Friday, 16 April 2010
Glueing up the Ash/Cherry bow.
I've glued the Ash backing strip to the Cherry belly using hide glue (The good old fashioned stuff which you heat in a pot and it stinks! I bought it on the internet as 'Liberon Pearl Glue' it comes as little round pellets which need soaking in water)
A pic is worth a thosand words so here's a few.
My glue pot is a 1Litre deep fat fryer from 'The Range' spot calibrated at 70 degrees C.
I rounded the back of the Ash backing strip slightly to help it pull down nicely when bound with rubber straps.
The glue is a nice thin syrupy consistency when hot and it was painted onto both surfaces with a brush, it wet the surfaces nicely but required a few applications to get it hot and well coated. Of course, as I put the two surfaces together the glue had cooled to a gel like consistence, hopefully this will be ok, I think it has 3 basic states, dry hard rock solid, slightly diluted snot like gel, and warm syrup.
The back was clamped on temporarilly at 3 points with G clamps and then bound with rubber strapping (~1" strips wide cut from old car inner tubes, or rubber roofing sheet). This process is extremely tiring as the straps need to be stretched taut all the time, so I was applying somewhere near my body weight as I was wrestling with the strapping. If you want a cheap workout, then this is the job!
Here are some more pics.
I will have to let it dry out for a week or so before undoing the strapping.
When I did the miniature I bound the laminations with hemp twine and re-flowed the glue with a hot air gun.
The bigger dimensions and greater thermal mass of the full sized bow preclude this. I did flex the bow slightly after it was bound up to hopefully encourage the gel like glue to spread and settle nicely, dunno if that's a good idea! This whole project is experimantal and is using materials and techniques which are new to me, that's the fun, just do stuff, see how it works. Even if the gluing is sound the Cherry Ash combination in such a short bow will be interesting, and if it fails I will have learned enough to make a decent bow with my better piece of Cherry.