Undertray Part 2

Continuing on with the undertray, I was able to fiberglass the edges during the evenings last week.  I used a very light fiberglass cloth and put two layers on each edge.  I could only do one edge at a time because I had to let the resin harden and trim off the excess cloth before moving onto the next edge.  Unfortunately bubbles are hard to avoid when trying to wrap around such sharp edges unless you are vacuum bagging -- and I don't have the vacuum bagging equipment.  The first side that I did had more bubbles then I would prefer so I used a fiberglass filler that you can mix in with the resin when laying up the remaing edges.  The cool thing about fillers is that you can add a little bit at a time to get the consistency that you want and then it will harden at the same rate as the cloth after you have layed it on top.  Here is a pic of one of the sides with the filler -- which is white.

I also fiberglassed the top side and I used a heavy piece of fiberglass cloth and then put a light layer on top of that.

After the resin hardened, I put a layer of "icing" which is basically a finishing puddy that is much easier to spread then the standard bondo.  It is mainly used for filling in pinholes and other small imperfections but it worked well here because the light fiberglass cloth has a really tight weave and it is a flat surface so it was especially easy to spread it.  After the first application I sanded it down with 180 grit sandpaper and then applied another layer and sanded again.  It was now time to mount it to the car so that all the holes would be drilled prior to paint.

I'm mounting the undertray to the side pods with a couple of strips of aluminum.  I'm not ecstatic about this approach but it will work for now and I probably won't use the large washers when I permanently mount it so that alone will make it look better.  Plus I think the aluminum will look a lot better after it is painted red.  It is something that I can easily change later if I want.

After I got the front secured, I needed to come up with a way to support the back.  At the last race I was at, I noticed that some cars used metal straps to do this.  I had some thin 1/2 inch wide steel so this is what I decided to use.  However, it was a litle bit of a challenge to figure out the exact length and the bends so I could another piece of 1/4" plywood that was only about 4 inches thick and put this where the undertray would go.  This allowed me to extend the steel past the plywood and helped me figure out where to bend the steel to get the shape and length that I wanted.

And here is a pic of the undertray mounted -- and I dropped it off with my paint guy today!