What is the best method of builing an MDF box?
3/4 inch or 1 inch MDF? Glue, glue and brad nails,glue and staples, or glue and screws?

 

It might be more time consuming, but, nothing with regard to woodworking, is stronger than glue and screws.

 

Thanks, That's what I was thinking. But I wasn't sure if it was good for sub boxes or not.

 

x2

Unless you are gonna pack some SERIOUS wattage thru your enclosure, 3/4" will be fine.

 

use 3/4" MDF

Use a good wood glue, and screws are not needed, but are helpful to hold the box together while the glue drys.

The glue will make a stronger bond than the actual wood itself..

 

Ok, so what wood glue? I've been looking at Gorilla glue. I've used it before and it seems REALLY strong.

 

I have always heard that (the glue's bond is stronger than the wood itself), but still have trouble trusting it- so I always double up.

 

Good ole' Elmers wood glue works great. 3/4" mdf, 1.5" screws every 3 inches. Then caulk the inside seams if it's a sealed enclosure.

Polyfill (pillow stuffing) can also be used if you have to build the box smaller than the spec for your speaker(s). If your speaker calls for .5 cubic feet, then you could go down to .45 cubic feet using a half pound of polyfill. Depends how worried you are about meeting manufacturer's spec. You might like the sound better without it.

 

Be sure to use screws designed for partical board and predrill holes to prevent splitting or blistering the MDF. I would use a PVA wood glue such as Tite Bond II. Poly based glues like Gorilla require moisture to cure and you really don't want water on your MDF.

 

For most enclosured 3/4 inch with some bracing is fine. If its something huge thats going to have a LOT of pressure in it, 1 inch might be a better idea.

I use Liquid Nails on all my joints. Cover the edge from end to end.
As said before, the screws just hold everything together while the glue dries. So, you can either hold the box together with clamps while it dries, or do as most people and use screws. I find it a lot easier to use screws than clamps. Make sure you predrill your holes or you WILL split the wood.

For the corners I run a bead of silicone along every bit of every corner, and smooth it down to make sure its a good seal with my finger.

 

thanks, bartak. I've got 2 15" L7's going in. So what would you say, 3/4 or 1 inch. BTW its going to be sealed.

 

You should probably be fine with 3/4 inch, and brace that bish GOOD.
Might consider doubling up the baffle though (two pieces of MDF, 1.5 inches).

If you can swing it 1" wouldnt be a horrible idea though. Still need good bracing though. Still nothing wrong with doubling up your baffle with it either

 

Yeah, I plan on putting a sheet of 1 inch and 3/4 inch on for the baffle. And triangulating braces every where on the inside. The way I plan on doing it each sub will have 1.80 cu ft of air space to do it's thing

 

Sounds like your doing it right

 

I agree 100%. This is what I do on all of the boxes I build.