Runs in my paint

[Terry]

Dear Experts,

After returning to scale modelling after 30 odd years, I decided to treat myslef to an airbrush. I have a Harder and Steenbeck Ultra and I realy like it, however I have started to build an Airfix 1:48 ME 109 Trop and things have not gone to plan.

I tried to spray the model with Vallejo sand coloured primer and it seems I have simply made a pigs ear of things. The paint has come out to thick and fast and has now run down the fuselage.

Can I get some advice on how to clear these runs i.e. wet & dry and what do I need to do to get the airbrushing technique right.

Cheers



Terry

 

[Ian M]

If buy "to thick and fast" you mean that there was to much paint coming out, its probably just to much air. Try turning the regulator down a bit.

As far as technique advice. Find some plastic bottles, old plastic packing and play with the air brush.

Try turning the air pressure up or down and see how things react. Then try with adjusting the viscosity of the paint and see how that reacts. It's all very personal preference, Some like thicker paint and higher air pressure others well thinned out paint and low air pressure....

Very much a case of finding your combination.

Ian M

 

[phalinmegob]

ian has said pretty much all of it, i used to have this problem and not mixing the paint so runny solved most of my problems. i have my compressor set at about 18psi. could also have the airbrush too close to the subject with a high pressure.

 

[BarryW]

Welcome back to the hobby...

What a coincidence, I returned myself just over a year ago after 30 or so years and the first kit I built was the same 48 scale bf109 trop.....

I agree , air pressure is the problem. Around 20psi and not too near the kit. Balancing air pressure with the viscosity of the paint needs a lot of practise. The needle size is also a factor as well, I would suggest a 0.2 needle personally though some would suggest a bit bigger, smaller is no good for modelling paints.

 

[tecdes]

Terry. I spray paint at about 6" from the model for primer & general painting. I also thin Vallejo primer about 20/15% & it goes on well using a Harder & Steinbeck.

I use a .4 needle & nozzle & keep the brush a constant 150mm/6" away from the surface keeping the brush moving to & throw. Using about 20psi.

First coat of primer I put on is a thin coat not trying to fill every space.

Just wonder if you are trying to cover in one coat & spraying to thickly.

The 6" distant & 20 psi is not an end game. Just been airbrushing some intricate work & the brush was about an inch away with a psi of 10.

What size needle nozzle have you ? Just thought you may not have latched onto the technique of trigger control. Hard push down for air all the time. Gently pull the trigger back for paint until you get a flow required. I on average adjust on an old plastic bottle until I get the flow I require before turning to the real thing.

Does your Harder & Steinbeck have an adjustable knob at the back to control the paint/amount you can pullback the trigger ? This helps when you are starting out.

Laurie

 

[m1ks]

Generally sound advice, with the exception of the adjustable knob to control how far back you pull the trigger for paint.

I personally find that flow adjusters and MAC valves (Micro Air Control, found underneath the brush in front of the hose inlet), to be a huge hindrance to newcomers, they have their uses once you're more used to handling a brush and can get some consistency in paint mixing and brush control, otherwise they're an unecessary expense and don't help anything.

First thing you need to do is practise, that includes you, the brush, the air the paint.

Find a setup that works for you, don't try for full coverage in one shot.

Typically, settings that work for me are

Enamel - Thin to milk consistency, (when you can swipe the paint up the side of a mixing pot and it largely runs down leaving a translucent coat, that's about right), I use medicine / night nurse type pots for paint mixing, cheap, readily available from the chemist.

25-30PSI, spray about 4 - 5 inches away from the model, full air, (always), enough paint that it coats until it just lays on 'wet' this takes practise.

Acrylics - Thin to milk consistency.

15-20 PSI, (15 is fine for solid colours, metallics sometimes need a shove hence a bit more air)

Spray about 4 - 5 inch, same as above, Acrylics flash off far more quickly and allow you to recoat much faster.

I alternate between an Iwata with a 0.5mm nozzle and my original chinese budget brush with a 0.3mm nozzle, I can get a consistent layer of paint or even similarly consistent fine lines with either and the above settings, the only difference is how far back I pull the paint flow trigger.

0.3mm is a good average, 0.5 is great if you do a lot of large models as it gives a greater coverage when fully opened up.

It really is essential that you practise the operation of the trigger and get that working right before you start using control knobs etc, air is easy, it's full press down always, then draw back and hold the trigger until you have the required flow of paint, old pop bottles are great for testing as you have a curved surface, if you can lay the paint on a curved surface without runs etc you know you're set.

Hope that helps.

 

[Fenlander]

The guys really have said it all. Airbrushing is not an automatic step up the quality ladder, it takes some getting used to and even then, mistakes can and do get made. It is all down to practice, trial and error on test pieces rather than the kit is the way to learn. Make note of what goes right and even more importantly what goes wrong. It is not a long drawn out process, take notes of the above and just spend an hour or two trying different settings and getting a feel for the trigger action. You will soon get that lovely Eureka moment and away you go. Don't let this get you down, OK, it needs sorting but it is sortable. Trust me, it will soon become natural.

 

[tecdes]

Great advice Graham.

Think that is the secret just go & practice practice. I spent a good numbers of 20 minute sessions before I got a clue.

Do that then read all the info given above which is probably well over the top at the moment for your stage in the proceedings.

Laurie

PS just read your first piece. DEAR EXPERTS. Careful that is seriously over the top Terry

 

[Terry]

Wow....The advice and guidance has been great, I have been practicing my technique on old pieces of plastic etc and have realised that the air pressure was far to high (30 psi) I have now reduced this to 18/20 with the smaller of the two nozzles that come with the ultra and am spraying about 6" away from the model.

I have got the runs out and re primed my model, I am very pleased with this, thanks to you guy's, however I now would like to ask for some more advice please....

I am painting my 109 with the Tropical camo scheme which has the blue underside with the mottled effect for the topside (if thats the correct terminology) my fear is getting the mottled effect messed up, is their a magic technique here?

Any ideas buddies???

T