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AFV Painting & Weathering
Answers to questions about the right paint scheme or tips for the right effect.
How to seal acrylic paint?
YellowAvalanche
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Posted: Monday, October 01, 2018 - 10:14 PM UTC
Hey together!


I am facing some basic issues with applying filters, for which I didn't find an answer yet. Counting on you, guys!

I primed with Vallejo bottle-primer. Painted the model with Mig acrylic paint, and then applied a Mig enamel-based filter, with solvents.
The underlying paint almost immediantly starts to dissolve, leaving the primer layer visible.

I also tried it with a layer of Vallejo gloss varnish over the Mig Paint, but no improvement at all..

Don't know if it was discussed before.

Thanks for your help,

Patrick
varanusk
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ARMORAMA
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Posted: Monday, October 01, 2018 - 10:36 PM UTC
Hello Patrick,
This is very strange, neither acrylic paint or varnish should be affected by an enamel wash.

How long did you let the paint dry? Was it thoroughly shaken before applying? Can you test other bottles of paint?
YellowAvalanche
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Posted: Monday, October 01, 2018 - 10:56 PM UTC
Hey Carlos,

I tryed it with Vallejo Model Air Paint as well. The same issue.
It was shaken well before use, I would say 1 minute gets close to this.
The paint dried for almost 5 days, before I applied the filter, so it should have been quite dry.

varanusk
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ARMORAMA
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Posted: Tuesday, October 02, 2018 - 12:54 AM UTC
Definitively strange. Maybe the primer is faulty? As said, it should not have affected at all...
Vicious
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Posted: Tuesday, October 02, 2018 - 10:51 AM UTC

Quoted Text

Definitively strange. Maybe the primer is faulty? As said, it should not have affected at all...



Quote ... very strange I have already used AK and Ammo washes and filters, home made stuff, oils with turps and white spirits directly on acrylics of various brands (life colors, Humbrols, Vallejo, Citadel, Italeri, Andrea and Mission Models) or with various clears coats without any problem even directly on Humbrol enamels, maybe I'm lucky or I have a very light hand, however I never do general washes but only pin washes anyway it should not change much

Kevlar06
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Posted: Tuesday, October 02, 2018 - 11:53 AM UTC

Quoted Text


Quoted Text

Definitively strange. Maybe the primer is faulty? As said, it should not have affected at all...



Quote ... very strange I have already used AK and Ammo washes and filters, home made stuff, oils with turps and white spirits directly on acrylics of various brands (life colors, Humbrols, Vallejo, Citadel, Italeri, Andrea and Mission Models) or with various clears coats without any problem even directly on Humbrol enamels, maybe I'm lucky or I have a very light hand, however I never do general washes but only pin washes anyway it should not change much




If I read it right-- he has the problem of Enamel washes over acrylics, and its not unusual at all for an acrylic to react with an enamel thinner. Remember, Enamel thinners are pretty "hot" in comparison to acrylic paint carriers. Its really a "myth" of modeling that you can paint enamels over acrylics-- or acrylics over enamels--you can get away with it for sure if you use an AB and light coats, but if you are soaking the acrylic base with a caustic enamel washes (which it sounds like he's doing) you should expect trouble. And then there are Ammonia and ISP based Acrylics and there are Acrylic Lacquers. Acrylic lacquers (like Tamiya) are formulated to withstand pretty hot thinners (their lacquer is close to true lacquer thinner). ISP based and ammonia based acrylics will succumb to enamel thinner depending on the quantity used. Acrylics over enamels are a better way to go, (although Tamiya's thinner will also attack enamel paint. white spirits, turpentine, turpenoid, and mineral spirits are fairly mild, whereas enamel "paint thinner" is much stronger, so depending on the thinner being used, it can also cause problems with an acrylic base. I'd say check to see what each type of thinner will do to a test "swatch" of acrylic paint. And don't forget your primer-- primers are applied to give the second layer of paint something to "bite". If your primer is not up to par, the second layer of paint might peel right off given enough enamel thinner.
VR, Russ
BunkerBuster
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Posted: Tuesday, October 02, 2018 - 12:37 PM UTC
I've always used Testors Acryl gloss clear before doing any washes over the base paint. It's an extremely tough clear coat once dry. The only thinner that will affect it is true lacquer thinner.
Kevlar06
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Posted: Tuesday, October 02, 2018 - 01:13 PM UTC
Yes, I forgot to mention you need a good barrier. I use Testors Dullcoat in the spray can, decanted from the container right into my AB (I get a finer, better controlled spray that way). I let it dry for 24 hours, then I apply my washes. It sounds like you were using an Acrylic (IPA, Ammonia or H20) based barrier, so of course it wouldn't do much to protect from an enamel thinner wash. Dullcoat is lacquer based, and provides an effective barrier for enamels (but even lacquer based barriers will succumb to heavy enamel thinner washes--so go easy). You can also use an oil based wash (I like Windsor and Newton--Abteilung 501 is good, but more expensive for about the same thing) with turpenoid (which is a synthetic turpentine and comes in various strengths) which would probably work fine too, and is a little less "hot".
VR, Russ
deathdork
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Posted: Tuesday, October 02, 2018 - 04:04 PM UTC
how about the classic future floor polish solution
Vicious
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Posted: Tuesday, October 02, 2018 - 04:14 PM UTC

Quoted Text


If I read it right-- he has the problem of Enamel washes over acrylics, and its not unusual at all for an acrylic to react with an enamel thinner. Remember, Enamel thinners are pretty "hot" in comparison to acrylic paint carriers. Its really a "myth" of modeling that you can paint enamels over acrylics-- or acrylics over enamels--you can get away with it for sure if you use an AB and light coats, but if you are soaking the acrylic base with a caustic enamel washes (which it sounds like he's doing) you should expect trouble. And then there are Ammonia and ISP based Acrylics and there are Acrylic Lacquers. Acrylic lacquers (like Tamiya) are formulated to withstand pretty hot thinners (their lacquer is close to true lacquer thinner). ISP based and ammonia based acrylics will succumb to enamel thinner depending on the quantity used. Acrylics over enamels are a better way to go, (although Tamiya's thinner will also attack enamel paint. white spirits, turpentine, turpenoid, and mineral spirits are fairly mild, whereas enamel "paint thinner" is much stronger, so depending on the thinner being used, it can also cause problems with an acrylic base. I'd say check to see what each type of thinner will do to a test "swatch" of acrylic paint. And don't forget your primer-- primers are applied to give the second layer of paint something to "bite". If your primer is not up to par, the second layer of paint might peel right off given enough enamel thinner.
VR, Russ



I repeat in my experience with enamel / oils paints, washes, filters directly over water acrylics and vice versa, with or without clear cotes, I have never had any problem with both hardwere store thinner as turps, low odor turps, pure gum turps , white spirit or with humbrol enamel thinner or other more 'expensive and of good quality, I have never had problems with both AB and brush, clearly I would never do the same thing with laquer, however, my experience can' differ from others, it seems that these problems often happen more frequently in the US and it gives me to think that some of your thinner are more 'hot that in Europe and Australia the 2 continents where I lived and modeled, even the names of the various thinner change from nation to nation.....for me it is a myth of modeling that you can not go with enamel/oils on acrylics without a barrier of protection .... everyone have is own experience...
mudcake
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Posted: Tuesday, October 02, 2018 - 06:44 PM UTC

".....and then applied a Mig enamel-based filter, with solvents"

What solvents? That might be the answer to what happened.

I've had same experience as Vicious, no problems.

YellowAvalanche, ALWAYS practice/try out new paints, filters, washes, techniques etc. on an old scrap piece of plastic or model. That way you won't be risking your model.
warmonger
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Posted: Tuesday, October 02, 2018 - 09:51 PM UTC
I always put a coat of future on mine. That should protect it from about everything except Windex.
Klaus-Adler
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MODELGEEK
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Posted: Tuesday, October 02, 2018 - 10:31 PM UTC
I use Games Workshop Purity Seal and that seems to a great job, and i haven't had any issues with using solvent based washes or filters over it Games Workshop Purity Seal
YellowAvalanche
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Posted: Wednesday, October 03, 2018 - 06:33 PM UTC
Hey guys,

at first, thanks for your many replys!
To mention, I am moddeling since I'm 9 years old, and since 4 years I switched to acrylic paints.

I always use a primer, that's no problem.



Quoted Text

".....and then applied a Mig enamel-based filter, with solvents"

What solvents? That might be the answer to what happened.



Oh, sorry if it was wrong expressed. There is no additional thinner used.
As an for-real example, here the steps I used on my Firefly, with the products behind of them:

1. Vallejo Primer (from the bottle)
-> Let dry for 24h
2. Mig acrylic paint (https://www.migjimenez.com/en/real-colors/410-scc-15-british-1944-45-olive-drab-.html)
-> After that, let everything dry for at least 24 hours.
3. Mig Filter (https://www.migjimenez.com/en/filter-jars/357-brown-for-dark-green-.html)
-> The filter starts to dissolve the paint, and when you go over the same spot again, you whipe it right off.

That's really odd to me, but it's common sence, that acrylics get dissolved by thinners..

But two years earlier, I used Vallejo Model Air acrylic paint, with the same filters, same approach, and the paint didn't seem to come off.
varanusk
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ARMORAMA
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Posted: Wednesday, October 03, 2018 - 08:03 PM UTC
Something is obviously wrong here. Your sequence seems correct, and it is not a myth that you can safely use enamels or oils over acrylics: I (and many others) have been doing so for years without issues.

Did you use any thinner for the paint?

I can only recommend you to change each product, one at a time, on an old kit and see which one could cause the troubles...
YellowAvalanche
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Posted: Wednesday, October 03, 2018 - 08:05 PM UTC
Yeah, it seems that I would have to eliminate the variables of the issue.. maybe trying out an enamel-based clear coat?
Vicious
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Posted: Wednesday, October 03, 2018 - 08:23 PM UTC
is soo strange to me i always do (AK/Ammo) filter or directly on acrylic paint or on acrylic AK-ultra matt varnish 183 without issue...i do also figurines with acrylics base ad after with oils without any clear/varnish and some time i dont like the result and wash the oils off with hardware store turps or withe spirit and never one single problem...do some test and try also instead using the filter try only with some enamel thinner like turps or similar to see what happens
mudcake
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Posted: Wednesday, October 03, 2018 - 08:32 PM UTC
I'm wondering if maybe you're spraying on a very thin coat and that is causing it to come off.
YellowAvalanche
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Posted: Wednesday, October 03, 2018 - 08:39 PM UTC
Also to mention: I spray the Mig paint directly without thinners, out of the AB.
Further, I tested how the paint reacts to humbrol enamel thinner; It dissolves the paint and even the primer.
Vicious
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Posted: Wednesday, October 03, 2018 - 08:59 PM UTC
Can be what Tony say coat so thin that the thinner leak underneath and dissolve/lift the paint with the base I am usually little bit to heavy maybe is for that I never have that problem
Kaktusas
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Posted: Wednesday, October 03, 2018 - 09:38 PM UTC
Theres one more variable, called "force". If you rub your model with brush soaked in enamel filter hard enough, acrylics will start to come off (especially around edges). I almost never have problems with washes, as you dont brush them realy, but you have to go gentle with filters, and not use "force to remove excess wash/filter with brush soaked in thinner (like white spirit). The longer i wait, the easier it is, but if i do it carefully, i can do all steps one after another without too much trouble. Sometimes it seems natural to us, and we just cant replicate results achieved by beginners (just like you cant jerk your car when its starting to move, even intentionally).
YellowAvalanche
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Posted: Wednesday, October 03, 2018 - 10:08 PM UTC

Quoted Text

Theres one more variable, called "force". If you rub your model with brush soaked in enamel filter hard enough, acrylics will start to come off (especially around edges). I almost never have problems with washes, as you dont brush them realy, but you have to go gentle with filters, and not use "force to remove excess wash/filter with brush soaked in thinner (like white spirit). The longer i wait, the easier it is, but if i do it carefully, i can do all steps one after another without too much trouble. Sometimes it seems natural to us, and we just cant replicate results achieved by beginners (just like you cant jerk your car when its starting to move, even intentionally).




I never use too much force. I just gently streak the filter over the model. But even with no force on the surface at all, it comes off.

I don't see myself as a beginner, since I'm into the hobby for a long time. But this effect is new to me, and I cannot find an answer.
Kaktusas
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Posted: Thursday, October 04, 2018 - 05:52 PM UTC

Quoted Text


I never use too much force. I just gently streak the filter over the model. But even with no force on the surface at all, it comes off.

I don't see myself as a beginner, since I'm into the hobby for a long time. But this effect is new to me, and I cannot find an answer.


Dont take it personal. By saying "force" i mean rubbing, repeated strokes etc. I try to achieve everything with 1, max 2 strokes. As with every material, you must find optimal way to work with it. For AMMO filters, i find them quite strong (too opaque), thus applying small amount is tricky. So i use white spirit to wet brush, then apply diluted filter. Gloss coat somewhat helps, but i can still feel paint softening. Thus i got to plan ahead, so that area coated with filters is not touched by anything until it cures.
Same goes for "novice". Its not that you dont have experience in modeling, you just need more confidence working with given paint/filter products. There is an option using acrylic weathering products. This would completely eliminate your problem.

And remember, "If brute force doesn't solve your problem, you are not using enough"
YellowAvalanche
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Posted: Thursday, October 04, 2018 - 06:00 PM UTC
No problem, I don't take it personal

Yea, I observed, that going over the same surface for 3 times even without using any kind of pressure, makes the paint come off.

I'll try to do it with just one, and I'll be fine, I hope.

BTW:
In the next few days, I hope I can share some pics of the Firefly with you guys
 _GOTOTOP