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HP Classic Calculator (HP-65) back label
06-04-2019, 05:42 AM (This post was last modified: 06-04-2019 06:21 AM by [kby].)
Post: #24
RE: HP Classic Calculator (HP-65) back label
I'd encourage people not to sell the original "spoon" technique short—with a bit of practice it works really well. I say this as someone who tried it half-heartedly a few years ago, with predictably half-hearted results. Recently, I've tried again, and worked on my technique a bit. The attached was from a cosmeticallly pristine machine, but I'll point out that it's been removed and replaced at least a half a dozen times in the past few weeks (not that I would recommend that practice—I mention it to show that with some patience it need not be fatal to try again!).

I use GEM Teflon coated razor blades in the removal; these are the this are the thinnest and sharpest razor blades I know of (I have a bunch because they are used to make oboe reeds). The part number is 62–0178; they are aluminum and .23mm (.009") thick. That is just so you can get the corner/edge of the blade under the label. Once that is accomplished (after the heat), then it's best to (gently) apply the pressure along the side (not the sharp edge) of the blade to work more and more of the label loose enough to grab. It's best for someone with small fingers and short fingernails, so that you can grab the label without making a dent with your nail (although that is not fatal if it isn't too bad).

I then like to use label remover to remove all of the old adhesive. The original is usually the harderst in this case. The label should be smooth and shiny (not quite a specular mirror, though) on the back when done. I quick wipe with either isopropanol or acetone is good to degrease the back at this point (the paint in my experience has seemed resistant to both, but I would not push it with acetone, but you shouldn't be getting any on the front. Degrease the back of the calculator (after removing the adhesive with label remover) with an isopropanol wipe.

The glue I currently use to replace the label is Elmer's Craft Bond. I'm sure there are many other things that will work; this one is one of those that you are supposed to be able to have it act as both a permanent and temporary bond. I use it in the more "temporary" sense, although it seems pretty stuck then. It removes easily with label remover if you need to do a redo. To use it in this way, I spray a very thin coat (essentially one pass) on just the label. The nice shiny label now has an even matte finish on the back. Let it dry 3-6 minutes, then attach the label. You might need to use the spoon again over the next few days to get all of the bubbles out from underneath pernanently—just put something between the spoon and the label like a piece of paper. I do not spray any glue on the calculator—just the label.

Either before degreasing or after attaching if you're careful, I have used a black paint extra fine marker (it's actually paint, not just an oil sharpie) to touch up minor scratches if they are away from lettering (such as one you might get when trying to get the razor blade under the first corner and having it miss). If you let the paint just barely dry and gently wipe it with a tissue, you can get it to be prety invisible—your eye only sees the surrounding texture and color as long as it's not distracted by a glaring glint of silver.

I will try to post more pictures with more "realistic" cases over the next few days.

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RE: HP Classic Calculator (HP-65) back label - [kby] - 06-04-2019 05:42 AM

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