However, onto the actual point of the post…  As with many painting projects of this size, there are numerous parts that edge onto each other and as such you cannot afford to have any overspray of one colour onto another.  The mottled effect I’ve achieved relies on the black undercoat being used to create darker patches, so any overspray would actually be visible.  So the way to ensure that you don’t get any overspray is to mask areas off.  This could be an area that you’ve already painted or an unpainted area you wish to keep unpainted.  There are a number of different ways of masking off and you will likely find that you will use a mixture of them all in order to achieve the results you want.

Masking Tape.  Without a doubt one of the best ways of achieving a crisp edge.  You can cut masking tape on a cutting mat to achieve non straight edges, you can actually use a hole punch if you wish to mask off anything round (or the other way round).  There are a number of things you need to think about when using masking tape.

• Firstly the choice of masking tape is paramount, it’s no use masking off an area only to find that when you remove the tape, it takes off paint.  I would always recommend spending out a bit of cash for Tamiya Low Tack Masking tape.  It’s yellow in colour and comes in a number of widths – I’d also suggest you just buy the refils rather than the whole dispenser which is pretty useless in my mind.
• Don’t leave the tape on too long or in a particularly hot or cold environment as it may cause the adhesive to change and pull off paint when you remove it.
• Generally you want to put masking tape on before any other masks.  I use a rubber ended sculpting tool to flatten the edge into place – works wonders and means that you don’t push the tape on too firmly and damage the layer underneath.  Don’t be afraid to gently remove the tape and reapply if it’s not quite right.

Masking Fluid.  This is probably the second most used masking item out there and is basically a rubber based liquid that you ‘paint’ onto the area you wish to mask off.  Once dry you can remove it by using an eraser and it should peel off as a film.  It takes a little bit of practice to get used to and if you use a brush to apply it, make sure that the brush is well soaped else the fluid will stick to it and mess your brush up.  I use a rubber ended sculpting tool to apply it and just rub the excess off with my fingers.  I’ve only got a couple of tips really.  The first is that you need to test your masking fluid on the colour you are currently using.  For example Humbrol Maskol will leave a greasy mark where it was on Space Wolf Grey, where as Windsor & Newton Masking Fluid doesn’t.  The second is to experiment with the fluid before you apply it to your actual piece.  It’s very easy to put too much on and find it pooling into an edge (a cocktail stick can be used to pull it down).

Plasticard Strip.  If I have a gap that isn’t big enough to use either of the above masking methods and is a straight ‘gulley’ then I search my supply of plasticard strip.  I’ll trim to size and then use a bit of masking fluid to glue it into place.  Simple, but effective.  Don’t be tempted to use paper however as as soon as any paint hit’s it, it’ll warp.

A block template.  Ok, I’m sure it’s got proper name, but you can hold something in your off hand and use the edge to spray along.  I’ll do this with a piece of plastic (actually an old store card) when I’m running along something that doesn’t need as clean an edge as masking tape gives you, such as where a little bit of overspray on the edge doesn’t matter but you don’t want too much.  If you’re really skilled it’s possible to hold shaped templates away from a surface and airbrush to achieve a blended shaped edge…

End result looks really nice, however it is very subtle.  I need to darken the shadows more than I did for certain.  Providing I can keep the consistency of the grey paints good, then I could also push the highlight colours up more.  They’re primarily edge highlights, so providing they’re smooth I could almost go right up to white for a huge difference in contrast.  I also need to highlight the larger chips and add a bit of wash into the various scuffs to create some depth and variation to the area.

As I said in a post yesterday, I’m fairly happy with the end effect, although it’s not as subtle as I’d have hoped.

As I still had the garage available, I took the opportunity to do some more airbrushing.  I didn’t get on nearly as well as I did on Sunday, I managed to thin one paint down too much and at the end of the session realised that I had a obstruction at the bottom of the cup underneath the needle…  Oh well, I’ve learned the hard way and won’t make that mistake again.  I also need to keep my work area a bit clearer if possible.  I found that I had cans of spray and things in my way.

I did manage to refine my salt technique a little however and have more ideas for further improvement.  I applied less salt on the first layer and tried to use smaller pieces.  The second salt layer got applied via a salt grinder – in fact one that often sits on the dining table.  Instead of running a cold tap and scrubbing with a toothbrush, I used the back edge of a knife to ‘ping’ the salt crystals off.  Once I’d got most of them off, I gently went over with a toothbrush that I dipped into a pot of clean water – not much mind you, just enough to dissolve some of the salt.  Once dry I repeated the process with the knife and toothbrush.  One thing I have discovered is that small salt crystals applied on the first layer are extremely difficult to remove, as they are protected by two layers of paint and a layer of hair spray which results in an uneven bumpy texture.

One thing that I will be doing in future is to apply less hair spray as the binding agent.  Probably just holding the can further back will be enough, but I found as I was removing salt with the knife, that every now and again I came across a rubbery bit that had caught around the edge of the salt.  This peeled away OK, but did cause extra work and could expose too much of the base colour.  I will also be using even less salt for the first layer and will filter out the smaller crystals (which are difficult to remove).

In order to finish the bulk of the tank I need to do a couple of things.  Firstly I need to shade the tank.  Initially I’ll deepen the shadows with thinned Adeptus Battlegrey.  Then I’ll apply washes of blue, purple and brown into the recesses.  The brown will also be applied more heavily the close to the tracks I get.  I then need to highlight the whole tank with Fortress Grey.  I’m currently torn between dry-brushing and actually painting the highlights as I would a marine.  Fundamentally I only need edge highlights as the actual armour will be done.  Then it’s tracks, mud and finally details.  Once I’ve done these two I reckon that I could get an average tank done over a two day period, giving it enough time to dry as well.  This is good as I have a mate who I’m helping to get his guard army painted and currently has around 12 tanks and 2 baneblades…

The basic concept of salt weathering is that you paint your surface one colour, then apply rock salt to that surface (using something like hair spray), then apply a second colour and wash the salt off under a cold tap.  This reveals chips of the first colour through the second.  I actually did double salt weather.  Firstly the tank was undercoated black, once dry I applied a moderate spray of boltgun metal from an old can I had.  First layer of salt got applied and then once the hair spray dried I airbrushed the whole tank with a 50/50 mix of Adeptus Battlegrey and Codex Grey (very nice colour).  Second layer of salt got applied now, which was airbrushed over with straight Codex Grey.  Once everything had dried I rinsed the salt off under the cold tap and using a soft toothbrush.

Now I discovered a few things.  Firstly if left under water too long, the micron-thin layer of airbrush paint will quite easily rub off, this actually can be used to create some really cool wear effects on areas that would naturally wear, however you have to be very controlled else you rub off strips of paint rather than little scratches.  Secondly, the codex grey layer wasn’t thick enough, in comparison to the layer underneath is rubbed off very quickly, this may have been the hair spray however.  Thirdly, the rock salt used for the first layer was too large, I ended up with some ‘chips’ that would actually be the size of your head :s  Fourthly, I would have been better using a salt grinder for the second layer of salt application.  This would have created a much finer and more controllable effect and given the effect of being more battered than battle damaged.

Overall I’m well chuffed with the outcome and will be refining it and using it for my Dreadnought.  The tanks look battered and worn enough for them to be classed as above gaming level already – and they still have details that need to be picked out, tracks to be painted and mud effect applied.  My biggest disappointment is that I decided to paint a red/black door on the top of the rhino.  Mixed my paint up without any hassle, sprayed it and it looked fantastic – but I realised this morning that my triangle point isn’t dead centre – shit   I need to work out the best way of fixing this – thinking about it, I could just spray the doors black and then go over the top with red again and hope for good enough coverage.  Might be easier than trying to strip the door – thinking about it, I could always spray that area codex grey as a base coat…

One thing that I have come across now though is the subject of storing paint.  In order to put regular acrylics through an airbrush it’s necessary to thin them down.  There are a number of different ways of doing this, but I am currently thining with Halfords Screen Wash (like you use in a car).  This contains various lubricants, chemicals and wood alcohol, it atomises in the airbrush brilliantly, is cheap (and relativly safe) and appears to disolve most lumps that can occur in the paint.  Now due to the nature of the new airbrush (gravity feed + dual action) I used significantly less paint than I did in my old airbrush (vacuum fed + single action) – in fact to do two tanks I used less than 2ml of actual paint, unlike the 12ml (a whole pot) to do two tanks and two marines.  Coupled with the fact that I don’t need to filter it through gauze to remove the lumps, means that I can get paint ready to go into the airbrush in a matter of a few minutes.  Using 2 to 3 parts screenwash to paint means I’m mixing up around 3ml of physical liquid every time – putting this into a 25ml glass jar is a little excessive to say the least.  So the solution I’ve found is to purchase some 3.5ml plastic paint pots the same as you get in childrens paint sets.  I’ve also ordered some 7.5ml dropper bottles for larger quantities of paint.  The price of these (just under 8p each) means that they’re disposable.