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| Side Bend Question http://www-.luthiersforum.com/forum/viewtopic.php?f=10102&t=9404 |
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| Author: | alambert [ Mon Nov 20, 2006 2:07 am ] |
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I think I may have gotten my cart before the horse. When reading Guitarmaking: the authors indicate they bend their sides over a hot pipe, in my other book, Classic Guitar Construction, the author boils the wood then place it on a mold/bender for a week, I decided the boiling and bending might be best for my first time. So I looked at several other peoples bending molds and saw some with heater blankets, some with light bulbs and some with both. So I decided to make one with bulbs. It’s 14 inches wide and has 4, 40 watts bulbs in it. I also made a tin boiling tray. What I didn’t realize was the folks with the heated molds don’t seem to be boiling the wood. Mine with 4 bulbs is not going to get to 300 degrees so I think I still need to boil before putting the wood on. Also I have a steam sauna shower that’s about 5x5x10 feet. I considered putting the wood in there with the steam on instead of boiling. Just for a fun experiment I ripped a 3/32 inch slice off of a standard 2x4 and boiled it for 1.5 hours. Simmered it might be a better word. It cracked when I tried to bend it. So here are the questions. 1. How long should I boil my EIR? 2. Given my 4 bulbs how long should I leave the wood on and what percentage of the time should I have the lights on? 3. Should I use the sauna? If so how long? 4. Should I be concerned about the 2x4 experiment? Or is that just the nature of pine? |
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| Author: | Mark Tripp [ Mon Nov 20, 2006 2:20 am ] |
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EIR is one of the easier woods to bend - you probably shouldn't boil it. You can just spritz with some distilled water - I like to wrap mine in kraft paper and wet the paper down too. Have you checked the temp on your bender using the light bulbs? 250 - 285 should be plenty for EIR. I like to cook my sides for about 15 minutes, then let them cool. I then bring the heat back up for another 10 minutes, and let cool again - seems to help "set" the bend. Then they get clamped directly in the form. I use a heat blanket, so others with experience with bulbs will chime in I'm sure... -Mark |
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| Author: | Michael Dale Payne [ Mon Nov 20, 2006 2:26 am ] |
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Do not boil, do not use steam !!!!!!!! I have never heard of a luthier boiling side wood. This seems unpractical to me plus the adding all that moisture then waiting for it to evaporate is not a good idea. The wood will not dry at the same rate everywhere. This can lead to cracking. Steaming while may be viable will be difficult to keep ripples out of the sides. Pipe bending and form bend are the only two good choices in my opinion. If this is your first bend pipe bending is a good choice, because you need to fell the bend happening to understand when wood is ready to bend. That said Form bending is easy but be sure wood is at temp before you start the bends. This means you need a good thermometer. A from bender if powerd by light bulbs should use 3 200W CLEAR bulbs. |
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| Author: | Pwoolson [ Mon Nov 20, 2006 2:34 am ] |
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To answer your questions directly: 1. How long should I boil my EIR? You shouldn't. Period. Boiling is a misnomer that has done nothing but confuse newer builders. The only water you need to introduce into the equation is that of a light mist to keep the sides from scorching. Mist the sides, wrap in craft paper and bend them on the form. Boiling actually has some sort of structural effect on the wood fibers (sorry, I'm not a botanist so I don't know the terminology) that makes them more prone to breaking and tearing. 2. Given my 4 bulbs how long should I leave the wood on and what percentage of the time should I have the lights on? Take a trip down to your local hardware store and pick up a temperature probe. Should be around $10. See what you are actually capable of acheiving, temp-wise, when it's all fired up. Take the guess work out of it. If you can get into the 250-275 range, that will be fine for EIR. As Mark said, about 15 minutes for the first bend, let it cool and hit it again. I take mine out while they are hot and get them into the mold while they are still a bit flexible. 3. Should I use the sauna? If so how long? No, I wouldn't bother. It's heat you want, not steam. 4. Should I be concerned about the 2x4 experiment? Or is that just the nature of pine? could be a bit of both. Until you get the hang of it, your first bends might not be flawless. Chances are pretty good that pine was being bent as a flat sawn piece so that's a bit more tricky than a nice quarter sawn piece would be. |
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| Author: | crazymanmichael [ Mon Nov 20, 2006 2:48 am ] |
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at one time boiling was a recognized method of achieving bent sides. for example irving sloanes books on building used the boiling method. and as they were all that was available when i started i boiled sides. it worked well with eir and mahogany, and had one advantage with rosewood, namely that it removed a lot of the oils that some find make gluing difficult. that being said, i would not choose to boil now given the better alternatives available. but if you boil, bulbs are not necessary. if you don't boil, 40w bulbs will not give the heat required. 3x150w is probably the minimum, whilst 3x200w is better. better still is a heating blanket. |
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| Author: | Shane Neifer [ Mon Nov 20, 2006 4:54 am ] |
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Alan, If you e-mail me a reminder I will send picks of my Fox Style bender and will even send youu off a copy of a plan for it just for the cost of the copies. Although I have a heating blanket now that I have yet to install I have just used light bulbs with great success, 150 watts x 3 though. You don't need/want to boil but it is method that is still used by some. You will be amazed at how well this wood bends when heated after it is thinned to .085 or so. Shane |
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| Author: | alambert [ Mon Nov 20, 2006 5:44 am ] |
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Thanks for the replies. Sorry to be such a newbie. So basically I turn on the bulbs and once the mold is hot (say 30 minutes?) lightly spray the wood with mineral water, wrap in craft paper, and slowly put to wood in the bender. Is that about right? I'm guessing you slowly work the wood on to the bender over a period of 5-15 minutes? is that about right? Then clamp it down? Also what is Craft paper? If some one has a nice doc or site that covers my questions please feel free to link me. |
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| Author: | alambert [ Mon Nov 20, 2006 5:48 am ] |
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[QUOTE=Shane Neifer] Alan, If you e-mail me a reminder I will send picks of my Fox Style bender and will even send youu off a copy of a plan for it just for the cost of the copies. Although I have a heating blanket now that I have yet to install I have just used light bulbs with great success, 150 watts x 3 though. You don't need/want to boil but it is method that is still used by some. You will be amazed at how well this wood bends when heated after it is thinned to .085 or so. Shane[/QUOTE] I already built the bender. Its 14 inches wide and is covered with 2 pieces of sheet metal. I put some canvas on top of that. The "cover" is another piece of canvas and another piece of sheet metal, basically to sandwich the wood. I have 4 bulbs inside. Very close to Sloan’s design with exception of the lights, width and top. I went with 14 inches because I originally planed on doing sides for 2 guitars at one time. That was before I realized I didn’t have to leave the wood on there for a week. Does that seem ok? |
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| Author: | Shane Neifer [ Mon Nov 20, 2006 5:50 am ] |
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Alan, Craft paper is just that brown wrapping paper you use for packages. As for bending, you get everything hot and then start bending fairly quickly. LMI has a decent and cheap video on using a fox bender. I may post something on the process in the next few days. I need to insulate my new guitar making studio, it is supposed to get to minus 17 C here in the next couple of days!! Shane |
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| Author: | alambert [ Mon Nov 20, 2006 5:55 am ] |
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Thats pretty darn cold. |
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| Author: | Shane Neifer [ Mon Nov 20, 2006 6:07 am ] |
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That was my thought also, but with a stronger superlative!! My wife (a prairie girl) says I (a coastal boy)am a wimp because I hate the cold! I would much rather have warm rainy winters than cold clear ones! Anyway, I will just get that insulation up and the heaters on and I will just stay in and look out at the cold! Except that I need to process more top sets from logs that are outside  .
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| Author: | Shane Neifer [ Mon Nov 20, 2006 6:11 am ] |
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A Friend of mine, a proffesional luthier, bends both halves at once, but he has converted an arc welder into a heating unit and does it all very fast. Most of use just bend one side at a time, conserving the heat and trying to keep the temps constant. That big surface area may make it difficult to heat up and maintain temperature. I will post a pic of the Fox Bender (you can see a picture of it on the LMI site as well I think. Shane |
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| Author: | crazymanmichael [ Mon Nov 20, 2006 6:39 am ] |
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do not use mineral water as it has the potential to leave deposits on or stain your wood, use distilled, and if your bender is 14" wide, i think you are going to need 6 x 200w bulbs to get such a big area up to suitable temperatures. to wrap their sides for bending some folks use craft paper, some use aluminium foil. if you are using stainless steel slats, craft paper is ok, but if you are using plain steel slats aluminium foil will also help prevent staining. |
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| Author: | old man [ Mon Nov 20, 2006 7:54 am ] |
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Alan, I use bulbs, 3- 150 watters in a form that is 6" wide. I'm going to switch to 3- 200 watters for the next set. It works well, but a bend takes me about 30 minutes per side. Ron |
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| Author: | Rod True [ Mon Nov 20, 2006 8:09 am ] |
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I agree with Michael, if you bender is double wide (which is sure sounds like it) you will not get enough heat out of 4 bulbs, let alone 40 watts. You should have at least 200W bulbs in there and I would think about adding another two as Michael suggested. I've offten though of making a double bender but didn't want the expense of double wide spring steel and I don't know if you can get a 12" wide blanket. Would be fast though eh guys? |
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| Author: | Rod True [ Mon Nov 20, 2006 8:14 am ] |
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Now, last time I was there (over 12 years ago so take this for what it's worth) the folks at Larrivee steamed their wood in a steam box like you see in the Lee Valley catalog 
Than the put both pieces into a double bender. I see on their shop tour though that they have switched to pre-bending the waist on a pipe and then puting both sides into the bender. 
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| Author: | Rod True [ Mon Nov 20, 2006 8:15 am ] |
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The steaming and boiling has been donein the past as has been mentioned, but it seems that there are better ways to do this now and most builders have gone away from boiling/pre-steaming the sides. |
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| Author: | Shane Neifer [ Mon Nov 20, 2006 8:21 am ] |
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Rod, Ted Thompson does it the same way and David Webber as well probably. Ted porbably developed the system they use, it is quite simple and very effective, but you need a BIG tranformer thingy, they use converted welders. I was there when Ted was pre-bending the waists on a pipe, I asked why, we talked about and he may try without pre-bending. Shane |
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| Author: | Rod True [ Mon Nov 20, 2006 8:34 am ] |
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I know John McQuarrie of Northwood Guitars in Langley (Larrivee protege') does it this way too. Pre-bending the waist than into a big double bender or just bending both by hand on the pipe. John's mold bender had a stove element in it. He said every time he fired it up, he was worried about fires. He had a fire extinguisher at hand and never really felt comfortable, so now he just bends most by hand. Hey, so when are you down in the valley next, it's a balmy 10* down here. Bring you shorts and tee shirts and get out of the cold. 
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| Author: | Shane Neifer [ Mon Nov 20, 2006 8:50 am ] |
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I don't want to here about warm weather!! A freind is off to Florida, the B**tard!! I will call when I am down next, probably at least once before Christmas.... I just talked with a buudy of mine who I am helping make a flaminco and have him lined up to get the insulation up in the shop tonight before the big freeze comes....Sometimes I miss Nanaimo (I grew up there)......although with a population approaching 100,000, it is FAR too BIG for me now! Shane |
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| Author: | alambert [ Mon Nov 20, 2006 8:52 am ] |
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[QUOTE=Hesh1956] Alan I thought it should also be mentioned in the thread that Side benders have been known to start fires..... If you end up upping the bulb wattage which I think that you need to do too your bender will get very hot. You have also mentioned that canvas is part of the bender. With this said please don't leave the thing unattended at any time if it is on and/or plugged in. Some folks here will install timers as well as an added safety feature.[/QUOTE] Should I get rid of the canvas? Here is a photo with out the "lid". the lid is basicly the same as the top... 
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| Author: | Rod True [ Mon Nov 20, 2006 9:16 am ] |
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That's cute. Looks like a little pet. I would get rid of the canvus and just use the steel slats. Add a couple more bulbs and I think your good to go. Although I would be worried about the bulbs being to close to the wood. If you had 200W bulbs in there, I would think you would have scorching. How are the bulbs lined up? Is there a bottom to this rig? Do you have any other pictures for us to try and help out a bit more. |
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| Author: | alambert [ Mon Nov 20, 2006 9:18 am ] |
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[QUOTE=Rod True] That's cute. Looks like a little pet. I would get rid of the canvus and just use the steel slats. Add a couple more bulbs and I think your good to go.[/QUOTE] With exception on the bulb it's hollow on the inside.. so slats. |
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| Author: | alambert [ Mon Nov 20, 2006 9:19 am ] |
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[QUOTE=alambert] [QUOTE=Rod True] That's cute. Looks like a little pet. I would get rid of the canvus and just use the steel slats. Add a couple more bulbs and I think your good to go.[/QUOTE] With exception on the bulb it's hollow on the inside.. so slats.[/QUOTE] thats NO slats. |
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