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Side bending?!? Lots to learn... http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=10593	Page 1 of 1

Author:	Brad Way [ Sun Jan 28, 2007 8:49 am ]
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So I bend my first sides and I still have much to learn. I will give you the background and maybe a few can chime in give me a few pointers... Wood. Granadillo .080 thick Setup Doolin Style Bender One blanket Temp Probe "Router Speed control" temp control SJ Shape Foil to wrap wood First side everything seemed to go well however when I took the side out of the bender it seemd there was a crack on inside the waist. The crack was not all the way through and looked like the grain was lifting. I put a little glue and clamped it back in the side bender overnight. I look ok in the morning but it still feels like there is a small flat on the outside where the crack is. I guess I just rushed things.... The bend the second side today. This time I took much more time when bending. When I bent the waist I turned the cauls knob bolts 1/2 turn every 30 seconds. It seemed to help keep things good. When I took the side out of the bender the spring back was better and the shape was good with no cracks. However, it seems that there is a dark discoloration in the waist area. How much water do you use? How much is a spritz?!? How do you prevent discoloration? Where do you put the temp probe to get a good temp reading? I think I was getting a bad temp reading which made me think the temp was under 300 but was actually over. How long do most people take bending a side? I think I am going to use this side set as my sacraficial set to dummy proof my processes but need to figure out what I am doing wrong to make sure then next set isn't messed up. Thanks!Brad Way39110.7019791667

Author:	Bob Long [ Sun Jan 28, 2007 10:45 am ]
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Hi Brad, First of all, take comfort in the fact that Granidillo is one of the most difficult woods to bend. IMO So, it's only gonna get better. When I put mine in foil they are pretty wet. I spritz them untill they are soaked then let them drip standing up, like for just a minute. Then into the foil and onto the bender. I don't know why the grain lifted on the first side but it can be fixed. There is a thread on that on the forum right now. The Granidillo is very oily and the black stain is probably the oil cooking out. When you took so much time to bend the second side it was worse because it cooked longer. About temp. I turn my control up about 3/4 of the way then listen for the water sizzleing, then crank it down. From the time it sizzles untill it's all cranked down is maybe 4 min. Get some cheap material to practice on, and before long it'll all be good! Hope this helps Long

Author:	JohnAbercrombie [ Sun Jan 28, 2007 10:46 am ]
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[QUOTE=Brad Way] However, it seems that there is a dark discoloration in the waist area. How much water do you use? How much is a spritz?!? How do you prevent discoloration? How long do most people take bending a side? [/QUOTE] Brad- I've never bent grenadillo, so I can't offer much good advice. Hopefully more expert voices will chime in- some of the participants here have bent many hundreds of sides. I usually try to bend some offcuts from the sides (if there are any) to get an idea of problems to come, but it's never real predictable for me. re: discolorations- Is it a burn-type mark, or just resins from the wood that have exuded during bending? If it is burning, I'd say that you need more water or shorter bending time. Going too slowly can end up 'baking the wood' and actually make cracking more likely. I usually take 'a few minutes' (ie 2-3?) to bend a side once things heat up. I usually just stand the side in a bucket of water and slop some water on the wood with a cloth till it's wet, lift and let it drain, then wrap in foil. Once the wood is in foil it's a bit tricky to see what's happening with steam production. I keep a spray bottle of water handy and shoot some on the foil or the slats just to get an idea of how hot things are- this is also a way to cool things down as well. Some very resinous woods (like EI Rosewood) need very little water and seem to bend with the oils in the wood easing the process. Fun, ain't it?? Cheers John

Author:	Dave Rector [ Sun Jan 28, 2007 10:56 am ]
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Brad, I ust the technique that John Hall shared here on the OLF some time back. I take a piece of craft paper (that bworn paper like you wrap packages in) and make a piece big enough to cover each side of the piece I'm bending. Then just soak the paper under the faucet till it's nice and wet. Lay one piece of the wet paper on each side of the side wood and stick it between the slats along with the blanket. Once it gets heated up you can see the steam coming out and it's time to bend. I don't go particularly slow with the bend unless it is a really brittle wood. Couple of minutes to get everything bent and then turn off the heat. Once the side cools back down to room temp I reheat it one more time and it seems to reduce the springback nicely. Oh yeah, I also use 2 blankets so it gets hot really fast. Not necessary, but I like it just fine.

Author:	Brad Way [ Sun Jan 28, 2007 12:04 pm ]
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Hesh...my stack from top to bottom is.... Spring Steel Slat blanket wood in foil Spring Steel Slat I think one thing that would help is to use a few metal spring clamps to clamp the slats and wood together. If I could keep the blanket and wood in good contact then I think it will bend better. Maybe Granadillo wasn't the best to start with. I was once told that mistakes happen from a lack of experience and experience comes from making mistakes. By the way I just watched the Taylor Factory Friday video of their benders. Amazing...no water...minimal spring back...2 sides at once...and quick. Thanks for the advice.

Author:	tippie53 [ Sun Jan 28, 2007 12:10 pm ]
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here are the instructions for bending . http://www.bluescreekguitars.com/tutorial10.php I am sure this can help. I have been using this technique for years. I bent 200 sets last year. john hall

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