3/4 mdf plus glass?

[todd217]

will a box build out of 3/4 mdf then covered in a couple layers of fiberglass be strong enough for the ti12d? i did some measuring yesterday and using 2 layers of 3/4 may not work.

[Eric D]

I would not waste the time or effort with the fiberglass, that won't add any useful strength to the MDF.

If you use 3/4" with some internal bracing, that will hold up to any thing you throw at it.

[gridracer]

3/4 MDF should be fine on its own just use some internal bracing. Also I use resin on the inside of all my boxes it does make a difference. damn eric posted as I was typing

[Eric D]

If the box is for SPL use I would consider a coat of resin on the inside. If it is for SQ, then be certain not to coat the inside with anything other than maybe a liquid sound deadening product.

The whole point of using MDF is for its sound deadening properties. Coating the inside with something like polyester resin will reduce these properties and make the box "ring" more.

If you build a sub box with HDF instead of MDF, you will know what I mean.

[brenzbmr@sb]

sheez if i could just find some HDF

[Eric D]

sheez if i could just find some HDF

Check with a bowling alley. I am sure there is at least one on the big island. When they redo lanes, they use it for sub floor construction, and they may have some somewhere from some prior refurbishing. Or they may be able to point you to the contractor who did the work, and they may have some somewhere.

[scottn29]

You could always use 1" MDF, it mostly has to be special ordered, but I know mine in St. Louis comes from Illinois somewhere. But after I went into the lumber yard and ordered it I had it in 2 days.