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View Full Version : Why doesn't superglue work?



Kahoolin
08-26-2009, 04:00 AM
OK, I've been building models for over 20 years now and I have never been able to get superglue to actually make any sort of strong bond. I've tried all different varieties, tried putting heaps on, tried putting a tiny amount on, and everything in between. I'm currently using Gale Force 9 hobby glue which comes highly recommended, and still today this happened:

I have some Cadians that I've glued West Wind metal heads on. I carefully filed the heads and Cadian neck holes to make sure they fit, carefully glued them on, waited a week, and then yesterday when I was basing I dropped two of them from seriously about two centimetres (an inch for Amricans) onto a cardboard box and both their heads fell off. I have NEVER been able to get a good bond between plastic and metal, or even between metal and metal.

Am I doing something wrong, or is superglue just not as good as I think it should be? How the **** can I play a game when every time someone falls over their freakin head falls off? :mad:

Anyone got any tips?

Valdore
08-26-2009, 04:38 AM
Hmmm, I know what you mean, I don't know whether it help, but when doing a joint between plastic and metal I tend to put a bit of superglue as well as a little plastic glue on. Don't know whether it helps or not, but other than that your only option is pinning really to strengthen the bond or magnets, but then you have to get the magnets to glue in place.

vman
08-26-2009, 05:17 AM
Kahoolin try selleys quick dry gel from bunnings
takes ages to dry but when it does its strong

u can also try some setting agents and other superglue related products that aid in use of the glue

in general superglue does my head in a bit, but you need to find a good one

Theres alot of rubbish superglues out there

Kahoolin
08-26-2009, 05:49 AM
Kahoolin try selleys quick dry gel from bunnings
takes ages to dry but when it does its strongThanks mate :) I love how it's called "quick dry gel" and you say it takes ages to dry!

Rafen
08-26-2009, 05:52 AM
When im working with plastic and metal. I like to pin the model between the plastic and metal and then use superglue and it holds like a charm :) of course it depends on what you are pinning, but in this situation it would work wonders. Also don't put super glue on top of another layer of super glue the bond will not hold and will break and just gunk up the joint. This can be resolve by filing the old superglue out.

TSINI
08-26-2009, 06:03 AM
the problem with superglue is it requires surface area to attach, its not a thick glue, even when you glob it on, most of it evaporates and its only the areas of metal and plastic that are touching that get glued.

i too have glued west wind production heads onto cadians for my conscripts (so theres a lot of them) [it looks well cool don't it :D]

i use some serious industrial adhesive, it works just like superglue, but its much much much stronger and dries in about a second BUT even i have had difficulty. because of the small surface area,

the other day while giving my conscripts a badab black wash, one head fell off. lol.

its also difficult because the metal head makes the model quite top heavy, so when they fall over, they really hit the ground with their heads first.

my suggestions would be some of the following:

spend longer shaping the bottom of the heads to match the neck of the cadian body
put enough glue to fill the neck of the cadian body, and hold the head still with some pressure until it grabs (this is what ive done, and for the majority its holding)
if you're careful, maybe use a blob of epoxy resin instead, its thicker so would grab better



also one big problem with superglue which i didnt know until a little while ago is that superglue goes off if it is left in warm rooms for lengths of time, its best to store it in the fridge

hope this helps.

Schnitzel
08-26-2009, 06:24 AM
I'm in the same boat as you. Darn stuff never wants to work for me. Often results in me saying screw it and busting out my green stuff.
Speaking of which... I'm starting to run terribly low. :eek:

ThePov
08-26-2009, 07:20 AM
I'm in the same boat as you. Darn stuff never wants to work for me. Often results in me saying screw it and busting out my green stuff.
Speaking of which... I'm starting to run terribly low. :eek:
Agreed. I've only gotten superglue to work ONCE for me, and don't ask me how I did it, I don't know. Most of the time, I just put a thin layer of greenstuff on the part of the metal model where the glue would go and stick it on. When the greenstuff fails to hole (which it most likely will) you can then use plastic glue on the green stuff, and it stays like a charm.

BDub
08-26-2009, 07:51 AM
Well for me superglue works great, but you have to respect its limitations. Some things that might help are; first, use a thicker variety and not cheap stuff either. Get yourself some maxi-cure or similar. Don't use too much! In fact use just a little on each (clean, not greasy) surface (very important). Put the pieces together and then pull them apart - they will both start getting tacky. Put them back together (and here's the trick) spritz the joint with an ever so slight amount of super glue accelerator (yeah, get some of that too). That will make as good a bond as superglue will allow.

Now for the specifics of your situation. You should pin those heads! Superglue will break very easily with dissimilar material bonds. The plastic and the metal do not react the same way to impact and that will crack your bond easily. Secondly, don't file the joint surfaces so smooth - make them level but leave them scored or scratched up. This will give the glue something to grip. This is a good idea with most things like plastic arms on IG guys. Scratch it up slightly but not deeply at all.

I hope this helps.

Aldramelech
08-26-2009, 08:33 AM
Yep, sound advice.

Most people just don't understand how glue's work, and thats half the problem. Plastic glue "melts" the plastic together and this is why you get such a strong bond. Super glue doesn't work like that, it needs a good surface area to grip. Even when dry it is very brittle and breaks easily. It is super important that the areas being stuck are Clean! lots of people overlook this. I use it for metal on metal and don't have many problems. For metal to plastic I tend to use Green Stuff or Miliput.

VinceBlack
08-26-2009, 08:52 AM
Get yourself some zip-kicker accelerant. This stuff makes super-glue dry instantly and with a stronger bond. Is great for those pewter models that never want to glue. its cheap and easy to use, just don't spill it on plastic because it will eat the plastic, but a little doesn't hurt.

I never model without it anymore

BuFFo
08-26-2009, 09:21 AM
I use a super glue called Zap A Gap and it works perfectly for metal to metal and metal to plastic bonds.

Culven
08-26-2009, 09:32 AM
I think the main points have been covered, but I may resates some as I relate my experience.

As said, plastic "glue" isn't really a glue. It is a solvent that allows polystyrene to bond with polystyrene. This means it is basically wleded together. Hence the stronger bond.

Super glue is an adhesive that tries to hold the parts together. This also means that the surfaces being attached have a great deal of impact on the final bond.

- Both surfaces need to be clean of grease, mold release (which is on all metal and plastic parts), and grit (dirt, dust, filings, etc.). This is why it is important to wash the parts before assembly.
- Surface area will affect the bond. The greater the area that is being held, the stronger the bond. This usually comes into effect when using a thin superglue on improperly fitting parts. The solutions are: (1) use a thicker superglue (GW, GF9, and Zap-a-Gap are all medium thickness superglues that will help fill small gaps) and (2) make sure the pieces fit as well as possible.
- Surface texture affects the adhesion of the superglue. Smooth surfaces (such as a cast surface of a plastic part) aren't great for attaching with superglue. Typically, filing/sanding will provide enough texture for better adhesion. Another trick is to score the surfaces so that there is some texture for the superglue to hold.
- Anticipate the stresses on the model. Superglue is a strong, but rather brittle material. Too much stress on the join will typically cause the glue to shatter and the part to fall off. This is where pinning comes in. If a part will be subject to stresses (typically if the bit sticks out from the model and will be used to pick it up or the model will land on it when it falls over), it really should be pinned.
- Treat the models well. I have heard complaints about superglue not holding from some players who proceeded to put the models in a box where it was knocking around with other heavy models. Superglue simply cannot hold with this kind of abuse.

Dave38x
08-26-2009, 09:42 AM
Never had an issue, always made sure joints are flat and clean. If that didnt work i just use a bit of Greenstuff as well :)

AnthG
08-26-2009, 11:41 AM
First - wash your hands with soap. Why? get the natural grease off of them. Also make sure the parts to be bonded are clean - surgical clean is best!
Second - accept that this stuff needs time to cure or set and will naturally shear or break unless it is pinned.

Prepare the surfaces of the materials to be bonded - make sure the metal part is shiny and has a level of abrasion on it: i.e. sand it, file it. You are looking for microscopic score marks here to act as a key for the glue to settle into. Then clean it. Do the same with the plastic piece. Make sure the dust from filling is really gone.

This is great for the small stuff i.e. where a 1mm drill bit will destroy either or both parts. Beyond that - pinning is your best friend.

Same rules apply for the bigger stuff. It really does matter how much you splodge on - the more you put on the less chance of a bond. The products work best with the thinest contact points. So pin with a quality liquid and then if necessary back fill with greenstuff or the thicker gels. Glue the pin into the larger piece first.

For both methods I find a little blu tak to support the pieces being bonded can help the process. Test fit all the joints, then prepare the blu tak - make sure it can support the weight of the piece you are attaching. Apply the glue followed by the blu tak, then leave it for several minutes! Do not expect it to have worked in seconds!

And for those who would like a little more detail about this magical product and to discover the use of baking powder for gap filling - look here: http://en.wikipedia.org/wiki/Cyanoacrylate. :)

mchawkeye
08-26-2009, 02:55 PM
Superglue is great. What has been said before is absolutely true. the glue, by it's nature goes brittle when cured, consequently any knocks or jars will snap the bond. also, the bond will deteriorate if it is a good few yeas old or left in the sun as it is effected by UV.
So Pin. always Pin.
If you use thick SG and can;t be arsed waiting for it to go off, find some activator- or kicker- and use a small amount on the join. The glue will harden instantly. Don't apply kicker to to much glue at once, though. The reaction can be...energetic.

Or, use epoxy.

oni
08-26-2009, 03:13 PM
It's very rare that I use super glue. Mainly only when I have two painted bitz that need joined. Plastic glue needs bare plastic to work. When it comes to metal on metal or plastic on metal I'll use straight green stuff to make the bond. It's worked well thus far.

Kahoolin
08-26-2009, 03:35 PM
Thanks for all the replies guys. I guess the answer to my question is that super glue is not as good as I think it should be!

It's a bit strange that we can send unmanned craft to explore other planets, yet we haven't invented a chemical that will reliably hold a tiny bit of plastic to a tiny bit of metal without pinning it. I've tried the sanding thing, I waited a week for it to dry, I'm not going to pin sixty heads, so I'm just going to greenstuff the buggers. I've done that before and it's worked, so superglue is now officially out of my toolkit. If it's not going to do the job then it's fired :D

EmperorEternalXIX
08-26-2009, 04:22 PM
Your best bet is this stuff: http://home-and-garden.become.com/krazy-glue-advanced-formula

It's Krazy Glue Advanced Formula Gel, and comes in a little all-green tube.

Testimony to it's greatness: Once I was gluing a model, and I put his arm on in a position I didn't like. It hadn't even been more than 20 seconds when I decided, "Screw it, I'll just break it off and reglue it." With ALL MY STRENGTH AS A GROWN MAN, I couldn't do it.

That isn't to say its indestructible or dries fast, but it's pretty amazing as far as it's durability goes. I once threw a model against the wall to demonstrate!

Just be warned: This stuff will glue your fingers together INSTANTLY and you will hurt yourself pulling it apart. And it will also instantly glue any modeling pieces to your fingers just as easily.

Kahoolin
08-26-2009, 04:51 PM
Once I was gluing a model, and I put his arm on in a position I didn't like. It hadn't even been more than 20 seconds when I decided, "Screw it, I'll just break it off and reglue it." With ALL MY STRENGTH AS A GROWN MAN, I couldn't do it.Now THAT'S what I'm talking about. Thanks for the link.

Rafen
08-27-2009, 10:41 PM
Your best bet is this stuff: http://home-and-garden.become.com/krazy-glue-advanced-formula

Just be warned: This stuff will glue your fingers together INSTANTLY and you will hurt yourself pulling it apart. And it will also instantly glue any modeling pieces to your fingers just as easily.

It would hurt because superglue was originally made as something to suture the skin on the field hence it sticking so well to skin. :) Just a fun fact throw-in out there.

j-orge-287
08-28-2009, 03:47 AM
Superglue is ironically worse than plastic glue. It does work if you leave it alone for about 24hrs. The only problem is holding the pieces together. I haven't tried to use a pin but that works in theory. Recently I used blobs of blu-tac to hold the bits place, the problem is you leave bits stuck to the model where there is excess glue use a knife or similar to take the blu-tac off, some will stick but when you spray the model it should be alright.