The annoying thing about this kit is the body tube. Not because it’s square but because of the spirals. They’re deep and wide enough that… look, I am not anal about tube spirals. There are few rockets I’ve built where I was really concerned about the spirals being a little bit visible. Most of the time with Estes tubes, the spirals are shallow and narrow enough that I just count on the filler primer to do an adequate job of addressing them. (And don’t even talk about launch lug spirals; I’ve never even considered trying to fill those. My attitude is, launch lugs are ugly, spirals or no spirals, and the best way to improve their appearance is to not look at them.)
But most of the time I do not want the spirals easily visible from ten feet away, and on this rocket, filler primer was not going to make that happen.
So I got out the wood filler, which had mostly dried out even though I put it in a more airtight container than it came in. I used most of what was still workable and then went to the store and bought another container. I would’ve gotten only 8 ounces but the 16 ounce container was only $1 more and I couldn’t see paying that much more per ounce — I’ll probably get through more than 8 ounces of it, right? Right?
Hm. I now own a vacuum sealer. I wonder if putting the container inside a vacuum sealed bag would help keep it from drying out?
It’s been a long time since I’ve actually filled spirals and this time I thought I’d try some of the ideas Dan Petrie posted about a couple of years ago. I bought some plastic razor blades a while back. I had a syringe which on close examination turned out to have lost its seal, but I found another at the drug store.
Of course with this tube there’s an additional complication. Or a lot of them: holes. I was going to have to fill the spirals without also messing up the laser cut holes in the tube. I wasn’t looking forward to it.
The syringe was an interesting idea. I’ve never been happy with trying to use a hobby knife to apply filler as Chris Michielssen does and I was curious to see if the syringe would work better. Well, yes and no. In places it did. In others I had trouble getting the filler to flow well, even though I thinned it beyond what I thought it might need. I’d get nothing and then a huge glob.
“This thing’s meant for thin liquids,” I thought, “not stuff with the consistency of… hmm… icing?”
Which led — after I was done — to my Googling cake decorating supplies. There actually are icing syringes, though the ones I saw mostly seemed too large and not conducive to one-handed operation, which you kind of need to go around a body tube. What I liked better were icing squeeze bottles, but then I said, oh, duh:These bottles are what I use all the time for glue, and would probably work fine for squeezing thinned wood filler onto a spiral. That bottle may be too small for the job but they come in larger sizes. (I bought mine at an art supply store.) The main difficulty would be in filling the bottle through the very narrow mouth. I imagine what might work is to put some filler and water in a zip bag, seal it up, squeeze it around to mix (opening it to add more water or filler needed), and then cut off a corner of the bag and squeeze the contents into the bottle.
For that matter, if you have an empty one of these you might be able to repurpose it:Or, ya know, these, especially if you have a big rocket to deal with? Or if you wanted to thin a lot of filler, dump it in the bottle, and then vacuum seal it until the next time it was needed? Except vacuum sealing might just squeeze all the contents of the bottle out. Never mind.
Hmm, wonder if you could freeze it, and then vacuum seal it.
Anyway, I was not all that happy with the syringe, but the plastic razor blade seemed to work well. The result was rather sloppy (no, let’s be honest, I was rather sloppy) but it may be okay after sanding.(Sanding I do not find to be a problem. Yes, it raises body tube fibers. But then you hit it with filler primer, sand, more primer, sand, and it’s fine.) I had to go into basically every one of these holes with the back of a hobby knife blade and clean them out, and I had to wad up a paper towel and push it through a couple of times to get globs of filler out of the inside of the tube. And I suspect the spirals are not filled quite as well as they could be, but they do seem pretty good, and like I said, I’m not that anal about it. Hopefully after sanding and priming it’ll be okay.