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| Side ripple/fold http://luthiersforum.com/forum/viewtopic.php?f=10101&t=40496 |
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| Author: | WilbPorter [ Tue May 28, 2013 9:03 am ] |
| Post subject: | Side ripple/fold |
My current builds of cocobolo and ovangkol has some side ripple as you can see from the pics after I drew a soapstone straightedge around the sides. Obviously the visible soapstone rubbings show high spots. Mostly these are very small ripples and I canscrape them flat. However, I want to avoid these problems in future builds. Wondering whether I used too much moisture in bending or too much gobar pressure when gluing on back and sides. Any suggestions would be welcome. Thanks. Sent from my GT-P3113 using Tapatalk 4 Beta |
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| Author: | arie [ Tue May 28, 2013 9:56 am ] |
| Post subject: | Re: Side ripple/fold |
how are you bending your sides. machine? iron? other? |
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| Author: | WilbPorter [ Tue May 28, 2013 10:05 am ] |
| Post subject: | Re: Side ripple/fold |
I'm using a fox bender with a heating blanket. I don't have a temperature monitor , just a controller. So amount of heat might be an issue? Sent from my GT-P3113 using Tapatalk 4 Beta |
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| Author: | Fred Tellier [ Tue May 28, 2013 10:09 am ] |
| Post subject: | Re: Side ripple/fold |
How much water. I don't think you used excessive heat as the coco will darken quite a bit and give off a lot of burned black sap if over heated. I just dampen the coco a bit before bending. I have never bent ovangkol so don't know about it. Fred |
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| Author: | Daniel Minard [ Tue May 28, 2013 11:26 am ] |
| Post subject: | Re: Side ripple/fold |
I always expect some "rippling" in the sides after bending. Some of it may disappear after a few days in the mold, but the rest will need to be sanded out. Lay a straightedge across the high spots to see how much material will need to be removed. Depending on how thick the sides are & how high the humps, you should be able to block sand the sides smooth. I have been using Supersoft II for quite a while now... Much better results than with water. |
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| Author: | James Orr [ Tue May 28, 2013 12:14 pm ] |
| Post subject: | Re: Side ripple/fold |
I had ripples before finding a way to add tension to the bending process. Adding the tension essentially eliminated them. I bend the waist first, but not all the way; I'll leave it so it's 1/2" or so from the form. Lower bout, upper bout, then finish the waist by setting it all the way. It pulls everything tight to the form. I think I read about this method first from Lance, and then from Todd's bending videos on YouTube. Works like a charm. No ripples. |
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| Author: | WilbPorter [ Tue May 28, 2013 1:48 pm ] |
| Post subject: | Re: Side ripple/fold |
Thanks guys. James, that's the method I have used as well. I am using solid mold, but it is not the full width od the sides. Four pieces of 3/4 ply laminated together. Sent from my GT-P3113 using Tapatalk 4 Beta |
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| Author: | arie [ Tue May 28, 2013 2:14 pm ] |
| Post subject: | Re: Side ripple/fold |
from what i can see is that you need better support. make a full width body insert for your fox. use a slat between the blanket and the wood and use springs to pull it down the sides of the upper and lower bouts. i put in about 3 to 5 degrees of draft on the bout ends to adjust for springback as well. |
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