What part of the cycle do you paint your model (or model pieces)?

There are no cut-and-dried rules, every model is different. My advice would be to assemble parts of the same color and paint the entire assembly as a single unit. For something like a U-Boat (although I have never built one) I'd probably try to assemble the entire hull and paint it at one time.

Personally I never paint pieces on the sprue because to me it is a waste of time. By the time I cut them from the sprue and clean up any seams or pin marks there would be very little left of the paint.

I'm currently building armor. I used to build cars.

I find that I'm removing all the parts the kit will need off the sprues first, cleaning them up ( removing mould seamlines, removing or filling in ejector pin marks ). Then I assemble the kit as much as I can. Some parts will be added after I paint. Then I paint. Then weathering. That's the steps I roughly follow. As you build more kits you'll get a sense of what needs to be done and in what order.

Glenn

I'm building plastic mecha kits (like Bandai Gundam stuff) I do the following:

1) Remove parts from the sprue
2) Sand the parts as needed
3) Glue one section together including all the areas that need to fit inside once they are glued
4) Resand as needed to remove plastic/glue bulges from gluing
5) Putty as needed
6) sand again

Then i prime the section. If has a joint (like an elbow) I prime in two light coats so that all parts of the kit get atleast a light coat.

If there are still imperfections I sand/putty/sand again and then a final light coat of primer.

Then I paint each section seperately and then assemble the kit into the final robot. The parts are designed to fit and hold into one another at this stage..

I think MusicCity has the right idea. I would just add that studying the kit instructions helps me alot in this area, and each model is as you very different. For instance, if there are areas of the model indicated by the instructions that need to be painted, such as an aircraft's interior air intake. It will be very difficult to paint this tight-spaced area with a paintbrush later on. So it may be best to paint these areas before assembly. The same goes for tank, car, sci-fi and other modeling subject construction. The idea is to "be able to find an easy, most convieneint way to paint a part or sub-assembly so that it looks it's best when the model is complete." As far as painting the model parts while they're attatched to the sprue..I don't. Reason is, It adds another step (per part) in preparation for assembly to the model. I simply employ toothpics, tweezers, dabs of putty and other methods to hold the various parts while I paint. I can now add weathering washes, more detail, etc..without having to stop and clean-up sprue attachment points, sanding, etc. Then I all I have to do is simply attach them to the model. Another example of this, as you may have seen in FSM, is when some modelers will dry-fit the model with strips of masking tape. This gives the modeler a very good indication of any problems he'll likely have to solve, fit problems, missing parts, warpage, and also paint sequences. Next thing you'll know, you'll have aquired a system for building and painting models that best suits you. This is a tough subject to "nail down", because it's subjective to personal experience, like choosing the best airbrush! Look closely at the instruction sequences to help better determine when it's best to paint and assembly certain parts.
Hope this helps ya, good luck!

All these posts were very helpful. I appreciate you making them.

I am pretty much doing what you are advising me to do. It seemed to come a little more natural after I actually started building my U-Boat. I am seperating all the parts out into containers that will be painted in one particular color. I am then planning on putting together whole sections out of those containers where possible, and then I will paint the boat in major sections.

Good deal, now you've got it!