How to cut thin strips of painted decal paper.

Member's Area Hints and Tips Modelling
An area for members to pass on Hint's and Tips for other members.

How to cut thin strips of painted decal paper.

Postby wally » Thu Jan 22, 2015 12:05 am

Hi there, I am going to let you in to a little secret. On occasions I use painted decal paper for various applications on my models, sometimes for touch up / repair, sometimes for other effects. The problem has always been that it seems impossible to cut consistently thin slivers of decal without crazing the paint at the edges.

Holding a straight edge over the paper and using a scalpel / knife results in a clean sharp cut on the side under the ruler, whereas you get a crumbled or crinkly edge on the other side of the cut.
With this Wackett model I could not be assed masking the canopy:
Image
So I sprayed a small section of decal paper with the dark blue (Tamiya Acrylic) and had an idea as to how I could cut some thin slivers. As you can see in the picture above I succeeded and this is how it is achieved:

1. Hold steel straight edge down over the decal paper setting the correct thickness.
2. With a new sharp blade, score the decal paper with 2 light strokes, you will have now:
a. cut through the paint with no damage to the paint and
b. cut through the transfer part of the decal paper. Next
3. Move the straight edge a few mills down from your "score" and this time even using a not so sharp blade, cut with several strokes right through the decal paper backing till the sliver comes off the painted sheet.
4. What you have now is a sliver of painted decal paper with a score down the middle. The measured side of the sliver has both edges nice and hard and straight with no paint crumble or crinkle, the bit where you cut right through the backing paper has only one good edge.
5. Dip the decal sliver in water put on wet paper towel, when loose slide the crappy half off the paper and discard, then apply your nice bit as required to the model.

You see what crinkles up the paper / paint is is pressure required to cut through the backing paper with the gradually increasing thickness of the blade. So the wacketts canopy frames are all painted decal paper, as are the canopy sills nicely covering the joint. The top of the rudder has a sliver of dark blue to correct a paint line part of the rudder join was white due inept masking. The Chippy's wing roots are slivers of light blue painted decal paper. The are a few chips and scratches repaired in such a way.

Use clear decal paper, not white (white paper is too thin and readily curls up tightly when cut in thin slivers.. the paint can't hang on to the surface that well in those circumstances.)
User avatar
wally
Devotee
 
Posts: 2632
Joined: Thu Nov 18, 2010 8:10 pm

Re: How to cut thin strips of painted decal paper.

Postby DesTROYer » Thu Jan 22, 2015 5:23 am

Great tip. Thanks Wally.
User avatar
DesTROYer
Devotee
 
Posts: 3850
Joined: Sat Feb 16, 2013 6:26 pm
Location: 37.8136° S, 144.9631° E

Re: How to cut thin strips of painted decal paper.

Postby David E » Thu Jan 22, 2015 8:37 am

That's how I do most of my canopy frames. The decal strips usually need some solvent and/or future to snuggle down.
I'm not older than dirt, but I do remember when it was new.
User avatar
David E
Devotee
 
Posts: 2808
Joined: Fri Nov 19, 2010 11:45 am

Re: How to cut thin strips of painted decal paper.

Postby RayS » Thu Jan 22, 2015 9:05 am

Wally, have you thought about scoring the paper before you paint it?

I have seen this method done with existing decals where the colour of the decal was not correct. Very good for older miscoloured (single colour) decals.
Ray
*****
Bench stuff:
...lots
Image
User avatar
RayS
Devotee
 
Posts: 1652
Joined: Fri Nov 19, 2010 8:20 am
Location: The Bush Capital

Re: How to cut thin strips of painted decal paper.

Postby wally » Thu Jan 22, 2015 9:36 am

RayS wrote:Wally, have you thought about scoring the paper before you paint it?

I have seen this method done with existing decals where the colour of the decal was not correct. Very good for older miscoloured (single colour) decals.



hmm good thought, though this presupposes that you what size sliver you will require.. with a planned job like the canopy frames yep that should work, though maybe paint will fill the score and end up with a ragged edge again because of it? For unplanned repairs and touch ups you dont know what size to score the paper
User avatar
wally
Devotee
 
Posts: 2632
Joined: Thu Nov 18, 2010 8:10 pm