Estes Mini Arcas, #2441, Finished

I built and masked the original BT-55 version of the ARCAS.

To be honest, this BT-20 version wasn't a fun build.

The small balsa fin support pieces are hard to form out of balsa. 1/16" thick fins don't allow you to sand a diamond taper. 

The red color mask was difficult on the downsize model.

Here's the upper end and nose cone showing the mask.

The ARCAS is a sleek rocket with a great looking red/white job.

I wish it were the original, easier to detail and paint BT-55 size.

Estes Mini Arcas, #2441, Part 20, Fin Taper Decals TIP

In April of 2024 on TRF, Neil W made a great suggestion about simulating fin tapers on the Mini Arcas.

The fins are only 1/16" thick, sanding a diamond fin taper would be very difficult.

TIP: Neil suggested a light gray printed decal set onto the rear half of the fins.

I had been wanting to try this ever since - Thanks Neil!

I drew up some fin tapers with a 10% black. Extras were copied and pasted - I did need them.

I'm not releasing this decal for home prints. My fin supports are a little thicker than the kit supplied pieces. My decals probably wouldn't fit your build. 

It's a challenge to fit the decals to the root edge details.

Add the fin fillets and they'll require individual fitting. Good thing I made the outside and trailing edges a little wide.

Here's the finished look. From a few feet away, the illusion is good. 

Maybe it's a bit dark. If a 5% gray were available I could have used that.

The overhanging edges were trimmed off with a "sawing" motion using a single edge razor blade.

Estes Mini Arcas, #2441, Part 19, Decals

I referenced Peter Alway's book, Rockets Of The World to double check the decal placement. ARCAS reads up, the ATLANTIC RESEARCH CORP. reads down on the other side.

Sight down the body tube to check the vertical alignment of the long decal.

TIP: Many people post about using a drop of dish detergent in the soaking water. They claim it allows a slippery decal, easier to position. 

On YORF, Micromeister brought up a good point. The dish soap can dilute the adhesive on the backside of the decal. 

Wet the area where the decal will be placed. Dip your finger in the water and rub the painted body tube leaving the (painted and sealed) tube a bit wet. Then slide the decal off the backing onto the wet model.

Here's the ARCAS decal between the two small lugs.

Estes Mini Arcas, #2441, Part 18, Launch Lugs

I didn't glue on the lugs before painting the rocket body. 

I thought they would be in the way of the complex mask.

Sometimes I skip the launch lug fillets. Bubbles are a pain!  

     

I wish the lug placement were different. I would prefer the the ARCAS name decal not in line with the launch lugs. 

The lug glue areas were scraped down to the body tube. Don't scrape too wide, you'll want the lug to cover where the paint was taken off.

The glue line on the small lugs is narrow and even down its length.

Set down the glue line and even the line with a fingertip. Use white glue because it dries clear.

Both lugs are glued in place. 

Even without a glue fillet, they aren't going anywhere.

Estes Mini Arcas, #2441, Part 17, Pulling The Tape!

The mask was pretty clean, 

There was some small bleeds under the corners.

Instead of scraping - 

Try pushing the little paint overspray tics back into the red. 

I use a pocket knife, it's not as sharp as a hobby knife. Too sharp a knife might cut in and chip out the white paint underneath.

Here's the cleanup results up until now.

I'll follow with some white touchups. 

Ace Premium enamel is sprayed into a cup and applied with a brush. Applied light and carefully, the Ace paint mixes and "melds" into the paint already on the model.

Estes Mini Arcas, #2441, Part 16, Taping The Mask

I wasn't looking forward to this mask - 

The rear "peaks" have outside mask lines. The first angled tape strip is set down. Below it you can see the pencil line for the next piece.

The upper peaks are inside masks with rounded sides.

The curve was cut with small scissors. That curve on the left side almost works like a hinge, allowing you to set the tape at a few different angles until the tip meets at the top.

The top and bottom pieces are in place.

The open center is covered with brown masking tape.

I tried wrapping some grocer bag plastic around the fins but the peaks of the lower red masks were in the way.

Brown masking tape covered all the fin area.

Estes Mini Arcas, #2441, Part 15, Complex Mask

The kit supplies a wrap around masking guide. It's printed on 20 lb. stock, it's a bit floppy.

Center one of the long stripes between two fins. Check back and forth with the other side and be sure the top is even with the end of the body tube.

It took a few minutes to get everything in line. Sight down between the fins from the rear.

Tape down the guide with small pieces of tape, leaving the "V" ends open for pencil tracing.

Trace around the guide using a soft, sharp pencil.

Any pencil lines that remain after spraying the red can be easily erased.

Estes Mini Arcas, #2441, Part 14, Finally! Gloss White

After three passes of gloss white and sanding - 

allowing 48 hours between coats - 

I finally have a decent finish of the tail cone and fin support pieces.

After 48 more hours I'm going to attempt the complex red mask!

Estes Mini Arcas, #2441, Part 13, Shock Cord & Streamer

When forming a paper shock cord mount, I like to form the glued up mount to fit the inside of the body tube.

Estes has developed new plastic, self-adhesive shock cord mounts for the BT-50, BT-55 and BT-60 tubes. The BT-20 and BT-5 tubes are too small. 

Note the pencil mark on the rubber cord to be used as a depth gauge, 1" down inside the tube.

I use tweezers to insert the paper mount to the 1" depth before pressing the glued mount to the inside of the tube.

The chromed mylar streamer had rough cut ends. 

For easier placement of the clear tape, the upper end of the streamer was lightly taped down to my work surface.

Estes Mini Arcas, #2441, Part 12, First White Coat

The first white undercoats always show the glue blobs you didn't smooth out before spraying.

On the left - One side, very rough fillet areas.

On the right - I wish they all looked this good! There would be less work before final paint sprays.

Something I don't think I mentioned earlier - Look close at the balsa grain. It doesn't run down the leading edge line. The grain is parallel to the trailing edge.

Here's one quarter view after sanding with a well used piece of 400 grit. All the glue boogers have been lightly sanded to surface.

I'm going to try a "shading" decal to give the impression of diamond shaped fins. More coming up . . .

Estes Mini Arcas, #2441, Part 11, Fin Support Gluing

That score line is open, I had to fill it with some CWF applied using the tip of a knife blade.

On the right side, the filler is sanded to surface.

Note the pencil marks, they are just inside the length of the fin supports. I also marked the high points of the tail cone/body tube joint.

Glue is set down in between the pencil lines and the fin support pressed in place.

The fit of the supports isn't tight into the root edge, not as close as I'd like. Glue fillets will help fill the gaps.

Estes Mini Arcas, #2441, Part 10, Fin Gluing

 

The paper fin marking guide gave perfectly spaced fins. 

Part H (fin alignment and spacing tool) fit very well.

With the fin notches in line with the tail cone/body tube joint -

The trailing edges are about 3/32" from the end of the tail cone.

The fin support pieces should fit tightly into the root edge corners.

Go light with the glue fillets to allow a close fit of the support pieces to come.

Estes Mini Arcas, #2441, Part 9, Fin Supports

The fin supports were butted up against each other and shot with filler/primer. Sanding followed.

On the instruction sheet there is a full size cut template.

Setting the fin support over the template, my sanded pieces ended up a bit short. I was trying to be careful not to change the length, but they ended up short. 

I used a single edge razor blade to "score" the center break line.

Cut about half way through! Score a line.

Here's a support after bending and breaking at the cut line.

Great - another gap to fill.

Estes Mini Arcas, #2441, Part 8, Fin Primer & Sand

A strip of tape was set down the root edge to prevent the primer/filler from soaking in.

The tape strip was needed because the root edges weren't  straight. 

The fins were set on scrap cardboard for the filler/primer spray.

Here's the before and after sanding the fins and short launch lugs.

The filler/primer soaks in a bit and helps seal the surfaces.

For me - Balsa grain filling and tube spirals filling is a two-step process - 

STEP 1: After applying and sanding the Carpenter's Wood Filler (CWF) 

STEP 2: The sprayed and sanded filler/primer fills in any remaining grain.

Everybody has their best methods.

Estes Mini Arcas, #2441, Part 7, Fin Fill

When applying the CWF, clear that small notch above the root edge round cut out.

After sanding the dry CWF, round out the root edge cut out with a small rat tail file.

Here's the before and after CWF sand.

The small notch above the cut out aligns with the boat tail / body tube seam.

The fit of the fin root edge was very good.

The original ARCAS fins had a diamond taper. This smaller version just has a rounded leading edge. It would be very difficult to sand a diamond taper in 1/16" thick balsa.

Estes Mini Arcas, #2441, Part 6, Fin Supports

The basswood strips were sanded down to 1/16" square.

About 12 lengths were cut. I'll only need 8, I'll pick the best shaped for the build.

The originals were left on the balsa sheet. Angled pencil lines were drawn for a cutting guide.

I used a single edge razor blade to cut the sides. 

Draw pencil lines on the top and bottom apex for a sanding reference.

Shade the sides for a visual contrast when tapering the ends.

On the right - 

The ends are tapered using the pencil lines and shading. Without the pencil markings it is difficult to see how much you are sanding off. Use 400 grit on a sanding block.

Round off the length of the support and the tips.

The pic on the right shows the underside, still square.

Estes Mini Arcas, #2441, Part 6, Fin Supports?

Here's one reason why this kit has an "Advanced" skill level.

These fin supports were tough to shape when the original Arcas was a larger BT-55 size.

Check out the original K-26 kit instructions: CLICK HERE

"Sand a 14 degree angle after cutting the support in two?"

What makes it even harder - forming the smaller supports out of balsa!

The laser cut balsa supports are only 3/4" long by 1/16" thick. 

I made a special trip to an actual hobby store to find some strip basswood. I'll be cutting these out by hand. Basswood doesn't have grain pores to fill like balsa wood does.

The picture on the right shows an attempt at forming the first support. I can't imagine trying to shape and fill seven more of these from balsa!

Estes Mini Arcas, #2441, Part 5, Tail Cone Fix

Next time you make a tail cone, try placing the glue inside the end, opposite the glue tab.

I decided to make a double layer "super shroud". This makes a much stronger piece.

For more detail, I wrote an article for the Apogee Peak Of Flight newsletter: CLICK HERE

Notice the lower step inside the cone in the right side pic.

Glue one cone inside other.

Let dry with a coupler inside (don't glue the coupler in) to maintain the round shape.

After all is dry,

Cut off the upper overhang using the ridge as a guide for a razor blade.

Sand the upper side square using a sanding block with 400 grit.