1) My final bonus mystery photo I closed with last time has absolutely everyone stymied!
or
2) I'm the only person who ever sees this blog.
I favor (2). So if you notice in that pic, the motor mount is securely glued and filleted into place in the body tube. Unfortunately, I neglected to glue in the motor block, which you can see sitting beside the body tube. I neglected to double check the instructions before gluing the motor mount in. So, kids, do you see why you should seek wiser counsel if you wanna learn to build rockets? Anyhow I'm going to count on the good old engine retainer hook to hold the motor in at the forward end during liftoff & hope (pray, really) that it holds the motor in at launch.
So I got all the fins spot-filled with CWF, over areas where the balsa still appeared to be bare:
Afterwards I sanded everything smooth again with 400 grit sandpaper. Then I glued the fins on one at a time with the Estes Fin Alignment Guide. When I first put the rocket onto the guide I noticed that the little paddles on the guide didn't really line up too well with the fin lines I had drawn by ticking the body tube's bottom using the little round guide, then extending from those tick marks using the Ultimate Body Tube Marking Guide. So I bit the bullet, photocopied the instructions and cut out the body tube marking guide. After wrapping this around the tube it was clear that I had gotten off on my marks, so I re-drew the lines. Everything looked all better afterwards:
As previously mentioned I'm using Titebond Quick & Thick (hereafter TBQT) in this build. It's a joy to use for sticking fins on, IMHO. I apply a line of glue to the fin's root edge, wipe it off & let that dry for one minute, then reapply a line of glue and stick the fin on. I used a clamp on the first fin only, but I don't think I needed to use any clamps, really - they tend to pull the fin off the guide line. And with this glue, after reapplication of the glue to the root edge the fin sticks in place right away and all I needed to do was double check that the fin aligned with the aft end of the tube and the guide line and step away.
Above, I had just glued the fourth fin on and things are looking good! After the last fin dried I removed the rocket from the guide:
Then I glued the launch lug on & filleted that. I chose not to use CWF or anything to fill the spiral in the lug for this kit.
Finally it was time to fillet the fins. I was looking forward to doing this with the TBQT. I decided the fillets I made for the Baby Bertha were too flimsy. I still have to fly her to see if I'm right lol, and I just saw tomorrow's launch is canceled. Bummer. Anyway I used the masking tape technique again for these fillets but I put the tape way wider apart to theoretically produce beefier fillets. There was probably a good 1/2" channel into which I streamed the glue. This proved to be an unwise choice, as they say.
When I was done with the first set the fillets looked like 1/2" to 3/4" exuberant, white, heaped-up keloid scars. I couldn't remember if the technique I read had me scraping off the excess glue or not (pro tip: IT DID). So I chose to just leave these fillets alone & let them dry. Here's how they looked after over 24 hours of drying:
As you see the one on the left is still somewhat white. I think it's fascinating to see that the glue is starting to collapse in on itself, making a nice straight line. After I had applied the one on the left I toned down on squeezing out the glue for the right-hand one so that one is almost totally clear and collapsed. Here's another set on which I used better glue discipline, and made attempts to smooth them out with a paper-towel wrapped finger:
By the last fillet I laid down (on the top in below pic), I think I had it down, though I don't think I tried to smooth that one at all and had I it might look even better:
A concern at this point is the relative weights of the fillets, I should think. I mean, that first set was massive and clearly outweighs the last. So I'm wondering intuitively if when it flies it will arc toward the heavier side. At any rate I don't believe this is going to be an issue that affects the ability of this rocket to fly safely.
So now on to priming and painting. My scheme is to emulate the kit panel, i.e., paint the nose cone and two of the fins black, then everything else yellow. To get there, I plan on first applying a coat of grey primer, then then sanding with 400 grit sandpaper. After consulting with an expert I'm choosing to NOT do any type of wet-sanding. He says that's generally used more for MP & HP rockets with fiberglass & other materials & not so much paper & balsa, so his word's good enough for me!
So after sanding I will spray a coat of white primer and sand again. Then I'll repeat the grey, then the white. Finally it will then be ready for finish coats. I think I want to mask off the majority of the bird and paint the black bits first. So next post should be up in a day or two. Stay well!
No comments:
Post a Comment