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From: pbromaghin on 20 Feb 2010 02:23 On Feb 19, 2:09 pm, zekfr...(a)zekfrivolous.com (GregS) wrote: > In article <41eb97d4-a2e4-4e00-9081-942bfb300...(a)f15g2000yqe.googlegroups..com>, pbromaghin <pbromag...(a)gmail.com> wrote: > > >On Feb 18, 5:28=A0pm, "edi...(a)netpath.net" <edi...(a)netpath.net> wrote: > >> Cutting bottom straps off camera bag today, I accidentally made a tiny > >> cut about 1/4" long in "second bottom" layer of bag. =A0Bag apparently > >> is polypropylene. > >> Any ideas on how to fix it - so it doesn't spread? > > >Try the handyman's secret weapon - duct tape. > > https://www.mightymendit.com/ R.I.P. Billy
From: Doug Jewell on 20 Feb 2010 03:19 Better Info wrote: > Polypropylene is one of the more difficult plastics to glue. The adhesive > for rubberized compounds (as in a bike-tire repair kit) will have no effect > on poly plastics. Not even super-glue will stick to poly plastics. That's > why the cap for super-glue tubes is made of poly. I've had good success bonding poly plastics with cyano-acrylate glues (eg superglue), by giving the materials to be bonded a wipe with xylene first, and then applying the CA glue just as the the last smear of xylene evaporates. -- What is the difference between a duck?
From: Better Info on 20 Feb 2010 06:12 On Sat, 20 Feb 2010 18:19:41 +1000, Doug Jewell <ask(a)and.maybe.ill.tell.you> wrote: >Better Info wrote: > >> Polypropylene is one of the more difficult plastics to glue. The adhesive >> for rubberized compounds (as in a bike-tire repair kit) will have no effect >> on poly plastics. Not even super-glue will stick to poly plastics. That's >> why the cap for super-glue tubes is made of poly. > >I've had good success bonding poly plastics with >cyano-acrylate glues (eg superglue), by giving the materials >to be bonded a wipe with xylene first, and then applying the >CA glue just as the the last smear of xylene evaporates. Thanks for the tip. It'll give a new use for my container of xylene. I hadn't thought of mixing/using solvents as a catalyst for unrelated adhesives+plastics before. I wonder if methyl ethyl ketone might be an even better intermediary, as that seems even more reactive to a wider variety of plastics than xylene. _____________________________________________________ My plastics and paints solvents-reaction list, from least reactive to most. Rated by experience only, from life-experience random fix-it projects: Kerosene : Dissolves waxes, to make a penetrable liquid lubricant. Another usage, draw a few lines of a candle-wax over a scratched CD/DVD then add a drop or two of kerosene, rub it all in and then buff with a soft dry cloth to fill up the smallest of scratches. Makes the CD/DVDs readable again. For quicker evaporation use Naphtha instead. Kerosene dissolves waxes much more slowly than naphtha. The same method can be used on scratched or scuffed-up reading/sun glasses, naphtha method preferred. White gasoline Isopropyl alcohol : Dissolves powdered rosin to make an easy to apply friction enhancer, great for small belt-drive systems that are slipping due to belt-fatigue or oils on the belt. I've had many a throw-away VCR in the past that was fixed instantly with a couple drops of this liquid-rosin on the one or two rubberized drive belts. It will also dissolve many ink and pigment vehicles more safely than any of the following solvents, but will require more elbow-grease. A slower but safer way of removing them. Naphtha : Dissolves/penetrates most gum and rubber compounds, the best label-adhesive and tape-adhesive remover which will not harm the underlying plastic. It is also the same combustible sold as Ronsonol, Zippo flint-lighter refill. You can buy it at 1/10th the price from a hardware store under the label of Naphtha. It also rejuvenates the paper-feed grip on printers where the feed rollers have hardened and glazed themselves too much, without harming the printer's plastic case. Pine Oil : I've only used it to "disappear" special-effects plastics in novelty items and special-effects projection systems. As its index of refraction perfectly matches most clear-sheet plastics when immersed in this compound. The sheet of plastic perfectly disappearing (visually, without harm to the plastic) but any dichroic or other surface-effect application on that plastic remains. Hmmm... I guess it's not technically a plastics-solvent then. Nonetheless it's a fun optical-experimenter's liquid. Orange Oil : Not much experience with this, but I know it will ruin some plastics, permanently. Toluene Methyl cellulose : ? I think it is called. It's the solvent used in the original "Magic-Markers", not Sharpies, an unmistakable aroma. A few centiliters beneath the felt nib rejuvenates any dried-out Magic-Marker. It is also the solvent used to produce the child's "Permanent Plastic-Bubbles" toy. I'm guessing the name of it, the bottle is back on my lab-shelves somewhere. If you've ever smelled a Magic-Marker you are knowledgeable of this liquid compound. DEET insect repellent [N,N-Diethyl-meta-toluamide], worth mentioning. : The most annoying of plastics solvents in the world; as it seems to melt most of the commonly used plastics for watch-bands and watch-faces, fishing-lures, plastic compass housings, sunglass lenses and frames, etc., etc. And you don't know about it until a day to a week later when your hard-plastic compass-case or sunglass frames are now a smeary black melted mess and the compass or sunglasses are totally ruined. Most annoying is if you get a DEET covered finger-print on your new plastic-lensed sunglasses and that's the only thing it managed to melt. There is no cure. These melted and smeary qualities of the DEET afflicted plastics never changing afterward, into perpetuity. Other than a way to get your body and clothes to be repellent to insects, DEET serves no other useful purpose in anyone's life anywhere on the planet. IMHO. :) Xylene : This and the following two will dissolve the most stubborn of silk-screened or baked-paint labels, use this and the next two with caution or you may destroy the plastic that a label is printed on. It can also be used to safely remove most cements used for glass-optics without harming the housing or the baked pigments on the metals. Is also used to un-cement permanently prepared microscope slides that have been fixed (made permanent) with Canada Balsam. Methyl ethyl ketone : Don't huff it you damn kids! You have enough brain-damage already. And ... GET OFF MY DAMN LAWN, you lousy kids! :) Acetone : Seems to dissolve, or ruin, most anything if applied long enough, will even un-cement cemented achromats if the achromat is immersed in acetone for an appreciable amount of time. This is the same solvent as in nail-polish remover and superglue (cyano-acrylate-glue) remover. Buy 4 oz. at the nailpolish counter for $5, or a quart of it for $2.50 at the hardware store. Though the last two seem interchangeable in reactiveness at times depending on the plastic or pigment vehicle. Most of them easily available and inexpensive from any hardware-store in the paints and solvents dept. There was one fantastic solvent that someone gave a pint of it to me once, it is used to bond plexiglas to plexiglas. Just place plexiglas parts edge to edge and flood the meeting surfaces with a drop or two; instant, permanent, water-tight bond; as if the parts were originally a solid unit. But the vapor-pressure of it is so high that it evaporated through the thin seal under the metal cap in less than 2 months. Before losing it all from the metal container to the atmosphere I managed to construct a full set of plexiglas shelves for all my chemical supplies. And even made a giant water-prism to place on a windowsill to project a wide and bright rainbow across the ceiling every morning. The plexiglas water-prism being 4x4x4x12 inches. I never did find out what that solvent is called. I imagine I can find out by surfing the net or calling any custom plexiglas design companies. It had already served its purpose so it's just a mild curiosity now. It was nonetheless an interesting plastics solvent I had not used nor known of before. It would be interesting to see a household and inventor's usage-list of commonly found solvents. There's my contribution. Bonus points for reading: What's the most reactive solvent in the world? And no, it's not sulphuric, nitric, phosphoric, nor hydrochloric acid. Nor is it lye, to cover the bases. (pun intentional) Hint: The astute might guess correctly.
From: John McWilliams on 20 Feb 2010 11:00 Better Info wrote: > On Sat, 20 Feb 2010 18:19:41 +1000, Doug Jewell > <ask(a)and.maybe.ill.tell.you> wrote: > >> Better Info wrote: >> >>> Polypropylene is one of the more difficult plastics to glue. The adhesive >>> for rubberized compounds (as in a bike-tire repair kit) will have no effect >>> on poly plastics. Not even super-glue will stick to poly plastics. That's >>> why the cap for super-glue tubes is made of poly. >> I've had good success bonding poly plastics with >> cyano-acrylate glues (eg superglue), by giving the materials >> to be bonded a wipe with xylene first, and then applying the >> CA glue just as the the last smear of xylene evaporates. > > Thanks for the tip. It'll give a new use for my container of xylene. I > hadn't thought of mixing/using solvents as a catalyst for unrelated > adhesives+plastics before. I wonder if methyl ethyl ketone might be an even > better intermediary, as that seems even more reactive to a wider variety of > plastics than xylene. << Snipped bits out >> Excellent compendium. My experience with orange oil is that it's a good solvent for removing sticker gums from bottles, or metal, but as you say, some plastics react. And that there are lots of things that are cheaper by a big margin at the hardware store vs. the drugstore, or depending on what it's called. Isn't toluene a major ingredient in a number of glues? And I too cannot recall the name of the solvent for plexi- used it 20 years ago, and it does do the job, especially if you've done a dry run to make sure the pieces fit together well.... -- john mcwilliams
From: Doug Jewell on 20 Feb 2010 15:28 Better Info wrote: <snip lots of useful stuff> > Bonus points for reading: What's the most reactive solvent in the world? > And no, it's not sulphuric, nitric, phosphoric, nor hydrochloric acid. Nor > is it lye, to cover the bases. (pun intentional) > > Hint: The astute might guess correctly. I would have to say Dihydrogen Monoxide by a long shot. Although it is useless on most plastics, and needs an additional reagent for most metals, it is a very effective solvent indeed. In many cases, even if it won't dissolve the substance directly, it can act as a carrier for other chemicals to dissolve a huge range of substances. Gotta be careful with it tho - it is a powerful inhibitor of lung function, and thousands die every year due to it's lung-inhibiting properties. There's also a great body of evidence that indicates it's vapours are a powerful greenhouse gas. Even so, I find it so useful that I keep copious quantities on hand at all times. -- What is the difference between a duck?
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