Thursday 2 October 2014

How to Join The Backing Strips?

This is a classic illustration of the difficulty of answering the old question "How long does it take to make a bow?"
I've been pondering all week how to do it.
There's a slight hump at the grip, and if I thin the slats enough they will bend over it easily, but I don't want them too thin.
I could steam bend them a bit to fit better over the hump. I'd pretty much decided to do a long V splice to join them, but do I cut the splice before or after steam bending? Having done the splice do I glue the slats together first to make one long strip, or do I glue them on to the bow and glue the splice all at once?

Decisions decisions!
Over the last few days I've fiddled and fettled the strips to get them a little thinner, but they still seemed a bit stiff to bend at the splice, so I made a jig steam bend a curve where the hump will be. With any steam bending preparation is the key, so I got the jig all set up so I could get the steamed strip in there and strapped down before it cooled.

Once I'd bent the two strips I cut in the long V splice, This will overlap the Z splice nicely in such a way that the joints of the two splices don't line up and the back and belly layers each strengthen the other. (see pic).
I'm hoping to get it glued up this evening so it can be curing overnight. I'll apply glue to the whole lot and strap up the central area where the splice is first to make sure that it doesn't get pulled apart as the rest is strapped down. I'll make some pencil marks on back and belly to help check alignment, then I'll bind it up with rubber strapping working out from the middle. Once it's all strapped I'll tie it into a slight reflex. More pics tomorrow! The bottom pic shows the wallpaper stripper I use to generate steam, the coil of pipe is covered with a bit of old duvet to keep the heat in, and the steam chamber is just a 5l plastic container wrapped in some polythene packing foam. You'll notice the bark is popping off the backing strips.

Update:- I've got the bow all glued up and bound with rubber strapping. It then been strapped to a long bit of 3x2 at the grip with a block under each tip pushing it into a reflex of a couple of inches.
I'll see how it looks in the morning.

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