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I bent the sides(Brazilian rosewood) for the classical I am building and have some "ripples" in them,mostly in the flat part after the waist towards the lower bout.
Nothing dramatic,but more than I usually get.
I am bending by hand using an iron.
I don't think it had anything to do with the way I did it because it happened to both sides in the same place. The grain at that point changed from quartered to flat sawn.
I know this topic has been covered in the past.
Last night I wet those areas and clamped it into the mold with some pieces of wood on the inside.
Any other ideas?
Thanks,
Brad

Brad, I had this happen to a set of Indian a while back. i was able to sand it out, although it left some areas a little thin, it did work.

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Lance@LuthiersForum.com

Brad

I think you have the right idea. I would touch it up on the iron as best as you can and then clamp it back in the mold so it can cool and dry. Maybe do this a few times if it seems to be helping. Than sand out what you have to. if you do end up getting the side a bit thin I would glue a patch on the inside to strengthen it.

Josh

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If the iron doesn't work I'd just sand them out. Torres sides were barely over 1mm thick, and I tend to think thinner sides lend toward better tone anyway.

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something I have done more than once, keeping in mind I have one of those little hand held electric steamers with a hose attachment.

assuming that you have a mold that is split into two halves, stack the halfs on top of each other to make a double height half mold and secure them. Steam the rippled areas with a steamer and secure to the mold with blocks and clamps working from one end to the other, steam and clamp as you go. I found that clamping about every 2"- 3" worked for me. You only steam a little each side of the rippel and it really does not take much but speed of clamping is a must. I have had to do this a couple of times both times it took following this proceedure twice to get rid of all the ripples.MichaelP38687.6164236111

"hand held electric steamers with a hose attachment"

Michael--sounds interesting.... where do you find something like that?
Nelson

Brad,

I had the same problem with some walnut (crotch-wood.) I took the same action you did but I have a small heating blanket and used that too. It seemed to work the best when I added a little water, but I suspect that is what may have caused some of the ripple to begin with.

John O

[QUOTE=npalen] "hand held electric steamers with a hose attachment"

Michael--sounds interesting.... where do you find something like that?
Nelson
[/QUOTE]

I assume you mean the hand held steamer. I got it at Walmart. They have some real cheap ones but I got the more expensive one by Bissel I think I paied $60 for it a couple years ago. It has a head on the end of the hose that looks like the pick-up hed on a shop vac. Diane got one of the cheap ones to carry with her when she is on the road, to steam the driving wrinkels out of her pants. I tried it but it just barly gets hot enough to make steam. I like my Bissel better.

Thanks for all the help,guys.
I took the sides out of the clamps and the ripples are much flatter now-I think I will give it one more try with heat and or steam and then sand them out after that.

So, would you guys say the more water used in bending, the more chance of ripples...as a rule?

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[QUOTE=L. Presnall] So, would you guys say the more water used in bending, the more chance of ripples...as a rule?[/QUOTE]

That has been my experience yes, but how does one explain the folks that actually soak there sides submerged in water before bending.

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I know and a lot of well known people do it that way. It is in the benedetto tapes, the Wayne Henderson book has him cooking them on a hot plate.... just a different way to go I guess.

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You know , part of the issue maybe a percentage of saturation thing. Some areas of the plank may absorb more or less of the spirited water and therefore not cook out at the same rate. I have often wondered if a form and complete body shaped caul might not help eliminate this issue

Michael, I think Bob Taylor mentioned something like that in the Factory Fridays sidebending video...said the heated, all-over contact with the mold (upper and lower) literally irons the sides flat...so you're on to something I think!

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I know I'm one of the minority that does submerge and boil the side pieces before bending. I even add salt to the water mixture as I read somewhere many years ago that Stradovarious built many of his violins from driftwood he took from the sea which has a high salt content level. There has been mention of the fact by many after him that believed the salt content in the wood possibly had some effect that made his instruments somehow more responsive and resonant. I don't know that there is any truth or validity to this but, why not? However, I have found that if you don't have a caul to flatten all the areas of the sides in your mold that the flat sawn areas will tend to warp (cupp). Most quarter sawn pieces i don't experience that. But I still like the old method of soaking the sides. I never have scorching problems from just using a hot metal source. Just my two cents.

I've bent hundreds and hundreds of sides, and I've done dozens and dozens of tests to try to figure out what causes these ripples. After all my research I've came to the conclusion that it is in the wood, not the method. You'll notice that when one side ripples the other side will do so as well and in the same spots and patterns. What I would do is when one side would ripple I would try altering thigns slightly on the next side. More water, less water,moreheat, less heat, longer cooking time, less cooking time, more time before starting the bend, less time before starting the bend. None of these things ever changed the outcome on the second side. It always did as it's brother did.

Sand out the ripples and hope they are not too thin after they are flat. Normally you can send out the ripples without any issues, although there has been a time or two when it was too severe to sand out..but that is really rare.

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I've read this thread with great interest today, since the dreaded side ripples have struck again here.

I'm building a classical with Honduran mahogany back and sides. First time I've ever built a guitar with mahogany. All I've read about bending mahogany basically states that it is not as easy to bend as other woods, and that less water is better.

This mahogany set is well quartered. Still, I figured that, since mahogany doesn't bend as well as, say EIR or walnut, I'd thickness the sides slightly thinner than I usually do -- about 0.075". I usually thickness EIR and other woods to about 0.085" for my classicals. The thinner sides bent without problems, but the first one had noticeable ripples, so I increased the heat on the second one. I use a silicon heating blanket with a thermal control, so I can accurately dial in the heat setting. I bent the first side at 280F, so for the second, I cranked the control up to 300F. The second side showed ripples just as prominent, if not more so, than the first (it's still clamped down to the mold, so I haven't had the chance to check it more closely just yet).

I do not have a male-female mold -- just a male with a caul for the waist and blocks to hold down the sides at the ends.

At this point, I'm thinking that I will have to discard this set of sides and try again. Next time, I'll leave them thicker than I normally do -- about 0.095" or so, and then, if they ripple, I'll have some meat left that I can sand or scrape down. I'm also wondering if a thicker side might resist the ripple effect a little better?

The main thing that concerns me about bending a thicker set of mahogany sides is that it appears that mahogany likes to wrinkle at tight bends, like a classical's waist. Maybe I should try sanding the waist area a bit thinner before bending?

Best,

Michael

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Hey Jeff,

I hear if you add some onions and potatoes as well you can get a very nice rosewood stew.

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What I have found works for me for mahogany that has rippled, (don't forget every bit of wood is different so this might not work for you).

Make a male caul to fit the area with the ripples. Wet the area, and put it back in the bender take it up to 280 and hold for 3mins. Don't allow it to cool in the bender but take it out while still hot (don't forget the gloves!) put in the mould and tighten the male caul against the side. This of course assumes that your mould is solid sided, if not use one of your steel slats in behind the wood. Leave it to cool down overnight.

This has worked for me, I'm not a great fan of sanding out ripples if it can be avoided.

Colin

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