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cutting CA glue

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I just finished gluing in a cermanic insert in the end of one of my bottle stoppers and now see I got some CA glue on part of this insert. It is a high gloss black insert, and I have tried to buff out the spot to no avail. Is there some solvent that would cut through this glue spot?
 
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Acetone softens/dissolves CA. Many nail polish removers contain acetone. Methyl ethyl ketone is less volatile than acetone.

Other debonders may use nitromethane, which is not as volatile as acetone.

Goof-off also makes a superglue remover.

Apply with a swab, then, scrape off--the solvent will soften the stuck-on adhesive (if not dissolve), but you'll need to remove both solvent and dissolved glue. Paper bags (shopping bags) are a mild abrasive and also an absorbent for the superglue/solvent, and would be my choice of mild abrasive.

All these solvents are likely to also bleed into your finish and attack your finish (if any), so you may need to refinish the wood portion after you've removed the CA.

Usual caveats about protecting your lungs, internal organs, skin, eyes, etc., and about flammability of solvents.

Best,

Hy
 

john lucas

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I have never found a solvent that will remove CA from glasses. In fact I got a big drop on my Knife and tried everything in my shop and nothing cut it. I don't have Methylene Chloride but tried acetone, CA debonder (which sort of worked but not very much) alcohol, Naptha, lacquer thinner, mineral spirits, and gasolene.
 
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I have never found a solvent that will remove CA from glasses. In fact I got a big drop on my Knife and tried everything in my shop and nothing cut it. I don't have Methylene Chloride but tried acetone, CA debonder (which sort of worked but not very much) alcohol, Naptha, lacquer thinner, mineral spirits, and gasolene.
John,

If you're talking glasses as in eyeglasses--most likely, they are plastic lenses, and you cannot cleanly remove CA (because CA is also a plastic). If you're talking glasses, as in the container that is used to contain recreational beverages, I'm surprised that acetone (and some elbow grease) didn't remove the CA. I use a jam-or-jelly jar (glass with a metal screw-on lid) with acetone to remove CA glue from pen bushings.

Best,

Hy
 

john lucas

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Acetone didn't make a dent in it on the plastic lenses but it also hasn't worked on removing drops stuck on my knife. How long do you have to soak it. I was just wiping with a towel and acetone.
 
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Is it stuck on the blade or the handle? Because it dissolves slowly its more efficient to try to shear it off with a razor blade then clean the remainder with solvent. On the handle might be less luck if its bonded to the finish. You still might be able to carve the bump flat if you can get the razor flat to the surface so it doesnt dig in to the finish. Then you can polish it as best as you can.
 
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Acetone didn't make a dent in it on the plastic lenses but it also hasn't worked on removing drops stuck on my knife. How long do you have to soak it. I was just wiping with a towel and acetone.

I think someone replaced your acetone with H2O! Acetone on plastic lenses is a very risky move. If it were to happen to my glasses, I think I’d contact my optometrist for advice. Hate to ruin a $300 pair of lenses if they have a no-harm solution.

The acetone I have will remove dried CA over a couple of minutes. I often drop the nozzle and cap into a jar of it and after a few it comes right off.
 
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Acetone didn't make a dent in it on the plastic lenses but it also hasn't worked on removing drops stuck on my knife. How long do you have to soak it. I was just wiping with a towel and acetone.
John,

CA on eyeglasses (with plastic lenses) is pretty much toast for the glasses. They do have antireflective coatings (the glasses), but it's a very thin coating without a lot of strength. Eyeglasses are generally made using polycarbonate types of plastic, which is different than CA, but the chemistry is reasonably similar, and CA will bond very well to polycarbonate.

For the knife: Is the CA stuck on the blade, or handle? If handle, what type of handle material? If blade, easy. You really do want to soak the CA; acetone evaporates quickly, so I would soak a paper towel, wrap the blade in the paper towel, wrap aluminum foil around the whole thing, and let sit (and soak) for a good 20 minutes. This will soften the CA enough to scrape it off easily. If handle: Beware destroying the handle with acetone. Wood or horn would be fine with the acetone treatment, but any lubricants (if folding knife) or adhesive between tang and handle, or finish materials (lacquers, etc.) would be toast.

Again, take care against flammability, and also your lungs and other organs.

Hy
 

Bill Boehme

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By far, most eyeglass lenses are CR-39, an acrylic monomer developed by PPG. They have slightly greater optical clarity than polycarbonate under difficult high glare conditions. However, I prefer polycarbonate because of less chromatic aberration in peripheral viewing angles for higher magnification lenses. There is a new material called Trivex that offers some of the best features of CR-39 and polycarbonate including less chromatic aberration. I might "look into" Trivex lenses since my current glasses are pretty well beat up.

I don't know if it has anything to do with the Crizal coating that I had on my glasses, but some tiny CA specs eventually came loose ... or maybe it was because they were so dirty and greasy that nothing would stick.
 
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I believe (but this is speculation; my knowledge is for glass-based optics) that AR coatings, even with polymer lenses, are thin films of metal oxides. For glass-based optics, they are deposited by evaporation, which is a high temperature process. For plastic lenses, it is likely a chemical vapor deposition process. There have been many publications (but I don't think anything commercial) about nanostructured antireflective coatings (AR) that do not depend on metal oxides.

If you believe Wikipedia, CR39 is "allyl diglycol carbonate" and not acrylic monomer. Based on the wikipedia article, the polymer chain of CR39 is a carbonate-based polymer, although the structure of the repeating units are straight chain (well, allyl) hydrocarbon rather than aromatic hydrocarbon. Both plastics (CR39 and polycarbonates) have naturally high absorption in the UV range, unlike acrylic resins ("plexiglas", "lucite", etc.). This actually leads to an interesting question: Do CA finishes protect the pen (or other similar item) from UV damage? Acrylic ("plexiglas") does transmit UV better than polycarbonates ("lexan" and similar)

Sorry to geek-out. I've been reading technical proposals at work, and need to write a number of recommendations on these proposals (which are (i) putting me to sleep, and (ii) interfering with my turning wood) by Thurs. 12/21.

Hy
 

Bill Boehme

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I have a CA finish on a box elder vase that is several years old and the red is still about as red as it has ever been despite what all the naysayers say: "Nay". Does my one instance of using CA on FBE mean anything? Who knows. I haven't tried sitting it out in the summer sun ... and don't plan to.

Here are some things straight from PPG:
  • http://www.ppgoptical.com/Optical-Materials/CR-39-monomer.aspx -- it says that CR-39 has lower CA than polycarbonate (the other CA, chromatic aberration), however, there are some caveats. Lower index of refraction means much thicker lenses at higher magnification so off axis vision can have greater CA under certain conditions. This is one of the trade-offs when deciding which material to use.
  • https://www.google.com/url?sa=t&rct...006/CR39.pdf&usg=AOvVaw1-8BigF56ai7vp3x3TUHkR -- properties of CR-39. There are numerous differences in optical properties of CR-39 and polycarbonate. The process for producing lenses also differs considerably. CR-39 uses a cast process while polycarbonate is heated and then injection molded under high pressure.
 

john lucas

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Bill I have been doing a different type of test on my Box Elder. My first tests were extreme. Cover the BE with whatever UV finish I could find and then then put it outside in direct sun. None of the finishes stopped the color change and almost all read was gone in 2 days of summer sun. This new test is I cut 2 pieces. I layed them both on my tool cabinet. It gets almost no direct sun other than very late in the evening. One I never flip so it doesn't get any sun at all. The other one I filp each day (they are just small triangles). I started this in august and so far I don't notice any change at all. This will obviously be a long term test but is would be closer to having a piece sitting on the shelf in your house. Oh and there isn't any finish on either one.
I've had several optometrist try to remove the CA from my glasses over the years. My guess is they don't try very hard because they want to sell you another $300 pair of glasses. As for the knife, well I just carefully slid a razor blade under it. I was trying not to scratch the knife blade but then again it's the knife I use every day and kind of like your new car. You are really really careful with it until you get the first ding, then who cares.
As a photographer I am familiar with lens coatings. The newer coatings are incredibly durable on camera lenses. My boss who smoked used to put his cigarette out on the front of a lens just to show customers how tough it is. Not so with eye glasses. I quit using the AR coatings on my lenses because they scratched easier and my $300 lenses were toast in nothing flat. Today I'm going to order a pair from Zenni optical online. $68 vs $288. We will see if they are any good but at that price it's worth a try. I'm hard on glasses.
 
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