Wednesday, July 30, 2008

Planked bottom


Planked bottom
Originally uploaded by Phil_Parker.
Once the sides of the launch are planked the much curvier bottom has to be covered. In theory you simply affix the die-cut balsa wood parts. The instructions advise using tape to hold the box part in place, spraying the outside with "Windex" if required.

In the UK, Windex isn't available but at a guess it will be a window cleaning solution which contains ammonia - a chemical known for softening wood although I think alcohol will work as well. I can't stand the spell of ammonia and didn't have anything similar handy so I soaked the wood in water. This made no difference, just wet wood.

Most of the part fitted very well. I fixed it along the keel line and down the sides, holding the springy balsa with planking clamps screwed into the basswood parts. The front would have fitted except that when I bent it, the wood split along the grain.

Repairing the split was out of the questions, a glue joint wouldn't hold and a braced part wouldn't bend, so I had two options, re-make the part in another sheet of wood or cut off the bow part and replace it with a solid block carved to shape. Well without a suitable sized sheet of wood handy I went for the second option. The die cut part on both sides now finishes at the end of the keel strip.

Other than that this went well. The sheet overlaps the sides but will be easy to trim back. At the stern I need to do a bit of filling but can use offcuts of balsa for this. The clamps worked well, in fact I don't know how you could do this operation without them as conventional clips won't hold and the wood is being bent in lots of directions at once. Perhaps using superglue you could tack it in place a bit at a time but I prefer alphatic resin - there's something wrong to me about using superglue on wood.

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