Fiberglass vs. Wood

[Jacob Dryer]

How thick of fiberglass do you need to reach the rigidity (is that a word?) of 3/4" MDF?



I'm looking to build a box similar to Jeff C's to hold two 8's and was thinking about FBing the back instead of using wood to give it a bigger volume.



Any thoughts?

 

[Fudged Undies]

In my limited experience, you will save about a 1/4 to 3/8's of an inch. You will still want to have some type of dampening between the FG and the sheet metal the glass may/will come in contact with. I'm no expert, though I did my own FG enclosure. I would strongly suggest you do some research on the web on how to work with FG as it can be a bit tricky. If you need some info, drop me a line.

 

[Adam Yee]

You want pretty much the same thickness of fiberglass to wood ratio. if its 3/4" go 5/8" minimum. The biggest misconception of fiberglass is that you can go much thinner, but this is not true. Fiberglass is only good when space is limited and you need to make use of every inch possible.



If you want, you can add additional pieces of "dynamat" or a sound dampening material during the fiberglass process, this will help with the flexibility and sound properties of the enclosure. I would recommend doing this either way tho. You might be able to go down to a 1/2" if you use a fair amount of dynamat in the glassing process. To make it more clear... when glassing cut a few pieces of dynamat and place them into the mould.. they will set in place when the glass dries and will help dramatically.