South Front Yak-1

[Seawinder]

I acquired one of these a few months ago and am considering it for a build in the near future. Closer inspection of the parts unfortunatly reveals sink marks on the fuselage sides corresponding to the internal framework. Most of the sink marks are in the area with the representation of the stretched fabric. Has anybody dealt with this issue yet? I have a feeling it will show under paint if left as is, but filling/sanding is going to damage some of the fabric effect.

Pip

[learstang]

Pip, would you post a picture so we can see (I don't have this particular kit)?

Regards,

Jason

[John Thompson]

I acquired one of these a few months ago and am considering it for a build in the near future. Closer inspection of the parts unfortunatly reveals sink marks on the fuselage sides corresponding to the internal framework. Most of the sink marks are in the area with the representation of the stretched fabric. Has anybody dealt with this issue yet? I have a feeling it will show under paint if left as is, but filling/sanding is going to damage some of the fabric effect.

Pip

Two possibilities:
(1) Apply coats of Mr Surfacer until you're satisfied you've built up enough to fill in the sunken area, then rub it down smooth with isopropyl (rubbing) alcohol applied with a cotton swab. Nail polish remover usually works too, although it depends on the formula - some may attack the plastic, which the rubbing alcohol won't.
(2) Build up several layers of Future, then rub down with Windex or a similar ammonia-bearing window cleaner. I've done this before, to fill in excessive rib detail on control surfaces; the dried Future resists most paints (especially acrylics)  with no problem, but you might want to experiment first.

John

[Seawinder]

Pip, would you post a picture so we can see (I don't have this particular kit)?

Regards,

Jason

Hi Jason.
Here are two shots of the problem area. The sink marks are quite subtle, and the plastic is white, so it was hard to get them to show clearly, but they're there! You can make out the most forward two in the unmarked version, and all four are marked in blue in the second version.




Pip

[Massimo Tessitori]

Hi Pip, I would go with a small amount of putty put with a thin spatula whose edge is parallel to the struts. Then you can work with a curved blade in each single recess between the struts. Then sand carefully parallel to the struts in each single recess.
Regards
Massimo

[Seawinder]

Hi Pip, I would go with a small amount of putty put with a thin spatula whose edge is parallel to the struts. Then you can work with a curved blade in each single recess between the struts. Then sand carefully parallel to the struts in each single recess.
Regards
Massimo

Yes, I think it's do-able with care. It won't take very much filler -- the marks are very slight.
Pip

[4bogreen]

[/quote]

Two possibilities:
(1) Apply coats of Mr Surfacer until you're satisfied you've built up enough to fill in the sunken area, then rub it down smooth with isopropyl (rubbing) alcohol applied with a cotton swab. Nail polish remover usually works too, although it depends on the formula - some may attack the plastic, which the rubbing alcohol won't.
(2) Build up several layers of Future, then rub down with Windex or a similar ammonia-bearing window cleaner. I've done this before, to fill in excessive rib detail on control surfaces; the dried Future resists most paints (especially acrylics)  with no problem, but you might want to experiment first.

John
[/quote]

I would go for option one. Add the Mr Surfacer, then sand the greater part with a glass fiber pen and then rub it down with the isopropyl alcohol. My Modelsvit yak has the same problem 

[Seawinder]

I would go for option one. Add the Mr Surfacer, then sand the greater part with a glass fiber pen and then rub it down with the isopropyl alcohol. My Modelsvit yak has the same problem 

Not surprising since it's the same mold. Thanks for the suggestion, but what is a glass fiber pen? Never come across one of those before.
Pip

[4bogreen]

This is a glass fiber pen. I use it for sanding PE or difficult area's


Regards,

Remco

[Seawinder]

I'm finding myself with more questions:

1. Some of the kit profiles seem to show under-wing stars with black outlines, and such stars are provided, but the instructions only call for stars without outlines. Is it likely that different styles were used for upper and lower surfaces on the same plane?

2. Of the 13 markings options for 2nd production series planes (with the small, half-round windows behind the cockpit), only 5 are shown with radio masts. Were they really so seldom found on machines in 1942?

Pip

[Massimo Tessitori]

Hi Pip,
I have had a look to photos in my archive, and the most part of early Yak-1s is really without mast and black outlines. If you post a scan of the sheet, we can try to find the relative photos.
Regards
Massimo

[KL]

1. Some of the kit profiles seem to show under-wing stars with black outlines, and such stars are provided, but the instructions only call for stars without outlines. Is it likely that different styles were used for upper and lower surfaces on the same plane?

I think I wrote something like this few days ago    :

Stars with black outlines were standard from May 1940 to June 1941.  Black outline was supposed to disappear from stars in summer 1941.
Yak-1s camouflaged in black+green in factory didn't have black outlined stars.

HTH,
KL

[Seawinder]

1. Some of the kit profiles seem to show under-wing stars with black outlines, and such stars are provided, but the instructions only call for stars without outlines. Is it likely that different styles were used for upper and lower surfaces on the same plane?

I think I wrote something like this few days ago    :

Stars with black outlines were standard from May 1940 to June 1941.  Black outline was supposed to disappear from stars in summer 1941.
Yak-1s camouflaged in black+green in factory didn't have black outlined stars.

HTH,
KL

So very sorry to make life difficult for you. It's just that the South Front kit seems to be fairly well researched. None of the profiles show black outlined stars for the upper fuselage; some of them appear to show black outlines for the stars under the wings, although none of the directions call for outlined stars anywhere. At the same time, outlined stars are provided in two sizes on the decal sheet. I was mainly trying to make sense of that somewhat confusing situation.

Pip

[Massimo Tessitori]

Eventually, there are more photos of Yak-7 with black outlines. This could depend on the factory, however it's safer not to use them if it's not demonstrated by a photo.
Regards
Massimo

[KL]

Eventually, there are more photos of Yak-7 with black outlines. This could depend on the factory, however it's safer not to use them if it's not demonstrated by a photo.

The question was specific: Yak-1 only.  Yak-7 was obviously defferent.

Star with black border was an official form of VVS markings.  Black border wasn't an addition to impove contrast.  Two types of stars on one plane would be an exeption.
Enlarged stars were also required by one 1941 order.  Some orders were not specific, so different interpretations were common.
KL