What debonds super glue besides debonder?

GMorrison

OK but MEK is really bad for you so don't breath it.

Yes, but only in California.

Eric

I understand normal CA is not waterproof, and keeping the joint moist will weaken it (there are, apparently, waterproof CAs but the normal ones are not).  Also, as noted above, they are not shock nor cold resistant.  But I find a bottle of CA debonder is not outrageously expensive and a bottle has lasted me a long time.

Ain't  that the truth.  When my wife was a crew chief in 130s she came home a bit high after they were using MEK on the inside of the cargo bay.  She didn't remember anything about driving home but woke up the next morning on her bed still in her fatigues.

OK but MEK is really bad for you so don't breath it.

Isn't it nice to have all this information now?

I remember when superglue first hit the market.  It wasn't a year before we got a report from a civilian police department that it had been used in a bank robbery.  The crooks glued everyone's hands to walls and counters and then robbed the place.  At that time they didn't know how to neutralize the stuff so they had to find another way to free the people.  

That had to hurt. I hope they used medical personnel.

Guys ( & gals?)

I accidentially found out that MEK (aka the solvent they use in plastics shops as glue) is a great debonder. CA, epoxies, JB-Weld, you name it.

I was using it on a home-made version of a Touch'n'Flow, and my CA'd tool fell apart. Epoxied it together, and it came apart again while sitting in the bottle. Its why they use dental alginate to hold the things together.

Plus MEK is cheaper than the solvent-glues on the market (Tenax-R, the Weldbond one, and others) as you can get a quart for about $12.

Try it. I did, and I don't use tube'd styrene glues any more.

Notes on the Touch-n-Flowe tool

 I use an improvised suction-bulb to load my Touch'n'Flow (Never suck on it!) Its the drip chamber from an IV tubing set. Pop it on the end of the pipette, put finger over the top hole, squeeze the chamber, and ~gently~ release it, but watch the level of solvent in the tool rise to avoid over-filling and loading the bulb.

 I also use an improvised bore-cleaner for the tool, just in case I do get the tip clogged with styrene: 0.20 mm guitar string!  You get 36" for about a buck in any music store. Saves yourself $8 or more replacing the tool just because you clogged it.

I can attest to the freezing method.  Last winter I left a finished model in an unheated car for about 4 hours., intending to drop it off for display at the LHS on the way home.  When I took it out, several of the PE detail parts I had added using CA as the adhesive had popped off, including some delicate dropped flaps that I had labored to get just right .  The difference in thermal expansion between the PE & styrene was enough to debond the CA.

Regards,  Rick 

ben1227 wrote:

Thanks...So the special hobby-specific debonder is pretty much acetone? And I read somewhere that moisture speeds up the bonding process of CA glues, so CA accelerator must be mainly water...And that's the reason it bonds to damp skin so quickly I guess...

From what I recall, it's the minute traces of water on surfaces being joined that initiate the polymerization process in CA adhesives.

I don't know that "commercial" CA accellerators are mostly water, but you learn pretty quick not to try to wash a CA spill off your hands with water. As soon as the water hits it, you get an instant hard shell for your fingers.

I only use CA for dis-similar materials, like PE and plastic. I use Tamiya Extra Thin liquid for seam, as it melts the plastic together. Properly applied and with a little touch up sanding, and you can't even tell there was a seam there.

I use the accelerator all the time with CA, but what I do is put a bit of CA where I want the piece glued, then dip the piece into some accelerator than touch them together. Instant bond! Great for those bits that seem to move with other glues.

I don't know about the debonder contents. Probably Acetone or something similar. I've known about the freezer trick for years, so that's how I done it in the past. CA has very good pull strength, but doesn't withstand much shearing force. It's hard to pry it off, but a tap sideways often pops it right off. Cold just accelerates the process.

And yes, moisture quickens the bond. As you've undoubtably discovered!

Some mountain climbers dip their fingertips into CA to form a protective shield against abrasion when rock climbing. Gloves lose too much sensation. 

Acetone. Safest form is nail polish remover.

CA will come off skin in a day or so due to the natural oils.

If you actually need to debond CA try putting it into the freezer for a couple of hours. CA is a fairly "weak" glue in that it has low shear strength and is subject to temperature variation.