This is a big topic so here are the generals:
-Use the appropriate mat for your situation. Strand Mat for curved surfaces and regular Weave Mat for semi-straight surfaces. The Strand mat will conform to any shape within reason.
-Mix only enough resin and hardener you can use in 5-15 minutes depending on temp. and other variables.
-Apply Resin from the middle of your work are and work it outwards. Don’t over soak it but also make sure its fully soaked. Make sure its completely covered but don’t make the fiberglass swim in it.
-Go back through these steps until your first layer is on. Let dry 1/2-1 hour before adding another layer or until cool. If you get it too thick at once you can have a resin fire (its sucks and you will ruin your project and more)
-After final layer add a smooth coat of resin. Also reffered to as Gel Coat. Note that the colored Gel Coat is a color Additive to the Resin.
Fiberglass Box Panels
Usually you have 5 panels made out of a structured material such as MDF. The 6th one is the fiberglass. You must devise a plan to do this. A few ways are to make a Mold with Plaster, Aluminum Covered Styrofoam or a stretched fabric form.
The Stretched Fabric form is most prevelant. This is where you use some small pieces of wood to make a pattern. When the fabric is stretched over it the desired shape appears. Complex Radius's can be formed easily with this method. The cloth most used is simple speaker grill cloth. Resin is applied to it and will harden. This cloth is used only to serve as a form. After it has dried Fiberglass mat is laid directly over top it and is glassed in place. When done the grill cloth and the wood pieces remain as part of the object, so plan accordingly.
Next is the Aluminum Covered Styrofoam. Why Aluminum covered you ask? Well thats easy! If it wasn't Aluminum covered the Resin would eat through it (heat and chemical reactions). With this method we usually use the blue or pink Styrofoam found at home improvement stores. This stuff can be stacked and glued together. Then it can be cut to shape with sharp razors, hot wire systems or sand paper/sanding devices. Then you simply cover it with Aluminum Foil with minimal creases. Cover the creation as supplied in the General Directions.
The last topic I want to touch off on is Spare Wheel Well Enclosure.
This has become a popular enclosure lately. The easiest way I can figure to do it is as follows:
-Line the wheel well with Strand Mat and glass in place. Using 1.5 Oz strand mat I would say 3-4 layers is plentiful.
-Make sure you glass 3-6 inches past the actual spare tire compartment.
-Cut a board to fit in the desired area. Use Resin to "glue" the board down.
-Mat over the board to the excess mat coming out of the well. This mat should sandwich the board and make a solid enclosure. 2 Layers of mat doing this with a 5/8 MDF board should be plentiful.
The New way too make fiberglass boxes and other items:
The fiberglass strand is an old way to do it. This way I’m going to show you is the easiest and fastest way to do it.
Step one: make the base the way you want it lets say a 10”X12” piece of ¾”MDF for the bottom and another one for the back. Like this just look at the back part for right now.
Step two: make your speaker rings what ever size you want or for square or round what ever you want. Use a router with a circle cutting attachment a ¼” straight bit, or jig saw.Cut 2 rings per sub about 1½” bigger then the outside measurement of the sub.
Cut one to the size of the outside of the speaker maybe a hair more ¼”
Next figure out what the speaker hole is going to be and cut the other ring like this, all the away around ½ way through and a third away around on the other half
Next attach both together with wood glue and screws. Let dry and take screws out. Like so now you have a recessed speaker ring. Notice the center whole all the way through this is perfect for mounting.
Next mount the ring(s) on the board like so. 2x4’s work great one screw in ring to board and 2 from the bottom up.
Now after you get the rings mounted now you stretch the material on. I use fleece blankets very cheap a $2.50 for a blanket at Walmart or where ever. It stretches great. Heres what it should look like after stretched. I staple it on it seems to work the best.
Next mix up resin to the correct ratio. Apply it really heavy make sure it soaks in good. Get the ring edges and all other edges extremely good. It should look like this.
Next cut out the fleece from the rings and now the inner rings of MDF. Use resin and silca powder and mix together to make a thick paste and add hardner and pour on the inside on the box and brush it around. Do that till its about 3/8” think for your average subs and thicker for beefy ones. Don’t put too much in at one time or you will get a fire. You can use heat to get it drying just for a little bit.
Next do the bondo work to smoothen it out and then paint it or wrap it in vinyl or what ever.
This guide was created by Basstronics and Sinister Audio. Pictures courtesy of Sinister Audio.