JC's Planes and Projects

 

Top Flite Giant P-47 Thunderbolt

Glassing and Priming - and Trial Assemby.

6/10/01 - I have been working slowly but steadily on the project now for about six months. With the advent of nice weather I have been doing more flying than building. But I do have enough accomplished to add another page to this diary. I got the "bones" all done more than a month ago. I have decided that I would like to try a painted finish for the first time. This required that I glass the model. After a lot of testing, I decided to use the following system using epoxy resin.
  1. Sand the entire structure and fill all dings and low spots with a lightweight spackling compound like Permalite. Use a sanding block where possible to avoid sanding unevenly. I like to use the rubber sanding blocks that grasp the paper with metal studs. Take the structure down to about a 220 grit.
  2. I used .6-oz glass cloth for the entire structure. I bought mine from Dan Parsons. He advertises in some of the model magazines. There are other outlets that will get you the same thing for half price, though. The glass is extremely delicate. To avoid snagging the cloth I put on latex "examination" gloves. To cut the cloth you can use an Olfa cutting wheel and mat or a good pair of shears like Fiskars.
  3. Cut the cloth slightly oversize and lay over the structure. Mix up a batch of Pacer Z-poxy Finishing Resin. This resin is a 50/50 mix epoxy. Once you have the epoxy mixed, add an equal amount of denatured alcohol. So the final mixture is 50/50 resin/alcohol. It will be a very thin mixture. I use a 1.5" soft polyester brush. Don't blow you budget on the brush because you will go through more than one. Brush the thinned epoxy over the glass as it lays on your model. It will soak in and bond the cloth to the wood. Let cure 24 hours.
  4. After curing the excess glass can be trimmed off with a razor blade or sanded off with 220 grit paper. The glass is now bonded to the wood, but the weave of the cloth is still apparent. To fill the weave, mix up some more epoxy but this time use less alcohol for thinning. The ratio we want for filling the weave is 70/30 epoxy/alcohol. Brush this on your part and let cure for 24 hours. Note: it helps to have the part horizontal so the epoxy mixture can level itself. Beware of runs and blobs! The appearance after this step should be a smooth shiny surface. If you still see some weave, mix up some more epoxy and give the area another coat.
  5. Now that you have your entire model glassed and the weave filled it is time to sand. This is not as bad as it sounds especially if you get some help from Black & Decker! I use the Mouse sander. Use some Acetone to wipe down the entire structure to remove the waxy surface. Now you can start sanding wet or dry. The object is to create a uniformly dull surface. Any low spots will reveal themselves as shiny indentations. I am not a Top Gun competitor, so I tried to get 99% of the surface dulled. There were still small shiny spots as I moved on to the next step. Note: Approach the sanding cautiously with the Mouse until you get a good feel for how fast a certain grit will remove the material. It is pretty tough stuff, but you don't want to sand into the glass fibers or wood.
  6. Your structure should now be completely glassed and sanded to a smooth dull finish. Here is my twist! Get some Bondo Red Spot Putty and Glazing compound. It is available at any auto parts store, and large stores like Meijers in the automotive section. Take a baby jar and pour in some acetone. Squeeze some of the Glazing putty into the acetone and mix thoroughly. The object is to get a nice thin mixture that can be painted on the model. After painting the structure it should look like the photo below. 

 

The fuselage after being "painted" with a mixture of Glazing compound and acetone. Note that the coat is thin enough that you can see the wood beneath. Any more and you will just have to sand more off.

7. Get out your Mouse and start sanding again. The glazing compound will fill the very small voids and surface scratches. To get a finer finish, I bonded some 3M Wet/dry paper to an old Mouse sandpaper pad. Unfortunately, I have not been able to find Mouse-ready paper in anything finer than 220 grit. You will find that the Glazing compound will sand very easily and you will have an extremely smooth finish when done. Again, I am not a Top Gun contender so I live with some imperfections. If you can't then apply some more Glazing compound thinned or straight with a plastic spreader. When done sanding the structure should look like the picture below. The red color is an excellent sanding indicator!

Structure ready after the Glazing compound has been sanded off. It has an overall "dirty" red color with filled imperfections a solid red color. It is now ready for any type of primer.

 

This is one of those "pay-off" moments! After working on pieces and parts for a long time I just had to put it together to see what it is going to be like. The structure has been primed with Krylon white sand-able primer. I chose white because the bottom of the plane will be silver and the top will be primarily light gray with a smoke gray camo scheme. I felt that a lighter primer would let me use less colored paint. Just a theory.

 

The plane is now ready for as much detailing as I care to do. After taking it this far, I feel that it would be worth experimenting with panel lines and rivets. I also have the Top Flight cockpit kit for this model. The structure as shown above, including landing gear, air tank, and cowl weighs 11.5 pounds.

Back to Main Jug Page

Home