What's gone wrong now?

[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

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

 

[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

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.

 

[Andy the Sheep]

I'm positive there are no serious compressor leaks as the system holds pressure for at least a week after a session.

Gern, I understand (but I might be wrong ) from your explanation that sometimes you don't empty/drain the air tank of your compressor after a painting session. This could lead to air moisture condensing inside the air tank and, subsequently, to rust.
Too damp air and/or rusty water feeding your airbrush could be the cause of your troubles.

 

[Mark1]

I have the same issue sometimes with vallejo gloss clear,usually its because I've mixed the paint to thick and then put to much on to try and level it out.

 

[Flip]

Should I go back to that as it was originally created for their paints?

I would have thought MLT would do a better job because of the retarder. Have you tried adding a bit more retarder only?

 

[Gern]

Gern, I understand (but I might be wrong ) from your explanation that sometimes you don't empty/drain the air tank of your compressor after a painting session. This could lead to air moisture condensing inside the air tank and, subsequently, to rust.
Too damp air and/or rusty water feeding your airbrush could be the cause of your troubles.

I've never drained my compressor Andrea. I have an AS-186 which has a clear reservoir under the pressure gauge. Is that where moisture is supposed to collect? There's a spring loaded plunger at the bottom which I assume is to let out any moisture. I've checked and it's bone dry and I can't see anything inside the reservoir.

 

[Gern]

OK guys, thanks for all the help - again! I've got some new paint and some plastic spoons for testing (Well soaked in warm soapy water and rinsed). I'll be trying things out over the next week and I'll let you know how I get on.

 

[stillp]

I've never drained my compressor Andrea. I have an AS-186 which has a clear reservoir under the pressure gauge. Is that where moisture is supposed to collect? There's a spring loaded plunger at the bottom which I assume is to let out any moisture. I've checked and it's bone dry and I can't see anything inside the reservoir.

There's a brass tap underneath the black tank at the bottom of the AS186 Dave. Try loosening that, with some pressure in the tank.
Pete

 

[Gern]

There's a brass tap underneath the black tank at the bottom of the AS186 Dave. Try loosening that, with some pressure in the tank.
Pete

Ooops!



So how often should I drain my compressor?

 

[stillp]

Well, you won't wear it out by draining too often. Depends on how much you use it, and on the weather - maybe once a week.
Pete

 

[stillp]

You certainly needed to drain that Dave, but personally I still think that your problem is that the paint is too thick. Try an extra splosh of thinners (either MLT or X60).
Pete

 

[Tim Marlow]

Looking at that Dave I’d drain that tank every time you use it. You’ve got more than a little corrosion there and personally I wouldn’t want it to get any worse and damage the tank. Don’t think that’s been causing your problems though, as you say, there’s a moisture trap and filter in the air path (the clear reservoir under the pressure gauge) that stops it getting to your airbrush.