|Peter Venn||23/05/2021 10:42:47|
9 forum posts
I am currently about to start painting parts of my 5 inch gauge Adams O2 tank engine. I have been researching the subject and clearly want to spray paint where possible. I have got Christopher Vine's book entitled "How (not) to paint a locomotive" but I'm getting more confused than ever! Mr Vine dismisses airbrushes out of hand and only refers to them in one five line paragraph in the entire book, saying that he did not use one. This seems a little unkind to the airbrush fraternity! I have an airbrush with a small compressor which delivers 23L of air per minute at up to 4 bar. It seems to spray quite well using 2K etch primer on some trial scrap sheet and I don't see why I can't see any obvious reason for not using it for most of the work on the engine. I cannot find any information on the Internet about using airbrushes for slightly larger areas of work.
Is there a limit to the recommended area that can be painted effectively with an airbrush? Mr Vine suggests buying a semi professional paint sprayer such as the DeVilbiss one but these are approximately £350-£400 which I am loath to spend. I would appreciate any information and technical expertise.
|Speedy Builder5||23/05/2021 11:12:47|
|2406 forum posts|
I am also at that stage, after talking to a French paint supplier, he encouraged me to go for 2 pack epoxy from an aerosol can. These cans have a ring pull valve in the base of the can. Pul the ring , give the can a really good rattle and you have 48 hours to use the paint up. Having said that, I have still been using the remainder of the can on parts that are either not seen or tools etc. The epoxy is "non Brittle" gives effective scratch and stone chip resistance (So the brochure says). As the paint was mixed to my requirements, dull gloss and to a specific RAL colour, I have been pleased with the result, and not overly expensive at 25 euro for 400ml can.
it may seem expensive, but there was enough in a can for two coats of paint and do the complete chassis on a 5" 0-6-0 tank loco plus the buffer beams etc - with 20% left over.
|Tim Hammond||23/05/2021 11:15:06|
|66 forum posts|
I have an elderly Badger airbrush and used it to paint an aluminium alloy front wheel of a motorcycle: it produced a very acceptable finish.
|Nick Clarke 3||23/05/2021 11:19:00|
1253 forum posts
The first thing is that at 23L per minute your compressor will not run one of these 'professional' sprayguns.
If you search this forum you will find quite a few posts on air brushes (search both airbrush and air brush)
In addition do not scorn the humble 'rattle can' aerosols - available in many standard colours off the shelf, but also go to your nearest auto refinisher suppliers who can mix hundreds of BS and RAL colours and put them in aerosols for you. They will be able to advise you on the type of paint as well.
My local supplier is Jawel Paints who have a website and are local to the midlands. (satisfied customer only) but there are many others across the country.
1221 forum posts
Please could you give details of the paint.
I guess it may be difficult to import it from France.
|Derek Lane||23/05/2021 12:01:50|
522 forum posts
The problem with airbrushes are that some especially the cheaper ones do not have changeable needles and nozzles which means that any medium that is sprayed through them needs to be thinned quite a bit. I have only ever used them for decoration on some turning that I did which was fine..
Something along the lines of this type I would have thought a better prospect for larger areas.
|Speedy Builder5||23/05/2021 13:15:14|
|2406 forum posts|
JA - Pm sent with web site address
|Paul Lousick||23/05/2021 13:18:29|
|1854 forum posts|
You could spray paint a 5" gauge loco with an airbrush but they are not realy suitable for large areas. I used one for painting the spokes on the wheels of my 6" traction engine but only on the small black section using signwriters enamel paint. The main parts of the wheels were sprayed with 2K paint usings a touch-up (small) spray gun. (available from auto accessory suppliers for less than $50). (pin stripes done with Beugler roller)
One of the problems with airbrushes is that the paint has to be thinned more than with a bigger gun to go thru the smaller nozzle. To get an even surface, the overlapping layers of paint should be wet so that they blend together and 2K paint dries very quickly and on a larger surface with an airbrush may not do so.
Why not try a test to see how well your airbrush covers a similar size area as on your engine ?
Edited By Paul Lousick on 23/05/2021 13:20:36
21431 forum posts
As Derek says a lot of airbrushes can't easily handle the viscosity and pigment size of enamels, 2K etc and if they can you need to thin them a great deal so runs and many coats start to become a problem.
Also the width of area covered is quite small so difficult to keep a wet edge on larger panels.
A small decent gun in the £100-150 range and a compressor that has a FAD (actual output) of 3-4CFM minimum would be a reasonable starting point. If I'm not using cans then this is the one I tend to use on models as it takes side bottles and cups but I don't tend to have such large areas as tenders and boilers where something a bit wider would be better
|Dave Smith 14||23/05/2021 14:00:39|
|191 forum posts|
+ 1 for the Iwata Neo. A good easy to use brush that is not expensive. I spray enamels, acrylics and cellulose with mine quite happily. I use airbrush cleaner at the end of each session to clean out before taking it apart to final clean in an ultrasonic cleaner. It will spray large areas but it takes some time because the need as Jason says to maintain a wet edge. The 63" wingspan Hurricane in the photo was painted with it. Although the paint is semi matt.
|Jon Lawes||23/05/2021 14:04:12|
652 forum posts
I purchased a cheap mini version of the automotive spray guns on ebay as a throwaway experiment for my locomotive and sprayed it with thinned enamel. I was very pleased with the result. After my son (an experienced modeller) installed the decals we gave it a light dusting of lacquer, which was carried out in a recently warmed garage. It wrinkled and made the finish look like elephant skin.... I suspect the metal hadn't reached room tempterature when I sprayed it. Live and learn!
|Martin Kyte||23/05/2021 14:09:23|
2554 forum posts
To be fair to Chris Vine, I think the book was his journey through the painting of Bongo a 71/4" gauge loco, so some fairly big areas to spray. I'm not sure he intended writing a general book about painting.
|Nicholas Wheeler 1||23/05/2021 14:22:39|
|739 forum posts|
One of the sub £30 mini HVLP guns used with 2k paint will do everything you want. Your small compressor will probably work OK for painting even large models; painting more than one car panel at a time will need a bigger one.
|norm norton||23/05/2021 15:14:14|
|162 forum posts|
I understand what you are asking. My answer is that you need to select the spray gun tool depending on the nozzle size needed. Air brushes might use nozzles in the range 0.5 -1.0mm, small touch-up guns 0.6 - 1.0mm and bigger paint guns 1.2 - 1.6mm.
For a 5" boiler I would be looking at 0.8 - 1.0mm. For the frames or wheels 0.6mm will be ok.
A mini HVLP gun seems to shift more paint than the airbrush with for example a 0.6 nozzle. So the better air brushes, like a Paasche VL with #1 0.5mm to #5 1.0mm nozzles can almost do a boiler. But better would be a cheap HVLP Detail Spray Gun 0.8mm or something like a Finex mini-HVLP gravity gun with changeable 0.6 and 1.0 nozzles. With the bigger nozzle sizes you need 4cfm (100 litres/min) at least and a 50litre tank so your compressor needs uprating.
It is worth buying a decent airbrush with different nozzles, but a basic mini HVLP gun with a couple of nozzles. But your bigger cost will be a compressor, and some filtering in the air supply.
Edited By norm norton on 23/05/2021 15:18:58
|Richard S2||23/05/2021 15:18:00|
218 forum posts
I am a regular user of airbrushes over many years. My oldest brush is 45 years old and has been spraying cellulose and enamels from car panels to models for most of it's life without any replacement of parts (top of picture below).
It has a fine needle, will manage most types of paint, but is only capable of a 2 inch wide fan down to 1/16" wide. To spray a wider area say 1sq ft (30cm x30cm), you would need to retard the paint to maintain a wet edge. The amount of paint it will lay on is less, so will need to be built up in coats.
The next a'brush I have is the same brand (Badger USA) and model, but of 2020 manufacture. It has a medium needle/nozzle size and can throw paint on at a greater volume, but still with a 2 inch wide fan. So again, a retardant would be of benefit. I have always been impressed with this brush (usual disclaimer) for their versatility within my needs. I also have a Paasch, which has a very small reservoir, for low volume fine work.
I had to get used to the viscosity mix using etch primers on both and had to adjust the ratios to obtain a smooth fine application on small parts. I have been using paints etc from Phoenix with no issues, but with a bonus, in that the small jars are the same thread pattern as my airbrushes!.
So the bottom line is that if you wish to paint a larger area with an airbrush of restricted fan width a volume, you may have to settle for flatting down with wet or dry after colour and top coat with a slow drying clear coat.
So if you only paint mainly large areas, then a larger gun with a wider fan may be preferable, of which I have no significant experience, but imagine the costs will be lower.
Badger 200 series (1974) top. Badger 200-3 (2020) bottom.
Good luck with your projects(s)
638 forum posts
Fwiw HVLP guns are the least suitable for small compressors, they were designed for wasting less paint in an environment where it's in constant use all day, the clue is in the name, High Volume, it uses a high volume of air at lower pressure to reduce overspray, they use far more air than standard guns with zero benefit for occasional use.
|norm norton||23/05/2021 18:02:49|
|162 forum posts|
HVLP - agree fully.
I think a lot of the HVLP description is a marketing gimmick. Those guns I described still need 30-40psi and probably behave just like historical spray guns.
|Nicholas Wheeler 1||23/05/2021 18:29:02|
|739 forum posts|
You think using less paint for better coverage together with much less overspray is zero benefit??
Using them with high solid 2k means just 2 coats of paint, which dramatically reduces your chances of screwing something up.
638 forum posts
You'd have to spray industrial amounts of paint before you start saving money on paint, when I trained in body repair and paint spraying at Leicester college 20 years ago, we were taught the HVLP guns didn't atomize the paint as well as standard guns.
HVLP was brought in for environmental and money saving reasons, technically speaking, it's an inferior way of applying paint.
|448 forum posts|
another request for details please Bob
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