Postby Phil Clark » February 6th, 2011, 7:50 pm
Primer.....I'd stick to good old fashioned cellulose.......cheap & easy to use. Sourcing it can be an issue these days as many commercial paint stockist no longer carry much in the way of solvent based paints due to recent changes in legislation. I've seen 5ltr tins on evilbay, plus one of the local places to me in Gateshead can still get it.
With the colour scheme you have in mind, I'd go with a white primer rather than a traditional grey. Your white top coat will cover MUCH faster, and the white base will make the red nice & bright......some reds can turn a little deeper in tone with a medium grey primer.
Thinners....cellulose. The primer I use is normally thinned 60/40 (60 paint, 40 thinner)
Number of primer coats......I'd go with 2 with a light rub down between coats just to knock any imperfections off. Depending on how many coats of dope you've applied to seal the Diatex, this could also help fill the weave if you've been a little light on dope. Don't go overboard and be to aggressive with the rub down here as you run the risk or going back into the fabric on hard edges......I like using the fabric flatting pads intended for use on orbital buffing machines....used wet, these are very good and a little more gentle than wet & dry. 6-800 grade should be all you'll need.
Top coat.......over the past 4-5 years, I've become a real fan of water based top coats (namely Warbirdcolours.......I may be a little biased as I'm the European agent for this product....but hay ho!!) They are fast drying, very low odour and thinned with water makes switching between colours and final cleaning dead easy. This product is catalysed with a covalent bonder....once cured for 2-3 days, they are VERY hard wearing. The colours available are obviously all 'military' WW2 colours, but this does include a number of slightly different shades of white & red.
If you don't want to go the water based route, then I like solvent based acrylics for their ease of use, though the same problems apply to sourcing these as with cellulose....suppliers are fairly few & far between these days.
Both the water based & the acrylics give a satin finish....I assume you'd want a gloss, so I'd consider a gloss clear to finish the job and seal everything down. For me, there is only one to use and that's Klass Kote gloss clear. This is a 2 part epoxy based product. Stinks to high heaven, not cheap and quite time consuming to use (you can't just mix it & use it, you have to mix A & B together 50/50, wait 30-40 mins for the reaction to start, then add the reducer, then use it....and anything left over will be useless the next day).....but it does give a V good finish that is bullet proof to pretty much any solvent.
Masking....DON'T try and use cheap paper masking tape, it'll bleed all over the place, especially over fabric. Only use cheap paper tape to back off with newspaper.
For a model of this size, I wouldn’t paint the whole thing white then add the red over the top....the surface areas involved are large and it’ll add unnecessary weight. I’d mask the white, spray that, and then re-mask for the red.
All straight edges are best done with a plastic fineline tape (I use a 3M 6mm fineline tape)......slightly flexible, it will also go round corners as well. Plastic tapes seem to bleed a lot less than paper ones. For the tight corners in your scheme, I'd cut masks for masking film and combine these with the 6mm tape......they look pretty tight and it’s unlikely a fineline tape will go round them all without the odd crease.
The main tip I have when applying the 2nd colour to help prevent it bleeding under the tape is to go over ALL edges with the base colour (white in this case) first....this seals the edge of the tape, but if any paint does bleed under, it's the same colour as the base so will be invisible once the masking is removed. Let the base colour dry, then start on with the main colour.......light dust coats 1st just to get colour on the surface, followed with a final flow coat that once cured will give you the nice smooth finish. If you hit it with a heavy coat straight away and the white hasn't sealed the tape edges completely, the red may still bleed.....apply a couple of light dust coats first and the chances are dramatically reduced. Again, a gentle flat back between coats is a wise move to remove any imperfections, dust particles etc... that may have got on the job as you go. I'd generally expect to build the colours up in around 3 coats.
When removing masks, I never wait until the paint is 100% cured, I find if the paint is still V slightly soft, it leaves a crisper edge as the soft paint peels better than completely dry paint that can sometime chip. Always pull a mask off away from a painted edge whilst keeping the tape/film as flat to the surface as you can.
Hope that helps............
Phil