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Silicone blanket temp for removing the fret extention?
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Author:  Linus [ Thu Feb 23, 2017 3:54 pm ]
Post subject:  Silicone blanket temp for removing the fret extention?
I'm getting ready to remove the neck on an early 60's epiphone basket case.
I'm going to use a small silicone blanket and the temp regulator. What temp should I set for doing this?
Author:  Chris Pile [ Thu Feb 23, 2017 3:59 pm ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
Most any glue starts breaking down around 180 degrees.
Start low, and go up.
Author:  Craig Bumgarner [ Thu Feb 23, 2017 4:46 pm ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
For extension, I rely more on a hot artist's spatula than overall heating. It is nice to warm it up some, but the hot spatula does most of the work. Be sure to tape off and protect the top when you do it.
Author:  Linus [ Thu Feb 23, 2017 6:32 pm ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
Thanks. I'll be careful although it's getting retopped. The top is partially crushed in and it has a ton of side and back cracks. More work than it is worth ($$$) but I'm treating it as a learning experience.
Author:  david farmer [ Thu Feb 23, 2017 8:45 pm ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
Are you re-topping for sure?

If you have plastic binding and /or inlays, a heat lamp allows keeping them in the cool shadow w/ reflective covered cardboard.
If your re-topping keeping the neck in good shape is more important than the top.
Author:  Hesh [ Fri Feb 24, 2017 6:17 am ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
david farmer wrote:
Are you re-topping for sure?

If you have plastic binding and /or inlays, a heat lamp allows keeping them in the cool shadow w/ reflective covered cardboard.
If your re-topping keeping the neck in good shape is more important than the top.


What David said.

I'll add that lately I have been heating things more slowly and over more time giving the heat more time to migrate into the joints. When working the spatula it should feel "gooey" with some give or the glue is not hot enough (or it's unserviceable glue sometimes found on imports...). This "feel thing" for the gooey glue feel applies to removing bridges as well. If it feels "crispy" it's not hot enough yet.

Read your top runout too and work the spatulas in an appropriate direction as to not lift fibers. I often put a small piece of masking tape on one side with an arrow pointing in the runout direction. Of course the other side has the other direction.

We use heat lamps too and cardboard shields faced with reflective foil reflecting outward.... I use reflective HVAC tape for the gaps around the shield and bridge or extension as added protection to avoid bubbling finish. Bubbling finish can ruin your day....

Smoking and stinking a bit and oils raising to the surface with say BRW is standard fare and to be expected. I love the smell of burning BRW in the morning....:) Almost as nice a smell as Ov*tions roasting over an open pit fire....:)
Author:  bluescreek [ Sat Feb 25, 2017 7:44 am ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
https://www.youtube.com/watch?v=RurSR88jc8s
I use a heat blanket. I do use it at full then turn it down after a few min but the glue breaks down at about 145F. I use a pampered chef icing knife that is my favorite took.
Shouldn't take too long as long as they used wood glue. I have run into some odd balls through the years.
Author:  dberkowitz [ Sun Feb 26, 2017 8:01 am ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
Hash, this has always been a hard one as I simply don't do it that often. With the heat lamps, how long are you letting them work? I find Titebond gets gummy if you overheat it, but a little DeGlue-Goo works wonders in both loosening the joint and keeping it from rehardening while trying to get the tongue to release.
Author:  Hesh [ Mon Feb 27, 2017 5:50 am ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
dberkowitz wrote:
Hash, this has always been a hard one as I simply don't do it that often. With the heat lamps, how long are you letting them work? I find Titebond gets gummy if you overheat it, but a little DeGlue-Goo works wonders in both loosening the joint and keeping it from rehardening while trying to get the tongue to release.


Hash here.... :D Sheesh all of a sudden I'm hungry.... :? :D

Stew-Mac recently did a shop secrets using a heat lamp on extension heating it for IIRC around 15 minutes from a distance of around 6". Don't quote me, it's been maybe six months since I watched that emailed video and I could have it wrong.

I only heat for maybe 30 seconds with the lamp nearly in contact with the extension, shields in place, reflective tape over anything that can melt, etc. Then I do an initial poking around with my pallet knives.

Usually the shield goes right back on and I heat a bit longer before trying to debond things with the pallet knives. I'm looking for that gooey feel and since the extension is hot as long as I replace the shield and heat again for 10 - 20 seconds periodically the glue stays gooey until the extension is released.

Bridges are the same thing and reading runout is your friend and taping any gaps with reflective tape is insurance against bubbling finish.

What struck me about the Stew-Mac video was it seems to me the longer one takes to do this, they were heating for maybe 15 minutes the higher the likelihood that the phone will ring, the ACLU will be knocking at our door for a donation, a homeless person will need a donated guitar string, etc. Any distraction at this time can make one forget they have the lamp on and that can be dangerous.

As such I've stayed with the faster, closer contact with the lamp method and never, never permit myself to get distracted.

BTW it did happen once in our shop that someone got distracted. Of course Luthiers fix what ever we break, that's where the real skill set may actually be..... but you don't want to go there. Any heat lamp or heating blanket operation should have your undivided attention at all times.

Anyway, sorry for the safety message, just want everyone (the guitars) and the Luthiers (the people) to be safe at all times.

EDIT: Wanted to add that it's not unusual for things to start to smoke, just start.... and stink.... and oils to rise to the top surface of the wood. All to be expected you just don't want combustion..... :? :D

Where the swearing starts is when some yahoo used enough glue to glue the heel cheeks to the guitar sides.... Some very colorful language can be heard at our place when that happens...... Don't people know that the beauty of a dovetail is that it's a mechanical joint only relying on glue to keep the joint closed not the neck on...... :? :D [headinwall] gaah laughing6-hehe
Author:  Woodie G [ Mon Feb 27, 2017 7:38 am ]
Post subject:  Re: Silicone blanket temp for removing the fret extention?
We usually use a 2.5" x 6" 75 watt silicone blanket for extensions, set quite low - it is not unusual to see a 20 minute heating cycle and a surface temperature of about 150-160 degrees when the glue under the extension is ready to release with a warmed, wet stainless steel palette knife. Like others here, we use foil, cork sheeting, and card stock to protect the top and any other areas. For instruments with shrinkage-prone inlay work, we go to a heat lamp, monitoring with a wireless non-contact thermometer in a laboratory stand, and rely more on the warm knife and 140-150 degree F water to get things done.

Quote:
...the higher the likelihood that the phone will ring, the ACLU will be knocking at our door for a donation, a homeless person will need ...


I prefer the quaint but very effective fiction that I am either available to receive callers or 'not at home' - walk around the back of the house while I am working 300 pounds of fresh manure into my little kitchen garden will temporarily render any caller - even close relatives and representatives of Publisher's Clearing House in possession of oversized checks - dumb and invisible...or at least those that choose to intrude without a pair of wellies, a cultivator, and a cooling beverage or three in hand. The boss extends this sort of policy to the shop with a strict 'appointments only' policy, but has found that a certain segment of the population still feels that they possess the innate ability to negotiate a welcome, despite evidence to the contrary. Once again a polite fiction is employed - that of the difficulty in hearing the shop door chime over the central dust collection system.

As to organizations or campaigners: since when did the generous nature of my purse suggest to these worthies of various causes and calamities that I wish to be beggared of my time? Was the brusque dismissal of their various prior suits for my attention insufficient to convey my lack of receptiveness to their blandishments and solicitations?
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