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Skew ChiDAMN!!
22nd July 2005, 09:13 PM
I've tried a few inverted turnings over the last couple of weeks, with mixed success. About 1 in 4 have moved during reclamping, although I'm damned sure I clamped 'em up squarely. The movement's only a mm or so, but it's still unacceptable. It seems the joints are creeping over time while the glue sets; at first I tried band-cramps but have found G-cramps & cauls on both axis has less failures.

Less, but still about 1 in 6. :(

As they're just test runs, prototyping a few ideas, I'm only using PVA and scrap lengths of KD but I'd appreciate any suggestions to improve the success rate before I try my luck with some "real" wood...

ie: HELP!?

Captain Chaos
22nd July 2005, 11:11 PM
Hello Skew, in regards to inverted turnings , you may like to check this site out.
http://wmyoung.proboards23.com/index.cgi?action=display&board=chaos&thread=1119101360
ScrollinFriends - Has anyone turned "Inside-Out" ornaments?
Regards,
Barry.

gatiep
22nd July 2005, 11:12 PM
I take it what you are doing is what is also known as 'inside out turning'. Use some Titebond original with brown paper sandwiched inbetween. If you slide the joint to expel excess glue and air you don't have to clamp it. If you are doing 4 pieces glued into one, glue 2 sets of 2, then once set glue those together. Whenever using clamps you can bet that the pieces will move unless the clamps are 100% perpindicular to the surfaces being clamped, which is not easy.

No clamps will give a 100% success rate unless screwed up in the first place.

P.S> Don't use white PVA for this no clamps trick, use the Titebond/brown paper sandwich.

kevin42
30th July 2005, 06:42 PM
G/daye Skew. Hope this helps. Before doing up clamps, place a clamp along the length of the pieces with a block of wood on each end(with glad wrap or grease proof paper tween blocks and end of pieces).Tighten side clamps only until pieces touch, then tighten up end clamp,then alternating between side clamps gradually tighten them up.The end clamp holds the pieces in alighnment while the alternate tightening of side clamps helps reduce any possible skew effect(no pun intended)of any one particular clamp.Happy clamping. P.S.let us know if it helped.

Skew ChiDAMN!!
31st July 2005, 01:17 AM
Thanks people, I've managed to turn 5 in a row with no problems now. :)

It was actually my own fault, of course. gatiep got me thinking along the right track... I've been gluing up with Triton (yellow) PVA and brown-paper, turning, seperating, flipping and regluing for the 2nd turn and this is where I've been spotting the misalignment.

But, of course, just 'cos I've spotted it then doesn't mean the slippage has been happening then! Or rather, not only then. Being protoypes I started off in a slap-dash fashion and as I noticed the problem I've taken more & more care with the alignment of the 2nd glue-up. Stupidly, I haven't taken anywhere near as much care with the first!

Oh, my aching ego... http://members.optusnet.com.au/~amcardle60/Smilies/banghead.gif