After working on my Venerable Dreadnought last night here are some handy tips if your working with metal models.
* Use a file to smooth off any of the off cuts of metal still attached to the model, if these aren't cut off properly they stop pieces joining correctly.
* The small threads of metal which you get regularly cut off with a knife, these can stop models from joining correctly also. Not only that, but if you miss any when painting they look a eye sore and could be more difficult to remove.
* I personaly use G.W's glue, though I'm sure other glues out there will do the job. When gluing don't be shy and be generous with the glue and make sure both parts have glue on the surface. Use the brush from the bottle several times on the surface!
* If your having problems getting parts to stick together, hold them together with a bit of pressure and count to 60. A minute holding them yourself with a bit of force will often help them stick.
* Plan what your doing when building your model. Build the legs first for example and letting them dry while you build the body, then do the arms will help and create a more stable base when you come to put all the pieces together.
* Often its handy to have other items around, these can be used to support the model when drying in various positions.
* Leave the model to dry and settle at least 24 hours, usually heat helps glue dry quicker so a warmer area should help.
* When gluing metal to plastic make sure your not tight with the glue, the more the better. I have mixed up a bit of plastic glue and metal glue together and it becomes a very solid adhesive.
* Finally have patience, metal models are very annoying for me at least and often parts will fall off because not got a smooth surface or because not had enough time to stick together. Take your time with it and make sure you use plenty of glue and let each part dry while you work on the next.