We have finally reached the stage of building the hull.
I have built a table the same size as the Hoverwing to build it on so it is at a good working height. Experience over the years has taught me to make things simple and comfortable to work on; it makes life so much easier.
The foam sheets were laid out on the table and marked out according to the drawings, however I have opted to take 3 inches / 75mm off each side thus reducing the width of the craft by 6 inches. There are three reasons for doing this , the first is because the door width of my workshop is 8ft and this would make it difficult to get the craft out through the door. The second reason is there’s no need to build such a big trailer, the third reason is because I can.
After marking out the foam sheets I then made up stringer guides for marking out the shape of the hull. This worked out perfectly, I then drew round the stringers with a marker pen giving me lines to work to when it came to glueing the foam together.
I have opted for using the epoxy method and vacuum bagging, I note that other builders have on occasion gone for gorilla glue and have found it to be a powerful expanding glue that is perhaps wrong for this stage of the build and ended up having to use many heavy weights to hold it down. As it turns out vacuum bagging isn’t that difficult to do.
We made up a vacuum pump using an old vacuum pump from a refrigerator. First thing to do is identify that the pump actually works, then step two is to identify which pipe sucks in as that’s the one you want. We added in a distributor vacuum from an old MG car, these vacuums can be found very cheaply, and a micro switch so we were able to calibrate the pump to switch off at 144lbs. We also added in a one way check valve so that the bag would maintain the pressure until the pump kicked in again.
We did this by making up a trial bag for practice.
4 screws in each top sheet to stop them from moving inside the bag during the vacuum process, polythene sheet down and blankets to cover the vacuum pipe, bag sealed with duct tape, pump on and the job’s a good one.