Wednesday, December 22, 2010
Mast is finished and looks wonderful. Now if it would only stop raining I could take her for a sail.
My regrets at buying the cheapest version of polytarp for the sail is continuing to build. I was determined to stay with the philosophy of 'thriftyness' for the PDR but I should have bought the $60 polytarp rather than the $20. The stresses on the eyelettes used at the top of the sail and on the downhaul are showing already, with the poly tearing after only one and a half outings (half an outing due to broken mast). The tears were happening with the plastic eyelettes and the metal ones, so I don't think eyelette material has had anything to do with it. I've gone fully plastic now.
To compensate I've put in a couple of tough canvas patches on those two parts of the sail. Hopefully it will solve that problem.
If you're wondering what the white bits are along the stitching, I used masking tape instead of pins to keep the seams in place for sewing. I figured after the first time in the water they'd get wet and fall off. Surprisingly, they are proving a little more tenacious. Probably outlast the polytarp.
Saturday, December 4, 2010
I've nearly finished my new mast, this time using Australian Hoop Pine. This is from various sources, though mostly Boatcraft Pacific:
An Australian native pine. Native to the drier parts of rainforests of Queensland and Northern NSW in places that have rocky soil with lower fertility. Most of the timber that is used commercially now comes from plantations. The trees grow to 60 metres tall and can live for 450 years. The trees grow slowly and usually very straight. The first major use for the plantations was to provide replacement masts for the sailing ships, indeed a small portion of a plantation established for that purpose survives in the Brisbane suburb of Sherwood. From an ethical, sustainable point of view, Hoop Pine is streets ahead of most of its plantation-grown exotic softwood counterparts. The best is #1 Clear Grade Dressed All Round Hoop Pine (I used this). This is the finest, most defect free grade available. This specification states that knots, tight or otherwise are not permitted, sloping grain is not to exceed 1 in 5, no pith can be present, no resin pockets, or bark pockets, and it is not to have any checks. According to Bootle, "WOOD IN AUSTRALIA, Types, properties and uses", Keith R Bootle, First Published 1983, McGraw Hill; It has an Air Dry Density of about 530 kg per cubic metre and its mechanical properties are very similar to Douglas Fir (Oregon, Pseudotuga menziesii). It is very suitable for boatbuilding, is easy to work and it does glue well. It is suceptable to rot, so normal precautions need to be taken. Its only limitation is that it is not suitable for steam bending.
You can see in the picture where, as I haven't got enough clamps, I've used the clamp and tape method. Put on your clamps, tape everything up, move the clamps along, tape again, and so on...
I'm also up for some sail repairs. The top of the sail seems to have been under some pressure and I think I'll add a canvas reinforcing patch just to keep it all together. I also found some plastic grommets. There was only one packet of them left at Bunnings so I bought it and the recommended brass ones. I put the plastic ones towards the bottom of the sail and the brass ones at the top (you need more than 10 for a sail).
I bought one of those punch-and-die kits for putting in the 'brass' eyelets/grommets and found that even though they had less contact with the water being at the top, they still rusted. Obviously just a thin brass coating that the salt water can get through pretty easy. The plastic ones are less than $2.00 a pack of 10, you don't need special tools to put in place and they have already outlasted the brass ones.
Anyway, just matter of varnishing the mast, patching the sail and I'm back in the water.