RE: PRIMUS Build
 

:D On the occasion that I have let some of the jet guys fly my pattern planes or my 35% 3D Stuff I was amazed at how good they flew. Many have flown pattern before. A few of the guys are ex IMAC and really know their what they are doing.

RE: PRIMUS Build
 

Looks great, Skip! Here's a coupla' shots of mine with a Bridi Sun Fli IV for comparison...

RE: PRIMUS Build
 

:DBeautiful work. I really like the visibility of you color scheme.

RE: PRIMUS Build
 

Tried to get it as close to the Kazmirski prototype as possible....with the exception of the "Taurus" logo on the nose of the fuse.

RE: PRIMUS Build
 

Haven't finished my Primus yet but here is what it looks like after all color was put on. Next steps are sanding out with 1500 grit, touching up small imperfections then clear coating.

RE: PRIMUS Build
 

Great looking plane, what type of finish is on it?

RE: PRIMUS Build
 

JPurcha,
It is covered with Doculam clear laminating film the painted with Klass Kote.

RE: PRIMUS Build
 

Those are some beautiful birds. A lot of the 1/2A guys are using Doculam these days. They lightly spray paint onto the back/adhesive side. It apparently doesn't affect the adhesion. It's very affordable and I understand it shrinks with heat.

I thought all of you Taurus/Primus fans might like to see this. Kazmirski once built a pusher version:

RE: PRIMUS Build
 

Raineday,
That is an amazing airplane. I can't believe he did that. Way too much time on his hands.

Doculam has a very agressive adhesive, I don't think you need to add anything to it to get a really strong bond. It activates at about 200 degrees but works best at 225-250. At 300 degrees it will shrink so hard it will warp open structures. I had planned to cover the open bays of the wing with doculam then overlay silk. When I changed from dope to two part epoxy it made sense to just paint the clear mylar. You need to use 600 grit to rough up the doculam over open wing structures as anything coarser will cut through (ask me how I know, and how many times I sanded through till I learned my lesson!!!).

This is the first bird I've painted with epoxy in a long time. I would not have doped the bare balsa if I'd know how well the doculam would fill the grain. Also the doped balsa surface prevents air from bleeding out from under the doculam, so you have to be really careful about getting bubbles under the film. Next time I'll prep the wood, apply doculam, then prime and sand out.

KlassKote two part epoxy is a very nice product. The paint masking was done with 3M fine line tape which I found at a NAPA parts store. Get the blue version and not the green, it goes around curves much easier. I used 1/8", 1/4" and 1/2" to mask the plane. The canopy was masked with Bob Dively liquid masking film. The fillets on the rudder/stab and canopy were made from a two part light sandable epoxy from Aircraft Spruce and Specialty called Aerofil, the touched up with light weight spackle.

To apply the KlassKote I used an inexpensive HVLP touch up gun from Harbor Freight and a Badger airbrush. The KlassKote was mixed one part catalyst to color and reduced 6/1. Pressure was 25 lbs psi. Higher pressures work but don't flow out as well.

Doculam is available in 500 foot rolls but you have to buy two rolls minimum. I bought 24" X 500' by two rolls and the cost with shipping was about $40. Enough for the next few hundred planes I build.

The rudder, elevator, throttle servos are already inside the fuse, and the tank is mounted. Once clear coating is finished I will bolt in the HP .61 Gold Cup, install aileron servos, install all control horns and pushrods, put in the receiver and battery then go fly. Should be fun.

RE: PRIMUS Build
 

Got four flights in on the new Primus/Taurus today. Flew great with an HP .61 Gold Cup on APC 12X6.

RE: PRIMUS Build
 

Great news Lou! Excellent job on the build.

RE: PRIMUS Build
 

Lou, that finish looks fantastic. I had been reading up on KlassKote awhile back, but invested in Brodak dope in the end. I also plan to use an inexpensive Harbor Freight gun soon. Does yours look anything like this one that I I bought? If so, I'm glad to see how well it works. Congratulations on the successful flights.

RE: PRIMUS Build
 

Raineday,
My HVLP gun is different. On line its about $36 and is purple with the paint cup on top. I haven't tried precision painting in a long time and it shows. I made every mistake in the book and a couple that weren't even worth mentioning. I will learn the SPA most basic pattern so I can fly in the Atlanta contest later this year.

KlassKote is expensive. It costs $160 for the paint to finish this plane. It works ok but when they tell you not to spray on top of a coat for 48 hours they really mean it. I rushed the painting by putting a color on every 24 hours and it does not seem to have bonded well to the prior coat. My fault, I was in a hurry. Also I need to get some good lamps for the garage so that as I am spraying I can see what I am putting on, this is especially true with the clear coat.

After using it I can recommend it, but I believe dope is just as good if not better if you want a hard durable finish. The magical agreement with either Klass Kote or dope is "patience" and lots of it. You just have to make up your mind to take your time and wait for each coat to cure. I believe that Brodak's dope is made for them by Aircraft Spruce. I like it and plan to use it again on my next SPA plane. Having just finished the PRIMUS I am anxious to choose and start on my next subject. Are there any SPA legal planes that have elliptical wings and stabs?

Incidentally my next wing will probably be foam. I have a Feather Cut and have done a lot of wings in foam (when flying RC Combat you have to have lots of wings). A foam wing covered with glass cloth and fuse covered with glass cloth may be the fastest way to get a good finish with minimum steps.

RE: PRIMUS Build
 

Thanks for the info, Lou. The plane still looks great. When I talked to John Brodak on the phone he told me Randolph makes his dope (the same company as Aircraft Spruce I guess?) The main concern I had when buying my gun was getting one with an extremely low CFM number since I only have a small Craftsman compressor. Price was a big factor in my choice of finish, plus I have plenty of experience with dope and none with two-part paint.

I've been dreaming about getting a Feather Cut setup. So many of the great '70s designs used foam cores and although most are available here and there, I really want to learn that skill.

RE: PRIMUS Build
 

Lou, is there no cowl on the right side of the fuselage when the engine is mounted 90 degrees?

Jim

RE: PRIMUS Build
 

Jim,
I started trimming the right side away thinking there would be some part of the fuse left and it would wrap around the muffler. I kept cutting and cutting and finally realized there would be so little left it wasn't worth trying to save, so I got out the saw and finished off the right side. If you look at the photos you can see how the muffler strap had to be accomodated, plus the needle valve stuck right up where the side of the fuselage would go, and then the bumps on the carburetor needed clearance. The engine also has some offset to the right which moves things closer to the right fuse side. Tried to keep some of it but couldn't

I did think about enclosing the engine by carving blocks to shape around the engine (like the old CL stunters) and putting a nose ring on it. That would work fine but it would have been impossible to get to the nosewheel after it was enclosed. With my penchant for dorking nose gears I thought it would be better to be able to easily get at the adjustments.

RE: PRIMUS Build
 

I think you got your LE and TE mixed up. Looks like the LE is straight to me.
REALLY nice looking plane and I think my next plane in line after I finish my Kaos. I love these old planes and wish there were more around to build. I have been flying since the 50's, so I remember these and have flown most of them. Love them all. Looking really good, keep up the good work.
Ed

RE: PRIMUS Build
 

Hi Ed. Those dashed-line squares are not aileron hinges. The original Taurus had a formed balsa shell LE. They are scabs that help attach the shell to the wing sheeting. The TE is actually at the top of the drawing.

David

RE: PRIMUS Build
 

I guess I got the LE and TE mixed up. I never built a Taurus, but did fly one many years ago. Been to long to remember everything. I did have the Top Flight Orion and was going to order the PRIMUS until I was told that the King Altair was about ready. THAT is going to be my next build and the PRIMUS will have to wait until after I get that one done. Guess I'm going to have to get me a set of glasses though.
Ed

RE: PRIMUS Build
 

I came across an interesting video once, on VHS. It was by Bob Hunt and Bill Werwage (Robins View Productions in PA) called Balsa Molding Techniques. In it, Bob Hunt showed how to make a molded balsa LE like you would use on the Taurus. It was commonplace technique back in the Taurus' day. It was supposed to be quite strong...

I don't know if those guys are still around, but if you are interested, I found their old phone number at 610-746-0106 in PA.

Bob

RE: PRIMUS Build
 

I think you'd have to define "strong". I recently, (2 years ago) finished a Taurus with the molded L.E., which holds up well UNLESS it hits something---then it's just like an eggshell[&o] That's the way it has to be repaired too--fitting the "eggshell" pieces back together, then gluing.

Duane

RE: PRIMUS Build
 

Ed--I congratulate you on your choice of airplanes---you will love the King Altair:):D Vic Husak, was a close friend of Ed Kazmirski in the mid 60s, and the King is the result of conversations where Vic and Ed talked about designing a better and larger pattern plane--each had their own version. The King Altair is closely related to the Taurus--only larger and more advanced in design with a symmetrical and tapered wing. The short nose moment and long tail moment are characteristic of the Taurus. Jeff's kit is very nice and redesigned for lightness. Please let me, (us) know how it is going.

Duane Wilson

I realize that this thread is over a decade old but was wondering if any of you Primus- or Taurus-lovers know of a kit that might still be being produced for either of these planes????

Thanks,

Bob

Taurus kit
 

Hi Dave,

Thanks very much for the tip. In the mean time, I had gone up to eBay and found amamodels who had a short kit, so I ordered that. I guess that I am set for a while.

Does anyone have any experience/knowledge/comments with the amamodels Taurus short kit? So far, everything that I've read about amamodels has been pretty positive.

Thanks,

Bob