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dubbleyew eight
1st Dec 2013, 04:17
tearing my hair out here.
I have a sheet of perspex in the workshop.
either the australian heat or just age has set off the glue that tacks on the brown paper protective sheeting.

has anyone come up with a sure fire way of getting the brown paper free after the glue has gone off?

Loose rivets
1st Dec 2013, 05:10
You can now buy Goo Gone in sizable bottles. It has been nothing short if miraculous over the years. Never seen it harm plastic.

Don't come crying to me if yer perspex gets curly.

onetrack
1st Dec 2013, 07:44
dubbleyew - Try a heat gun set on moderate heat?

Remove the residual adhesive with White Spirit, neat Windex, or Pascoes "Oomph".

OFSO
1st Dec 2013, 08:42
Try red wine.

You drink the bottle, then get p*ssed off with trying to get the paper off the perspex, and throw it away.

Takan Inchovit
1st Dec 2013, 09:45
Put cheap masking tape over every square inch of the paper leaving at least an inch of overhang around the entire perimeter of the perspex, leave it for twelve months and then carefully try to peel it off. Let me know how you go.

Otherwise if time is a concern try low heat and start to roll it off, not too much as there is a sweet spot of temp that will work.

Fareastdriver
1st Dec 2013, 09:49
What are you trying to save? The perspex or the brown paper.

FullOppositeRudder
1st Dec 2013, 10:05
I've done a bit of work with perspex in recent weeks and had similar challenges. I was only working on small pieces - about 3" x 2", and a pristine finish was not essential.

I share your frustration. There was no sure fire way of winning on this one. I had a mixture of success with heat (out in the sun for half an hour at this time of the year). I also tried various solvents on hand - metho, white spirits and De-solve-it (http://www.ferret.com.au/c/RCR-International-229526/Citrus-Based-Multi-Purpose-Cleaning-Solvent-from-RCR-International-p13131). None of them were instantly effective but I'm an impatient sod. In the end I got the result I was after. One side was relatively easy - the other one not quite so. I found that using a cheap small box cutter blade in fully extended setting from Bunnings as a "shaver" worked quite well. Caution is needed so that you don't slice into you finger, or or even more critical part of the anatomy.

It seem that this gets more complicated as the perspex (or the paper adhesive combination) ages. It might be easier and quicker to get a new sheet if you have a large area to deal with.

Good luck
FOR

dubbleyew eight
1st Dec 2013, 10:05
HA HA HA HA HA HAHA HAAA
fareastdriver you take the cake :}:}:}


by way of explanation
the windscreen of a W8 Tailwind is $70 worth of perspex.
every time I replace a windscreen I make one of the holes too tight and in wiggling it on and trying to unjamb it I crack it.
so I have this rejected windscreen.
I need a tapping table for some threads but the tapping guide keeps on curling up. so thinks I chop up the reject windscreen and sandwich the drill and tapping guide between two sheets of perspex. that'll keep it both flat and readable.

all was going well until I tried to peel off the brown paper......

cattletruck
1st Dec 2013, 10:31
has anyone come up with a sure fire way of getting the brown paper free after the glue has gone off? Sandpaper :E.

I built a louvre window for the holiday house and used perspex rather than glass because the window is 15,000km away and I didn't know what the final dimensions would be ($50 worth of parts and probably $2000 worth of labour if my time wasn't free).

To drill accurate holes into the perspex, I placed the slat into its position then I used a wire and a cigarette lighter to heat the wire and push thin holes at the perfect spot. Then I would drill out the hole carefully using the wire hole as a guide and not getting any heat build up. It worked very well.

Ok, ok, have you tried hot water and a sponge as I would think the solvent used would be water based.

Lon More
1st Dec 2013, 10:35
the windscreen of a W8 Tailwind is $70 worth of perspex.
After buggering it up twice the cost of getting a prof to do it would start to look attractive.

Solid Rust Twotter
1st Dec 2013, 10:42
Can of bug spray. The solvent combined with the oily liquid usually gets it off in a few minutes. Need to wash your hands well afterwards though. Makes your sandwich taste pretty foul if you forget.

500N
1st Dec 2013, 10:46
" the tapping guide keeps on curling up."

Laminate it.

dubbleyew eight
1st Dec 2013, 11:04
500n thats why it curls up. it is already laminated.
it is the measuremax guide given away free by hafco.

lon more my boy you are so incredibly wrong. :E

I16
1st Dec 2013, 11:08
Brown paper only sticks to Perspex when it is pinched.

Blues&twos
1st Dec 2013, 11:39
Photocopy the old drilling guide and laminate the new one?

Or is the challenge of the brown paper now impossible to leave?!:ok:

G-CPTN
1st Dec 2013, 11:54
Have you tried applying hot water?

Or paraffin?

White spirit maybe . . .

Piper.Classique
1st Dec 2013, 13:06
WD 40 or Duck oil

OFSO
1st Dec 2013, 13:43
I remember reading many years ago of someone buying a kit of parts to build an aircraft and not getting round to peeling the protective paper off the perspex windscreen until six months after it arrived at his house.

And he discovered it didn't come off - at least, it wasn't removeable without damage to the perspex.

SawMan
1st Dec 2013, 13:58
Peel the paper before working with the perspex. If it doesn't peel, return it to your supplier as defective and keep at that until they send you a fresh piece with peel-able paper! This won't speed your project along but once they get tired enough dealing with you, they will know better than to try selling you old perspex again!

Back to reality, don't use the new perspex as a pattern- make a pattern with the holes in the right place with thin plywood or heavy cardboard. If you get a few holes or the shape wrong, glue more of the same over the mistake and try again. Once you get everything right, transfer the pattern to the perspex and it will be a perfect fit.

What the paper does after that is not my problem- perhaps it will remove itself at Vmax once installed?

onetrack
1st Dec 2013, 14:54
dubbleyew - You're not alone with your problem, you have plenty of friends. Google finds some interesting suggestions and stories ...

https://www.google.com.au/search?q=how+clean+sticky+paper+off+perspex&sourceid=ie7&rls=com.microsoft:en:IE-SearchBox&ie=&oe=&gfe_rd=cr&ei=m0qbUsmzDciN8Qe-0YDQCw

(Practical Machinist forum seems to be a reasonable source of advice)

The general consensus seems to be, to use ...

1. Eucalyptus oil

2. Heat gun with care (SWMBO's hair dryer will possibly do, but don't get caught using it!) :)

3. Spray with canola oil/cooking oil and cover overnight with Gladwrap (Saran wrap to our Nthn Hemisphere friends)

The most interesting response was from the CSIRO bloke who claimed AEROGARD is the best drilling and tapping lubricant for perspex! :ooh:

Perspex or Plexiglass cleaning help needed (http://modelsteam.myfreeforum.org/archive/perspex-or-plexiglass-cleaning-help-needed__o_t__t_44725.html)

G-CPTN
1st Dec 2013, 14:57
De-natured alcohol (methylated spirit) sounds good.

dubbleyew eight
1st Dec 2013, 15:48
I have tried many things and many of those suggested.
this stuff could be used in the repairs to fukishima since it steadfastly remains unaffected by anything I've tried.
if soaking it for a night in the wash trough hasn't done it then it is in the bin and scratch that idea.

fleigle
1st Dec 2013, 16:46
W8
To put things into perspective, the Co-pilots side window of the Hawker 125 my son was piloting a few weeks ago delaminated at altitude when the heating element fried itself....replacement cost was probably more than you have in your Tailwind.
Lets start a "What aira did you build" thread, mines a Fisher Classic
Cheers,
f:ok:

cockney steve
1st Dec 2013, 23:14
I have not googoo'd this so cannot vouch, but some 45 years ago, I made the Acrylic canopies for Premature Baby incubators.

Rohm and Hass were the manufacturers of "Oroglas" (Philadelphia, USA) which was the equivalent, rival product to ICI's "Perspex" Oroglas was softer and less brittle. There should be comprehensive tech. details available from the manufacturer....we only removed the paper where absolutely necessary....solvent-welded joints and hot-bend lines, until reaching final washing and silk-screening instructions and brand-name. Otherwise, the paper protected from scuffs and scratches.

really hot water should move it....ISTR the adhesive was Latex-based, you could tear off an inch-wide strip of peeled-up paper but the adhesive would stretch several inches before tearing....used to roll it into little "snot-balls" :O

PingDit
1st Dec 2013, 23:36
If all else fails, you could try putting an ammonia-soaked rag into a polly-bag/bin-bag liner with the offending Perspex, sealed/tied overnight. It takes dirt off oven parts very well but I can't vouch for the condition of the Perspex in the morning!

radeng
2nd Dec 2013, 00:25
My Perspex sheets ('surplus' from work!) has a blue transparent plastic coating. Just as much of a bas**rd to get of!

dubbleyew eight
2nd Dec 2013, 13:48
I have solved the problem.
all the things that should have worked didnt have any effect at all.
only things that would have destroyed the perspex....

recycling bin has it all.

that's another bit of junk cleared out from my workshop.

cockney steve
3rd Dec 2013, 19:43
recycling bin has it all. Unfortunately, Acrylic sheet is made by a catalytic reaction....the cunstituents are mixed and poured into the space between two glass sheets,sealed round the edges to form a giant "pouch". Once mixed,that's it....AFAIK, it doesen't recycle.

you can suften it to mould / bend / stretch / twist excessive heat causes it to blister on the surface and internally sufficient heat to melt it, destroys it. Methyl Methacrylate and Dichloromethane (Methylene Chloride) are solvents but alter it's characteristics and do not completely dissolve it.
we used to make a cement from the above two chemicals, plus a small vial of catalyst (forgotten what it was...Benzoyl Peroxide, possibly?)
had to throw it away after about 10 days and start again.

..Occasionally, we would strip the paper off, only to find a piece of swarf, dirt or a bug encased in the sheet. The rep for the company said wy should think of the poor beggars making the Bell helicopter bubbles, when they had a reject for an "Inclusion"

radeng
3rd Dec 2013, 20:45
Chloroform and Perspex shavings make a good cement for Perspex.

ExSp33db1rd
4th Dec 2013, 05:04
In the Good Old Days, when airport Customs used to stick a sort of mini-advertising label on ones' suitcase to indicate that one had 'passed', I was moaning to a colleague recently joined the airline from "abroad", about the tatty appearance of my suitcase compared to his, mine was covered with semi-torn, part removed labels, whereas his was almost pristine looking.

Peanut Butter, he said, smear it on and leave it overnight, then they'll come off easily. They did. Then of course you have to clean the Peanut Butter off your suitcase - guess you could always lick it off ?

Try it on your perspex, but don't put it on your bread - unless you're American, in which case it's almost mandatory.

Can't stand the stuff, but it does wonders for removing sticky labels off stuff.

Loose rivets
4th Dec 2013, 05:27
Academic now, but did you try GooGone? I have never, ever known it to fail - or mark stuff.

dubbleyew eight
4th Dec 2013, 05:50
not seen any googone locally.

the original project was a mould. one must realise that having a drill and tapping guide that curls does not detract from the mould quality.

all good workshops have a bin. ...for a reason.

John Hill
4th Dec 2013, 05:52
Cockroaches eat brown paper... maybe you can persuade some to camp out on your perspex until only the perspex is left!

Loose rivets
4th Dec 2013, 08:30
My cockroach is gone! Came back to Texas to find him missing. I'm bereft. He used to come onto my desk and waggle his antennae and generally be quite entertaining. Remarkable creatures. They don't work like we do you know . . . and not many people know that.

cockney steve
4th Dec 2013, 20:03
@ Radeng. sniffing the Methyl methacrylate monomer didn't do much...the Dichloromethane was "interesting" a bit like Cellulose thinner (mainly Acetone) is interesting, but can give you a headache....Chloroform is not the best idea in a factory and machinery environment....yes, it works, but it's durability , clarity, machining and polishing characteristics, not to mention age-discolouring and myriad stress-cracks, made it a non-starter.

In idle moments one found that wasps have an afinity to DuraGlit.

(a polish-soaked wadding used to clean polished metals,- also good for buffing scuffs out of acrylic)
catch your wasp (an upturned paper cup) slip a piece of acrylic across as a lid, drop in a piece of wadding....after a few moments , mr Wasp will chomp frantically on the wadding....if seperated in time, he staggers around in a (drunken?) stupour before keeling over and croaking.


ah, well, the job was a bit monotonous after one had mastered the various techniques


incidentally to DRILL Acrylic (inc. plastic car numberplates) without having a big ,ragged breakout on the back, grind a flat, vertical face in each cutting edge of the drill (normally, the re is a "lead" created by the spiral flute, this converts the normal "chisel" action to a scraping action.....clean breakthrough, no snatch, no distortion.