel

While on this angle I fixed these holes in the plug which were caused by the hot glue and wooden struts used to support the parting boards.

Long Range fuel tank finally out of its layup.

2x 20 litre Jerry Cans show that the capacity calculations I did seem about right - approx 35 litres.

This shows how 'form fitted' the front of the tank is.

On it's back and ready for PVA mold release for the lower cowl mold.