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  #1  
Old 12-07-2017, 03:02 PM
L20A L20A is offline
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Default Removed my John Pearce Arm Rest Bad Results!

So I tried a John Pearce arm rest on my Guild D-55.
It's been on the guitar for a little less than a year.
The rest never fit the guitar very well and the look finally made me remove it.

I used a hair drier and dental floss to remove the rest.
It came off relatively easily but what I saw when the rest was off was not good.

The finish has become distorted. Kind of wavy.
It looks like the lacquer reacted to the adhesive which seems to have softened it.
I hope that it will be able to be buffed out but for now it looks awful.

Wish that I had never tries the rest now.
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Old 12-07-2017, 03:34 PM
Scottj121 Scottj121 is offline
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Sorry to hear that. I've been Leary of putting one on myself. I did however get an Abel armrest from Strings by
Mail that is removable. It looks pretty good and doesn't seem to harm anything. It can be moved to different guitars. Cost about $75.00.
Hope you can buff out the finish.
Scott
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Old 12-07-2017, 03:48 PM
Tony Done Tony Done is offline
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I can empathise. One of my guitars has a JP armrest and a nitro finish, and it looks as if it been moved at some time, with some damage to the finish in the attempt. I'm OK with the look so I'm leaving well enough alone.

Are you sure your technique was OK? IIRC (I'm sure he will put me right if I'm wrong) Wade Hampton Miller advocates using a pick to lift them.
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Old 12-07-2017, 04:25 PM
L20A L20A is offline
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The removal didn't cause the problem. It looks like a chemical reaction between the lacquer and the adhesive.
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Old 12-07-2017, 04:30 PM
chitz chitz is offline
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I've had a JP armrest sitting here for over a year trying to find the courage to install it.

My fears are what the OP is experiencing, or some other kind of damage to the guitar.

So it sits... and sits... and sits.
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Old 12-07-2017, 05:13 PM
Tony Done Tony Done is offline
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Is it a nitro finish? If not, I wouldn't worry.
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Old 12-07-2017, 06:07 PM
Guitartanzon Guitartanzon is offline
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I have them on all of my guitars. ..what i do is cut out sections of the tape an only have 3 small anchor points about 1 or 1 1/4 in long .....place at both ends and middle.
It stays on fine and touches less surface area and makes it easier to remove if you want to.
sometimes I used my own thinner & slimmer 3m auto tape and do the 3 pt anchor system

Nirtros tops like my gibsons are a bit more sensitive to removal...then tend to
indent or nail scar if you ry to rub and peel the tape left off with hard pressure..It takes patience and very slow going....this is where the 3 pt adhesive system works better.

I actually bought 4 of these instead of the John Pearse they were ok.....and a lot cheaper...
i used my own 3m tape

see

https://www.ebay.com/itm/2-different....c100506.m3226
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Last edited by Guitartanzon; 12-07-2017 at 06:37 PM.
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Old 12-07-2017, 06:29 PM
Todd Tipton Todd Tipton is offline
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When I am not wearing a long sleeved shirt, I use a guitar sock. If you shop around, you can usually find one for less than $20. No...I'm joking! :-)

I cut the toes off an old sock: Wahla! Guitar sock!

Side note: when my daughter was a little girl, she REALLY thought there were such things as guitar pencils. I always insisted on mechanical pencils, and that was the only place she had seen them...lol

Last edited by Todd Tipton; 12-07-2017 at 08:26 PM.
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Old 12-07-2017, 06:48 PM
Tico Tico is offline
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Sorry to hear this, but thanks for posting.

I've posted in JP armrest threads that I'll consider one after they've been on guitars for 100+ years with no reports of finish damage after removal, like what is reported in this thread.

I'm not going to let some accessory company profit while they use my $$$$$ guitars as guinea pigs.

But to you guys willing to gamble with your guitars: Thank You.
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Old 12-07-2017, 06:53 PM
Gasworker Gasworker is offline
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I have never had a problem removing them but I have never used a hair dryer before. I just used a couple of picks and some patience.
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Old 12-07-2017, 07:12 PM
jpd jpd is offline
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Quote:
Originally Posted by L20A View Post
The removal didn't cause the problem. It looks like a chemical reaction between the lacquer and the adhesive.
Had the same happen on a *non-catalyzed* nitro finish. Learned a big lesson about the reaction of the tape with different finishes
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Old 12-07-2017, 08:42 PM
Guest 1928
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Quote:
Originally Posted by L20A View Post
...The finish has become distorted. Kind of wavy.
It looks like the lacquer reacted to the adhesive which seems to have softened it...
This is a common reaction between lacquer and pressure sensitive adhesives. You see the same thing after removing a pick guard. It's not always obvious unless you get the light right, but I can nearly always spot it.

The good news is that it will diminish some with time. I wouldn't do anything immediately. Give it at least a month, then consider wet sanding (with a block, not your hand) and buffing. No finish work is quite that simple, and don't undertake that yourself if you're not skilled in working with delicate finishes. However, it can be made near invisible.
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Old 12-07-2017, 09:30 PM
Wade Hampton Wade Hampton is offline
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Quote:
Originally Posted by Todd Yates View Post
This is a common reaction between lacquer and pressure sensitive adhesives. You see the same thing after removing a pick guard. It's not always obvious unless you get the light right, but I can nearly always spot it.
Todd is completely correct about why this occurred: it didn’t happen because of any “chemical reaction,” it was the result of mechanical compression of a finish that was too soft for some reason.

The only time I’ve experienced anything similar was when I took delivery on a custom made guitar that had been sprayed with what turned out to be a defective batch of lacquer. The finish on that guitar never did fully harden.

A couple of years later I ended up trading the guitar back to the builder, and when I removed the armrest in order to be able to reuse it on another guitar, there was a similar imprint underneath it as L20A has described.

John Pearse himself always cautioned me to never put an armrest onto to a guitar with a nitrocellulose lacquer that was newer than six months old, because the finish needed to fully harden before an armrest should be mounted, for the very reasons I’ve just explained.

So if an armrest is put on a new guitar with a finish that hasn’t fully hardened, or there’s some problem with the finish (which is more common with factory-built guitars than you might expect,) then this sort of imprinting can occur. It doesn’t even have to be nitrocellulose, either - in fact, some the modern “catalyzed lacquer” finishes can be the worst culprits in this regard.

Quote:
Originally Posted by Todd Yates View Post
The good news is that it will diminish some with time. I wouldn't do anything immediately. Give it at least a month, then consider wet sanding (with a block, not your hand) and buffing. No finish work is quite that simple, and don't undertake that yourself if you're not skilled in working with delicate finishes. However, it can be made near invisible.
To which I’ll add is that the unfortunate thing about this, in addition to the damage and distress that L20A is dealing with, is that at least half to two thirds of the people who read this discussion will skim the posts, then walk away under the impression that it was this Pearse armrest’s adhesive that caused a chemical reaction.

Even though that isn’t what happened at all.

It won’t matter. Many folks will glance through this thread, the phrase “chemical reaction” will jump out at them, and that will be their takeaway.

For you hands-on types, however, I can show you a way that replicates exactly what happened with L20A’s guitar, and you can do this in your own home kitchen.

Get two slices of bread, a jar of peanut butter* (creamy, not crunchy, if you have some) and a carrot. Spread a layer of peanut butter on one piece of the bread, then slice the carrot into 1/4” strips. Place some of these carrot slices 1/4” apart onto the peanut butter layer, then place the second slice of bread over that, and press down.

Then eat hearty!

No, I’m kidding; you’re not done. Lift off the second piece of bread, then lift the carrot slices off the layer of peanut butter.

What you will see is a succession of lines in the exact shape of the carrots slices that were there only a moment before.

That’s what happened to the finish on L20A’s guitar: a form of mechanical compression, nothing more.

Hope that makes sense.


Wade Hampton Miller

*If you don’t have any peanut butter, cream cheese will work equally well. A cream cheese and carrot sandwich might even be better, too, once you take off your lab coat and settle down for a tasty snack!

Last edited by Wade Hampton; 12-07-2017 at 09:35 PM.
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  #14  
Old 12-07-2017, 10:14 PM
Guest 1928
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To be clear, I never said it wasn't a chemical reaction, or that it was. I actually don't know. I only know that the result is similar. Further, I've only seen this particular thing with lacquer finishes, but I don't recall having removed a pick guard from a varnish finish guitar. Poly finishes seem impervious. I have seen what I'm pretty certain are compression dents from mandolin arm rests - the clamp-on type.

One theory with the pick guards and JP armrests are the the adhesive material prevents plasticizers from off gassing leading to the uneven ripples in the finish. This seems reasonable enough, but I'm not a chemical engineer. It may not be entirely chemical, but I don't think it's entirely mechanical either. I just can't say with certainty.
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  #15  
Old 12-07-2017, 10:16 PM
L20A L20A is offline
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I was hoping that Wade would chime in. First of all this guitar is a 2005 Guild. The guard was installed less that a year ago. Perhaps the word chemical isn't correct but there was some kind of reaction that has affected the finish.
Wade, have you removed an arm rest on a guitar with a nitro lacquer finish? If so any problem like mine?

I'm sick about the result from the removal. I used the rest with confidence that it would not cause this kind of problem when removed.
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