O.T. Adhesives

[bborr01]

I don't recall seeing any threads about UV curing adhesives so I thought I'd start one. I've seen this stuff used in the dentists office and a couple of other places so I ordered a three bottle kit and a separate UV light and combined they cost me a little under $20 off of Amazon. The three different bottles of glue are different viscosities from what I've read and they seem quite strong. I glued the frames on a cheap pair of reading glasses and even though it was a place that was prone to cracking it is still holding a couple of weeks later.

And I also ran across some Youtube videos of using super glue and baking soda to form parts.

There is always something new under the sun.

[boslab]

I do like UV cure, it’s cool ( it’s not cool during curing, it gets hot, very hot. At least the one I bought does)
they use UV cure laquer on can lines to coat the inside of food tins.
most glass glues are UV cure.
I don’t know much about the wavelength of the cure lamp, I’ve seen some quite good looking ones on eBay but haven’t tried the dental one on ordinary glue.
perhaps someone with more knowledge can enlighten us please?
I was told some ordinary glues do in fact UV cure,
mark

[darryl]

I made an extension cord today, and rather than use the existing clamp pieces, I tossed those and used microcord to put about 10 wraps through the screw slots- then ran CA into it, followed by a dusting of bicarb. It holds the wire perfectly, and the resulting 'knob' of cord/ca/baking soda makes a great finger grip or pull. There was considerable heat, and for a while too. But that did mean that the CA was curing, and to what extent. I guess you'd have to know this type of plug- the big yellow one with the clumsy protruding clamp pieces that catch on everything. The plugs are solid, but those clamps gotta go-

The urethane glues are pretty solid too, maybe more so by having a slight amount of give-

Anyway, it's tedious to wrap the cord several times through the slots, could be a drawback if you don't have the dexterity to do it- the end result makes a perfect strain relief.

You could do spot welding with the UV cure, and you could essentially 'sew' a bead along a chosen line. I wonder how quickly you can cure a single spot- hmm hopefully quickly enough that you can move along while you're fabricating.

I like the urethanes for the range of durometers they are available in. Is there a really soft one that can be uv cured?

[JRouche]

I like adhesives.

I had a crown, my tooth break two weeks ago. The temporary crown they used the UV lamp to cure the adhesive. It is very secure. Till its not. It is a brittle type adhesive, like super glue. I dont use that crap for anything. JR

[Ian B]

Superglue and baking soda; I saw that once before. Allan Millyard (the bike engine splicer) glues strips of Abrabelt - a sort of abrasive mesh - into loops with it, makes mini sanding belts. He uses superglue and baking soda, seems to work.

Is there something about the chemistry of baking soda, or would any fine powder do the same? I'm thinking the likes of epoxy filler.

Ian

[alanganes]

Superglue and baking soda; I saw that once before. Allan Millyard (the bike engine splicer) glues strips of Abrabelt - a sort of abrasive mesh - into loops with it, makes mini sanding belts. He uses superglue and baking soda, seems to work.

Is there something about the chemistry of baking soda, or would any fine powder do the same? I'm thinking the likes of epoxy filler.

Ian

If I recall correctly, the CA adhesive cures by absorbing moisture from the surfaces that you are gluing together. I think the baking soda provides some moisture to activate the cure and also absorbs and bulks up the glue. I'm sure someone here more knowledgeable will correct or expand on that. No idea if epoxy filler would behave the same way.

[CarlByrns]

Superglue and baking soda; I saw that once before. Allan Millyard (the bike engine splicer) glues strips of Abrabelt - a sort of abrasive mesh - into loops with it, makes mini sanding belts. He uses superglue and baking soda, seems to work.

Is there something about the chemistry of baking soda, or would any fine powder do the same? I'm thinking the likes of epoxy filler.

Ian

Model airplane builders use baking soda as a filler bc it's cheap and works as well as micro balloons.

[ikdor]

I like the UV cure ones too but they're not very common. Some cure hard and others soft. Some types remain sticky which I dislike with a vengeance.
Don't inhales the CA baking soda fumes, if I recall it's cyanide gas.

[Bob Engelhardt]

If I recall correctly, the CA adhesive cures by absorbing moisture from the surfaces that you are gluing together. I think the baking soda provides some moisture to activate the cure and also absorbs and bulks up the glue. [...]

I'd say that you're right about the moisture. Baking soda is used for the Oogoo, home made version if Sugru. The silicone in that is also moisture cured and depends upon the soda for it.

[MichaelP]

Dental UV cured adhesives do not work as the glues we use. The "regular" ones are designed to work with very particular human tissues. There are some primers and very specific adhesives that help adhere other materials to metals, etc., but, again, they don't work the way you can expect.

UV cured resins/composites (vs.adhesives) can find a use in a shop. I can envision a few very specific shop tasks where certain adhesives could be used with combination with resins/composites, but it wouldn't be something the majority of us will ever encounter.

So look into industrial UV cured glues rather than dental adhesives.

[lynnl]

If I recall correctly, the CA adhesive cures by absorbing moisture from the surfaces that you are gluing together. I think the baking soda provides some moisture to activate the cure and also absorbs and bulks up the glue. I'm sure someone here more knowledgeable will correct or expand on that. No idea if epoxy filler would behave the same way.

That may be right. I don't claim to know otherwise. But you may be confusing CA with the urethane adhesives like Gorilla Glue which do specify dampening the surfaces before applying the glue. Whereas CA seems to work fine on perfectly dry*, non-porous surfaces.

* - at least no sensible moisture.

[alanganes]

That may be right. I don't claim to know otherwise. But you may be confusing CA with the urethane adhesives like Gorilla Glue which do specify dampening the surfaces before applying the glue. Whereas CA seems to work fine on perfectly dry*, non-porous surfaces.

* - at least no sensible moisture.

Lynn, you got me curious about whether or not I was recalling that correctly so I consulted the oracle and found this:

"The most common monomer is ethyl cyanoacrylate. Several related esters are known. To facilitate easy handling, a cyanoacrylate monomer is frequently formulated with an ingredient such as fumed silica to make it more viscous or gel-like. More recently, formulations are available with additives to increase shear strength, creating a more impact resistant bond. Such additives may include rubber, as in Loctite's "Ultra Gel", or others which are not specified.

In general, the C=C groups rapidly undergo chain-growth polymerisation in the presence of water (specifically hydroxide ions), forming long, strong chains, joining the bonded surfaces together. Because the presence of moisture causes the glue to set, exposure to normal levels of humidity in the air causes a thin skin to start to form within seconds, which very greatly slows the reaction; hence, cyanoacrylates are applied as thin coats to ensure that the reaction proceeds rapidly for bonding. Cyanoacrylate adhesives have a short shelf life—about one year from manufacture if unopened, and one month once opened."


That was clipped from a Wikipedia article HERE but here are lots of other references about. I guess even the minute amounts of moisture that are found on most surfaces are enough to do the job.

[lynnl]

I guess you were right. Sounds like just the moisture in the air is sufficient for bonding even what we would normally describe as totally dry surfaces.

[bborr01]

Dental UV cured adhesives do not work as the glues we use. The "regular" ones are designed to work with very particular human tissues. There are some primers and very specific adhesives that help adhere other materials to metals, etc., but, again, they don't work the way you can expect.

UV cured resins/composites (vs.adhesives) can find a use in a shop. I can envision a few very specific shop tasks where certain adhesives could be used with combination with resins/composites, but it wouldn't be something the majority of us will ever encounter.

So look into industrial UV cured glues rather than dental adhesives.

I'm not using dental adhesives. The reason that I mentioned dental UV adhesives is because that is where I usually see them used.