Album of my latest build, with questions on my technique

I recently completed my third Skill Level 1 build - Estes Mini Honest John.

https://imgur.com/a/Hn4Wt

First of all, I spent way too much time working on such a cheap little rocket like this one. But I'm about to start some nicer, bigger rockets, and I've still got some issues with finishing, so I considered this a kind of practice rocket, and tried to work out some of my problems before moving on to the bigger guys. I made a few mistakes, but then I managed to learn some new stuff by correcting those mistakes.

You'll see I tried to bevel a fin - and before you say it, I know, there's little point to beveling or airfoiling a rocket of this size. But it was included as an alternative fin profile in the directions, so I decided to try it.

It went pretty well - until the masking tape I was using ripped the edge off the fin. So I traced another of the fins on some spare balsa I had and made a replacement. I was pretty sure it would be trickier than it seemed, because I reasoned there was no way to know if I was holding my hobby knife truly perpendicular to the balsa, even with my ruler, but it turned out really well, and you really can't tell which fin is the fake.

From this, I learned a couple things: 1. When it comes time to bevel a fin on a larger, more powerful rocket, I can do it. 2. How to cut my own fins.

From there, I rounded the edges, and here's where I had another problem. If you look closely, the trailing edges aren't truly straight; they're kind of round. Perhaps this was just carelessness, or maybe it's because I wasn't using a sanding block. I was holding a bit of sandpaper down tight to a metal bottle opener I have, about the size of a credit card.

Anyway, the finish is what gave me real trouble. I used Elmer's Wood Filler to fill the spirals - probably a waste of time in this case, as they were pretty tight - but I wanted to practice that. When I sanded it down, however, I kept trying to remove the bits I could see that were still on the surface, and by the time I was done, I had scuffed up the body tube pretty badly.

Did any of you have this problem when you were first starting out?

Here's a few things I'm wondering

• Should I use a filler that's easier to sand than Elmer's? I emailed John Coker of jcrocket.com to ask him for advice, after viewing his "Basic Painting" video on Youtube, and he uses something called HobbyLite filler. Anybody have experience with this? Is it easier to sand down without scuffing the tube?
• Should I sand with a higher grit sandpaper? I think I started with 320, then moved up to 400, and still got a fuzzy tube.
• What about the idea of doing a primer first, and then using the filler? My thinking here is that the primer would act as a buffer between the tube and the sandpaper.
• Do I just need to go slower and be more careful?

Moving on from this point, I had an issue with some major fuzzies on the rocket body, most of which I managed to sand out, but I continued to have some unwanted texture. There were paint flaws, yes, which I mostly sanded out. But also, the whole rocket felt kind of textury.

Anyway, I got the rocket finished, and apart from some minor discoloration from wet sanding, it looks pretty good. The decals kind of mask the flaws, but I still know they're there. By the time I was done with this rocket, I was really ready to be done and move on to something else. Still, I found this to be a valuable learning experience.

Any thoughts?

At least the way I do it---Shape and install the fins--prime everything--apply filler--sand filler and primer--re-apply primer--sand if needed(usually is)--paint----note: use a high build sandable primer---I use automotive primers. Rustoleum is fine and can be found at most big box stores. Knock down fillers with 320 grit and overall sand with 400----hope this helps---H

A few random observations:

- RELAX your doin' fine. Building rockets is fun and relaxing. Flying rockets is fun and exhilarating.

I at least round the fins on every rocket I've ever made because that's how I learned it in the '69 Estes catalog.

I'd say you need to thin your wood filler a little more and try to follow the spiral a little better. I use wooden coffee stirrers, maybe an eighth inch wide ? I use emory boards to sand the filled spiral, from the Walmart make-up section.

Your first shot of primer didn't look that bad. I use 400 grit at that point, not alot of pressure, no wet sanding (preference). BUT I'd say you needed at least one more iteration of prime/sand. As you go on your fingers will become educated as to when you stop that process.

When taping fillets, remove the tape as soon as you smooth the glue to avoid ridges.

Looks to me like you got a nice classic orange peel finish with the color, no shame there you're in good company ! Some causes: Didn't shake the rattle can enough, too hot, too cold, nozzle issues, too far away. Some solutions: place nozzles in a cup of thinner between uses, hold can upside down an spray to clear nozzle after each session , warm can in hot bath for a few minutes before spaying, shake it for 2 minutes at least.


p.s. Study the "S..." out of hcmbanjo's blog !

Every model you build teaches you new things.
Every new build will be better than the last.

You might be applying the CWF too thick!
https://modelrocketbuilding.blogspot.com/2010/09/carpenters-wood-filler-mix-ratios.html

There's no need to tape off a LPR rocket for glue fillets.
You would normally do that when making larger models using messier Epoxy.
Set down a bead off glue and wipe off with a fingertip.
Titebond Molding and Trim Glue will give wider, rounder fillets than yellow or white glues.

Here's a complete build thread on the Estes Mini Honest John, in reverse order.
https://modelrocketbuilding.blogspot.com/search/label/Honest John

You've got the first lesson down - Build and learn.

I'd submit to you that almost all your problems with the finish came from poor surface prep. In my limited experience, that's how it's been.

The excess wood filler on the surface can be solved by applying the CWF more sparingly. I don't know what your application method is, but I've gotten the best results by using a dull hobby knife (or just a putty knife) to press the CWF into the spirals and immediately scrape off excess that's not been pressed in. I then lightly sand with 220 and 400 grit to the point where I can no longer feel the seam when passing my nail over it.

With regards to the primer, what brand did you use? When you're trying to smooth a surface that's got a lot of scratches and imperfections, a high build primer, often called "filler primer", is a good choice. High build primers are meant to be applied and sanded multiple times to give a smooth surface for paint. I like Duplicolor's High Build formula. You CAN apply small amounts of CWF on top of a primed surface to fill small holes or seams - it will still stick at this point. I wouldn't wet sand primer. Since the water is only meant to prevent very fine grit paper from clogging up, it's not much use with 200-400 paper that has fairly coarse grain. Don't be afraid to use rough grits to get rid of those big fuzzies. The point of fine grit paper is to remove the scratches leftover from fixing big imperfections.

I've never liked paint and primer in one formulas, especially if you've already used a legitimate primer. But good finishing is 95% skill, only 5% tools. Some of the guys on here could get better finish than me with 99 cent wally world paint, because they've good technique and a certain feel for the process.

Your first shot of paint (from the picture where the primer was apparent through small holes in the paint) was far too lightly applied. It could be cold conditions, bad nozzle, or simply not enough paint on the surface. Try to get even coverage using 2-3 light coats applied a few minutes apart.

There's not a lot from there on that you could have done to fix the orange peel surface, other than sanding it all off and starting again at the surface prep stage.

Finishing is sometimes frustrating but keep at it. I saw your ISX build thread and you've clearly gotten better as a builder already! Gratz on the new bird and enjoy flying it!