What's gone wrong now?

[Gern]

OK guys. I tried your suggestions of more thinning, reduced pressure and spraying closer to the surface.

I did a thorough clean of my A/B before trying again and now I still have the 'orange peel' effect although it's more like the sandpaper as Ian mentioned, but I also have splatters of paint. :upside::sad:

I'm thinking it may be the paint. I got it as part of a job lot so I have no idea how old it is or whether anything has been added before I thinned it with MLT. Either way, I've ditched what's left and I'm going to my local Hobby Store tomorrow to get some new.

Meanwhile, back to cleaning off my latest paint. Again!

Just as an addition, at 15psi (according to the gauge on my compressor) I barely seem to get any paint flow. Is this because I usually spray at 25 psi and therefore I'm used to getting much more paint, or is there a potential problem?

[David Lovell]

Sorry it hasn't resolved its self yet Dave ,my only thought being grab the fresh paint if painting shiny things is your thang then perhaps a bag of plastic spoons (ebay) prime the backs of a few and practice till you find the right formula ,better than keep stripping down and starting again
Air brushes are airbrushes i have as much fun using my cheapo Chinese as I do my posh ones(yes the posh ones are nice to hold and you can feel the difference in quality)but they all spit paint if thinning and air pressure is incorrect.
I have what I consider to be a quality compressor (branded) set at just under 20 let the air through and it drops to a constant 17 or so ,I never change it or fiddle with it always mix to suit the compressor ,always making some test passes on a sheet of printer paper before letting loose on my hard work even then its still a mystery why what works today won't tomorrow. Dave

[Tim Marlow]

The sandpaper feel is definitely due to paint drying before it hits the surface of the model Dave.
Are you getting a wet paint film on the model when spraying (it should be easy to see)?
If not, you are using too much air and/or are too far away.

As you mentioned paint splatters as well, that effect is usually caused by incomplete paint atomisation. I’d say you therefore need a little more air pressure to properly atomise your paint. The only other cause I can think of that could cause this is incomplete mixing of paint and thinner. Are you mixing the paint in the airbrush, or mixing it away from the brush then adding it to the airbrush cup? I would strongly suggest mixing the paint before adding it to the brush if you are not. Incompletely mixed paint at the bottom of your airbrush cup could be causing the splatters.

This analysis makes me think you are spraying too far away from the model. I spray at a distance of about eight inches, just for a comparison. Try spraying a test piece at different distances to see what happens. Too far away us results in this dusty appearance, and too close results in spiders (uncontrolled paint runs). You are obviously looking for the sweet spot in the middle where the paint flows out on the surface before it dries.

Dave’s idea of plastic spoons for testing is an excellent one, by the way. You can then spend some time altering just one parameter at a time until you crack this. Don’t try and alter everything at once though, or you’ll never know which one has solved your problem. If you want to start today, and don’t have any spoons to hand, any hard plastic or metal kitchen debris (such as used Tim’s or bottles) should suffice as test subjects once they are washed and dried. Just have a bit of a dig through your recycling.

In my experience there is a fairly wide “sweet spot” for spraying Tamiya’s paint, and once you hit it you’ll wonder what all the fuss was about.

[Gern]

Looks like I got some hexperimenting to do. I normally don't have any issues with Tamiya, but this is the first time I've tried gloss so maybe that has something to do with it.

As for spraying distance, I got all the way down to about 1/2 inch because the amount of paint coming out of the brush was so small. It took a good 10-12 passes to get complete coverage of the red over yellow plastic. I didn't notice any sort of wet surface effect, but nor did I get any spidering. I wonder now if the pressure gauge is showing the correct reading? I'm positive there are no serious compressor leaks as the system holds pressure for at least a week after a session.

I'm going to try spraying the new paint with my old ( I got it just before Xmas so it's virtually new) Ultra A/B - it worked fine with a 0.4 needle around 25psi with both Tamiya and Stynylrez - instead of the new Infinity just in case there's some sort of problem with the brush.

My paint was thinned and mixed before putting it in the A/B. I added the thinner and gave the bottle a good shake by hand. Then I used a vibrating mixer for about 30 seconds so there shouldn't be any problem with the mix unless there's an issue with the paint.

Anyway, I'm off to my local pound shop for some plastic spoons and my Hobby store for new paint. Here's hoping I can find that 'sweet spot' Tim mentioned.

[BarryW]

I can be a bit like a stuck record on this!! As others suggest MRP lacquers will not give you any issues with spraying. I do note what you say about cost and using the existing stock of Tamiya paints and I fully understand that. I would suggest transitioning to MRP gradually as the budget allows. You won’t regret it. Spray MRP at a low psi, of 10-15 and you will get a beautiful smooth finish every time and, if not, perhaps from spraying a little too far away, it is easily resolved with a light spraying of MLT.

On the handbrushing issue, these lacquers can easily be touched up with an airbrush using some localised masking. As for those really fine details for which masking is impossible, you really only need a small number of water based basic colours for handbrushing fine detail over the lacquers, I have less than 20 VMC colours for that.

[Andy T]

I'm thinking it may be the paint. I got it as part of a job lot so I have no idea how old it is or whether anything has been added before I thinned it with MLT. Either way, I've ditched what's left and I'm going to my local Hobby Store tomorrow to get some new.

Just as an addition, at 15psi (according to the gauge on my compressor) I barely seem to get any paint flow. Is this because I usually spray at 25 psi and therefore I'm used to getting much more paint, or is there a potential problem?

The first bit jumps out to me. As you say, you don't know what has been added to the paint in the past. Maybe someone had pre-thinned it with an acrylic thinner and it isn't playing nicely with the MLT. I know they can be thinned with either, but I doubt both. Just a thought.

As for the paint flow - yes. If you have reduced the air pressure then you will have reduced the airflow (all other things being equal). Less air going through the 'brush will pull less paint with it.

As has been said, a picture paints a thousand words, so we may be able to help more if we can see the issue.

[Flip]

Dave,

I had heard the difference between Tamiya and MRP being described as "stratospheric". I am always wary of hyperbolae but nonetheless dipped my toe in the water with a just a couple of bottles of MRP. Tried them out on an Italeri 1:48 Apache AH-64D. Beautiful results.

The beauty of the MRP paints, I find, is that they are AB-ready (no thinning necessary). Pipette straight from the bottle to the cup and spray. If I have put too much in the cup, it can be poured/pipetted back into the bottle - no waste. A quick blast at the end with thinners and that's it: no need to strip the AB down all the time.

To put it in context, I use Tamiya Lacquers and MRP interchangeably, with the bulk of my paints still being the Tamiya ones. They're really good paints and I won't walk away from them, especially as they're easier to source :smiling5:

I recently made the Airfix Saturn V rocket. That was Tamiya LP-2 (Gloss White) all over. After a while of spraying there is a tendency for paint to collect on the tips of the protective prongs (I use an H&S Evolution CR Plus) and for paint to collect at the front of the nozzle. Periodically, therefore, I use an old paintbrush wet with thinners to gently clean these areas. If not monitored enough, I have found that these lead to paint splatters; especially when putting the air back on after a short pause.

The black on the Saturn V was MRP-172 (Super Gloss Black). I can spray until my heart's content and not get the tip issues described above. So is MRP noticeably better than Tamiya Lacquer? Too right!

But I also agree with Barry about slow migration. It would be good to have MRP in your arsenal, not to be the only component.

Hope this helps,

John

[Gern]

I can be a bit like a stuck record on this!! As others suggest MRP lacquers will not give you any issues with spraying. I do note what you say about cost and using the existing stock of Tamiya paints and I fully understand that. I would suggest transitioning to MRP gradually as the budget allows. You won’t regret it. Spray MRP at a low psi, of 10-15 and you will get a beautiful smooth finish every time and, if not, perhaps from spraying a little too far away, it is easily resolved with a light spraying of MLT.

On the handbrushing issue, these lacquers can easily be touched up with an airbrush using some localised masking. As for those really fine details for which masking is impossible, you really only need a small number of water based basic colours for handbrushing fine detail over the lacquers, I have less than 20 VMC colours for that.

I take your point Barry. When I start my next build - whatever it may be - I'll have a go at MRP. Three or four colours isn't going to break the bank is it? All I gotta do is find someone who sells them as John doesn't seem to have them.

It's just that I find it annoying that I'm having so many issues with this. I don't know how long Tamiya have been producing their paints, but folks have been using them with great success for many years. I've had a selection of Tamiya paints for a few years, but my 'go to' paints have been VMA. It's only been recently that I got fed up with the issues you sometimes get with them (tip dry, clogged A/B and susceptibility to scratching) so I decided to move to Tamiya - and this is the first time I've had problems.

[Gern]

The first bit jumps out to me. As you say, you don't know what has been added to the paint in the past. Maybe someone had pre-thinned it with an acrylic thinner and it isn't playing nicely with the MLT. I know they can be thinned with either, but I doubt both. Just a thought.

As for the paint flow - yes. If you have reduced the air pressure then you will have reduced the airflow (all other things being equal). Less air going through the 'brush will pull less paint with it.

As has been said, a picture paints a thousand words, so we may be able to help more if we can see the issue.

Can I just check I'm using the right thinner. I've used Mr Color Levelling Thinner 400. Is that correct? And is it just me, or does it have a strong smell of acetone?

[Flip]

Mr Color Levelling Thinner 400

That is what I use with MRP or Mr Hobby Lacquer. To avoid any potential problems, I use Tamiya Lacquer Thinner (more so the Retarder type now). John has both types in the shop.

[Flip]

does it have a strong smell of acetone

No. I open my bottle of acetone for that effect :smiling5:

[Gern]

That is what I use with MRP or Mr Hobby Lacquer. To avoid any potential problems, I use Tamiya Lacquer Thinner (more so the Retarder type now). John has both types in the shop.

Up until recently, I used Tamiya X-20A for thinning their acrylic paints. Should I go back to that as it was originally created for their paints?

[Gern]

No. I open my bottle of acetone for that effect :smiling5:

They both smell the same to me John!

[Andy T]

Can I just check I'm using the right thinner. I've used Mr Color Levelling Thinner 400. Is that correct? And is it just me, or does it have a strong smell of acetone?

That's the one, the 400 is just the bottle size (400ml)

Ive used it successfully in Tamiya XF & LP paints.

[Tim Marlow]

Me too, MLT is my go to thinners with Tamiya, Mr color, and MRP.