Is that in centigrade or Fahrenheit? In Fahrenheit it would be 175 to 197 degrees.
I wrote 80-90 degrees C. C for centigrade. That's just bit under boiling water (100 degrees C)
For me tha main revelation was to apply low heat for longer time. You may feel the surface is warm or even hot, but you need the glue underneath get warm and that takes few more minutes.
When removing board on guitar you want to feel the heat on the inside of the guitar through the soundhole.
I pull two frets and drill (1 mm) holes right in the fret slots. I use long brass pins to align during gluing, then pull them out after the glue dries. (No pins to damage tools for the next guy.)
Same here. I hate it when I damage my separating knife on pins or nails left inside a joint. Gibson uses something like 1/8" nylon pins left inside and they are pretty hard to cut through if you won't notice... but at least won't damage blade.
This might be of some interest. Using a meat thermometer and a ~35 year old T-Fal brand clothes iron I find that the "synthetic" setting gives a surface temperature of 201 - 203 F (93 - 95 C). I assume that might work pretty well to remove a fret board?
There are lower settings on the dial so maybe trying for just a bit lower like 190 F (88 C) might be a bit better?
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
I set mine on "wool", I believe it is. I think the highest setting is linen and the one below it is wool.
Come to think of it, I ould use an infrared thermometer and see how hot it is (in my spare time...if I think of it...), but it's pretty hot, and I don't have problems with finishes, bindings and scorching of fingerboards.
I took a small scrape of ebony fret board stock and placed it over top of the meat thermometer probe then shielded the rest of the probe and placed the iron (at 223 F or 106 C) on the ebony surface. At the start when the iron was put in place the probe was a 69 F -- after only 3 minutes it was 100 F and by 5 minutes the probe was reading 143 - 145 F (62 - 63 C) after which it stopped advancing -- meaning we had apparently reached equilibrium (heat incoming and outgoing was aproximately equal).
This is not an exact duplication of a fret board that is glued in place and with frets but it does show that heat penetrates 0.25" of ebony much faster then I would have thought to be the case anyway.
One point in anticipation of a question -- the cardboard "head shields" on either side were thinner than the ebony so no, the surface of the hot iron did not touch them and at the end of the experiment they were slightly warm but not hot. The ebony scrape was hot to touch on both sides. So I think the heat actually does penetrate ebony rather quickly. Not so sure about less dense woods though?
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
I set mine on "wool", I believe it is. I think the highest setting is linen and the one below it is wool.
Come to think of it, I ould use an infrared thermometer and see how hot it is (in my spare time...if I think of it...), but it's pretty hot, and I don't have problems with finishes, bindings and scorching of fingerboards.
Yes using an infrared thermometer would the best way to do the experiment.
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
Rather than start a new thread I thought I'd just re-activate this one.
This morning I took the fret board off as per suggestions presented last month in this thread.
Some pics of the process shown.
Comments:
I made one error starting at the fret board extension and actually dug into the maple extension support instead of the joint!! Being scooped out it probably did not get hot enough. When I realized my error I started farther up the board and it went smoothly from there. First time taking off a mandolin board. The glue had the consistency of "snot" so I suppose it was hot hide glue? It cleaned up nice with water and scraping.
So its off. But I have one important question -- maybe some others have dealt with it before?
First to explain. I'm going to take out the truss rod and epoxy a carbon fiber bar in the slot. Reason the neck was snapped off years ago and I need more support. Generally I think a truss rods are seldom used for mandolin anyway. Regardless, of whether that is true or not I need a stronger neck more then a truss rod
Question any thoughts about the easiest way to remove the wood that is glued in the channel over the truss rod?
One other question -- but this just my curiosity. Have you ever seen a neck joint like that? It seems like a dovetail with two (possibly three) screws. The two larger screws are easy enough to see. The third hole in the center (below) seems to be a smaller brass screw that is deeply counter sunk? Never seen this before.
The two smaller holes farther up the board are alignment holes that I drilled for proper alignment when I re-glue the fret board back in place.
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
...The glue had the consistency of "snot" so I suppose it was hot hide glue?...
Definitely not hot hide glue, it stays solid unless dissolved in water (or vinegar, or...). Maybe Titebond or some other plastic glue. Whatever it is, it's good that it cleaned up easily.
No easy way to remove the filler stick. A chisel about the same width or a little narrower is best. Just slowly chisel it out of there, then resharpen the chisel a few times when you hit the rod.
The dovetail neck joint is pretty standard, the screws were most likely to clamp the extender in place while gluing. Why 3 screws? Don't know. Kind of looks like a situation where someone thinks 'if a little is good more is better". The Siminoff book outlines a method of using a screw at a diagonal (like your "third" screw) to clamp the extender, but I don't know why the other two would be there. I'd say the screws are overkill by a large margin, and they can probably be simply removed at this point.
Definitely not hot hide glue, it stays solid unless dissolved in water (or vinegar, or...). Maybe Titebond or some other plastic glue. Whatever it is, it's good that it cleaned up easily.
No easy way to remove the filler stick. A chisel about the same width or a little narrower is best. Just slowly chisel it out of there, then resharpen the chisel a few times when you hit the rod.
The dovetail neck joint is pretty standard, the screws were most likely to clamp the extender in place while gluing. Why 3 screws? Don't know. Kind of looks like a situation where someone thinks 'if a little is good more is better". The Siminoff book outlines a method of using a screw at a diagonal (like your "third" screw) to clamp the extender, but I don't know why the other two would be there. I'd say the screws are overkill by a large margin, and they can probably be simply removed at this point.
Thanks John. I might have been a little unclear on the glue. It took that gummy consistency when I put a little water on it to remove it? I don't have much of a track record here but it did not seem like Titebond -- but who knows. But it did come off fine.
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
Water, particularly warm water, turns dried hide glue right back into glue, like it was when it was applied. If your glue didn't turn to "snot" until it was wet it could be hot hide glue.
Well I dug it out with a 1/4" and 1/8 chisels but ran into a new roadblock. It seems the nut that is set in the neck joint is larger then the slot. So it looks like I have to carefully dig into the wings of the tenon on the dovetail to free that nut? (PS not that 1/8" chisel is not chiped it is just under the terrycloth a bit -- but now both do need serious time on the stones).
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
That looks quite like typical white glue. The heat turns it into rubbery leathery substance.
I would remove the screws and pin if the support is securely glued to top, may save headaches of some future repairman if it ever needs retop (I did it few times without fingerboard and support removal).
Originally Posted by Bernie Daniel
Well I dug it out with a 1/4" and 1/8 chisels but ran into a new roadblock. It seems the nut that is set in the neck joint is larger then the slot. So it looks like I have to carefully dig into the wings of the tenon on the dovetail to free that nut? (PS not that 1/8" chisel is not chiped it is just under the terrycloth a bit -- but now both do need serious time on the stones).
Frank Ford has an article about truss rod replacement and I believe he decided to leave the nut in place and cut off the rod (using diamond bits in Dremel or something like that). Check frets.com
You probably don't have room there, but I once was trying to adjust a truss rod on an instrument and couldn't get a wrench on the nut ( one of my pet peeves, and often ranted about here) because the rod was too long protruding through the nut and into the pocket. I bought a small cable saw, wrapped it under the end of the rod and 'shoe shined' it until I cut the rod off in the pocket with no damage to the peghead.
(BTW, the wrench and rod worked fine after that.)
You might have it started well enough that a carbide or titanium drill bit might get through the remainder. Or not. Whatever you do, watch your fingers on this one.
You probably don't have room there, but I once was trying to adjust a truss rod on an instrument and couldn't get a wrench on the nut ( one of my pet peeves, and often ranted about here) because the rod was too long protruding through the nut and into the pocket. I bought a small cable saw, wrapped it under the end of the rod and 'shoe shined' it until I cut the rod off in the pocket with no damage to the peghead.
(BTW, the wrench and rod worked fine after that.)
Yeah this pocket is poorly designed and it is hard to get a tool on it but I'm thinking if I could get two small nuts on the end then get a small 1/4" drive socket on the outer nut I might be able to put enough torque on it to break the truss -- I would think odds are it would break where I have weakened it?
Or does Dremel make routers for metal? If so probably only for soft metals?
Note how I have chewed up the nut -- it is much softer material. Made me consider concentrating my attack on that?
Wonder if these carbide burrs would cut that stainless steel?
Last edited by Bernie Daniel; Sep-28-2018 at 12:55am.
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
You might have it started well enough that a carbide or titanium drill bit might get through the remainder. Or not. Whatever you do, watch your fingers on this one.
The closest my fingers are at this point is holding the Dremel tool -- what were you thinking about specifically just in case? I have no desire to inflict a preventable injury! LOL
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
Well the truss rod is out -- but it fought me every millimeter of the way!
I bought a couple of cobalt bits -- they ate through that metal (stainless steel?) like butter. I also used a small grinding stone on the Dremel. In the end I was left with a little shard of metal holding the two sides together and that I broke with the tap of a small punch. I did very little damage to the truss rod channel - -so that is good to go.
I will be filling that channel with marine epxoy and a carbon fiber bar soon
Once cut getting the severed rod out was another battle. I ended up tapping it out gently with a punch. But of course I had to enlarge the truss rod pocket and just barely cleared it. But in the end everything will be covered by the truss rod cover -- see outline -- so I'm good!
In the end the TRC will be a custom shaped aluminum cover plate (see pic#5) that will butt up against the nut and will be permanently epoxied in to place.
Indeed the entire truss rod pocket will be filled with the carbon fiber bar and a strong marine epoxy that is designed to bond to wood. Once closes and glued the truss rod pocket will never open again!
Thus the truss rod cover plate will become a structural component of the neck and head stock.
This the final attempt to save this neck -- if it fails the next stop is the trash can. LOL!
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
I wonder why you had to pull the rod out of the pocket towards headstock and not lift it at the cut end and pull it out towards body end?
Sure would have been easier that way? But the hole for the truss rod under the nut and bottom of the head stock was very tight -- so very little "play". That and the fact that the truss was set so deep in the channel made trying to raise the cut end of the rod high enough to clear the dovetail joint at the end of the channel impossible without breaking out the wood around the the hole. At least that was my assessment so I went the other way.
Bernie
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Due to current budgetary restrictions the light at the end of the tunnel has been turned off -- sorry about the inconvenience.
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