Wednesday, October 13, 2010

Keeping Filler in the Body Tube Seams


It's frustrating when Carpenter's Wood Filler pops out of the body tube seams. Depending on the width and depth of the seam, results are unpredictable.
This is an adaption from ideas suggested on TRF posts from BradyCross.

In the picture, the dried filler has been sanded down, just above the body tube surface. I didn't sand the filler all the way down to the surface - yet. The filler is still a slight raised area over the seams. Most of it was removed with 400 grit sandpaper.
The idea is to remove as much as possible, but not get close to where it could pop out of the seam.

A drop of CA was applied to the filler line and spread out down the seam. The CA would "lock" the filler down and glue it in the seam.
Now I can sand off the remaining filler bump to the surface of the body tube without much worry of the filler flaking out of the shallow seam.

I'll post again with the results after priming and sanding.

3 comments:

  1. Hmmm, I have never really noticed my Fill'n'Finish coming out from the spirals on cardboard/paper tubes. A couple of coats of primer and then paint seems to seal them in just fine. The exception may be where there was other damage where the filling was the least of my worries.

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  2. Just to validate your claim Chris; been using superglue to fill in tube seams and use as fin fillets with excellent results. Just remember it's superglue so you'll need to start off with some 200 girt paper then work to some 400 then finish off with 600 or 800 grit sandpaper. With a little work and paicents the results are astounding. Wish I could post a photo of my current project as testimony to the value of superglue.

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    Replies
    1. Hi John,
      Personally I couldn't use Super Glue to fill body tube seams. I find it dries too hard to sand on softer surfaces. I would probably sand into the body tube and balsa trying to take it down to the surface.
      This post was done a few years back. I no longer use CA glue to keep the filler in the BT seams. Maybe I've gotten better at it. It's not needed now.
      You've got to be careful with Super Glue in construction. It has its place but can become brittle over time. I've seen models come apart during boost when the CA glues crack and shatter.
      If this works for you - Great! We've all got out own ways to get rockets built.

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