Larson Bird of Prey - Build and Paint Article

This article is intended to document my experiences building a Lyle Larson Bird of Prey (BoP) Q500. The BoP is all composite Q500 that is highly prefabricated. So why spend the time to documenting all this then? Well, with a little luck I won't have to build again for awhile. This will be a good way to keep track of what worked and what didn't. I also discovered early there are a couple techniques that aren't common with balsa construction. This should illustrate the tricks of the trade. Most of the methods I'm using were taught or told to me by Lyle.

Making a V-tail Incidence Tool

This works if you have a plane that's already set up perfect.

The clear tape is called Blenderm and is also used to seal control surfaces. I picked mine up on-line from www.medicalsupplyco.com . It cost around $1 a roll.

The fillet is made with bondo.

Found the level at a garage sale for $.75. Pulled the bubbles out to help with incidence.

Sand the filler down and check fit.

Bolted wing on the fuse and shimmed fuse till wing was at 0 degrees. Sanded top of balsa till bubble was centered. Glued bubble to balsa with med CA.

Mounting Landing Gear

Use med CA to glue in 1" x 1" landing plate reinforcements.

Align landing gear. Check distance from firewall to assure the gear are straight. Drill and tap hole. You'll also need to counter sink the fuse to allow the bolt to seat. I picked up a counter sink from www.mcmaster.com . You'll need the 82 degree angle.

V-Tail Installation

Sand and trial fit until incidence of wing and tail are zeroed.

I used IC2000 CA on saddle for the extra drying time to hopefully avoid any problems.

Set wing flat on table or floor and adjust v-tail alignment. This trick worked well to get the tail seated.

Put incindence meter back on to check alignment.

Motor Mount Installation

Mounting the motor mount required blind nuts and 6-32 bolts. Even with my fat fingers I was able to get the blind nuts in place using the large hole in the firewall.

I used medium CA to secure the blind nuts in place.



Landing Gear

I used my 1" belt sanding to shape the landing. After roughing in the shape I went back with my orbital sander and 220 grit to sand out the marks. Finally, I hit the top with 320 to bring back some shine and cleaned with some wheel cleaner that was on the shelf.

I drilled the holes for the wheel attachment, 6-32 bolts, and secured with red loctite. Don't forget the loctite, seeing your wheel go rolling down the runway is not fun. Been there, done that.



Paint Preparation

First I sanded out the joints on the fuselages with my orbital sander and 220 grit sand paper.

Here's where I screwed up. I then used the watered down sheet rock mud method Darrol describes and Lyle recommends. This worked great for filling pin holes but I should have first applied icing (a easy sanding bondo) on the bigger blemishes. Here's the steps I took:

1) Mud fuselage and sand out
2) Primer
3) Use Icing fill seam offsets and bigger blems

The problem with this was when sanding the Icing the primer would sand faster and then I was back creating more pin holes. Not good.

Next time I'm going to use this process:

1) Icing
2) Sheet rock mud
3) Primer

I don't have any pictures but beige/yellow primer is the way to go. Transtar 6441- B is the Beige primer I used. My local O'Reilly autoparts store carried it. Here's a link to their new website:

http://www.tat-co.com/version2/products_productview.asp?product=6441B

This stuff worked great even for a rookie like myself. Sprayed easy, filled great and sanded very quickly.



Painting

To be honest, the whole painting process had me a little intimidated. By the time I had everything bought, it was a pretty substantial investment. I should be able to do 10+ planes with the paint I purchased. Getting the good stuff also made painting very simple. I did it all in one day and it turned out pretty well. I also told myself early it wasn't going to be pefect so just get 'er done.

I used PPG brand DBU basecoat and DC3000 clear coat. The clear is a new product and while I don't have any experience with the other clears. I can say the DC3000 went on very easy and thin. It worked well for me.

Basecoat in white. If you ever start spraying and it looks like silly string is coming out of your gun. Open up the material knob, you're shooting to dry and the paint is drying before it gets to the surface. Don't ask me how I know that.



I masked off the areas to be sprayed red and black. I also sanded the tail with 600 grit to remove the overspay. As you can see my tail feathers were reused and I was trying to use as little paint as possible.

Jim Allen from Fast Lane graphics supplied the stencils. Jim was very helpful and his stencils were outstanding. He can reached here:

jamesea1@earthlink.net



I sprayed the red. The method I used was to dust the first coat on the go back to the first part and spray a coat that gives you consistent color. Yeah, I had a couple runs in the basecoat but it didn't take me long to get the hang of it.



I wet sanded the edges of the color to remove the high spots (I wouldn't do this again, it's best to sand out the edges after your first coat of clear). The 3M pad I used was labeled Super Fine and is about 500-600 grit. The pads worked well throughout the process. The Fine version is 320-400 grit and worked well for sanding the primer and filler.

Finally, I shot the clear coat. Jim said to make sure the first coat is dusted on and allowed to tack. This is the method I used and it seemed to work well. Lyle recommends wet sanding the first coat with 600 and shooting another coat. I was running out of day and decided to forego this step.




Here is the finished product. All and all the painting went very well and turned great for my attempt. The DBU basecoats were easy to work with and dried incredibly fast. By the time I had the gun cleaned, the paint was dry.



These pictures can also be viewed in the TEAMseaholm Photo Album under the album titled Bird of Prey Build.


 
Publshed: 11.14.2004