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Preparing to Build


Building Surface

The wing and horizontal stab of the RCFW Hellcat were designed to be built directly over the plan while the fuselage is built on an elevated crutch. A flat surface is absolutely necessary as is a reliable method of accurately holding the parts in place while assembling them. There are many methods to do this and you may have a favorite already. If not you may try out my preferred methods as described below.

I normally build on glass and/or medium-density fiberboard (MDF) and I either weight the parts or tack glue them directly to the building surface. When tack gluing, both glass and MDF provide for easy clean up after construction is completed. As you will see in the gallery my method for building over the plans is to stick them to the building board with a light coat of spray adhesive and masking tape around the perimeter. I then cut small squares out of the plan so that the jig tabs on the parts can be tacked directly to the board. It is usually not necessary to tack glue every jig tab but only a few of them across the span of the assembly in key areas.

For weighting and positioning parts I have become very dependent on 1-2-3 blocks. These are designed primarily for use by machinists when setting up operations on the mill. They are precisely milled 1" x 2" x 3" steel blocks that are perfect for holding parts (like wing ribs) square to the building surface and for weighting them down. I have found a hundred other uses for them as well. They are not cheap but I have managed to acquire a dozen or so over time and I highly recommend them. Just be VERY careful with them if you build on glass as I do! (Ask me how I know) When applying wing or tail sheeting, zip lock bags filled with sand provide an ideal weight that will conform to a curved surface and will not leave any hangar rash behind.

Tools

I assume this is not anyone's first build project so you should already have and be familiar with the usual suite of building tools. The Hellcat does not require anything that is outside the norm. The one area that I would like to give some special attention to is that of sanding tools. It has been said, and I concur, that the difference between a good model and a great one can be summed up in one word, sandpaper. Most folks do not enjoy sanding and often it is a hurried and overlooked part of building. However, it is a key element to ending up with a really good finished product and it is worth the time. We can make it as easy as possible by making and/or obtaining the proper equipment. I like to have half a dozen or so sanding blocks with various grits of paper made up and ready to go prior to building. I usually have a couple that are 2-3 inches wide and 6-8 inches long as well as a couple 4-5 inches wide and 10-12 inches long. I even have one about 16 inches long for those long straight sanding jobs like shaping wing leading edges. I usually make up one side of each block with about 180-220 grit while the other side will have 80-120 grit. You might keep one around with some even finer stuff, say 320 grit, for putting a final finish on some parts. Mix 'em up a little so you will always have the right block for the job. I also keep a foam sanding block close at hand for those jobs where you need the block to conform to a curve. You will definitely want one when you start sanding a large sheeted surface. I make them up out of regular white bead foam, about 4-5 inches wide, 6-8 inches long, and and inch or two thick. Make it up with about 180-220 grit paper. For sanding inside curves (like wheel well openings) it is very useful to have a round block of some sort. I keep one around that is simply sandpaper wrapped around a 1 inch dowel about 6 inches long. One about a half inch in diameter is useful as well. Last, but not least, get yourself a good selection of nail files too. Any drug store will have them or you can liberate them from your wife or girlfriend's stash! If you want to spend the money there are some great pre-made sanding blocks available from various sources. One of the best is Perma Grit. They have a wide selection of sanding and finishing tools that are made to last a lifetime and can make the tough jobs much easier.

The other point I would like to make about sanding is simply to keep a good selection of fresh paper at hand. Much like your knife blades, don't be afraid to change out your sandpaper often. Good paper makes the job go much faster and your time is probably worth more than the paper!

Adhesives

Nothing out of the ordinary here. Medium CA is what I use for the majority of the build with some thin CA thrown in where applicable. You will also need some 5 and 30 minute epoxy as well as some yellow wood glue or Ambroid. (Sigment works too) Although not a necessity, I do recommend the use of liquid plastic model cement when attaching plastic to plastic, ie, assembly of the vacuum formed parts.



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