Sunday, 2 June 2013

Model preparation: Mold lines, gap filling and so on...

After the excitement of putting together my first Dakkajet and starting weathering with some pigments I realised I had rushed some of the model preparation, quickly filing here and there but neglecting to fill gaps and the like. As it was to be a gaming model rather than long term painting project I wasn't too concerned but was kicking myself as the base coat had been sprayed on and would be very difficult to reproduce.

A 'thick' undercoat has done little to disguise the obvious gap here.

Despite careful filing, the ridge across the top is still visible.
With the second Dakkajet still in the planning and assembly stages I realised filing alone was not going to cut it, so I used green stuff to fill the problem areas, filing them down first and then using sausages to fill the areas. I put a lot more than needed, with the notion of filing back as required. I was careful to smooth the green stuff down at the edges as my files tend to catch and pick up whole sections. Filing in only one direction is a must, as is using only light pressure and clearing the green stuff from the files regularly.

Green stuff, smoothed down across a larger area.

Allow 24 hours to fully harden before filing.

A 'gentle' use of the file leaves a smoother surface.

The nose was tricky with all the rivets, and looks messy until painted.
 At this point I took a leaf out of the automotive trade and painted the area to be smoothed, then filed down until there were no 'low' spots in the green stuff. The original plastic area doesn't matter so much, but the idea here is to file evenly until all the paint is gone at the area you are trying to smooth out.

You can see the 'low' spots here where the paint remains.

Nearly there...
 Of course, one of the critical factors in creating a smooth base coat is getting rid of all the plastic and green stuff filings from the model so they don't get caught up in the paint. Dust is also a big enemy, and to this end I washed the model using some soapy water (to remove some of the green stuff residue) and then rinsed it and allowed it to dry outside away from the dusty carpet. After this I started with a thin undercoat which could easily be dusted off once I had sorted out my colour scheme, there's no cure for painter's block though!

A little bit of elbow grease does wonders as well...
Looking much better!

Hindsight is a great learning tool.

1 comment:

  1. A huge difference! Well done on going the extra mile with your prep. =0)

    Quick tip on putty for filling though; if you're going to file it smooth afterwards, I highly recommend using Milliput.

    If you're not familiar with it, it is more like a clay than GFS when mixed, and water can be used to thin the putty and smooth it whilst it's still kneadable. Once it is fully cured, it's rock-hard and can take tooling very well (I usually give it two or three days somewhere warm if I'm going to file or drill it, so that it is as fully-cured as possible; if it's still a bit tender, it can gum up your tools and be a bit crumbly).

    If you dissolve a small piece in some water, the Milliput can even be used like Liquid GS, but with the difference that it is very hard once cured. This is excellent for filling in hairline gaps, or even tool marks on plastic models.