Paint bubbling in Sparmax SP-20X cup

[Shashman]

Hello all,

 

Apologies if this has been posted before (I'm new 😇), but recently paint has started bubbling in the cup of my brand new (used about 5 times) Sparmax SP-20X airbrush. 

I'm still relatively new to airbrushing so this might be something really simple to resolve... Well, I hope so at least because I never had this issue with my cheap Chinese airbrush this one replaced!

It's happened with Tamiya and Vallejo acrylics and most recently with Alclad Airframe Aluminium. All have been thinned (apart from Alclad) to semi-skimmed milk consistency. Pressures have ranged from 15-30 PSI, just for testing.

To resolve the issue, I've been taking off and cleaning the air cap, tip and needle. Now this seems to work randomly, so I'm confused. 

I'm always meticulous with my cleaning so now I'm starting to get worried that this brand new airbrush which I thought would be an upgrade over the Chinese clone is actually more hassle than it's worth? 😔

 

Thanks in advance!

 

 

[malpaso]

I don’t know the Sparmax but bubbling suggests clogged airways.  Have you stripped and soaked the nozzle assembly in thinners?  Also clean through the paint and air routes once the needle is out.
 

I’m happy using Tamiya or Gunze acrylic but Vallejo I find more awkward each time.  Possibly because it’s water based though I have no problem spraying games workshop paint thinned with water.

 

It took a lot lot more than 5 uses of my H&S before I was comfortably using it each time (I had similarly to you used a cheapy Chinese type for a while) and got better results.  But still there will be the odd paint mix that doesn’t play ball calling for an immediate field-strip rather than sensible cleaning at end of session!  A second more sophisticated H&S still had a learning curve, though the design is similar...but much easier to use now I’ve got the hang of it.

 

Thin, thin, thin.

Clean, clean, clean.

Practice, practice, practice.

 

Cheers

Will

[bmwh548]

Have you been taking the nozzle out each time? Perhaps the rubber seal isn't seated properly or maybe even damaged.

Check for paint build up on the tip of the nozzle cover (inside, outside). Use a wooden toothpick to clean it.

Does the nozzle cover have a rubber seal that goes between it and the body of the airbrush? If it does check to see if it's damaged. Also: don't overtighten the nozzle cover. If you do that it will go lower that it's designed to and possibly sit flush against the nozzle (blocking airflow). 

[Shashman]

Thanks for the replies guys, appreciated!

 

I don't actually take the nozzle off after each use. Is this where I've been going wrong? I have done full strip-down cleans of my Chinese one in the past (even have an ultrasonic cleaner) but this was only after heavier jobs. 

 

I really hope nothing is damaged as like I said, I've only used this airbrush 5 or 6 times and the 'heaviest' use has been applying a coat of Vallejo grey PU primer to a 1/48 Spit😬 Also the rings/washers/seals are meant to be PTFE so I would be extremely disappointed if damage was the source of this problem.

 

I'm at work now, but this evening I'll give the nozzle itself a good check and clean.

[bmwh548]

The nozzle seal is definitely rubber. If the nozzle cover has one it would be rubber too. I might be wrong but I think the only PTFE seal on this model is the one in the "middle" (between the paint cup and the trigger area). I can't find an exploded view on a quick search. 

You should avoid taking the nozzle out unless there's something really wrong with it. The nozzle seal is easily damaged on reassembly.

[Shashman]

The nozzle cap does not have any external seals, however the thread is greasy so probably covered with some kind of wax.

 

I clean the nozzle cap (as well as the other parts) vigorously with a cotton bud dampened with Vallejo airbrush cleaner after every single spray, no matter how minor the job.

 

Could this issue have anything to do with how tightly screwed in the needle chucking guide is, as I have played about with this before?

 

 

 

 

Edited March 2, 2020 by Shashman

[malpaso]

Further to my notes above, I found Vallejo PU primer was terrible stuff as it seems to find it’s way into places it shouldn’t.  It backtracks so it gummed up the air control valve.  Luckily I got the primer free (obvious now why it was given away) now I only use it by hand brushing.

[Shashman]

59 minutes ago, malpaso said:

Further to my notes above, I found Vallejo PU primer was terrible stuff as it seems to find it’s way into places it shouldn’t.  It backtracks so it gummed up the air control valve.  Luckily I got the primer free (obvious now why it was given away) now I only use it by hand brushing.

Hmmm, interesting. It's from their Air range though so also surprising, as it's designed for airbrush use.

 

Right I'll totally dismantle the airbrush this evening and give it a go in the ultrasonic cleaner.

 

I think I'll be switching to Mr Surfacer from now on. Seems everybody swears by the stuff. Can I thin this with IPA or Vallejo thinner? Or will I also need to buy their own brand thinner?

[Mike]

9 minutes ago, Shashman said:

I think I'll be switching to Mr Surfacer from now on. Seems everybody swears by the stuff. Can I thin this with IPA or Vallejo thinner? Or will I also need to buy their own brand thinner?

It's better than swearing at it Mr Surfacer in a bottle can be thinned with cellulose thinners, and I'd recommend Mr Levelling Thinner from Gunze.  It's the shiznit.

[Shashman]

19 minutes ago, Mike said:

It's better than swearing at it Mr Surfacer in a bottle can be thinned with cellulose thinners, and I'd recommend Mr Levelling Thinner from Gunze.  It's the shiznit.

 

I'm going to show my utter noobishness here and ask; Is Vallejo's airbrush thinner cellulose? I've spent so much over the past month on this hobby and if I can get away with using what I already have, all the better 😳

[Mike]

26 minutes ago, Shashman said:

 

I'm going to show my utter noobishness here and ask; Is Vallejo's airbrush thinner cellulose? I've spent so much over the past month on this hobby and if I can get away with using what I already have, all the better 😳

No, Vallejo is acrylic thinners.  Gunze Sangyo make Mr Levelling Thinners (MLT), and it has a self-levelling formula that gives it its name and makes it so good.  If you have any cellulose thinner, use that in the meantime, but do grab a bottle of MLT because it's awesome It's not cheap at around £10 a bottle, but if you use it only for thinning your paint (not cleaning your airbrush), it'll last you years.  I've had a bottle for years and even though I accidentally left the lid off one night, I've still got about a third of it left.  Oh, and it also smells nice compared to many other cellulose thinners.  Ask @Dads203 what mixers to drink it with though - he's the expert

 

Also, sorry for assuming you would know what I was on about.  We forget sometimes that people start at the beginning.  We'd all do well to remember this

[Shashman]

18 minutes ago, Mike said:

No, Vallejo is acrylic thinners.  Gunze Sangyo make Mr Levelling Thinners (MLT), and it has a self-levelling formula that gives it its name and makes it so good.  If you have any cellulose thinner, use that in the meantime, but do grab a bottle of MLT because it's awesome It's not cheap at around £10 a bottle, but if you use it only for thinning your paint (not cleaning your airbrush), it'll last you years.  I've had a bottle for years and even though I accidentally left the lid off one night, I've still got about a third of it left.  Oh, and it also smells nice compared to many other cellulose thinners.  Ask @Dads203 what mixers to drink it with though - he's the expert

 

Also, sorry for assuming you would know what I was on about.  We forget sometimes that people start at the beginning.  We'd all do well to remember this

Thanks, I really appreciate the information 👌

 

This Mr Levelling Thinner does sound like a good investment. Afterall, I've bought such weird stuff as hair spray (don't ask me what my face looked like at the till), floor polish, a hair dryer and about 1000 cotton buds, so it's not like I ain't trying! 😅

 

When you say self-levelling, give me a real world example? 

 

Can I use it with all paints too? I discovered the hard (actually, gloopy) way that Vallejo Model Air cannot be thinned with IPA...  (There's even an emoji for it!!)

[Mike]

12 minutes ago, Shashman said:

When you say self-levelling, give me a real world example? 

 

Can I use it with all paints too?

Self-levelling means that it helps the paint you apply to your model to settle into a level coat, avoiding orange-peel effects (looks like it sounds), and helps to stop paint drying on the tip of your needle, causing blockages that are a PITA to get rid of.

 

You can't use it with all paints, just what are called synthetic acrylics, such as those made by Tamiya, Gunze Mr Color, AK RealColor, Alclad, Enamel paints and such like.  Many acrylic paints such as Xtracrylix, Vallejo, Lifecolor and AMMO are latex-based, and those turn into a disgusting goo when they come into contact with any cellulose thinners, and some will also jellify in contact with Isopropyl Alcohol (IPA or Isopropanol), so if you're ever in doubt, ask here, or test a little in a tiny pot so you don't waste any paint or clog your airbrush.

 

It's still definitely worth a punt for use with Mr Surfacer, and you'll probably find more uses for it down the line.  If you get any of the Synthetic Acrylics, you'll find it improves the spraying experience, adhesion and even the robustness of the finish to later handling, which is great for modellers.  I also find it allows me greater control of the airbrush and spray fine lines without worrying too much about the airbrush clogging.  It's a shame it can't be used with everything, but if you have a look at Ultimate Thinners, you'll find a thinners that is pretty much useful for any acrylic paint, with a handy chart that tells you what proportions to use for best performance.  When I'm using acrylics that can't be thinned with MLT, that's my go-to thinner

[Shashman]

1 hour ago, Mike said:

Self-levelling means that it helps the paint you apply to your model to settle into a level coat, avoiding orange-peel effects (looks like it sounds), and helps to stop paint drying on the tip of your needle, causing blockages that are a PITA to get rid of.

 

You can't use it with all paints, just what are called synthetic acrylics, such as those made by Tamiya, Gunze Mr Color, AK RealColor, Alclad, Enamel paints and such like.  Many acrylic paints such as Xtracrylix, Vallejo, Lifecolor and AMMO are latex-based, and those turn into a disgusting goo when they come into contact with any cellulose thinners, and some will also jellify in contact with Isopropyl Alcohol (IPA or Isopropanol), so if you're ever in doubt, ask here, or test a little in a tiny pot so you don't waste any paint or clog your airbrush.

 

It's still definitely worth a punt for use with Mr Surfacer, and you'll probably find more uses for it down the line.  If you get any of the Synthetic Acrylics, you'll find it improves the spraying experience, adhesion and even the robustness of the finish to later handling, which is great for modellers.  I also find it allows me greater control of the airbrush and spray fine lines without worrying too much about the airbrush clogging.  It's a shame it can't be used with everything, but if you have a look at Ultimate Thinners, you'll find a thinners that is pretty much useful for any acrylic paint, with a handy chart that tells you what proportions to use for best performance.  When I'm using acrylics that can't be thinned with MLT, that's my go-to thinner

Another very helpful post, thank you mate!

 

And yes, as I mentioned in my previous post, I've definitely been glooped before!

 

Come pay day (yes, please, PLEASE come on) I shall be purchasing both. I've noticed that Mr Surfacer comes in different versions with different numbers. From what I've seen in youtube videos, does that indicate the coarseness of the 'grain'?

 

 

[binbrook87]

I've got a Sparmax SP20x and it's really good especially for fine work....but it doesn't seem to like all paints. I use Vallejo mainly and the model air even when thinned seems to clog the nozzle regularly so I only use that paint in my Sparmax Max4 with 0.4mm nozzle. I've recently started using Tamiya and don't get any clogging at all in the SP20x so I think the 0.2 nozzle is a bit more temperamental for some paints. You may need to try some different ones to see which works best. 

[Shashman]

1 hour ago, binbrook87 said:

I've got a Sparmax SP20x and it's really good especially for fine work....but it doesn't seem to like all paints. I use Vallejo mainly and the model air even when thinned seems to clog the nozzle regularly so I only use that paint in my Sparmax Max4 with 0.4mm nozzle. I've recently started using Tamiya and don't get any clogging at all in the SP20x so I think the 0.2 nozzle is a bit more temperamental for some paints. You may need to try some different ones to see which works best. 

Ah good to hear from another SP-20X fan

Yes, I picked the SP-20X because at that price and based on the reviews I read, it seemed very decent and good for detail work. I mean I came from a Chinese clone (which to be fair, was perfect as an introduction airbrush) so I was looking for a branded airbrush. I guess being better engineered and machined to a finer standard, it was never going to be as rough and ready as the Chinese one.

I do have a few Tamiya paints which I've used successfully, most recently cockpit green for my Spitfire XIV interior. To be honest I've mainly been buying Vallejo because they're cheap and easy to find on Amazon with prime delivery. I am still only just getting back into the hobby and finding my feet so at this stage I'm trying different brands.

[Mike]

3 hours ago, Shashman said:

I've noticed that Mr Surfacer comes in different versions with different numbers. From what I've seen in youtube videos, does that indicate the coarseness of the 'grain'?

Pretty much.  500 will act more as a micro-filler than 1000, but 1000 will give you a smoother surface.

 

A quick note about goop, and using MLT.  Whenever you transition from acrylic to cellulose/enamel or back again to a lesser extent, always make sure your airbrush is scrupulously clean as any gunge that's trapped inside your airbrush will react badly with the MLT and do the jelly-dance.  This will show itself by blocking your airbrush, sometimes causing spitting when a chunk comes through.  To avoid it, clean your airbrush well, and run a little bit of the thinners you're going to use through it to wet the cup and flush out any remainder of the previous type.  If you ever get unforeseen blocking/spitting, just chuck the contents of your paint cup in a gallipot (little plastic measuring cup - available on eBay.  Invaluable), and clean your airbrush again.  A pain, but worth it.

 

Just to go back to your bubbling issue although I'm sure someone's already answered, that can sometimes be caused by a blockage, or even something as simple as your needle or air cap being a little bit loose.  Snug them up and try again as your first response, then look deeper.