How to Make Fiberglass Bodykits for Cars

So you would like to duplicate body parts and panels for your custom car, but either want something or little different or don't have very much money? Follow along!

Instructions

Difficulty: Moderately Challenging

Things You’ll Need:

• Access for fiberglass mat & resin
• Several paint brushes & fiberglass rollers
• Styrofoam or plaster of paris
• Duct tape, cardboard, a deck of cards, modeling clay and mould release

1. Let's begin:
   Step 1
   Lay out a work area that is clean, dry and out of the elements. Warm is a bonus.
   Heavy paper or Visquine plastic should be taped to the floor to minimize spills and mess.
   Next set up a table, saw horses or an improvised "Stand" to elevate your work.
   If you have a panel to copy--Great!
   If you are creating one from scratch, you must build the "Modeling buck".
   The first step to build body parts or panels from scratch is the design.
   Draw out the basic design of what you want. For example, a simple mould to build would be: an Air Dam.
   To begin, build a "Buck". This will be a "Part" that you will make the mould from. It can be made from Scrap Wood, Plaster, Body Filler, etc. Just build the basic shape out of wood and chicken wire, etc. Then slather on the Plaster or Bondo, sanding and shaping as you go. Once it's close to what you want... you must "Pull a Mould".
   If you are "Copying" an existing panel, you must pull a mould from that panel. (the mould will be a reverse of the part).
2. Step 2
   Time to "Pull the Mould".
   Wax the item or use a release agent, then paint it with Gel Coat. If it is dull or painted, I would recommend spraying it with release agent.
   Tape off any areas that you do not wish to cover.
   NOTE: any areas that "Wrap Around" will need a seam. For example, if you build a mould over a panel and AROUND the edges, you will NOT be able to "Pop" the item off!
   To build a seam, cut playing cards lengthwise, place clay or release agent "Face to Face", then Gel Coat up each side of the cards. Try not to get too much in between.
   Allow the gel coat to dry.
3. Step 3.
   Next, once the Gel Coat has dried, lay resin soaked fiberglass mat over the gel coat.
   Make sure that you use enough resin, but not too much. Use the rollers to "Roll Out" any air bubbles. Air bubbles with cause weak areas.
   Once you have "Layed Up" several layers of mat, let everything set to dry.
   Braces can and should be made to ensure rigidity. You do not want the mould to flex too much. You can lay cardboard or something along those lines in a "V" or an "A" and 'Glass over it. Allow the 'glass to dry.
   TIP: You can trim SOME of the edges when the fiberglass is rubbery (not completely dry). Use caution, it could be very HOT to the touch.
4. Step 4
   Once it's dry, you will need to trim the mould down to it's regular size. Basically, clean edges with an inch or two lip. Trim with a Jigsaw or grinder.
   Paint sticks, plastic scrapers and putty knives can be used to pry the Mould apart. Insert a putty knife, prying carefully, then insert WOOD. Be careful NOT to scratch the inside of the Mould!!!
   Be careful not to crack the mould, although it should be 2-3 times thicker than the part, it can and will crack.
   
   Once the mould is separated, wash it with mild detergent, clamp it together at the seams, and drill holes for bolts.
   TIP: If there are quite a few Mould "Panels", they should be numbered.
5. Step 5.
   Now it's time to make a new part!
   Bolt the mould together spreading clay to smooth seams, spray in mould release agent or just wax. Brush in Gel coat and let dry.
   Now it's time to lay up the fiberglass.
   When you are making the part you must be careful to lay the fiberglass evenly. It is more important on the part to ensure uniform thickness. Large flat areas and stress areas can be reinforced with a Core Mat or heavier weave. Remember also, that the part should resemble the original in thickness, weight and details. If you created the part from scratch, use a steel part to compare or use your best judgement.
   One the new part is laid up, let it set for Hours, Days, Weeks, etc. While it's in the mould, it will stay uniform.
   Unbolt everything and pop your part out!
   It's really THAT easy.
6. Step 6
   
   More tips.
   
   Always use an area with good ventilation.
   Wear gloves to protect your hands and NEVER mix the resin too HOT. The catalyst (M.E.K.) causes a chemical reaction. If you mix too much catalyst the resin can and WILL burst into flames!
   If a Mould Marries to a part... you'll be sorry! Be careful and experiment before ruining a valuable part. (marrying occurs when the mould "Bakes" into the part causing them to become permanently attached)

Tips & Warnings

• Contact local boat repair shops and boat makers for supply referrals
• Experiment with designs
• If you are successful, sell extra parts to offset expenses
• Use extreme caution when working with fiberglass!
• Once resin dries, it is hard as a ROCK
• NEVER pull a mould from an expensive item until you have some experience.