Working with Fiberglass

[MZGirl]

Don, that would be great!  I just picked up a book about fiberglass and composites at the bookstore on the way home, so I'm looking to learn all that I can.  If you want to send anything through e-mail, my address is seasly1 at cox dot net.  Thanks!   :)

[dwilson]

There are 2 ways to make your belly pan, the right way and the just-get-trrough-tech way.  I should also add that since it doesn't sound like you ever made anyhting from glass before, you should not expect to make a nice looking piece on your first try.  The materials are pretty cheap, so if you have the time make some kind of a practice piece first.  I don't think your bike has fairings so alot of this will be free-hand and you'll have to find mounting points as you can't bolt it onto the lower fairing.  

1. Make the bottom: Do you want the bottom to be flat, curved or V shaped?  I would go with flat or V, curves are a little tough.  Take a piece of cardboard and cut it to the size of the bottom of the bike.  Using a magic marker and a ruler, draw out the exact shape you want it.  If you going to do a V shape draw a line through the middle where you plan to fold it.  After it's the size and shape you want, leave a little extra just in case and cut out 2 sheets of cloth fiberglass and lay them on the cardboard.  You can hold the glass on the cardboard with a light coat of 3M 77 spray adhesive.  The important thing to remember is that the glass be tight together and on the cardboard.  If you get air bubbles in it, it will look terrible and won't be as strong.  Mix your resin and apply liberaly.  Brush off the excess and set it somewhere flat to dry.  After it's dry, trim it to the exact fit on your bike.  Now you get to make the sides & front.

2. Making the sides:  Your going to need *alot* of small pieces of cardboard & masking tape.  On the bike, tape the cardboard to exactly how you want the bellypan to look.  Remember that the glass will take the exact shape and texture of how you set the cardboard up.  After you have the cardboard setup, tape the bottom to it with some thin masking tape, fasten it front, back and middle is necessary.  Cut some large pieces of cloth to fit over the sides and over lap the bottom by an insh or two.  Spray the cloth with the spray glue and stick it on where you want it.  When attaching over lapping pieces on the side, try to keep the weave lined up and make sure the over lap areas (seams) are neat as you'll be sanding these later.  It's important that you do this in one layer, don't try to do this quick by adding a second layer of cloth now, if you do it will sag.  Pay attention to the point where the cloth attaches to the bottom, it will want to sag just above that spot.  I don't know how to prevent that but you could try using pins on the top to keep it from sagging.  Apply resin, allow to dry...
3. Make the front (and or back): This is jut like how you made the bottom but easier.  Make a mock piece out of cardboard, lay 2 layers of cloth on it and add resin.  After you cut it to fit the rest of the piece, support it on the inside with tape and cardboard if necessary.  Add a layer or two of cloth around the seam to join it on and over lap about an inch or so.  Add resin, allow to dry.  Now you have a rough belly pan.  
4. Finishing:  Clean up the seams with a file, the 2 sided Nicholson file works great.  If you know anyone who does horse shoeing, the files they use work great too.  If you find a thin or weak spot, or just a spot that looks like c.r.a.p, add a small patch on it and file it out when it's dry.  When it's lookin good, you can add a light coat of body puddy and sand it lightly to get it nice and smooth, I don't bother with that much though, the body puddy is heavy and not necessary on the track.
I've heard another common method is to make a mock (or mold) out of cicken fence and simply cover that with glass.  I haven't ried that yet but plan to try it soon.  

[G1K@work]

Here's another tip:
Extra resin does nothing but add weight to your part.

Wet out the cloth over a piece of glass (I use an old window).  After you have applied the resin, and the cloth is totally wet out (you can tell when it gets transparent rather than the white color), use a bondo spreader to take off all the extra resin.  You'll be amazed at how much extra is on there.

Lay up the next layer of cloth while the previous layer is green (not fully cured), then you will have a chemical bond between the layers.  If you wait until the previous layer has cured, you will only have a mechanical bond between layers, which will not be as strong.  It is easier to get air bubbles out of laying up green layers vs laying up over cured layers.


Ryan