Starting out with airbrushes

[rodent279]

Evening all.

 

I have a couple of projects on the go, slow burners as I am not getting much time to spend on them. Have come to the conclusion that I need to invest in an airbrush, as one is an O gauge class 25, which is a lot of blue paint to apply by hand.

 

I've read a few of the threads on here regarding airbrushes etc, & have a couple of questions.

 

Firstly, I've heard mention of airbrush makes like Iwatu, Badger etc. Hobbycraft sell a couple of airbrushes made by Aztek, Humbrol & Spraycraft, for £15-£45. Are the likes of these any good, or is a Badger/Iwatu better?

 

Secondly, I have a small compressor which I use with a Clarke spraygun for work on the car. The spraygun is way too big for what I need. The compressor is if anything too small for car work, but might be ok for modelling. It's a Thomson 350W (~1/2hp). Not sure what pressure it works at, but I'd guess no more than 50psi. It manages the spraygun reasonably well, which needs between 15-60psi. The connector on the compressor is 1/4" BSP-will one of the above mentioned airbrushes connect to a 1/4" BSP fitting?

 

cheers N

[Edge]

Don't know about the compressor, but you might want to take a look at the Games Workshop spray gun if you are considering a budget airbrush. It'd be no good at the really fine stuff ( you can't really get that with a budget brush), but GW doesnt sell crap tools. They have a wide range of paints as well, a fair few of which are made especially for the spray gun

[AngryMeerkat]

Your compressor will be fine, it will give out any pressure you tell it to from 1psi up to its maximum rated psi. And because it will have a reasonably large tank, it won't be kicking in all the time due to the relatively low air usage of an airbrush. Around 20psi is in the ballpark for airbrush uses.

 

1/4 bsp is fine, if the airbrush and supplied hose don't come with an adaptor then these are readily available from all good model shops.

 

As for your airbrush, this is much about budget and preference, although there are shortcuts. My advice would be to avoid anything suction-fed (with the paint pot hanging underneath like most Badger airbrushes), and would instead go for a dual action gravity fed brush. If you can afford an Iwata then that is definitely the route to go, but don't be scared of the cheaper (usually Chinese) copies that are available on eBay. I have an Iwata for my proper job, but use a cheaper copy at home for modelling, and I find them both as capable as each other despite the £60 price difference.

 

Mark

[rodent279]

Thanks Gents.

Meerkat-my compressor is like me, simple. It has no way of adjusting the pressure. I'm not even sure what pressure it delivers, but at a guess around 50, maybe less.

[AngryMeerkat]

Thanks Gents.

Meerkat-my compressor is like me, simple. It has no way of adjusting the pressure. I'm not even sure what pressure it delivers, but at a guess around 50, maybe less.

Wow ok, that's quite rare in a compressor large enough to run a larger spray gun as they usually have a pressure gauge and a dial able to adjust the pressure. As this is lacking, it can be added in-line between the compressor air outlet and the airline, and is advisable as a safety matter if nothing else. The cheapest way to add the pressure adjustment is through a simple 'open/close' T-valve rated to the compressors maximum pressure and NOT its normal working pressure. This is of course assuming your compressor does have an air tank and it not just an air compressor?

 

50psi is VERY high for airbrushing, and I really wouldn't recommend it. If you can't add the pressure gauge/valve then another way is to use a brass adaptor piece between the compressor air outlet and the airline, with a small hole drilled in it. This will vent air before it gets into the airline and reduce the pressure at the airbrush. The problem with this method is that it is non-adjustable, you drill the hole and accept the pressure. I have a brass adaptor in my modelling drawer somewhere that is pre-drilled if you need and help or advice with this method.

 

Mark

[Katier]

Shouldn't be any reason the OP can't fit a proper valve/moisture trap/pressure gauge unit to the current compressor. It doesn't have to be mounted directly, indeed some people recommend a hose between the two both to help dampen out the 'beats' of the compressor and to allow the air to cool a little.

 

I have a coiled hose from my compressor to the valve, then a second pipe to the airbrush.

[rodent279]

Thanks again for that.

 

The compressor does not have a tank, and no pressure gauge either. Is this something that can be bought as an aftermarket device then? If so, from where?

 

The pipe I use when spraying using the Clarke gun is about 4m long, so that presumably sorts out pressure fluctuations.

 

cheers N

[TheAlchemist]

Hi Rodent279,

 

At one time I knew most of the airline equipment suppliers in Bristol.

 

My suggestion is to search on-line for "airline equipment" in Bristol. If you locate a local company with a trade counter they usually will be pleased to help you.

 

One point however, make sure to know the size of thread you want to connect to. Perhaps the outlet on your compressor. It may be that the connector is 6mm rather than 1/4BSP, sealing the wrong one to be airtight could be a problem. Unless you are familiar with airline connector sizes I have found it's best to take the outlet with you, there are several makes in common use, all with slightly different (patented) design.

 

There is a large difference in price, especially for regulators, filters and guages. If you buy the better ones they will be somewhat more expensive but in use will show their value in the ease with which they connect and disconnect  when under load. I use PCL components in my system. If money is no object Schrader seems the best.

 

I would be very hesitant to use any compressor without a pressure gauge, even the small diaphragm type which used to be sold for use with airbrushes; although these were designed so that the diaphragm would rupture at a relatively low (safe??) pressure. Somewhere on your compressor set-up you should place an item which might be considered  non-essential; that is a pressure relief valve. A burst could happen somewhere between the compressor and the tool you are using (Spray-gun, airbrush, tyre-inflator.) or even a connection not being secure. A flailing hose under pressure, even 30psi, can give, at least, a nasty thwack. The relief can be fitted on a 'T' as long as it is at the compressor end with no intervening shut-off.

 

Unfortunately the motor wattage is not a good guide to the maximum working pressure as the drive train (pulleys etc.) obviously can be used to achieve the power required, altough with lower displaced volume.

 

One last consideration is to select the range for the pressure gauge. I use a 0-60psi range as this allows me control at the lower end in the 1-10 range but permits me to use up to 38psi for my Land Rover tyres. The normal guage fitted for industrial use goes up to 12bar, 170psi and is difficult to set for an airbrush at 5-20 (max 30)psi.

 

Always remember compressed air is generally safe, compared to steam pressure, using some care to avoid the obvious pitfals is always advisable but don't let my remarks put you off what you want to achieve

 

I wish you success.

 

The Alchemist ( Jerry)

[Chris g]

OK, I don't know about the compressor you have, but some quick comments.

 

Compressor:

 

If the compressor doesn't have a tank, (air resevoir),  the problem is that you will get 'pulsing' and not a steady flow of air. 

 

You should have a pressure regulator and moisture / oil trap fitted to the compressor otherwise the paint can be contaminated.

 

For an airbrush you want to be able to regulate the pressure from 10 ~ 30 psi, (depending upon what you are trying to do).

 

Airbrush:

 

I've posted a link on the forum to a guy who has done some comparisons of airbrushes, (including Chinese copies) which should help.

 

For me,  I like Iwata. I've used Aztek and liked them but after several years use I don't find it is precise enough for what I want to do but for giving something and overall coat of paint its fine.

 

In terms of compressors, getting a Chinese made compressor with all the features you'll want (including low noise), is not that expensive nowadays (I've see complete kits of compressors and copy airbrushes on the internet for less than the cost of an Iwata airbrush.)

 

Picking an airbrush is a bit more complex, is this a one off job or is airbrushing something you want to get more into ? 

 

The answer will give you a feeling for whuch way to go, and how much to spend.

[Katier]

This :-

 

http://www.ebay.co.uk/itm/Mini-Regulator-With-Gauge-And-Water-Trap-Filter-/121085363446?pt=UK_Crafts_DrawingSupplies_EH&hash=item1c314004f6

 

Is the kind of regulator you need. It's the same one I use (available from a number of stockists), at the top is the regulator knob, pressure gauge in middle with air in/out then a spring loaded water trap at the bottom. You just mount it ( in the same orientation at the picture although I don't think it matters which is 'inlet' and which is 'outlet'.)

 

You don't 'need' a air tank, a long pipe will do reasonably well and I don't notice any issues with pulsing. Below is my setup the blue pipe feeds the airbrush and is narrow bore simply because that's what I had, not all airbrushers use such a narrow pipe. I think mines a badger pipe.

 

 

[rodent279]

Katier, that looks very much like my compressor! Is it a Thomson "Sprayit" 602-12?

[Katier]

Nope but most likely it was a compressor that was 'branded' regularly.

[rodent279]

OK thanks all, some food for thought there. My compressor is definitely 1/4"BSP, that is what the spray gun connection is and both ends of the hose fit either spray gun or compressor. Here's a fot of it. I think it looks very much like Katier's.

 

Of to one of the local model shops this weekend for a look at their airbrushes. I will check out ebay for a guage & regulator, but wonder could they be got from Machine Mart?

 

cheers N