Had to Iron Out a Little Ski Jump Problem…

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Re: Had to Iron Out a Little Ski Jump Problem…

Postby Ken Baker » Tue Mar 13, 2018 12:56 pm

Sticky!

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Re: Had to Iron Out a Little Ski Jump Problem…

Postby derick » Wed Apr 04, 2018 2:38 pm

A few years ago, I purchased an ‘81 Natural Mahogany L-1000 with an ebony neck. During the last 37 years I’ve owned 10 or so of these three-bolt precision-tilt G&Ls, and this is the only one that has displayed the classic ski-jump syndrome. While not extreme, I noticed the curve right away when the brown truck had left, and while loosening the neck bolts helped, it didn’t cure it.

The fact that neck stamp showed April of 1981 while the body stamp was December of ‘81, and remnants of red finish on the neck was enough to convince me that this body and neck did not leave the factory together. I attempted to “cure” the ski-jump with a fret-dress but was unsuccessful. I was pretty exited about getting this hog/slots/ebony with chrome plates and early black bridge bass, but it fell out of rotation because I couldn’t set the action as low as I wanted.

I’ve read multiple times on this board and others how the only way to permanantly fix ski-jump was a fretboard planing and a partial refret. I don’t know how exreme the condition has to be before that is the only option but, by comparison the heat and pressure procedure described here looked like a good and relatively simple experiment to try on this neck. So, I did.

iron.jpg
An aluminum square seemed it would transfer heat pretty well.
iron.jpg (136.25 KiB) Viewed 234 times


It worked to straighten the heel of the neck, but I overdid it a bit and managed to introduce a slight hump at the 14th fret. Having heard how these fixes don’t hold anyway, I gave the neck a couple of months to revert to it’s prior state. It did not.

Now, two months is not forever, but I could detect no change in the neck over that period of time. Meanwhile a wunkay neck came up on Reverb that I decided to take a chance on. This “new” maple neck, while the truss rod works fine has a slight hump at the 10th fret. Interesting. It also has a finish crack the goes under the nut, which seems a point of concern. Since this new neck was one that someone had given up on already I didn’t expect it to be perfect, and it isn’t, but I still think that I can make it a viable neck as it’s not all that far off. But, that's not what I'm here to talk about.

So, this weekend I decided to try the pressure and heat procedure on the ebony neck to lay down the hump that I had overzealously created. Since the pressure clamp would have to be at the point where the heat needed to be applied, an iron would not work (and I am currently thinking that an iron may be overkill.) I decided instead to use a halogen lamp as the heat source. I actually did this twice as I was being much more careful and measuring everything, now having much more respect for the efficacy of heat and pressure on a maple neck. A halogen lamp at 8-10 inches for four hours seemed to do the trick, the frets were uncomfortably hot and the neck itself pretty warm, but not alarmingly so.

halogen.jpg
I moved the lamp down for this photo.
halogen.jpg (156.51 KiB) Viewed 234 times


And… as of right now the neck is nearly perfect. I’m going to take it out to play tonight.

So, this is my experience. No guarantees expressed or implied, and maybe in a few weeks or years the defects will return. But at this point I am cautiously optimistic. Thanks to TDR1138 for posting his experiences in dealing with his imperfect neck.
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Re: Had to Iron Out a Little Ski Jump Problem…

Postby TDR1138 » Mon Apr 09, 2018 7:46 am

Thanks derick for the feedback and your experiences as well.

I agree that the iron is somewhat overkill. I did use mine out of convenience and also just not knowing what to expect. I've read that heating blankets could/would work, too. Since my iron has an auto-off feature and I had to keep monitoring it, I think that forced me to not just set it on and leave it for a while, so I was more aware of the heat that was being applied. But hey, whatever works...
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Re: Had to Iron Out a Little Ski Jump Problem…

Postby derick » Tue Apr 10, 2018 10:48 am

The iron did certainly do the job, I used it on medium for about 25 minutes, and it heated the neck significantly hotter than the halogen lamp. Although my (wife's) iron is the same brand as yours, it did not switch off by itself.

The real question now is, how long will the "fix" hold up? If there is a noticeable regression in the neck status, I will report it.
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