Two approaches to this. For all metal models wash down the model with Cellulose thinners using something like a goat hair brush. Leave to evaporate off and then spray the primer (thinned with the special thinners) using a decent airbrush. Once finished, quickly clean the airbrush using the thinners and then leave the model a couple of days to dry, etch and harden. Then it can be oversprayed with your favourite topcoat.
Etch primer also has a role to play with composite models, particularly those that consist of plastic r-t-r bodyshell with metal details. In this case I test the plastic somewhere it won't be seen with a couple of likely solvents - I usually end up using either Isopropyl alchohol or lighter fluid. This can then be washed over with a brush, or scrubbed using a cotton bud on the metal parts to thoroughly degrease them. Once the solvent has evaporated the etching primer can be slightly thinned in a metal, glass or ceramic container and brushed onto the metal parts. Then leave for a day or two before progressing with either a sprayed undercoat (grey or rust coloured enamel?) or the first top coat.
Revell, Humbrol and Molak are all fine enamel paints. I nearly always use Humbrol thinners with them. The alternative is the odd stubborn example, which can sometimes be thinned with lighter fluid. The latter particularly applies if brushing. Weinert paint is a type of cellulose; the solvent is toluene, which I get from Halfords in the form of their 'Cellulose Thinners’. It sprays well and takes nicely to clean metals or plastics and I’ve not had any significant problems with it – even when painting over enamels.
Magical decal softening solutions from the USA. Use exactly as per the instructions on the bottles…
Dave’s preferred finishing substance. Comes in convenient spray can form and dries to give a dead matt, flat, clear, finish with none of the whitening that’s sometimes found with lesser finishes. There is apparently some issue with using it over ‘metallic’ decals and paints. So don’t…
He he; I love this one. It’s a floor wax that happens to work very well for all sorts of jobs, I use it primarily as a clear adhesive for things like glazing and etched numberplates. It also has some use in helping to get a smooth finish, particularly before decaling. There’s loads more about it on this page: The Complete Future (external link).
My personal fave finish as it’s very smooth and hard wearing. Don’t attempt it if you haven’t got a decent airbrush though. Make sure you leave at least a week after decaling (especially if you’ve used any ‘Klear/Future’). Thin with Humbrol enamel thinners until it gets to the infamous ‘single cream’ consistency. Spray, clean the airbrush with white spirit. Stand back, admire…
I note that Ronseal have now released a ‘solvent free’ version of this varnish, which can only be a good thing for the environment. I’ve not used it yet as my old tin of Ronseal still has plenty in it. But, if you fancy giving it a try here are some thoughts: Leave at least a week between your last coat of paint and the varnishing to allow the solvents to evaporate away completely. Thin the varnish with whatever Ronseal recommend for brush washing, again aiming for a ‘single cream’ consistency. If it’s water based then thin it with filtered, bottled or boiled water to reduce the chance of contamination; which will always show in a varnish. A small drop of isopropyl alcohol may help by lowering the surface tension, but I’d be tempted to test it on something without, as lowering the surface tension will increase the chance of the varnish developing sags or runs. Leave it plenty of time to harden off before handling, as solvent-free paints and finishes always take a lot longer to harden off than solvent-based ones.
It's masking tape. It's made by Tamiya. It comes in various widths and it doesn't rip the paint off when you try and lift the tape...
We get asked quite often about what metal blackening we use. The 'Super Blue' is the preferred option for most metals, brass, nickel-silver, steel, etc, etc. The 'Aluminium Black' works on aluminium (d'oh!) and sometimes on other more stubborn or less reactive metals. Neither will touch stainless steel.
Use: If it's a raw casting that needs blackening give it a good polish with a wire brush. Brass bristles by hand on whitemetal; a steel wire brush in a minidrill for brass or hard metals. Then clean - I tend to use meths on raw castings and isopropyl alchohol on things like wheels as they're going to have plastic parts in them and may well be painted. By clean I mean rub a rag, tissue or cotton bud that's been 'wetted' in the cleaner all over the areas that are to be blackened. Then rinse and leave to dry. Incidentally the 'Cleaner-Degreaser' works very well but it's not always easy to get hold of.
Once the parts are dry you can start on the actual blackening. I make sure I've put the blackening solution in a shallow tray (so I don't knock it over) and have a pot of water available that's large enough to take the parts once they've been blackened. Then holding the part in a way that won't get finger grease on any parts that need blackening I use a cotton bud soaked in the blackening solution and rub it over the areas to be blackened. Once the parts are blackened enough the part(s) can then be dropped into the water to stop the reaction. Don't let the blackening form too thick a layer or it'll just flake off. Once dry the blackened surface can be polished - I use soft tissue. In fact all that I do is follow the instructions on the bottles...
I generally believe in the idea of ‘oil for bearings and grease for gears’, but there are exceptions. These are the products I use:
A very good quality PTFE-loaded grease that works very well even under high loads. I apply it to gear surfaces with (you guessed it!) a cocktail stick.
This is also a PTFE-loaded lubricant that works very well under high loads. It’s non-conductive so can’t be used on models where you’re relying upon current travelling across an axle-bearing interface. It’s very liquid when fresh out the bottle so I use the conventional ‘shake the bottle, squirt a little out into a jam jar lid, use a pin or piece of wire to pick up and apply small drops’ technique. This lubricant is kept in stock as I use it to lubricate the main bearings in my turntables (as in device for spinning LPs), but I’ve noticed that it can evaporate out of an open bearing so it doesn’t see much use on the trains any more.
My preferred oil for use with the trains. It’s not claimed to be conductive; but it’s certainly not a great insulator. This is a very pure, refined oil which comes in a small plastic phial with a hypodermic needle. Great stuff and I find it’s in general use as my preferred lubricant these days. Usefully, it’s also plastic compatible.
Electrolube still has a place in the repertoire, as it’s conductive. However it’s pretty aggressive to plastics and can cause them to rot. Certainly it’s worth using; but use with care and not near styrene.
Just in case you come across a job that requires a dry lubricant. Couplers are a good example.