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Epoxy V Cyanoacrylate For Screw Eyes (Place Your Bets )

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Hi guys,Just fitting a load of screw eyes and bit epoxy left so decided wee experiment. I always use epoxy and always will. Several reasons, cleans better, fit my bibs at same time and i think stronger. This is not a test of straight pull because i know both would hold rediculous weights, just a test ot torque or what force required to loosen. I have left eyes 3mm short of fully in and removed excess glue to eliminate glues acting against round eye part. So just a simple test of torque strength. Test piece is even grained w.r.cedar,nice wide straight grain. All screws in same line between grains. 40mm screws, holes drilled so just too tight to push in and slightly short. Glues poked in holes and smeared on screws (my normal procedure ) enough in all so that excess came out . Now i know most leave excess around eye to stop rotation but i just wanted to know if there would be much difference in mechanical bond strength. I will leave 24 hrs and test by removing with torque driver and increasing torque till failure. I have done 3 of each. I think the epoxy will be stronger, but will it? Place your bets if interested (you better be ,this took 10 times longer to type than setup experiment and i just typed all this already and deleted it instead of posted it!) So no cheating and trying first ,lets have some predictions, just a bit of fun.20161126_224942-1-1.jpg20161126_224942-1-1.jpg20161126_224942-1-1.jpg

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Epoxy are called epoxies because they contain epoxide groups that either polymerize with other epoxide groups within the epoxide or polymerize and react with the hardner.

 

When super glue is discussed on this site, in regards to sealing balsa and line ties, everyone means the cyanoacrylate product that reacts with moisture to cure.  It is used generically to describe the product sort of like how many ask for a kleenex when they want a tissue.  Different beast than an epoxy and different reaction occurring.  Super Glue is also the company and they  also make epoxies but I believe they are all two part based.     

 

http://www.supergluecorp.com/?q=original-super-glue/super-glue

Edited by Travis
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I have a habit of just saying super glue as you stated Travis. I actually don't use that brand name. I went out and checked the bottle comment one more time and the bottle does not show to be an epoxy. However I do know I read it somewhere, just don't remember where. Also yes I read about its true name years ago when it first started showing up on the market. I know I've been around for awhile. So from now on I'll call the adhesive, CA glue ...until I find where I read that at. :)

That's what I get for commincating with chemist. Any ways since we got that out the way let's hear the results.

Dale

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Not yet dale, and c.a.glue it is from now on,I didn't even know super glue was a brand, just what we in u.k call any c.a glue! And good you are 1 of few with cajones to give your prediction, either that or nobody's interested, is a pretty pointless exercise i know, just a bit of fun after the chore of fitting lure hardware with some leftover epoxy. Will test later as epoxy used is slow cure. One other issue, I have no idea what in terms of actual lbs or kilos force the numbers on my driver equate to. So, as its not to serious an experiment should i just post the numbers on driver? Or test a few by hand/feel? I could but in vice ,put bar through eye and add weights. I would like to keep it simple though, what do you guy's think?

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If I understand Gliders' test, it's to see which glue resists unscrewing, not pull out.  If the threads on a screw eye are truly smooth, there is nothing for either glue to bond to mechanically, so they just coat the surrounding material, or form a pocket, to make stronger female threads in the bait.  That will make pull out harder, but not unscrewing.

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If I understand Gliders' test, it's to see which glue resists unscrewing, not pull out.  If the threads on a screw eye are truly smooth, there is nothing for either glue to bond to mechanically, so they just coat the surrounding material, or form a pocket, to make stronger female threads in the bait.  That will make pull out harder, but not unscrewing.

 

Yes he is testing the shear strength of the material (torque).  We know that epoxy wins in this department.  He also is testing (whether he realizes it or not) the failure type: either cohesive or adhesive.  Cohesive the glue itself fails and adhesive the glue/substrate (cedar in this case) fails.  

 

I gave my answer it is epoxy based on the data that already exists.  Guys honestly the information is at our fingertips.  The data is collected in controlled settings by independent researchers and companies using standardized testing.   These tests follow the same procedure and remove variables from the testing to clearly and precisely measure these properties.  Essentially if your test shows something else it isn't do to the glue or epoxy but another variable.  

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O.k guys, the result,but first i am going to say i don't believe my eyes, and i mean i literally don't believe my eyes, i think the test will have to be done again and i dont know if i want to destroy more screws. Anyway, done 1st c.a.glue with lowest torque setting - sheered the screw but could feel it taking lots of pressure 1st, done at very slow speed so as not to just crack seal. Done 1st epoxy next, unscrewed without damage but took reasonable pressure. Done 2nd c.a.glue by hand with pliers--took a lot of pressure and ruined screw. Done 2nd epoxy next,same method- took reasonable pressure but nothing like as much as c.a.glue, screw undamaged . I have left 1 of each untouched to test tomorrow in case epoxy not completely cured, but kept some of mix and seems pretty cured to me. So, I have to say I'm very surprised by this ,it is possible the epoxy is not cured. Maybe i should try another epoxy, but this is super strong industrial epoxy. Anyhow there it is for what it's worth.20161127_214616.jpg

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I haven't done testing but I have used epoxy to mount hardware for the last 15 years without a single screw eye pulling out or becoming loose. I think where this question matters most is in mounting lips, which undergo considerable strain and shock impacts. I can often remove a lip mounted with CA by simply torquing it to the siide forcefully, shearing the glue bond. So I'm a little suspicious of CA's shear strength. Plus, frankly I don't want an instant bond when mounting a lip. I want to be able to adjust it multiple times if needed to insure it's in there perfectly straight. All that said, I'm pretty sure either type of glue is "good enough" for most purposes.

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Likewise bobp, used to make rough and ready wood salmon lures,almost semi - disposable, 30years ago,and in recent years for other species. Never had one come out. Have seen a couple commercially made lures eyes loosen with fish thrashing in net. For reason's you mention, I use epoxy and fit hardware and lip at same time. Was just to see what happened after previous similar thread,and happened to be fitting screw eyes when it came to mind and had bit epoxy leftover. Left a couple in ,and added 2 more with e-tex ,test them later. Like I say,done on a whim, have to say though, i was surprised by strength of bond particularly cause it was cedar, i thought that would favour the epoxy over say a more dense wood such as beech say. Anyway ,was bit of fun and will report final test in 12 hrs. Regards, glider.

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Certain baits I make are used in rocky bottom rivers, boulders actually. The lips hold great even with the baits being trolled and banged up against them. I drill "support holes" or slots in the lip. The CA glues are not quite instant in this application. I have the first bait that I made using CA glues and its fine as far as the glue is concern. It has been retired just to display.

Some time's I wish I had more time. :) This is very seldom tho. To me each product has its purpose for each individual. For me it's speed due to my time that I have to build the baits. Once the glue prove to me that it's durable, it's what I needed. Example, I haven't truly worked on a hard bait in a good month. Been working on some wire baits.

Cedar has an oil in it, could be the problem. Being dry wood it should still have residue in the wood. The epoxy may not like it as well. As Travis stated, so many variables. I do know this...CA works great for me until my latex gloves get glued together. Lol

Later,

Dale

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