What glues can I use to bond various materials?
Plastic to plastic:
Q: What glue should I use to glue plastic together?
A: That depends on the plastic being used. Lets start with the most common used in modeling, polystyrene.
Gluing polystyrene to polystyrene:
There are 2 ways to approach gluing styrene to styrene. One is to actually weld the parts together and the other is to attach the parts through an adhesive. Which way should you use? It depends. Lets look at ways to accomplish each, and their advantages and disadvantages.
To weld the plastic, one could actually try welding, but that isn't practical. When I mention welding the parts, I mean using a solvent to dissolve the surfaces to be joined, and letting the solvent evaporate. Most common model cements aren't cements, but are solvents, and take this approach. These liquid cements are either aromatic or alphatic solvents, ketones or chlorinated hydrocarbons. Here is a list of chemicals that are solvents of styrene and some of their characteristics.
evaporation odours cost
- Acetone 1
- Benzaldehyde
- Benzyl alcohol
- Chloroform strong
- Dichloromethane
- Ethylacetate
- Ethyl isopropyl ketone expensive
- n-Butanone strong
(methyl ethyl ketone,
MEK)
- Toluene 5 strong
- Trichloroethane
- Xylene 5 strong
1 very, very quickly
5 slow
Commercial liquid cements, what they are made from?
Testors MEK
Tenax 7R Trichloroethane (?)
Floquil DioSol Toluene/Xylene (ok, this isn't sold as cement, but it
can be used as liquid cement)
Q: How do I used liquid cement?
A: For most seams, hold the parts together, not too tightly, and use a brush or needle applicator to apply to the joint, allowing capillary action to pull the cement along. Once cement is applied, press the parts together tightly and clamp (rubber bands work well for the fuselage of aircraft). If the seam fits well, the little molten glue/plastic combination that oozes out will fill the gap and can be sanded when the cement has dried. Little filler should be needed.
Q: Which cement should I use?
A: That is a matter of personal taste. I have personal experience with Testors, Tenax, and diosol. I like Testors very much for most applications. I usually let it set up overnight before removing clamps and sanding. I like to wait longer if I am not too eager to work on the kit. It produces a very solid seam. Diosol is very similar.
Tenax 7R sets extremely fast. With Testors, I sometimes apply to flat surfaces then mate them. This is impossible with Tenax. You have to use capillary action. The joint is dry enough to sand within half an hour, shorter for small joints. It welds the parts, but because of the speed of evaporation, I have had bubbles for surfaces that didn't mate very well. It is fantastic for surfaces that mate very well.
Ethylacetate is very thin giving it good capillary action capabilities. It evaporates rapidly, is reportedly less harmful than those containing Tolouene and Xylene, and is cheaper.
Gluing vinyl to vinyl:
Q: With the proliferation of vinyl figures by companies such as Horizon, and small vinyl figures, what should I use to glue the parts?
A: One suggestion is to try cyanoacrylate, or superglue.
PETE plastic (soft drink bottles):
Bottles from 2 and 3-litre soft drinks offer the potential as a cheap source of plastic. Several questions have popped up in the past.
Q: Of what kind of plastic are soft drink bottles made?
A: Soft drink bottles are made of PETE plastic. PETE is an acronym for: PolyEthylene Terephthalate Ester or more commonly, polyester. Apparently, Kodak makes about 80% of the plastic soda bottles used in the U.S. Additionally, DuPont and Hoechst-Celanese also manufacture polyester. A big reason is that Kodak, DuPont, Himont, and Amoco are all major manufacturers of purified terephthalic acid, one of the raw materials used in making polyester.
Q: I thought that it was PET not PETE?
A: Well, PET incorporated (the folks that make evaporated milk and other stuff) didn't like the idea that their company name was being used as a common abbreviation, and their attorneys made it known. So to avoid any nasty consequences, the extended three letter acronym (ETLA) PETE is used instead of the old TLA 'PET'.
Q: Are their solvent type cements that can be used to join PETE plastic like there are for styrene?
A: Yes, there are, but they are pretty nasty substances. The known solvents for PETE are:
One would generally not like to use these at home.
Q: What can I use then to join PETE? Epoxy and tube model cement just lift right off.
A: Probably the best would be to use superglue. Some use PETE as wing- tip protectors for flying model airplanes. They recommend roughening the plastic with 100 grit sandpaper and using gel type gap filling superglue to attach it.
Hot melt adhesives, such as those used in glue guns, is also a possibility for the adhesive, but superglue is probably better in most modeling applications.
Dissimilar materials and materials other than plastic:
Q: What do I use to glue together dissimilar materials?
A: There is not one pat answer to this. 2 part epoxies and cyanoacrolates are probably the best. And depending on the application, one could also use contact cement.
Metal to metal:
Q: What do I use to glue together to metal parts?
A: This is particularly important to figure builders, since many figures and parts are made from white metal. One of the oldest and probably best ways is to join metal parts is by soldering them. If you don't want to learn to solder, then adhesives can be used. If the parts mate very snugly, particularly 2 flat surfaces, superglue works very well. For surfaces that do not mate quite as well, gap filling thick superglue is one option. 2 part epoxy is also something that can be used
Wood to wood:
Q: What should I use to glue wood to wood?
A: The best glue for wood is Alphatic resin, carpenters glue. It produces a joint that is stronger than the wood itself usually.
Wood to styrene:
Q: What should I use to glue wood to styrene?
A: There are several options. Some suggestions are:
Miscellaneous questions about glues and solvents:
Super glues:
Q: It seems that the super glue that I am using glues my fingers together better than the parts, why?
A: This is quite natural, considering why cyanoacrylate was developed. It was developed for doctors as a way to seal wounds without sutures during Viet Nam. In the field, with the many wounds, if a way existed to quickly seal a wound with out stitches, more people could be saved. So, biological things such as fingers are joined very well by CA.
Q: My superglue never seems to set the same. Some times it is slow, sometimes very fast, why?
A: Superglue sets through humidity in the air. When the humidity is higher, the CA will tend to set quicker.
Q: Should I use an accelerator to speed up the setting time of CA?
A: There is not definitive answer to this. There are advantages and drawbacks. Accelerators such as Zip Kicker tend to result in a weaker, more brittle bond than if you let it set normally. This is isn't a real problem if you are using the CA for filler, but if it is your main adhesive, a sudden jar, or a shearing force could break the bond. On the flip side, accelerators really do speed up the process. Especially in using thick super glues for filling.
A problem unrelated to the bond is the reaction of plastic to accelerator. Accelerators such as Zip Kicker contain 1,1,1- trichloroethane. This is a solvent of styrene. It can mar the surface. This can be quite detrimental if the model has already been painted and decaled.
Q: What are some basic safety notes about using CA?
A: Super glues are not unsafe to use if common sense is applied. If you use CA to glue a seem together, don't use too much. If you do, you are likely to find yourself unable to remove your fingers. Don't wipe excess CA with your fingers. If you do happen to glue a part of your body, use acetone to remove it.
This isn't a safety factor, but something to keep in mind. Keep your CA tube, dispenser, or whatever clean. When you finish using, clean the nozzle before replacing the cap. If you don't CA will build up, and make it difficult to remove the cap later, and will cause the seal to be less effective, and the CA to set up in the tube prematurely. As in all areas of modeling, cleanliness is next to godliness.
My standard styrene plastic glue is Ethylacetate. In my opinion, it is superior to all commercial liquid plastic cements.
It runs thinner than most so it has good capillary action, it evaporates quickly and thus runs little risk damaging surface details if some of it ends up outside the joint. Additionally it is reported as being far less harmful than those containing Tolouen and Xylene, as well as substantially cheaper (but try to purchase less than a litre...).
I find that I also need some sort of thicker, but still liquid glue, at present I use Revell's "Contacta Professional" as it has relatively little tendency to form strings. Most types that comes in bottles which has a thin metal tube to put the glue where you want I've tried have been OK.
I used to use ordinary white glue, thinned, to fix canopies and the like, but now I use Kristal Kleer. I've never been able to decide if this is just thin white glue, or if something else has been added.
To mount already painted parts, like bombs, where it's difficult to scrape off the paint, I use (very little) of some type of "universal" glue. You know, the sort which is supposed to glue plastic, wood, leather and so on, and is rather thick but clear. (Karlsons is my preferred brand, but Uhu and others work just as well.)
For resin, you need some sort of epoxy glue.
I haven't had any Cyanoacrylate glue at home since 1990. Must mean I don't like it much. But I guess it's essential for some types of jobs.
Have you used any of the so-called 'liquid glues' ? Oh well, they all work on the same principle: they dissolve the plastic surrounding the joint and then evaporate, leaving the plastic around the joint welded together.
The liquid glues are either aromatic or aliphatic solvents, ketones or chlor- inated hydrocarbons. Aside the commercial brands (f. eg. Humbrol, Testors or Super Weld) the following chemical substances can be used:
and so on.
If yo have never worked with the liquid glues, the procedure is following:
Also good types of adhesive are cyanoacrylate glue and 5-min. epoxy (any strong glue will do, providing you keep the parts together until completely cured) I myself have junked the tube glue long, long ago.
For plastic (polystyrene), I use Tenax and Faller. The Tenax in Creations Unlimited applicator is good for large applications, Faller for small areas (the applicator is too difficult to attach two small parts).
You should keep white (PVA) glue around for attaching the canopy. Super glues and plastic cement can glaze or craze the canopy.