masking canopies - i'm doin' it rong....

When doing canopies, a brand new blade is essential for success. I've tried Xacto and a couple of other manufacturers and found them to be pretty much the same so brand isn't the problem. I also try to do as little cutting on the canopy as I can. I'll prepare some thin strips of Tamiya tape (I have a piece of tile for this) and then lay them along the inside of the canopy frame. The problem I run into with this method is that while there is enough adhesive to hold the tape in place, it's not strong enough to keep from moving as the tip of the blade is drawn across it. What I do then is adjust my grip and hold it like a scalpel rather than a pencil. This allows me to use a little bit more pressure as I draw the blade across the tape, while minimizing the chance that the tip will get away from me and damage the canopy. Let the weight of the knife do most of the work. You may need to add a little pressure to get things going, but too much can cause problems. I was masking a solar panel on a TIE Interceptor to make a pattern so I could cut out a panel to fill it. I was cutting along the inside edge of the panel and it was like running your knife across a thick window screen. Because I was using too much pressure, when I came to a bump the tip of the blade jumped and nicked the flat surface of the framing around the solar panel. Fortunately, all it took was a little sanding and everything was okay. Had that happened on a canopy, two things would have happened. If I was building for me, I would keep on going and put it on the shelf and be happy with it (and try to ignore the ding). If I were building for a contest, it would have meant purchasing another kit and getting a pre-cut canopy mask set if available. I would add a set of metal scribing templates to your tool box. They come with varying sizes of squares, rectangles, circles, etc. which would aid you in cutting out shapes to help you mask. You can find them in plastic as well, but depending on how good you are with a knife, your circles probably won't be circles for long (but they are cheap and easily replaced). There are circle cutters out there, but I haven't seen one that would work in the sizes needed for 1/72.  What would you need a circle for when masking a canopy?  Picture the front panel of a Spit or Hellcat. Use the circle for the curve at the top and strips for the legs. Go to your local art supply house and look at the templates for architects, you'll find all kinds of shapes you can use. You might also try experimenting with a #10 blade instead of a #11.  Depending on the canopy, more cutting edge than the tip of a #11. Might be a little more controlable under pressure as well. Hope this helps.

That helps a lot actually - lots of good ideas.

One follow-up question as well as some comments below - so you cut very thin strips then all you are actually cutting on the canopy is where those strips come up against the frame rather than all way around?  I think that would help a lot. 

I have a scalpel blade I use for other applications - I think that's the #10 - and it cuts through everything easily.  I've thought about using it to try on the canopies but it's shape would make it difficult to use perhaps?  Maybe I'll try it.  It would be great for cutting strips on a tile though.

I have a plastic scribing template that I've not really tried.  I actually forgot I had it.  I will dig it out and experiment with it some.

I also use my scalpel for cutting canopy masking.  I find it a bit sharper than an X-acto blade.

To help cutting, after the masking tape is down on the canopy, I use a sharp double ended toothpick to press the tape hard into the demarkation lines, outlining what I am going to cut.  That helps prevent any movement of the tape.

 Just a though but I always found single edge razor blades to be sharper than #11 xacto. Also more fragile.

phil172

That helps a lot actually - lots of good ideas.

One follow-up question as well as some comments below - so you cut very thin strips then all you are actually cutting on the canopy is where those strips come up against the frame rather than all way around?  I think that would help a lot.

That is correct.  Most WWII sliding canopies consist of a series of square or rectangular shapes. All you are doing is using the tape to outline the inner border of the square and then trimming it at the corners. Once you have established the border of the area you want to mask, you can fill the area with tape or a liquid masking agent.  The concept is the same for the front canopy, you just have to make allowances for the more complex geometric shapes involved. Hope this helps.

oldermodelguy

 Just a though but I always found single edge razor blades to be sharper than #11 xacto. Also more fragile.

 

For certain. It's what I eventually turn too everytime I am trying to figure out how to get the smallest or finest parts off sprues. I'll have to see sometime if the double edge blades might be even sharper.

And then sometimes you stumble on something that just works.  So I'm working on a couple of canopies today - airfix 1/72 109 and spitfire.  Using the scalpel blade makes it a little easier.  It is a little sharper and it's not as cumbersome as I thought it would be with the larger blade/lack of clear point.  But, I have a sharpened wooden stick that I use to press the tape up into the angles, and I couldn't find it, so I grabbed my scribing tool.  (This is a stainless steel, much sharper than I thought, hook that was made by Squadron *I think*).  So I'm using it to press the tape down and notice that down most of the length of where I was pressing, it cut through.  So I tried it a little more and on a flat surface it cuts better than either blade.  It doesn't seem to work going over a curve, fwiw.

Congratulations on finding your solution! It's always there somewherer if we look.