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Saturday, September 12, 2009

Isolation Chamber Finished!

I finished my isolation chamber and it works great! except that I do not get a large flow through the HEPA filter probably due to the weak pressure gradient being created by the computer fan. I also have to either find gloves with a longer cuff or make my current glove's cuff longer and attach it to the Plexiglas. That way there will be no leakage of material.

Front. HEPA filter is a vacuum cleaner replacement filter.
Back. Computer fan sucks air through the filter.
 
Here is a picture of the board layout with the unfinished composite stringer.

Monday, August 31, 2009

Isolation Chamber

I am currently in the process of building a chamber out of Plexiglas so that I can cut and sand the fiberglass composite without it going all over my apartment or in my lungs.

 
Here is the current progress.
I plan on using computer fans and a HEPA filter from a vacuum cleaner to filter the air in the chamber before it is released into the room. Also, having slight vacuum in the chamber will help keep particles from slipping through the gaps.
Hopefully when I get this done I can continue my work on the skim board.

Monday, August 24, 2009

Composite Stringer

In order to give the board strength without adding to much weight, a composite stringer will be constructed. The stringer was cut out of 3/4" extruded polystyrene. Two cutouts were epoxied together to give the stringer a 1.5" width and sanded down to just under the thickness of the board foam. I could not get a long enough piece of fiberglass cloth from Lowes so it will have to be constructed in parts. Unless I spend some money, which I do not have, on a roll of fiberglass. I guess I'll have to eventually.

To glass the foam;
  1. Cut the desired amount of fiberglass
  2. Mixed an estimated amount of two part epoxy
  3. Layed the fiberglass on the foam
  4. Massaged the epoxy into the cloth (using latex gloves)
  5. Squeezed out the extra epoxy (using latex gloves)
  6.  Laid wax paper on the epoxy/fiberglass surface (epoxy does not stick to wax paper)
  7. Finally used text books to apply pressure to the composite in order to get a smooth surface and good bond between the foam and fiberglass.
 Finally putting those textbooks to some use!
 
The result
The results were pretty good except that I could not get the fiberglass to stick to the sides of the foam stringer. The common practice of applying a thin layer of epoxy and waiting till it gets tacky, then applying the fiberglass cloth and more epoxy seems to be needed.

Sunday, August 23, 2009

Cut Out

In order to get the shape I wanted, a CAD drawing was printed on transparency paper which was then put on a projector (its my sisters, don't ask lol) allowing me to trace the desired shape on the foam. I then cut out the shape from the foam using a utility knife. In order to make sure that board will be symmetric, I cut the board in half, used double sided tape to hold the two halves together, and sanded the edges. I am fairly happy with result.

Picture of the two halves.

Wednesday, August 19, 2009

Construction Plan

Due to the fact that I am extremely bored in West Virginia, I told my brother that I would make him a skim board. Here is the plan:

  • Foam core construction (3/4" extruded polystyrene house insulation)
  • Fiberglass with epoxy resin (epoxy does not melt polystyrene unlike polyester based fiberglass resin)
  • Maybe a final layer of carbon fiber (so sexy!)

Here is the purposed design as drawn in CAD.


Dimensions: 54" length, 22" wide, 3/4" thick, 2" rocker, 3/4" tail