This is a stupid one. Having got the wooden plug stuck in a tube, I then got it jammed inside the bottom of the real topmast. I figured that I could put some wood preserver on it and tap it into place before it swelled up. I was wrong – it is very well jammed now 😦
It is slowly shrinking down again as the wood preserver dries out, but the bit inside the tube isn’t shrinking quickly enough to meet the deadline.
If it doesn’t show signs of shifting in the next few days I’ll have to cut the end off, then cut out the wood from inside the topmast tube (very carefully!) and make a new one.
Really stupid time – I was cutting the end off a pipe for the bilge pump and the knife slipped. Ended up in my stomach. Fortunately:
The NHS is fantastic – the ambulance and A&E did a great job of looking after me and stitching me back together;
I have enough of a spare tire to prevent the blade going all the way through so stitches were all that was needed.
It is healing up fine. Main lesson is that never do DIY when tired – I hadn’t slept much the night before.
There is a stress concentration in the topmast tube where it leaves the main mast tube. This wouldn’t matter, except:
The topmast is thin aluminium so isn’t particularly robust;
There are scratches in the aluminium at the critical point from when I made the mast;
The topmast is already a bit over stressed in this design so as to reduce the weight at the top of the mast.
To stop the topmast buckling I’m making a wooden plug for the critical section from my last piece of decent Douglas Fir. The plug is in two halves glued together which allows the middle to be hollowed out. To allow initial working I screwed the two halves together.
After considering my options I made this on my metalwork lathe. This made it easy to get the outside to the right size along the whole length. I used metal-cutting tools – not elegant but gets the top done.
Next stage was hollowing out the middle. For reasons of speed I used my milling machine.
Then finished off with a powerfile / mini belt sander.
The mini-belt-sander is a very useful tool – I wish I had bought one years ago. Mine is Silverline – one of the cheapest – as it was light and compact for getting into awkward corners inside the boat. It has been excellent – highly recommended.
I’ve glued the two halves together inside a spare tube so it all lines up. I used Tightbond (waterproof PVA-type glue) as this should be fine in the conditions, is nice to work with and won’t stick to the spare tube (I hope!).
Once the glue has dried I’ll cut the square end off, neaten up the insides as far as possible and then put some wood preserver on it. It can then be inserted into the topmast.
Hopefully Custard will then be good for high-speed full-sail surfing!
Getting the sail finished was a bit frustrating but I got it done. The main cause of frustration was that I needed to have the boat ready for a family holiday in August and there wouldn’t be any time to test it unless I got it all done last week. However, it all got done in the end — phew!