Tuesday, October 16, 2007

How to glue different parts of model

When we build models, we always ask, how to glue together different non-similar parts. Here is some answers for yours questions.

What should I use to glue together dissimilar materials?
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.

What should I use to glue together to metal parts?
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.

What should I use to glue wood to wood?
The best glue for wood is Alphatic resin, carpenters glue. It produces a joint that is stronger than the wood itself usually. [In the US, Elmers is a common brand - the yellow stuff sold in hardware stores, *not* the white glue sold most everywhere else.]

What should I use to glue wood parts to styrene parts?
There are several options. Some suggestions are:
1) You could try using superglue with an accelerator. This would probably have to be thick superglue, unless you are using a very dense wood. Thin superglue would tend to absorbed by the wood like a sponge.
2) 2-part epoxy would probably be best, since it works well at joining dissimilar materials.
3) If the styrene is thick enough to withstand heat, hot glue may work well.

And Gluing Styrene to wood or paper is a pretty typical thing to do when assembling flying model rockets. Tube type plactic cement works fine - that's what Estes recommends. CyA also works. Glue soaking into the wood really isn't much of a problem. I use thin CyA to attach balsa fins to paper body tubes all the time - hold the parts in place and add several drops of CyA. It does soak into the end grain of the balsa and the paper tube so you have to use several drops instead of just one drop like you might between nonporous surfaces, but it works quite well.

It seems that the super glue that I am using glues my fingers better than the model parts, why? :-)
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.

Thank you.
materials from (www.ninfinger.org)