john hamilton wrote:

The hinges on our Fujitsu laptop screen appear to be 'all' plastic and they
get very 'difficult to move' making the screen difficult to fold up and
down.

We have have tried 'WD-40', but that seems effective for only a very short
time.

We are afraid to use ordinary oil as we thought it might effect the plastic.
We were thinking of using olive oil, but somebody has told us that olive oil
'degrades' and goes sticky, over time.

We have got some Camellia oil that was given to us, and it's made from
Camellias and it comes from Japan and is suppose not to 'degrade'. Still
it's an unknown quantity to us.

Does anyone know what would be a suitable and safe lubricant in this case?
Since we dont want to cause any problems with the plastic on this lap top.
Grateful for any suggestions, thanks.

Note: Following unrelated newsgroups removed from my reply:
misc.consumers.frugal-living
uk.d-i-y


WD-40
http://en.wikipedia.org/wiki/WD-40

FAQ page
http://www.wd40.com/faqs/#q8

I sincerely doubt that your laptop's plastic casing has been damaged as
others have insinuated. Because of low viscosity, WD-40 will drip away
and also evaporate away (due to the aromatic compounds) leaving behind
something akin to a shellac coating hence its claimed rust protection
due to the residue. As a lubricant, WD-40 works at first but then its
lubing effect wanes. While WD-40 is good at penetration and
displacement, it is only useful for temporary lubrication. The residue
left behind for rust prevention is not useful for friction reduction.
It is a "light" lubricant that also will remove existing lubricants.
For example, don't use it on your bicycle chain as the result will be
washing away the existing oil, it doesn't have enough viscosity to stay
in place, and you get metal-to-metal erosion.

Instead of WD-40, use a squeeze-tube applicator with needle (aka, a
"pen") for 3-In-One oil (also made by WD-40 company; see
http://www.3inone.com/faqs/), the multi-purpose blend. It won't wash
away existing lubricant and doesn't evaporate away over time to leave
behind a higher friction residue as does WD-40. See
http://www.wd40company.com/partners/msds/usa/ for the MSDS sheets.
Notice 3-in-one has nil volatiles while WD-40 has 74%. What you spray
on for immediate effect with WD-40 then evaporates away. The residue
left behind by WD-40 for rust protection is not what you want for lower
friction.

You could use silicone lube (but not now after you've already used
WD-40). While silicone grease is great (but requires applying to the
mating surfaces which means dismantling the hinges in your laptops),
silicone spray lube will have less than spectacular results. Works
great when applied but the hinge starts squeaking a week later (and
which wasn't squeaking before). If it has hexane, that damages some
plastics, like polypropylene. Check the ingredients as it is the other
"stuff" that might determine if you use that silicone lube product or
not. If you have to use a spray, put a paper towel behind to catch the
overspray, or oversoak an ear swab with the spray and use the swab on
the hinge. Silicone polymers will swell if exposed to hydrophobic
solvents (e.g., WD-40). Don't mix them. Unless you are going to
dismantle the laptop AND the hinge to thoroughly clean inside the hinge,
and since you already used WD-40, don't use a silicon spray. The
wetting agents in the silicon spray won't be sufficient to penetrate
into a constructed hinge to clean out the WD-40 still left inside.