Best approach to undercoating / masking this?

Started by Knightflyer, July 09, 2018, 08:09:03 AM

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Knightflyer

Following my recent trip to Germany I've developed a bit of a thing about ADAC helicopters (more about them elsewhere)

I've bought various 1/72nd scale BO-105s, BK-117s and EC-135s and have ended up with a spare BK-117, which I intend do do as below


From those of you with much greater experience of undercoating and masking for 'bright' schemes as below ......any tips please?


Oh to be whiffing again :-(

Dizzyfugu

"Good luck"?  :o

Common sense would suggest a yellow base coat overall on top of a very light primer base, then masking the stripes and add a coat of red.

JayBee

Despite what you might think, the best colour for an undercoat for yellow is PINK, not too dark a shade.
The red would also go perfectly well over that.

Jim
Alle kunst ist umsunst wenn ein engel auf das zundloch brunzt!!

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They are just physical manifestations of collisions between enigma & conundrum particles.

Any aircraft can be improved by giving it a SHARKMOUTH!

Knightflyer

Quote from: Dizzyfugu on July 09, 2018, 08:19:54 AM
"Good luck"?  :o

Funnily enough I was expecting some replies along the lines of "Good Luck" and "You Fool!"  ;D

Quote from: JayBee on July 09, 2018, 08:36:04 AM
Despite what you might think, the best colour for an undercoat for yellow is PINK, not too dark a shade.
The red would also go perfectly well over that.

Jim

I thought I'd seen about pink as an undercoat for yellow very recently on here? But I can't think what the model being discussed was?
Oh to be whiffing again :-(

NARSES2

Yup, pink is probably one of the best undercoats for yellow, especially if using a brush. Make sure that as Jim says it's not to dark a shade though. I have a bottle of Vallejo Pink which I then use in a ratio of about 1 pink to 4 white to get my base coat.

As for masking ? You could always "seal" the edges of the masking strip with Klear or similar. You mustn't be heavy handed with it and in all honestly you need to be minimalist with it, otherwise you will pull paint up, but with care it will work on something like that where it might be difficult to seal the masking strip properly simply by burnishing.
Do not condemn the judgement of another because it differs from your own. You may both be wrong.

Weaver

Another way to seal the edges is to give the model another light coat of the masked-off colour AFTER the masking's applied. That means that any runs or bleeds match the masked off colour instead of contrasting with it. In this case, you'd spray overall yellow, then mask off the yellow stripes, then give it another coat of yellow, then red. Any leaks would be yellow-on-yellow and therefore ignorable or at worst, easier to clean up.
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"I dunno, I'm making this up as I go."
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PR19_Kit

Fiendish in the extreme H, I've never heard of that idea before.  :thumbsup:
Kit's Rule 1 ) Any aircraft can be improved by fitting longer wings, and/or a longer fuselage
Kit's Rule 2) The backstory can always be changed to suit the model

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Regards
Kit

Knightflyer

Quote from: Weaver on July 11, 2018, 01:06:20 AM
Another way to seal the edges is to give the model another light coat of the masked-off colour AFTER the masking's applied. That means that any runs or bleeds match the masked off colour instead of contrasting with it. In this case, you'd spray overall yellow, then mask off the yellow stripes, then give it another coat of yellow, then red. Any leaks would be yellow-on-yellow and therefore ignorable or at worst, easier to clean up.

Okay - I think I follow that - but why doesn't the final coat of red not leak also in the same place as where the second coat of yellow might?
Oh to be whiffing again :-(

Weaver

Quote from: Knightflyer on July 11, 2018, 01:25:02 AM
Quote from: Weaver on July 11, 2018, 01:06:20 AM
Another way to seal the edges is to give the model another light coat of the masked-off colour AFTER the masking's applied. That means that any runs or bleeds match the masked off colour instead of contrasting with it. In this case, you'd spray overall yellow, then mask off the yellow stripes, then give it another coat of yellow, then red. Any leaks would be yellow-on-yellow and therefore ignorable or at worst, easier to clean up.

Okay - I think I follow that - but why doesn't the final coat of red not leak also in the same place as where the second coat of yellow might?

Sorry, good question (didn't explain that too well) ! The red doesn't leak because the second coat of yellow has already sealed up the gaps in/under the masking. We're generally talking about tiny gaps in corners or slight creeps where the edge of the masking tape isn't burnished down properly. The second coat of yellow should be more than enough to seal such gaps: if they were any bigger, you'd see them and do something about them at the masking stage.

You have to be careful not to overdo the sealing coat mind you, otherwise you end up with a massive step at the mask line.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

NARSES2

Quote from: PR19_Kit on July 11, 2018, 01:15:38 AM
Fiendish in the extreme H, I've never heard of that idea before.  :thumbsup:

Me neither, mind you I'm still struggling to understand it ??
Do not condemn the judgement of another because it differs from your own. You may both be wrong.

Steel Penguin

now that is cleaver, thank you ill have to remember it  :thumbsup:
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Weaver

I can't take credit for it folks: I'm pretty sure I read about it on here a long time ago actually.

Chris:

Runs and leaks happen when masking isn't perfectly sealed to the surface right? Either there's a panel line going under the edge, or there's an internal corner that you just can't get the tape fully down into, or there's a gap between pieces of tape that you missed burnishing down, or something else like that. These tiny gaps let (in this instance) red from the second coat leak onto the masked-off yellow from the first coat. Because the gaps are small, the red also seals those gaps, so that, if you were, for instance, to spray black on next, the black wouldn't leak under the masking in the same way.

The trick is to exploit this sealing effect in a positive way. If the next coat of paint after the masking is the same colour as what's under the masking (yellow in this instance) then a) the leaks won't matter because they'll be the same colour as the first coat, and b) the leaks will seal the gaps so that when you put the red on it won't be able to leak.
"Things need not have happened to be true. Tales and dreams are the shadow-truths that will endure when mere facts are dust and ashes, and forgot."
 - Sandman: A Midsummer Night's Dream, by Neil Gaiman

"I dunno, I'm making this up as I go."
 - Indiana Jones

Knightflyer

Quote from: Weaver on July 11, 2018, 06:16:21 PM
I can't take credit for it folks: I'm pretty sure I read about it on here a long time ago actually.

Chris:

Runs and leaks happen when masking isn't perfectly sealed to the surface right? Either there's a panel line going under the edge, or there's an internal corner that you just can't get the tape fully down into, or there's a gap between pieces of tape that you missed burnishing down, or something else like that. These tiny gaps let (in this instance) red from the second coat leak onto the masked-off yellow from the first coat. Because the gaps are small, the red also seals those gaps, so that, if you were, for instance, to spray black on next, the black wouldn't leak under the masking in the same way.

The trick is to exploit this sealing effect in a positive way. If the next coat of paint after the masking is the same colour as what's under the masking (yellow in this instance) then a) the leaks won't matter because they'll be the same colour as the first coat, and b) the leaks will seal the gaps so that when you put the red on it won't be able to leak.

Thanks Weaver, your further explanation of your initial explanation clarifies that nicely for me  :lol: I presume the same masking approach would work perfectly for things like RAF Target Tug aircraft etc
Oh to be whiffing again :-(

NARSES2

Quote from: Weaver on July 11, 2018, 06:16:21 PM

Chris:

Runs and leaks happen when masking isn't perfectly sealed to the surface right? Either there's a panel line going under the edge, or there's an internal corner that you just can't get the tape fully down into, or there's a gap between pieces of tape that you missed burnishing down, or something else like that. These tiny gaps let (in this instance) red from the second coat leak onto the masked-off yellow from the first coat. Because the gaps are small, the red also seals those gaps, so that, if you were, for instance, to spray black on next, the black wouldn't leak under the masking in the same way.

The trick is to exploit this sealing effect in a positive way. If the next coat of paint after the masking is the same colour as what's under the masking (yellow in this instance) then a) the leaks won't matter because they'll be the same colour as the first coat, and b) the leaks will seal the gaps so that when you put the red on it won't be able to leak.

After reading this and the original post again, plus scribbling a few notes (I often find scribbling things down helps my brain comprehend) , I think I now understand the principle. I'll give it a try at the next most suitable opportunity.  :thumbsup:
Do not condemn the judgement of another because it differs from your own. You may both be wrong.