Like the title says are screws necessary for building a box?
In the past I've always used glue and screws.
This time I want to skip the screws as I want the finished product to "dimple" free because I plan on painting the box instead of carpeting it So, if I can avoid a couple hours of poly-filling and sanding screw holes I will.

Thanks,
Ryan

 

We use nails and glue with lots of bracing to ensure that our boxes don't fly apart under extreme pressure. Do you have an air nailer? If not then you'll need some long, strong clamps, lots of them to give continuity of pressure throughout the flank that you're gluing.

 

Glue by itself will blow apart

 

I have tested this theory with a hammer..

I can take an enclosure that is held together with just glue
apart with only surface damage to the MDF

with an enclosure properly glued and screwed you can destroy
the panels before they let go

 

tongue and groove is stronger then a butt joint and with the right glue you should be good, (I would nail as well as advised unless you have many very large claps)

 

once the glue has dried you dont need screwes. i like using brad nails as well as screwes tho.

 

MDF is made of layers....the glue only has a surface bond
it doesn't take much to break the outer skin loose on MDF

where as when you use screws it clamps all layers and is multiple
times stronger than the glue surface bond

 

Thanks,

I'm convinced. I'll screw up my box when I build it

Thumper - thanks for the observation of the layers in MDF. Now that you've mentioned it, I've seen pieces MDF separate that have been glued together; the original layer remained glued to the other surface, but it was torn from rest of the layers. The glue isn't the weak point, the weak point is that MDF isn't one solid piece.

So, if I want a nice smooth looking finish, I'll need to spend the time filling and sanding the out the screw dimples.

Thanks,
Ryan

 

Like Father Yuli said. Screws and nails are only there until the glue dries. IF you are gluing and butting your mdf you may want the use some screws. If you are dado-ing (grooving) your joints glue and brads are more than enough. Also keep in mind if you dado you joints, you will basically have 50% more gluing surface = added strength. The core of mdf will draw more glue than the outside skin will.

 

And a layer of fibreglass across all the seams on the inside does wonders for strength as well.