Super detailing Guillow's P-51D Mustang

[Airframes]

Some good progress here.

 

[Skyediamonds]

Terry, thank you.
Spl Ed, I'll definitely take you up on that.

 

[Skyediamonds]

Unintended consequences: While working on the double planking of the fuselage, I failed to notice how it would affect the vertical stabilizer and rudder. They were both designed originally for the stick & tissue airframe and the"fattening" of the fuselage has distorted the mounting such that the rudder comes up too short. This is a direct consequence of the added material on the read decking. I decided to take a few corrective actions,, but in the end it really boils down to simply extending the length of the rudder at the (slight) expense of maintaining scale fidelity.

 

[Skyediamonds]

Problem solved. As the first picture shows, I compared the discrepancy of the rudder and simply cut out another one from the same 1/4" sheet balsa wood. I lengthened it enough to match the tail cone of the fuselage, sanded it to shape and (for now) all is well. I can anticipate a few more compromises down the road. The question is: what?

I could've sanded down the upper decking or cut away some of the saddle that the horizontal stab would go, but in the end, it really came down to the rudder.

Oops, sorry. I posted the "before" picture by accident. Here's the "after."

 

[Gnomey]

Looks good so far!

 

[Skyediamonds]

One of the things I neglected to mention was the plastic scoop that came with the Guillow's kit. The plastic scoop originally came closed up. At first, I only opened up just a small portion of the inlet. But upon reviewing it and how it really doesn't reflect the true outline of the scoop, I decided to cut all of it down to the lips. Then I followed up with sand paper and a small rat tail file to the corners to make them rounded. Really turned out very nice.

Then the plastic scoop was trial-fitted to the fuselage belly and sanded down to more close tolerances such that the fuselage belly and plastic scoop were literally blended together. Because the plastic was molded in white, I then removed it for painting the insides silver in keeping with the consistency of the all-metal finish.

 

[Skyediamonds]

I simply used a rattle can of silver spray paint. I'm still on my original goal of using Flite Metal foil for the cover of the whole model, save for the wings, and I didn't think it would look appropriate for the metal scoop to have a white interior. It's just these little things that I think will help make a difference.

 

[Wurger]

 

[Skyediamonds]

I've managed to find another picture showing the belly scoop inlet that was spray painted with silver to better advantage. I could have edited my previous post, but I would tend to think that the majority of our viewers would've already seen that post and ignored it and moved on.

So with that in mind, here's the updated picture of that same inlet.

The second picture shows the same inlet before the interior and exterior were painted silver. I realize this is not a very good photo, but looking carefully, one can see how the interior shows off white. If one were to view the completed model, this white would surly stand out and thus to avoid such inconsistency, I painted it silver.

 

[Skyediamonds]

Jumping back to the vertical tail, if you will, I cut out the trim. This was done before committing to anything else as the rudder had to be laid down on the board and I didn't wish to mar, or scratch any extra work that I was going to accomplish as the next series of posts will show.

 

[Skyediamonds]

Looking back at the photo of Big Beautiful Doll, we can see that the tips of both vertical and horizontal stabs are painted black. Since my intentions are to use a highly polished foil for the covering, I figured that it would be prudent to properly prepare the tips for painting instead. This meant that I would have to fill in the wood grain of the balsa wood. For this, I used the ol' Spackling Compound I mentioned in detail awhile back.

The 2nd photo shows the vertical stab masked off with tape prior to applying the compound. Then the compound was carefully applied.

The third photo shows me immediately peeling off the tape before the compound has a chance to dry. This will result in a nice, clean line. If I had elected to cut out the trim tab at this point, I would risk the chance of ruining the finish. So, thinking ahead was one of those (rare) good ideas for me.

 

[Skyediamonds]

The next step was to add the extra balsa wood at the base of the rudder to help smooth the fairing of the rudder to the rear of the fuselage.

After that, I masked off the area and applied compound filler to this area to help 1) fill in the wood grain of the extra fairing and 2) to help feather in the fairing to the rudder

Then I used my fingers to help smooth out the compound with the rudder

From there, I peeled off the masking tape before the compound dried.

Notice that the tip was masked off again for another application of compound. Just like the belly scoop area, this also required me to fill, peel off the tape, (carefully) sand, then reapply the compound to areas the were missed or needed more filler and so on.

This reapplication also will apply to the fairing at the base of the rudder as well. Sometimes three or more applications are necessary to get it just right. Between each application of filler, the tape would be masked off before the compound dried. After the drying of filler, I would reapply the tape prior to sanding. This is to help protect the surrounding balsa wood from excess sanding should the sand paper go past the intended area, which often did.

 

[Skyediamonds]

At the same time while waiting for the filler to dry, I would work on the horizontal stab and elevator. Just as with the rudder, I would extrapolate the trim tabs for the elevator from the drawing as well as the scale hinges (which I forgot on the rudder).

 

[Skyediamonds]

It is my intentions to pose the elevators slightly down.

I noticed that the trims to the elevator were also slightly downward as well. This suggested that the trim tabs acted to prevent the pilot from over controlling the elevators. Am I correct here? If so, what would be the correct nomenclature for the trim tabs? Would they be classified as: servo tabs? Trim tabs? Balance tabs?

Which also means that the hinges will be posed slightly upward. One of the key details I noticed on the hinges was the presence of counterweights. So, now the issue becomes how to properly replicate the hinges on such a small scale. Or, should I simply have the hinges made solid and pose them slightly upward on the theory that no one would notice.

 

[special ed]

Before you get too far along, take a look at the belly scoop, from the front on a full size P-51. I think you will see it is more of an oval or elongated opening rather than the crescent or semicircle Guillows supplied. This came to me because I just posted some P-51 photos in the AvPix Unlimited thread. Hope this doesn't spoil the excellent work you have done.

 

[nuuumannn]

Before you get too far along, take a look at the belly scoop, from the front on a full size P-51. I think you will see it is more of an oval or elongated opening rather than the crescent or semicircle Guillows supplied.

Intake

 

[Wurger]

 

[Crimea_River]

Agree with the guys above. I don't have an answer to your questions about the trim tabs except that I know that some tabs are linked so that they deflect in the opposite direction of the elevators i.e. elevators down, trim tabs up. I don't know if the Mustang ad that feature.

 

[Airframes]

I agree about the belly scoop.
Far as I know, the trim tabs could be set at 'Neutral', and adjusted as required by the trim controls on the console, port side of cockpit.
For filling the wood grain, in the days of all balsa flying models, this was done with sanding sealer and / or banana oil, although I don't know if these products are readily available these days.
However, an easy alternative is to mix gloss varnish (Polyurethane or similar) with talcum powder, to create a thick porridge. This is then brushed onto and into the grain and allowed to set hard. Once set, it is sanded smooth, and if required, further coats are applied and sanded, until the surface is smooth and all the grain filled. A final coat of varnish can be applied to provide a glass-like finish if desired.
This will give a good, smooth surface for painting, and a thin coat of primer, before the main colour, will ensure a good, smooth, hard paint finish.

 

[Gnomey]

Good work so far!