I was lucky enough to be given a plane which had suffered a violent vertical landing into the local cricket pitch. This was my first ever balsa wood plane and I wasn’t sure if I was going to be successful at its repair.
The planes fuselage was in two pieces with a decent section missing. The previous owner not only gave me the plane but also had the plans to go with it so, for a newbie, it made a world of difference. The issue I found was… how do I extend a broken balsa spar and yet maintain strength? I couldn’t find anything on Google that provided a succinct and adequate explanation so, I ended up designing my own.
The design I ended up with is simple and yet really strong.
I made a Z cut in the old existing wooden spar and matched it to the new piece then, while holding it in place, drilled a hole through the two pieces where the Z cut was. I then applied glue to the joint, pushed together and pushed a pre-cut piece of toothpick through the hole. I used a small clamp to hold then together while the glue set and it’s pretty strong.
Making it REALLY strong…
There were a couple of structural extensions I wanted to ensure were not going to break so I used a similar process like fibreglassing but instead I used the paper in a Tea Bag and Aquadhere glue. Now to be clear, the tea bags are specifically the T2 teabags (they are not tissue paper, they are made out of something a lot stronger). I spread glue on the joint first, then applied the tea bag paper around it then applied more glue just with my fingers to make sure it was completely wrapped. Once it hardened I could lightly sand it and it was seriously strong.
The plane did its first flight since being used as a tent peg today and flew really well, even with a bit of a rough landing.
Happy landings !
Rodney Clarke