RE: Cold Duck - Build
 

Prettiest hangar queens I have ever seen.:D

RE: Cold Duck - Build
 

Like most RC flyers I have a hanger full of aircraft ready to fly, all classic and pattern ships. The Kwik Fli III has been flown many flights and the Tiporare is in the queue to get flown soon.

RE: Cold Duck - Build
 

LOL, we just like giving you a hard time. LOL

RE: Cold Duck - Build
 

We were on the road all last week so I was unable to work on the Cold Duck until today. Last week I glued 1/8” X 1/16” bass wood strips on the trailing edge of the 1 ½” wide aileron stock from a Howard Engineering Kwik Fli III kit. The aileron stock was carefully aligned for centering and temporally rubber glued to the trailing edge of the wing and rough shaped with a razor plane. Today, I finished shaping the ailerons using 1 ½ ' long board with 50 grit sandpaper glued to it and another smaller block with 150 grit and followed up with 220 grit.

The next step will be cutting the root and tip pieces off each aileron and then shaping the leading edge of the aileron. On the original Cold Duck the ailerons extended to the tip of the wing but on this build the ailerons will stop about 1” from the 1” wide wing tip block.

RE: Cold Duck - Build
 

I cut the ailerons to length and glued the 1” wide rough cut wing tip blocks on. The ailerons stop 1” short of the tip block. A 1” piece of the aileron tip is glued to the tip bock and the trailing edge of the wing. The leading edge of the ailerons are not shaped yet.

RE: Cold Duck - Build
 

looking really good! She'll be dressed in orange in no time!

RE: Cold Duck - Build
 

The wing tip blocks have been sanded to the wing airfoil shape and will be rounded off later.

View of the wing tip, aileron tip and overall progress view.

RE: Cold Duck - Build
 

Test fitting the aileron linkage.

RE: Cold Duck - Build
 

Looks good 8178. Has the Tiporare flown yet?

RE: Cold Duck - Build
 

Not yet.

RE: Cold Duck - Build
 

The RJL K.61 power plants arrived! I’ve often thought about the buying some K.61s after MECOA started manufacturing them and I wasn’t disapointed. The workmenship and fit and finish is excelent. The cankcase mounting area is 39 mm wide like the majority of the clasic 61s (Veco and K&B 61, Webra Blackhead, HP) but the engine is longer at 98 mm. The K.61 hoursepower is advertized at 1.8 and the engine only whighs 17.5 oz. That makes the RJL more than two ounces lighter than my silver case Irvine 61s.

RE: Cold Duck - Build
 

The aileron linkage and center trailing edges are glued in place.

RE: Cold Duck - Build
 

I finished shaping the ailerons and installed the hinges.

RE: Cold Duck - Build
 

The wing roots were sanded to set the wing dihedral. The original had 1” under each wing tip. I reduced the dihedral to about 5/8” under each tip so the top of the wing surface has a very slight dihedral angle of about 1/16” at each tip. The wing roots were coated with 30 minute epoxy and the wing taped tightly together with masking tape.

RE: Cold Duck - Build
 

How much did all the balsa and foam wing cores cost you? Is it equivalent to purchasing a kit if it one was available?

RE: Cold Duck - Build
 

The balsa and wing core from Dynamic Balsa was $65. The wing core was $24 of the $65 total. I’ve used a few other balsa pieces, plywood, and landing gear blocks that I had on hand but not much cost involved. The shipping on the DB order was $12. I’ve spent around $100 for the basic parts plus the cost of extra stuff like the fuel tank, MonoKote, glue, motor mount, push rods and other hardware. I used the RCM plans that I had kept from 1971 so no expense there.

RE: Cold Duck - Build
 

I’ve been working on the RJL K.61 engine installation while the epoxy sets-up on the fiberglass covering for the wing center section. The engine fit in the nose pretty well with a little trim work on the fuselage opening. I haven’t done much sanding on the fuselage yet, but when I do I’ll be working to have the line starting at the nose ring flow in a smooth arc back to the fuselage top, sides, bottom and corners.

RE: Cold Duck - Build
 

The wing was glassed with two layers of tight weave 6 oz cloth and slightly thinned 30 minute epoxy glue. The first layer is around 2 ¼ wide and the second is the width of the fuselage. Both layers were laid up at the same time. I like to let the epoxy cure for a few days before starting the sanding process.

RE: Cold Duck - Build
 

8178, Once again, I must complement you on your build. Very Nice.

RE: Cold Duck - Build
 

impactiq,

Thanks for the positive input and your interest in the Cold Duck build. Like many on this forum I truly love to fly the classics and I find the time I invest in building them really adds to total fun factor. In the crazy snap together ARF world we live in it is refreshing to see the high level of interest in the RCU “Classic Pattern” forum where you get to build them before you fly them! And as you know, that is exactly how pattern flyers got their pattern ships in the 60s through the 80s.

RE: Cold Duck - Build
 

8178 - I notice that your glass overlaps the masking tape. Do you feather sand the edge of the glass down to tape thickness?

RE: Cold Duck - Build
 

8178- We are lucky to have a person like you on here. I know I have picked up on some of your "where to put what" ... and really like them. I will be using your idea with putting the retract valve and ON/OFF switch in the nose gear area, along with a few others. That is if there isn't a patent pending (LOL). IT really cleans up the look of the plane.

Can't wait to see "The Duck" done.

RE: Cold Duck - Build
 

Yes I do, but thinner than the tape. See the next post below.

RE: Cold Duck - Build
 

After the epoxy cured for a few days I used 60 grit sandpaper and a sanding block to sand the edge of the glass down to the inside edge of the masking tape. The tape protects the balsa while the sanding is done. The glass is sanded to a taper so there is very little ridge left at the edge of the masking tape. The remaining glass is lightly sanded to knock down any high spots.

View of the glass after sanding showing the wing with the tape on and after the tape was removed. Notice that some of the epoxy migrates under the edge of the tape and helps to support the edge of the tape during sanding. Next I’ll be putting on new tape that will be spaced out about 1/8” from the sanded glass, then adding a light coat of epoxy and doing the final sanding.

RE: Cold Duck - Build
 

The second, and hopefully the last coat of epoxy was brushed on to the center section. I’m going to be using MonoKote to cover the wing including the center section so the next step will be sanding the center section again to leave a smooth but sanded surface with some tooth so the MonoKote will adhere well.