Black Brant II build thread

[cellofellow]

Well, crap. This masking job wasn't very good and now I have a ton of under spray to clean up, and there's some black speckled overspray on the body too. I'm not even sure how to clean this up.

I still really like the overall effect I've achieved here.

 

[Art Upton]

Leave the fins as is and fly it.

Clean up the body if you want with a small artist brush* on white paint. If you want to make it match well, spray some of your white paint into the cap of some kind to dip your brush in. You could also touch up the fins a little also if you wished.

* you can get one at a craft or dollar store if you don't have one.

Edit: I never dared to try the fins like this, I kept them all black

 

[Art Upton]

I use Tamiya thin masking tape on the edges you can see in yellow, and then green frog tape for the wider areas on top of the Tamiya tape. Burnishing down the tape edges with my fingernail.

But I sure ain't no James Duffy , I didn't seal the fins as I probably will lose this , not sit on a shelf.

 

[cellofellow]

After some touch up paint I'm satisfied.

 

[Bruiser]

I'd like to offer up a couple of thoughts that may have helped with the build

Fill your spirals before gluing on fins

Use Avery label paper to paper fins. Seal the edges with thin CA. I think Neil posted a tutorial how to do it.

Use Tamiya tape for paint lines. Be sure to burnish down the edges.

If this was mine I would probably sand the fins down until they were smooth then try again. If I was in a rush I would then paint the fins black but if I had the time I would try the checkerboard again with Tamiya tape

JMHO,
-Bob

Oops, I just saw you posted while I was typing. You know, that's the thing... If your happy, that is what counts.

-Bob

 

[Rocket-Fan]

After some touch up paint I'm satisfied.

View attachment 671450

Looks fine. Send it!

 

[Art Upton]

After some touch up paint I'm satisfied.

View attachment 671450

Yep, time to fly it !

 

[Paul Howard]

My fin papering seems to have turned out crappy. Using Apogee's method where the paper is soaked through with water-thin CA was very difficult and a lot of the paper hasn't bonded well, but some of if has so I can't just peel it off. My choice of paper, tracing vellum, didn't help either.

View attachment 665730


Trimming the edges hasn't gone well either. I'm also starting to wonder if papering fins doesn't work on an airfoil because it's not flat, given I sanded these by hand. A test strip on a scrap piece of (flat) balsa worked pretty well.

Anyway, I've got some fresh balsa wood coming in the morning and I'm the meantime I'll see what sandpaper can do to rescue this at least in appearance.

The fins are the last structural bit to finish. With them glued and filleted it could be ready for a test flight sans paint and decals.

Hi, I often "paper" my fins with FreeFlight Silkspan or Tissue and either choose "white" because it dries clear enough to show nice looking streaky "character" wood and the hardwood leading and trailing edges I add. If I want color, I'll use colored tissue - either way I use shellac on them when I'm done but you can easily paint it as well. You may get a sorta very slight "lumpy" surface but you can either seal with balsa-filler/sanding-sealer first or do that later, but then you run the risk of sanding into the tissue or paper.

To apply the Silkspan or Tissue, I've used water based white glue, yellow wood glue, and water-based resins made for model aircraft finishing/bonding. What helps is to make sure the silkspan, tissue or paper gets wetted by the glue or use a mist spray bottle to wet it first, that way it will slightly stretch and shrink as it dries and that is how it really adds strength to the fins, plus it's fairly light. You can also put 2 layers of tissue on but let it dry completely between layers.

I practically always airfoil my fins but with sub-sonic airfoils (not scale super-sonic airfoils) and the tissue and silkspan works well and pre-wetted paper (copy paper for instance) will work better if wetted first.

If you do this, Make Sure to do both sides of a fin at the same time for even shrinkage and un-warped fins, apply so a "fold line" goes over the Leading edge and the spare slack paper goes off the outer edges and trailing edges and trim those edges when you're done.

I generally attach my fins with Yellow Wood Glue and so everything mentioned above bonds well with Yellow Glue.

I also generally try to use "through the body glued to the motor mount" technique and if you do that, paper the entire fin to it's root base helps even more for strength.

Hope all that helps - Paul

 

[SolarYellow]

Once yellow wood glue is completely dry, there's little that will stick to it worth a darn, including more of the same type of wood glue.

 

[cellofellow]

Here it is with the decals and clear coat (which is still drying) and basically ready to fly.

 

[Paul Howard]

Once yellow wood glue is completely dry, there's little that will stick to it worth a darn, including more of the same type of wood glue.

Hmm, I've had great results with Yellow Wood Glue (Alphatic Resin) sticking to itself - that's why I almost always pre-glue everything with it, let it dry, sand it slightly, then apply a small amount and it sticks faster and stronger. It also has made future repairs much easier to deal with for that property.

CyanoAcryclates however, I've Not had good results with CA sticking to CA - but that could be the type I'm using.

Also, in the world of model aircraft, a commonly used method to apply balsa sheeting onto a frame-built wing is to pre-glue with Yellow Wood Glue, let it dry, sand slightly, then get a Hot Clothes Iron and carefully place the sheeting where you want it then press the hot iron onto the sheeting and the heat will "weld" the surfaces together. I've done this multiple times on wings and fuselage "doubler" sections on my RC Gliders.

 

[cellofellow]

And now it's a glue thread...

That said, I'm aware that double-glue technique with PVA is the superior method for mounting wood fins to a paper tube. I had done that with my previous iteration of this rocket and while I had the fins break off it wasn't due to the glue job. But, I opted for a CA tack-on given that I was planning to use epoxy fillets and I'm now hoping that the fillets are enough to hold the fins strong.

There was no option with this kit to use TTW fins. Even if I wanted to mod the kit with tabs on my hand-cut fins, the whole motor mount area has couplers entirely surrounding the mount itself and there's simply nowhere that has a direct access from the body tube to the mount tube. Maybe the tabs could have mounted to slotted centering rings? But I would have had to slot the tube myself and slot the centering rings. I am, actually, basically a beginner (advanced beginner but just that) and that's a bit beyond me and entirely unnecessary on this rocket.

 

[Paul Howard]

Funny how many threads of "Build Logs" of rockets on this website and flying model aircraft on RCGroups.com become "Glue Threads", ha, ha.

 

[Paul Howard]

And now it's a glue thread...

That said, I'm aware that double-glue technique with PVA is the superior method for mounting wood fins to a paper tube. I had done that with my previous iteration of this rocket and while I had the fins break off it wasn't due to the glue job. But, I opted for a CA tack-on given that I was planning to use epoxy fillets and I'm now hoping that the fillets are enough to hold the fins strong.

There was no option with this kit to use TTW fins. Even if I wanted to mod the kit with tabs on my hand-cut fins, the whole motor mount area has couplers entirely surrounding the mount itself and there's simply nowhere that has a direct access from the body tube to the mount tube. Maybe the tabs could have mounted to slotted centering rings? But I would have had to slot the tube myself and slot the centering rings. I am, actually, basically a beginner (advanced beginner but just that) and that's a bit beyond me and entirely unnecessary on this rocket.

Just curious, what is "TTW" in regard to fins? Through The Wall?

I know what you mean about sometimes a better or preferred method just isn't possible or practical.

Cool rocket, I've thought about buying that kit everytime I've seen it. Also, you're definately tackling more on the paint job than I normally do - that is not one of my strong points.

 

[cellofellow]

Just curious, what is "TTW" in regard to fins? Through The Wall?

I know what you mean about sometimes a better or preferred method just isn't possible or practical.

I also generally try to use "through the body glued to the motor mount" technique and if you do that, paper the entire fin to it's root base helps even more for strength.

Yeah that's what I know as "Through-the-Wall" or TTW fins. I've not actually done it, none of my kits I've built before have it and I haven't done any scratch builds. One of the kits I have in my backlog has it.

 

[Paul Howard]

OK, "TTW fins" it is! Good abbreviation. TTW modifications on kits without it in the desighn and TTW on scratch-builds definitely is an attained skill but once you get the hang of it, you'll have stronger fins/rockets especially if those fins are Tissue, Paper, or Fiberglass covered first (greatly reducing snap-off at the base or root - I've even put a 2nd strip of whatever from the root attachment point to about 1/.4 the span of the fin just to have a stronger base/root when I thought it was necessary. Probably a good idea to do it first on a kit where it's part of the design like what you mentioned you have waiting in the too-be-built stash.

That was great that you did a build log, those are always fun to look at, Thanks for that!

 

[cellofellow]

Finally got it out to the field and flew out. It's quite the fun little rocket!

 

[RocketT.Coyote]

I've built several of the papercraft models from the 48Jleslie site. The scale fins were not very durable, so I designed some profile fins and covered them with origami paper. All models were given a coat of Krylon Clear.