Sunday, September 2, 2012

Making A Scoop Part 2

Now that I'm not frantically trying to get the car back together for the next race, I have some time to write this second post on the scoop.  In Part 1 I showed how I was applying bondo over the foam and sanding it smooth.  Here are the two main pieces (top and bottom) after that process was completed.


It was then time to cut the pieces apart again so that I could make five different "plugs" that I could fiberglass.  I used a hacksaw to cut the pieces.



I wanted a lip around the top and bottom pieces so that I could join them together using 10-32 screws.  In order to create that lip, I fastened each of the pieces to flashing that I bent so that it had a 90 degree angle.



I used some 1" long wood screws to attach the pieces to the metal.  The foam is dense enough to allow the screws to take hold of it but I had to make sure that I didn't overtighted the screws.  I used modeling clay in order to fill the gaps between the pieces and the metal.



Once all the gaps were filled, I could then lay out the fiberglass cloth and cut my pieces.  Even though this process can take a long time, I have found that it really pays off when laying out the fiberglass with the resin.  I used several layers of really thin cloth, one layer of fiberglass matt, one layer of heavy cloth, and then finished up with another layer of really thin cloth.  Here are a couple pics of me laying out the cloth.




The pic on the left shows the thin light cloth and the pic on the right shows the heavy cloth.  The thin light cloth obviously conforms to the curves and sharp turns a lot easier so it is important to start off with that.  Frankly, all of these pieces would have come out a lot better if they were vacuum bagged but I don't have that equipment so I made do with what I had.

After I had all my cloth cut, I then applied mold release wax and the mold release liquid.  The liquid is green and dries to a very thin film.  I applied two coats of wax and two coats of the liquid.  The pic on the left below does not have the mold release materials applied and the piece on the right does.


Ok, let the fiberglassing begin!!  Btw, I ALWAYS wear proper respiratory gear and have fans running when I do this in the garage -- fiberglass resin fumes are not good for you! 


After the resin dried, I could then use plastic wedges to remove the pieces from the plugs.  Here are the pieces before being trimmed all the way.  Btw, the red is just magic marker that I used when drawing my "cut" lines on the cloth.






I then trimmed them and glued them together with high strength epoxy.  I also laid a strip of fiberglass matt along the main seams.



The flat panel filter needed a ledge to sit on so i made some pieces out of aluminum and pop riveted them into the bottom piece.





One problem that I ran into was that the scoop was a little too long and wouldn't fit between the throttle body and the main bulkhead.  So I ended up having to cut off the front part of the bottom piece and in order to get it to fit in a short period of time I fabricated a piece of aluminum to fill in the front part of the bottom piece.  I also ended up trimming the front part of the top piece a little more.  But I eventually got it to fit.





I think it actually came out pretty good.  There is only one problem -- I don't like it very much.  :>)  Although I think it is much better than just using a cone filter, my helmet actually ends up being directly in front of it so I think I would be better off having a scoop that is in the air stream.  The wheels in my head are already turning as far as other possibilities and I just might be able to use the bottom piece of the scoop.  Changing it will probably end up being a winter project.


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