Sticky ink of old schematics

[CNe7532294]

Hello, I recently acquired some HP schematics. Been sitting in a warehouse for decades. Probably stored in winter cold and summer heat conditions with humidity (Mississippi River area). I want to digitally save them. The problem I’m having is the the ink either lifts partially or worse. It acts like glue and takes paper with some of the reverse drawings of the other side with it. As they are all folded. It’s also leaving its print on the plastic cover it came with to ironically protect it. Any tips and tricks to solve this as best as possible?

[Analog Kid]

Heat the sheets--carefully--in a low oven (< 150° F)? Maybe try one that you'd be willing to sacrifice first.

[Analog Kid]

If the sheets are Xeroxes^[1], what might have happened is that the toner has melted; photocopy toner contains plastic, usually styrene or equivalent, which can melt at high-ish temperatures and stick to whatever they're next to.

[1] Using this term in the generic sense, of course.

[CNe7532294]

Oh it’s bad…  attached is a schematic example that any HP CLIP offers. I’m trying a plastic spatula meant for caulking and putty from Home Depot. I hold the pages taut while trying to listen for more of a cracking sound than a tearing one. If it’s separate pages I have much better success as I can “attack with separating” at any orientation. Folds I have difficulty. I have to find my letter opener (it’s not sharp but it may be too blunt) for the tight spaces. If we’re going with heat, it’ll leave a print regardless but that maybe better than tears. If there are prints on both sides, the ink really is like glue… 

[Analog Kid]

That really sounds like toner, not printing ink. Ink wouldn't turn sticky like that, as it gets absorbed in the paper, while toner just sits on top of it.
(I know; I was a printer in a previous life.)

Good luck with your scraping.
Do you have any sheets that you can try heating in the oven? Like maybe a cover sheet or something? I'm thinking that might "set" the sticky substance and allow you to separate sheets cleanly.

[CNe7532294]

I’m gonna try this. How would a hair dryer sound? Thanks for setting me straight on what I’m dealing with so I can search/ask around more.

That really sounds like toner, not printing ink. Ink wouldn't turn sticky like that, as it gets absorbed in the paper, while toner just sits on top of it.
(I know; I was a printer in a previous life.)

Good luck with your scraping.
Do you have any sheets that you can try heating in the oven? Like maybe a cover sheet or something? I'm thinking that might "set" the sticky substance and allow you to separate sheets cleanly.

[CNe7532294]

To add to this, I just found a decade old topic on the HP/Agilent group. Will do some more reading.

https://groups.io/g/HP-Agilent-Keysight-equipment/topic/24809333#msg50411

I was also posting in this group since CLIPs are relevant to them and I didn’t know what to call it. Searches don’t turn up with sticky ink. Once again thanks for setting me straight Analog kid. RIP Dave. He would have experience on this.

[Analog Kid]

I’m gonna try this. How would a hair dryer sound?

Used carefully, should be just fine. Actually probably better than the oven, as you have air flow and can control the heat more precisely.

Try a "sacrificial" sheet first if you have one.

[amyk]

I think a hair dryer would definitely be sufficient to melt the toner, if a hot summer is what did it previously.

[Analog Kid]

^^^^^ It certainly could, which is why I said "used carefully".

[jpanhalt]

1) Long ago (1960's), Xerox and HP toner were said to be made from carbonized pollen.  I suspect today, it is plastic, but I haven't searched on what is used.
2) I am pessimistic about heat, but it's worth a try.
3) If it's a goo from aging of plastic toner, I would go to a non-aqueous solvent, including alcohols.   Some people have claimed to use white vinegar to remove the stickiness from old PVC coated wire shelving, e.g., ClosetMaid.  I had no luck with that, and water weakens paper.  Of course, solvents will make ink bleed, but that is not as serious with toner.  The older pollen-based toner was quite resistant to solvents.

Here are some solvents to consider:
a) VM&P Naphtha (light naphtha) -- weak solvent, similar to mineral spirits, but slightly stronger and evaporates much more quickly.
b) Diacetone alcohol (https://en.wikipedia.org/wiki/Diacetone_alcohol ) -- it's generally considered odorless
c) An aromatic hydrocarbon (toluene or xylene)
d) 91% or higher IPA or 95% ethanol  -- evaporate quickly and don't weaken paper; denatured alcohol in the US is mostly methanol and might be worth a try.
e) Acetone or MEK

Those are listed in approximate order of aggressiveness, except for the alcohols.  Because diacetone alcohol is virtually odorless, you will find it in many things.  It is used, for example, in dry erase/whiteboard markers.  For some reason, I have never seen it in consumer stores, like Home Depot.  It is/was available online and has unusual properties.  In my experience, it does not have much effect on older HP toner as used with LaserJet 4 and before.

[Analog Kid]

Here are some solvents to consider:
a) VM&P Naphtha (light naphtha) -- weak solvent, similar to mineral spirits, but slightly stronger and evaporates much more quickly.

Erm, maybe ...

c) An aromatic hydrocarbon (toluene or xylene)
e) Acetone or MEK

No. Definitely not! Those are guaranteed to dissolve the binder in the toner, which I'm pretty sure has been styrene (or a similar polymer) for quite some time now. That will create one gooey mess!

[John B]

What about just laminating them so you can then scan them without the ink sticking to the scanner bed?

[jpanhalt]

I agree that modern toner is more susceptible to solvents.  Up until the recent past  (2010) , I used an HP  LJ4  or MFP4101 laser printer to make transparencies for DIY PCB's.  I used to darken the raw transparence with dry erase, which has diacetone alcohol as its main solvent, and rub it off with Kleenex or toilet paper (images attached).  There was no smudging of the printed transparencies.   Those toners were resistant to diacetone alcohol.  That did not work so well with the Brother printer as its toner was softened by the solvent in the dry erase. 

Of course, any solvent would only be applied on the back of the page in the stuck areas, not scrubbed onto the printed side or soaked.  With my Brother printer today, xylene and MEK do attack the toner when rubbed on the printed side. MEK was more aggressive, as expected.

EDIT: Added image of untreated pad.

[jmelson]

Oh it’s bad…  attached is a schematic example that any HP CLIP offers. I’m trying a plastic spatula meant for caulking and putty from Home Depot. I hold the pages taut while trying to listen for more of a cracking sound than a tearing one. If it’s separate pages I have much better success as I can “attack with separating” at any orientation. Folds I have difficulty. I have to find my letter opener (it’s not sharp but it may be too blunt) for the tight spaces. If we’re going with heat, it’ll leave a print regardless but that maybe better than tears. If there are prints on both sides, the ink really is like glue… 

I have seen this when laser-printed or copier sheets are stored in plastic-covered 3-ring binders.  The plasticizer in the binder covers comes out and melts the toner.  it usually only affects the first and last 5 sheets or so, but often schematics are at the back of the manual.
Jon

[jpanhalt]

After more thought, if the printing is a polymer-based toner, then IPA  (on the back side) might rise to my #1 choice.  It is great at breaking adhesion, not only for hot melt snot, but it is also effective on rubber adhesives.  It doesn't dissolve those materials, it just wicks into the bond and breaks it.  It also doesn't affect paper much and is far more available than diacetone alcohol.

Edit: As for storing once opened, glassine or non-stick parchment paper might be considered.

[Analog Kid]

As for storing once opened, glassine or non-stick parchment paper might be considered.

How about waxed paper?

[jpanhalt]

Waxed paper will leave a residue of wax, which tends to make paper clear.  Parchment paper has been around for ages and is relatively non-stick -- which is why it is used.  I just discovered the non-stick version today at Walmart.   Less than $3 for a 15" x 40 ft roll.  I suspect that is a lot cheaper than glassine, which is a classical way to keep collectibles, like stamps, from sticking to each other.

[Analog Kid]

^^^^^ Sounds like just the thing then.
I can get parchment paper, which seems to be the right stuff to use here, at my local grocery store.

So OP, how's your work to preserve these documents going?

[CNe7532294]

OP, what schematics are we talking about?  It's likely that they've already been scanned by someone else.

85645A CLIP for sure.

Maybe another set for the 70000 and 8360 if all goes well. It came in a 90s mystery box. Completely mislabeled. So a mess.

Oh it’s bad…  attached is a schematic example that any HP CLIP offers. I’m trying a plastic spatula meant for caulking and putty from Home Depot. I hold the pages taut while trying to listen for more of a cracking sound than a tearing one. If it’s separate pages I have much better success as I can “attack with separating” at any orientation. Folds I have difficulty. I have to find my letter opener (it’s not sharp but it may be too blunt) for the tight spaces. If we’re going with heat, it’ll leave a print regardless but that maybe better than tears. If there are prints on both sides, the ink really is like glue… 

I have seen this when laser-printed or copier sheets are stored in plastic-covered 3-ring binders.  The plasticizer in the binder covers comes out and melts the toner.  it usually only affects the first and last 5 sheets or so, but often schematics are at the back of the manual.
Jon

You called it jmelson. The power supply was the worst of the bunch. 

^^^^^ Sounds like just the thing then.
I can get parchment paper, which seems to be the right stuff to use here, at my local grocery store.

So OP, how's your work to preserve these documents going?

Mixed results. Really good in the middle. Which is great cause that’s the RF and controller boards. The ones with the most pages and what I really care about. The others have a faded print in areas you ideally don’t want them in but can be digitally removed easily. As mentioned above, the PS section at the back was the worst. I might as well had been dealing with glue. Too much toner on toner adhesion. Tears everywhere. Luckily CuriousMarc did a reverse engineer of this already and I also can read it “in a way.” It’ll have to be digitally reconstructed. 

[CNe7532294]

Expanding to the method used.

1) Freeze them in ziplock as is overnight/morning with most of the air removed (not entirely a vacuum but with some air to avoid compression of papers and packs) and desiccant packs.
2) Rolled the papers like a newspaper in all orientations. Length, width, diagonally. ~80ish% of the papers came apart with ease and very little of the faded reverse prints appeared.
3) Spatula separation (plastic wall construction tool then a ruler that looks like a butter knife or pharmacist’s spatula; I have a letter opener but it’s too thick) if it didn’t come apart from just rolling them. Tried attacking from any angle I could. Completely works for separate pages but is much harder for foldouts. Thru the magnifying glass, there are fibers where toner met toner though.
4) Hair dryer for the ones that didn’t come apart in the above. Made sure they reached room temp first.
5) Finally more drastic measures, a tooth pick/BBQ stick and knife. Both used to try a push back rips back onto the paper. Tried all angles of attack like with the spatula.

Toner on toner and toner on plastic cover were the hardest to remove. The former especially.

[5U4GB]

Expanding to the method used.
[...]

From talking to an art conservator many years ago that sounds like what I very vaguely remember.  Which leads back to a comment for the OP, have you talked to an art conservator?  They do this sort of thing for a living...

[m k]

Toner is not done when the page is done.
Back in the day copier also added so much of it that you noticed when drawing over.

You can also try ironing pages, but that's pretty far from fault tolerant.
Means that even if paper is still fine the toner may be on a wrong side.
For double sides you obviously need some cooking aids.
Some kind of a round surface mini iron would be nice.

If memory serves printer films were 160 C heat tolerant.

Last resort is mechanical.
When bond is good enough you practically have two pages and one toner.
Hand scraping iron for windows is pretty sharp.
Curve scalpel blade is many times much more practical than straight one.