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Posts: 10
| Hi Everyone!
I was advised by member Dan Savage to post this in Bottom Feeding Luthiery Guild but can’t since I’m a new member. Based on correspondence with Dan he thinks that I should be performing a bowl bend on my Custom Balladeer.
I found this suggestion on another old webpost and wondered if any of you on this site can comment further.
“Strap the body down to a "neck jig' ( a little hint here; if no jig, and you must use a flat board....go to a craft store and get a masonite ring, used to make a wreath.... cover it with foam. I use the tubing that is used to cover 1/2" water pipes Placing the board inbetween the foam tubing.Rest the rounded body into this device)
Make sure the soundboard has good humidity in it !
After strapping the body firmly. Use a firm support under the neck...nearest the body... next strap down, a bit, the neck at approx. fret 1 or 2. Apply just enough tension to 'bend the neck down a wee bit. Use a straight edge and measure the angle. Let sit a day or two.
Next, leaving the guitar in the tension position...take a heat gun on LOW...direct for a minute or two, the heat towards to "plastic" body at the heat Sit a day.... then perform the heat 'treatment' process. Increase the neck strap tension a slight bit now.. Let sit several hrs. Using a straight edge, see if you have "made any progress with the process. If you feel you have...release the neck strap...and measure again with a straight edge...does it lightly touch the top of the bridge now? If so... you are done. If not...repeat process again. Hint', after neck strap is release...the neck WILL spring back upward a bit. Compensate for this action.”
Thanks all.
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Posts: 10
| Would the moderators please allow me to post this in the Bottom Feeding Luthiery Guild?
Thanks,
Barrie |
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Location: The Great Pacific Northwest | I made you a full member and moved you here to the BFLG area. |
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| Thank you Miles |
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Location: Pueblo West, CO | Hi Barrie,
Here's a couple of threads you can peruse.
Bowl Bending Attempt
1967 Balladeer Rebuild... Dan |
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Location: Pacific Northwest Inland Empire | RE: bowl bend protocol, as outlined above:
That pedantic style sure sounds like something I would write. I did a bowl bend on an 1113 Classical several years ago, & it had the hand-laid fiberglass bowl, which probably made the adjustment more feasible.
The method above is generally accurate. Above all, go slow. It won't take much angle change to make a big difference. Making the bowl-holding jig will be the biggest challenge. If you want to take a general shot at whether the bowl will bend, just put a bungee cord on the peghead & tail strap button, & let it sit for a few days. If the neck takes a different "set", after the tension is removed, & left to it's own device for a day, you just might be in business.
Best of luck! |
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Posts: 10
| Thank you for your input. It is greatly appreciated. I agree that the author of the original post that I found elsewhere would not be a good job match as a tech writer. This is the jig that I came up with and it seems to be working for me. It has been in this position for two days with two heat treatments on the back between the neck block and sound hole. It appears to have moved the neck down at the first fret by about .030 “.
I will check it tomorrow morning.
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Location: Pueblo West, CO | WRT heating the bowl for a bend, once the epoxy has cooled to the touch, it's as set as it's ever going to be. There's no reason to wait a day to check the results.
A little background. Epoxy is what's known as a thermoplastic resin. This means that you can heat it up, reshape it, let it cool and it will take the new shape.
Among the known qualities of epoxy, such as compression rating, stiffness, etc., is one known as Tg, or Glass Transition Temperature. Translated, Tg, is the temperature at which epoxy will 'transition' from hard and stiff to soft and pliable.
Most epoxies are room-temp cure, including the epoxy used by Ovation. Room temperature epoxy generally has a Tg of ~170 degrees. As the epoxy gets near this temp, it will begin to become more pliable. As the temp rises to about 180=190 degrees you can separate glue joints, such as neck-to-body joints.
The tricky part is that all of the glue joints on an Ovation are glued with the same epoxy that has a Tg of ~170 degrees. If you're not careful with the application of heat, it's possible to separate stuff you'd normally want to remain attached, such as the neck block.
Luckily, you'd have to fully heat soak the neck block to over 200 degrees cause that to happen, and you'd never get it that hot while doing a bowl bend. (Phew!)
That being said, once Ovation went to the SMC bowls (sheet molding compound) it was no longer possible to do a bowl bend. SMC bowls are molded at ~350 degrees and because they are a thermoset resin, once it's molded that's its shape, no matter how much heat is applied.
You can easily tell a hand-laid epoxy bowl from an SMC by looking at the neck block area. If it's got a wood block, it's epoxy. If it's got thin buttresses instead of wood, it's SMC.
Edited by DanSavage 2021-01-30 6:38 PM
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Location: Pueblo West, CO | jaynut17 - 2021-01-30 4:01 PM
It has been in this position for two days with two heat treatments on the back between the neck block and sound hole. It appears to have moved the neck down at the first fret by about .030 “.
Make sure to also heat where the sides meet the back so you don't just warp the back and create an indentation into the back of the bowl. |
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Posts: 10
| Thanks Dan! You are extremely knowledgeable. I’ll take a look at what has transpired so far and if more movement is required I’ll be sure to heat the side area that you mentioned as well as the back. Definitely a wooden neck block. |
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Location: Pacific Northwest Inland Empire | Thanks, Dan. That was much more eloquent, and comprehensible. I tried bending a Celebrity SMC bowl once. It was not pretty. |
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Location: Upper Left USA | May the Forces (Heat and Pressure) be with you! |
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Location: Upper Left USA | If I had to do it over I would block up the waist of the guitar to keep it from bowing there and force the movement into the bowl. Balladeer #1096 will not fit into a standard Ovation case but it plays well.
Overall I'm satisfied but there is always risk!
Learn from us and move forward!
Thank you Dan for the flashback! |
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Location: Denmark | DanSavage - 2021-01-30 1:30 AM ... You can easily tell a hand-laid epoxy bowl from an SMC by looking at the neck block area. If it's got a wood block, it's epoxy. If it's got thin buttresses instead of wood, it's SMC. Like this? 
Also I guess that we are talking Fahrenheit degrees.
Edited by tpa 2021-01-31 3:50 PM
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Location: Pueblo West, CO | Yep.
Here's a SMC bowl for comparison. Some models of Ovations used SMC bowls, but glued on the necks, such as the 1624 and Parlors. Yes, Fahrenheit.
Edited by DanSavage 2021-01-31 5:07 PM
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| Thanks for the input and encouragement everyone. I now understand why you refer to it as a bowl bend. I did get a better neck angle out of this and also a new/additional contour/slope/depression on the bowl midway between the neck block and sound hole. Much easier that doing a proper neck reset. I’m in a holding pattern now waiting for more fret wire and saddle blanks. I cut the original saddle down so much trying to avoid a neck reset that it is now far too low on the bridge. Removed the frets and I’m trying to take a twist out of the neck that the truss rod doesn’t seem to have any effect on using a bit of heat and humidity and clamping a strait bar onto it. I’ll post a few pics when I’m finished. |
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Location: Pacific Northwest Inland Empire | Neck twist? This is definitely "bottomfeeding":
 (necktwist .75 better view.JPG)
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Location: Pueblo West, CO | jaynut17 - 2021-02-01 1:43 PM
Removed the frets and I’m trying to take a twist out of the neck that the truss rod doesn’t seem to have any effect on using a bit of heat and humidity and clamping a strait bar onto it. I’ll post a few pics when I’m finished.
You are correct about the TR not having any effect on the twisted neck.
The only thing the TR does is to adjust neck relief.
Since you've already removed the frets, there may be another solution if the heat doesn't work.
Instead, buy a radius sanding block from Stwemac and sand down the 'high' side of the fretboard to 'remove' the twist. (10" radius for Ovation fretboards)
Keep in mind that this 'solution' will only really work if the neck is only slightly twisted as you don't want to sand too much off the fretboard. You also might need to deepen the fret slots on the side you sanded down.
Can you post any photos looking from the headstock to the body to show how much twist is in the neck?
Edited by DanSavage 2021-02-02 12:09 PM
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| Hey Dan!
I wish I had documented the original condition as well as everything I’ve done with photos but alas, I didn’t. I will take a few right after lunch to show what I’ll attempt to explain here.
Your bowl bend idea was genius but I found it very hard to heat the back with the guitar facing up and the neck pulled down. I melted a lot of my carpet on my guitar work station. Although the bowl finally improved upon the neck angle it was still not enough. That’s when I decided to make a new saddle first before going any further.
Although I had a twist in the neck originally, it wasn’t that bad after I rehumidified the guitar for several days. After the attempt at the bowl bend it seemed worse and that got me thinking that maybe the bowl bend wasn’t parallel with the top. I reversed my approach this morning and clamped a metal level across the back of the guitar quite close to the neck block and reheated the back placing more pressure on the high side of the twist in the neck. This happened to be the treble side. This turned out to work so much better for me. Two things happened in a very controlled way. 1. The bend became level and with it, the neck. Virtually no remaining twist in the neck. 2. I was able to accurately increase the bowl bend to exactly what was needed and it is quite a well defined line just past the neck block.
I quit removing frets for now but they are all coming out when my wire arrives. I will sand the neck. Not sure if I will radius sand it since I don’t have a 10 deg block.
One of the photos that I’ll add, will show that the nut is raised on the bass side. The headstock had a significant crack at the neck that I glued and clamped and it is rock solid but I guess a bit of tear material didn’t go back into place. I’ll make a new nut and adjust things that way. |
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| Photos of Barrie’s guitar Rehab.
One photo shows my original bending configuration. One shows the guitar turned over and where I placed the beam to heat the bottom in the eventual configuration. One shows the distinct crease at the end of the block after the bowl bend. One shows the neck and nut from the headstock. Neck is now quite straight but the nut is high on the bass side. One is purely for nostalgia. That’s a young me in the mid eighties with my 1974 Custom Balladeer 1114. Wide neck, 12 frets to the body. Beautiful! Never should have sold it!
Haven’t we all said that at some time? |
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| Pics
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Location: Pueblo West, CO | Hi Barrie,
Yes, bowl bends are best accomplished with the top down and the bowl up. As you've found one of the problems with softening the fiberglass bowl is that it's easy to twist, or even skew the neck or worst of all, twist and skew the neck.
I'm glad you were able to bring the twist back under control.
I think putting a new saddle in place before continuing is a good idea.
If you're just replacing some of the frets, there's no reason to sand the fretboard. I only offered that as a suggestion for a possible alternative.
The crack in the back of the headstock/neck area that your photo shows is pretty common in Ovation guitars.
It's usually an indication that the TR has been over-tightened at some point in the guitar's lifetime.
Early Ovations had the headstock set at a steeper angle than later ones. Because of the neck construction, these sorts of cracks occurred. It was the warranty work associated with these cracks that caused the factory to make the headstock/neck angle more shallow.
Edited by DanSavage 2021-02-02 7:16 PM
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Location: Pueblo West, CO | BTW, Is this pic of the neck twist before or after? 
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Posts: 10
| Hi Dan!
This is after correcting the bowl bend but because the nut is so high on the Bass side it gives the illusion that the neck is twisted. It's really quite true now. You can see how much higher the nut is on the right compared to the headstock. I took this with an iPad so it wasn't easy to square up the shot. I put strings on to check its playability and was very pleased. Night and day difference compared to when I picked up the guitar. Top cracks really tightened up with humidification and glued up very easily as well. I am doing a complete refret. Many had been filed down by the previous owner to try and eliminate fret buzz. What a hack! Guess that I shouldn't talk after taking the saddle down to nothing. Thanks again for all of your guidance. |
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Location: Pueblo West, CO | Great news, Barrie!
I'm glad to hear it worked out so well for you. |
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Location: Cork, Ireland | seesquare - 2021-01-30 11:12 PM
RE: bowl bend protocol, as outlined above:
That pedantic style sure sounds like something I would write. I did a bowl bend on an 1113 Classical several years ago, & it had the hand-laid fiberglass bowl, which probably made the adjustment more feasible.
The method above is generally accurate. Above all, go slow. It won't take much angle change to make a big difference. Making the bowl-holding jig will be the biggest challenge. If you want to take a general shot at whether the bowl will bend, just put a bungee cord on the peghead & tail strap button, & let it sit for a few days. If the neck takes a different "set", after the tension is removed, & left to it's own device for a day, you just might be in business.
Best of luck!
just to clarify the bungee cord method: is it like this?
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Location: Cork, Ireland | OK, after a beautiful 33-year relationship, this baby will now bend to my will. what do you think of my jig? A glass garden table and some luggage straps, books to keep the body from tilting. A pencil mark on the mitre block showes my starting point.
I was thinking about the various arrangements for supporting the round back and then I thought "the front is not round".
Now cooling, with fingers and toes crossed.
Does anyone have a protocol for bowl unbending?
Edited by sycamore 2021-05-24 7:03 AM
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Location: Upper Left USA | Take a look at this album and see what I did. Photo albums (ovationfanclub.com) This is all you need. Photo albums (ovationfanclub.com)
Edited by MWoody 2021-05-24 11:40 AM
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Location: Pueblo West, CO | sycamore - 2021-05-24 5:02 AM
A glass garden table...
I would be careful not to overheat the glass lest it shatter. |
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Location: Cork, Ireland | Good advice, thanks.
Alternatively, I could set the kitchen table on fire...
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Location: Pueblo West, CO | I should also add that you can only perform bowl bend on a cloth bowl.
SMC bowls can't be re-shaped. |
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Location: Cork, Ireland | Mine went OK. It did not bend as much as I thought but I've decided it's enough. I am still tuning it a semitone flat and the action is very acceptable now. |
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