Tuesday, December 10, 2013

Back to Bodywork

We left off with the sculpted wire and wood form having been measured and the drawn up in AutoCad. I then printed out full scale 2D profiles, side, top and end views and glued these to foam blocks that were a near net shape. The profiles allowed us to rough out the shapes with a tree saw blade, the long course blade cuts quickly through foam. Dan was going to tackle the tail and i was handling the nose and center section with the aid of some sur-form tools and coarse sandpaper. Many other hands pitched in here and there as well so if i don't mention your name forgive me, the 90 hour work weeks at this point are now a blur.
 Two pieces of  foam were glued together with the seem line down the center to produce our rough shape, but the glue seem is disintegrating a bit during sanding. This is one of the downsides of using 2lb. foam. Again the upside is it's quick to form and quick to the finish line. The green clay is a quick way of filling in the seam line. Body filler works poorly on this light foam because it is so much harder and doesn't allow for any finish sanding because the foam around the filler is so damn soft. So soft in fact that rubbing your hand against the foam will remove the foam! Dan did a really nice job with the carving work.

Now the foam buck would normally be finished off with primer and filler and polished out so a mold can be made off of it. WAY TO MUCH WORK! Time is of the essence so this male form will be used to be molded against rather than into, like a traditional mold. So instead of primer and filler i found that masking tape will seal off the foam.  Rubbing along one edge of the tape will stretch that edge allowing it to deal with the compound curve. There is a limit though and you can end up with wrinkles but who cares, we're moving forward. Packing tape works as well, it just doesn't like to stretch. The really sharp curves just get a heaping handfull of wax. Even if some of the foam sticks to the fiberglass the foam is so soft it will break and sand off quickly. Yes the buck is compromised but when you most likely only need one finished part it represents reasonable time management. That is Janina and Dan, now married with twins, helping out. This would not have been completed in 2010 without there help and Janina's impeccable cooking!
 Thats Dan looking as proud as i do with our successful layup and vacuum bagging. Yahoo! 

Here is the tail section after we removed it from the buck and have molded in an air scoop. We also sanded the interior surface and applied one layer of 1/8" thick foam, the green shading, and one layer of fiberglass over the foam to give the part some rigidity. It works surprisingly well. This green foam is generally used for infusion molding but i find it works well to reinforce and its easy to taper its edges with sanding.
Looking into the air scoop which was beautifully carved by Dan. Again the scoop, like our other bucks, was a positive shape and would be a 'lost buck' format. We covered the foam buck with tape and wax and then wrapped it in fiberglass. Once hardened we carved the foam out of the interior yielding our hollow scoop. This part was then deftly integrated into the tale. It will ultimately mate up to a molded air-box under the tail section. Next I'll go over the center section as it involved a new set of molding issues.

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