Masking discoloration

[BarleyBop]

thin them

I used the AK gen3 thinner. It may well have to do with drying time... the underbelly was painted a good week before the masking putty... and there was no noticeable discoloration along the upper/lower dividing line of the fuselage.

 

[BarleyBop]

and then add a small rope of blue tack to feather

...interesting. something to try out, which means the putty needn't touch the painted surface.

 

[MJY65]

...interesting. something to try out, which means the putty needn't touch the painted surface.

There may be a tiny bit of contact right along the edge of the tape, but it gets hidden in the blending of the camo colors.

 

[BarleyBop]

Of course, the last consideration, and now my brain hurts, is the primer. It was a MR Aqueous grey.

Thanks to all for your input and advice.

 

[Littlemarten]

Of course, the last consideration, and now my brain hurts, is the primer. It was a MR Aqueous grey.

Thanks to all for your input and advice.

What solvent system do AK paints use? Do they recommend only using their thinner? I don't recognize the abbreviation "MR"—who dat?

 

[Jakko]

MR Aqueous is, I suspect, Mr. Aqueous — the alcohol-based paints from GSI Creos.

 

[Ron2]

What solvent system do AK paints use? Do they recommend only using their thinner? I don't recognize the abbreviation "MR"—who dat?

3rd gen is acrylic and water based. Real colors is lacquer based. I use any water based thinner for AK 3rd gen but use AKs real colors thinner for their lacquer based paints.

 

[BarleyBop]

3rd gen is acrylic

Yup, and I used their gen3 thinner for it.

 

[Littlemarten]

Yup, and I used their gen3 thinner for it.

Well, I have to speculate, then. Acrylic paints cure slowly, and those with aqueous solvent systems cure more slowly than alcohol systems because the water evaporates more slowly than alcohol. If the mask is applied before evaporation (and thus curing) is complete, that could lead to the problem you experienced. It is also possible that the flat paint surface, even if fully cured, absorbed something from the masking putty. Had you used the putty mask to cover the entire area being masked off, the darkening would affect the whole area and might not be noticeable.

 

[BarleyBop]

Yup, that's about as much as we can ascertain, after the fact, in the uncontrolled conditions of this experiment gone slightly awry.

 

[urumomo]

Everything I read about that AK putty makes me a Hard Pass .
None of the masking materials I use have any of its negatives .

from some AI somewhere :
Key Tips for Using AK Putty & Avoiding Issues:

• Prevent Darkening/Residue: The oily, dark residue is common if the putty sits too long on matte paint. Apply it only when necessary and remove promptly after spraying.
• Surface Preparation: Ensure your base coat is fully cured before applying putty to avoid it lifting the paint. Using a gloss or satin varnish under the putty can prevent oily marks.
• Dealing with Sagging: AK putty can sag or flow due to gravity, especially over time. Use it for quick, immediate masking sessions rather than leaving it on overnight.

The majority of the complaints I read were of it welding itself to the model .

 

[BarleyBop]

Hmm, I suppose if I knew what I was doing, speed would not not have been an issue.

In my case it was hours, not days. I can say that I did experience 2 of those 3 issues: darkening/staining and sag (especially with gravity working against it).

In future, if I use it again, I will definitely put something between it and the surface ... or cover the whole area to be masked, not just the edges.

 

[urumomo]

such brand loyalty


Here , smoke this . It won't get you high , but do you like hospitals ?

 

[MRDuczz]

From what I've seen of other folks' results, it must be something I'm doing; their success is what prompted me to try it out!
Having worked with the putty, it has the advantage of being able to shape it in raised cords, that allows use of the airbrush to achieve a 'soft' edge if desired.
Both the liquid film and masking film will produce a crisp edge, which also is perfect for given situations.

I've used Silly Putty quite often for camouflage masking and sometimes it would leave the different color like you have in your photos. I don't know why it happens, but it was always evened out when I put on a clear coat prior to decals. I've never used the AK brand putty.

 

[Demolition]

What an interesting problem, love the troubleshooting in the thread and it was informative, I have nothing intelligent to offer as per usual lol, I've never experienced anything like this. Either way it looks kinda cool.

 

[Edbert]

as much as we can ascertain

One thing with what you saw, I had the EXACT SAME result with different paints.

The one thing we had in common was brand new masking material.

While the masking "worms" were a different product, they were both fresh from their packaging, I suspect there was some sort of preservative on them that did this. I used the same sticky-tack several times later with no ill effect.

 

[Littlemarten]

One thing with what you saw, I had the EXACT SAME result with different paints.

The one thing we had in common was brand new masking material.

While the masking "worms" were a different product, they were both fresh from their packaging, I suspect there was some sort of preservative on them that did this. I used the same sticky-tack several times later with no ill effect.

That makes sense—there may be a volatile component in the compound, left over from the manufacturing process, that causes this. The solution would then be to take the new material out of its container, spread it out on an impervious surface, wait an hour, flip it over, wait another hour, then use it on a paint hulk and see if the problem recurs. The 1 hour wait time is entirely arbitrary.

 

[BarleyBop]

spread it out

...nothing to lose at this point!

Unfortunately, I inherited too many of my grandparents' 'make do' genes, who never threw anything out, saving string on spools fabricated with can tops and old thread spools, some of which later would later be braided into rope... or plastic bags braided into mats, to name a few... country folk born in the 1890s could not help but look at any new material, including plastic, and think: "what could I use this for?" before even considering the garbage bin.

 

[Littlemarten]

before even considering the garbage bin.

"Junk" is something you save for twelve years, then throw out one day before you desperately need it.

 

[Bob T]

Sounds like I should "air out" my new can of AK putty...

Unfortunately, I inherited too many of my grandparents' 'make do' genes, who never threw anything out, saving string on spools fabricated with can tops and old thread spools, some of which later would later be braided into rope... or plastic bags braided into mats, to name a few... country folk born in the 1890s could not help but look at any new material, including plastic, and think: "what could I use this for?" before even considering the garbage bin.

Oh, I get this.
As I approach 70, I am desperately trying to motivate myself to get rid of stuff. A lifetime of stuff. I need a full Swedish death cleaning, before I go and leave the wife a mess. It ain't easy though...

 

[BarleyBop]

It ain't easy though

... especially since the folks left with your 'invaluable stuff' won't have a clue what to do with most of it.

 

[BarleyBop]

So I waited the week, and went back in FREEHAND to try and touch it up, as well as soften the upper/lower fuselage line.
Not gonna claim perfection, but happy with the results.

...now to LEAVE IT ALONE!
Then gloss coat, decals, panel lines, light weathering, matte coat.

Amazing how different each domain within modeling can be: aircraft vs military vehicle vs automotive vs ships vs figures! Not to mention sci-fi, fantasy, Gundam and dioramas, to name a few!

To date though, I've done many softskin vehicles and figures, only two tracked, one rally car, one 'toon ship and now working on my first aircraft.

 

[Edbert]

and went back in FREEHAND

The application and demarcation look great, and it could be the lighting but...is there enough contrast?

 

[styrenemachine]

Ok, maybe it is just me. I kind of like the color tonal variation. I think I will try it and even add some more shading and lighting inside the camouflage pattern.
BTW good looking plane!

 

[BarleyBop]

The application and demarcation look great, and it could be the lighting but...is there enough contrast?

Funny you should mention that. The light at my bench is pretty bright, and the relative contrast of the two colours is low, straight out of the bottle. I feel like there was more before I went back in to correct the discoloration; freehand spraying, though low pressure and narrow fan, took any crispness in the border between the colours out.

On the other hand, in the colour illustrations I've worked from, the tonal values are also quite similar and difficult to differentiate.

Ok, maybe it is just me. I kind of like the color tonal variation. I think I will try it and even add some more shading and lighting inside the camouflage pattern.
BTW good looking plane!

Thanks, it will be a while before I actually get results on purpose, so luck, and experience from building other genres helped a lot!