What's gone wrong now?
- Thread starter Gern
- Start date
Sounds like it could be either tip spatter; paint is a little thick or the pressure to low so it's being forced through the nozzle in pulses, or conversely its to thin and drying in the air ... is it like pebble dash or sandpaper? A picture could help.
It could be you mixed them the same 40% but not all paint is created equal.
It could be you mixed them the same 40% but not all paint is created equal.
Can you post a photo of it.
If its like sandpaper, its drying befor landing. = to thin + to much air. if its like pebble dash with larger bit in, most likely to thick and or not enough air.
You might have thinned them the same, but not all paints (even if the same brand) are created equally.
Side note best undercoat/primer for red finish is yellow
If its like sandpaper, its drying befor landing. = to thin + to much air. if its like pebble dash with larger bit in, most likely to thick and or not enough air.
You might have thinned them the same, but not all paints (even if the same brand) are created equally.
Side note best undercoat/primer for red finish is yellow
Waspie
SMF Supporter
That's useful to know, thanks Ian.Side note best undercoat/primer for red finish is yellow
I had the pebbledash effect a few times with primer until I turned the pressure down. (Never knew why then).
I'm spraying at about 27psi according to the gauge. I'll try dropping it - any recommendations?
I guess I'd best remove the paint and start again?
I'd love to be able to show a picture but my camera skills are non-existent. I'm 90% sure it's not tip splatter though. I've seen that before and it appears very random whereas the pebbledash effect I have is very consistent over the whole surface.
Thanks for the tip about the primer colour Ian.
I guess I'd best remove the paint and start again?
I'd love to be able to show a picture but my camera skills are non-existent. I'm 90% sure it's not tip splatter though. I've seen that before and it appears very random whereas the pebbledash effect I have is very consistent over the whole surface.
Thanks for the tip about the primer colour Ian.
27psi seems quite high. I usually airbrush at about 15psi, but I have a side feed brush so it might not be completely transferable.
Sounds like you need a little more thinners as well. From your description I’d say you’ve got orange peeling. I believe this is caused because the paint has been too thick to flow out properly on the surface, drying too fast.
I’d go for a little more thinner, spray a little closer, and use a slightly lower pressure and see if that cures it. You should see a wet paint film on the surface for a little while after application.
Sounds like you need a little more thinners as well. From your description I’d say you’ve got orange peeling. I believe this is caused because the paint has been too thick to flow out properly on the surface, drying too fast.
I’d go for a little more thinner, spray a little closer, and use a slightly lower pressure and see if that cures it. You should see a wet paint film on the surface for a little while after application.
Waspie
SMF Supporter
I'm usually in the 15 to 20 psi range. Only time I have anything higher pressure wise is when I use the AB as a duster to blow away dust of such. Then it's wound back down to my usual 15-20 psi.
The method I use for mixture has been honed after listening to the likes of Tim etc on here.
I start with a 50/50 mix, give it a good stir, then keep adding thinning agent until it drips on its own accord from a brush or the mixer I use. (That works for me). Together with the psi. Took me ages to get it right but once I found what worked I've stuck with it.
The method I use for mixture has been honed after listening to the likes of Tim etc on here.
I start with a 50/50 mix, give it a good stir, then keep adding thinning agent until it drips on its own accord from a brush or the mixer I use. (That works for me). Together with the psi. Took me ages to get it right but once I found what worked I've stuck with it.
In the old days, before I developed common sense, I used to use Ronsol lighter fluid as a dilutent when spraying humbrols. It was a common idea, widely promoted in magazines. They sprayed superbly, but I thought about it one day and realised I was creating a fuel air bomb. I bet it would have been easy to set fire to the airbrush then LOL….Perhaps setting the AB on fire might help .
TAXI
Jim R
SMF Supporter
I use lighter fluid to degrease a model prior to painting but never heard of it as a thinner.
The things we did when we were young and knew no better.
The things we did when we were young and knew no better.
Dave,
I use an H&S Evolution CR Plus. I was getting a similar thing to you and it was driving me insane. I, at the time, was working in the same pressure range as you with a 0.2mm needle as standard (to force the paint through the small gap). Nowadays my standard setup is 0.4mm at 15psi max, sometimes only 10 psi.
The reduced pressure and increased nozzle size aid in:
I must confess that I am unfamiliar with the abbreviation "MLT" but if it includes the words Levelling Thinners then that's spot on
. I would echo the sentiments above that the thinner ratio should be upped to at least 50%.
As an addition, I am really against hype and the latest fashions but I have found a marked improvement by migrating to MRP. The Tamiya paints are really good (I have plenty of them
) but the MRP paints perform markedly better and the issue you report, coupled with the amended AB settings, has been eliminated. The AB settings and thinner ratio should be more than enough as a minimum though!
Happy spraying.
John
I use an H&S Evolution CR Plus. I was getting a similar thing to you and it was driving me insane. I, at the time, was working in the same pressure range as you with a 0.2mm needle as standard (to force the paint through the small gap). Nowadays my standard setup is 0.4mm at 15psi max, sometimes only 10 psi.
The reduced pressure and increased nozzle size aid in:
- reducing tip drying
- reducing resultant clogging of the nozzle
- reducing overspray
- reducing air drying
- reducing "spider" formation
I must confess that I am unfamiliar with the abbreviation "MLT" but if it includes the words Levelling Thinners then that's spot on
. I would echo the sentiments above that the thinner ratio should be upped to at least 50%.As an addition, I am really against hype and the latest fashions but I have found a marked improvement by migrating to MRP. The Tamiya paints are really good (I have plenty of them
) but the MRP paints perform markedly better and the issue you report, coupled with the amended AB settings, has been eliminated. The AB settings and thinner ratio should be more than enough as a minimum though!Happy spraying.
John
MLT is a common abbreviation for Mr Levelling Thinners John
Perhaps setting the AB on fire might help .
TAXI
I've heard that warming primers can improve the finish but I suspect setting fire to them may be just a tad extreme. Still, if all else fails ....
Dave,
I use an H&S Evolution CR Plus. I was getting a similar thing to you and it was driving me insane. I, at the time, was working in the same pressure range as you with a 0.2mm needle as standard (to force the paint through the small gap). Nowadays my standard setup is 0.4mm at 15psi max, sometimes only 10 psi.
The reduced pressure and increased nozzle size aid in:
You will have to have your AB closer to the model, though.
- reducing tip drying
- reducing resultant clogging of the nozzle
- reducing overspray
- reducing air drying
- reducing "spider" formation
I must confess that I am unfamiliar with the abbreviation "MLT" but if it includes the words Levelling Thinners then that's spot on
As an addition, I am really against hype and the latest fashions but I have found a marked improvement by migrating to MRP. The Tamiya paints are really good (I have plenty of them
Happy spraying.
John
I asked about MRP a while ago. Everyone says they are excellent when sprayed but, like Tamiya, very difficult to brush paint. My budget won't allow me to swap all my paints just to improve my spraying so for now I'll persevere with Tamiya. I'll be trying the suggestions offered and I'll let you know how I get on.
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.
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?
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.
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?
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David Lovell
SMF Supporter
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
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
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.
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.
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.
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.
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.
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.