Friday, December 13, 2013

Estes Paveway III Build, Part 9A Upper Tube Length?


That upper BT-20 tube seems longer than the one shown  on the face card picture.
I tried to take a picture of the upper assembly at the same angel as the face card photo.
It was reduced until the lower (BT-60) body tube was about the same diameter. This was overlayed onto the face card picture.
It looks like it is twice the length it should be!
The paint scheme profile picture also shows it to be shorter.

Now the questions - 
Was the supplied tube longer for stability reasons?
The BT-20 is the same length as the supplied motor mount tube. Was this done just for kitting convenience?
Which length is closer to scale? Does it really matter?


From a quick Internet search, here's the GBU-24 Paveway I, II and III.
This kit is based on the third bomb at the bottom.
The upper tube is shorter than the one supplied in the kit.

A rough guess shows the tube is about twice the length of the upper fin root edge. I'll probably end up cutting the tube.



After looking at side views of the model I ended up cutting only 1/2" off the upper tube.
One wrap of masking tape was used as a cutting guide. An old casing was slipped in to provide something to cut against.

It's a small change but does look closer to the face card and above pics.

3 comments:

  1. Chris, I'm curious how you go about sanding off that first coat of primer to get that mottled appearance? It never does that for me when I try this.

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  2. Hi furroy,
    It's just the way I do it, it may not work for everybody else.
    This is gray automotive primer/filler a bit thicker than most primers you find at Home Depot. It is a scratch filler and helps fill in the remaining body tube seams and balsa grain after the CWF step.
    I spray only one coat of the automotive filler/primer. Let dry and remove most of it with 220 grit. If you see any white of the body tube showing through stop and change to 400 grit to remove the last of the primer.
    This leaves the primer in the seams and recesses.
    Then I follow with white undercoats.
    To get to this "mottled" look you might not be sanding down enough to the body tube surface. Primer is really made for car finish scratch fill and an undercoat for better adhesion of the final color coats.
    Even with sanding down this far to surface I've never had any color coats lift of any body tubes or fins.

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  3. Looking at this again:
    It might be the brand of primer you are using.
    I use Duplicolor Primer/Filler from an auto parts store. Be sure is says primer/filler not just primer.
    You mention "sanding off the final coat".
    I only use one coat of this primer/filler, probably thicker than what you would spray.

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