Supports?

[crumptinite]

So I bought 2 sheets of MDF but what kind of wood should I use for my inner supports and/or braces?

[HaRuMaN]

Pine 2X4's are cheap and would be more than sufficient. 

[crumptinite]

thanks for the fast reply. Do you think 2 would do the job of a upright cabinet?

[HaRuMaN]

thanks for the fast reply. Do you think 2 would do the job of a upright cabinet?

Depends on how long they are.  I know my local Home Depot sells some that are different lengths.

Oh, and don't bother with the treated ones (greenish color).

[GregD]

MDF supports itself.  Are you talking about supports for a crt monitor/tv? 

[EightBySix]

I'm surprised to have not seen people use modesty blocks to join mdf panels for cabs....

[mcseforsale]

Just use standoffs/cleats.  I used 1x2 "select pine strips" as furring strips.

http://www.homedepot.com/h_d1/N-5yc1v/R-100074242/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=1%22+x+2%22&storeId=10051

These are much nicer than the furring strips.  They're straight, dense and strong.  To get a 3/4" overlap on the edges, glue/screw them in about 1 1/2" from the edges.  I have mine drilled from the inside, so there's no external screws/patching.  In the pic, you can see the new one ready for the back/door of the cabinet...





Once the cross board are on (for the top, back and front), the entire thing is triangulated and pretty strong. 



The only cross bracing that I DID do was to put a 1 x 2 cross brace at a 45 degree angle inside the cab from the furring strip holding the angled back piece to the furring strip holding the back on each side.  So, basically a 11" triangle at each corner.  This made the cab very strong...like a fence door.

AJ

[crumptinite]

Yes supports for monitor but also to connect the mdf pieces for added support.

[crumptinite]

Those pine strips would have been a great idea but I already have a few 2 x 4's laying around now. Couldn't i just cut them down to size?
For an addon question what kind of paint should I use on the MDF. Any kind of spray paint or bucket paint that is preferred? I've heard that MDF is tricky to paint.

[mcseforsale]

2x is fine.  It'll be stronger and heavier.

As for painting MDF, There's been a lot of discussion between oil vs. latex (water) based paints.  But all agree you need to primer first.  

Also, you will be better served sealing all the cut edges of the MDF prior to painting since MDF is very porous and can suck up paint and still leave a crappy edge.

So...go to your nearest store and get a big bottle of yellow wood glue (buy the cheapest...elmers wood glue is OK...Gorilla is overkill and a waste of money in this application...save the Gorilla for the main build.   ).  You will be mixing 1 parts water to 3 parts glue.  I mixed mine up 4 table spoons at a time.  So, 3 table spoons yellow glue and 1 table spoon water.  Mix it thoroughly and use a foam brush to apply it liberally to EVERY cut that you've made in the MDF...dab that stuff in there with the foam brush.  Make sure the edges look wet with the mixture as you go.

It will dry in about 30 mins and leave a TOUGH, sandable finish.  Don't bother doing this on the outside of the MDF where you didn't cut.  

Once it's all dry, use some 120 grit sandpaper (on a sanding stick or block where possible), to smooth it down as it will be rough.  Don't think you're going to be sanding a lot out of the cuts...these edges are now very tough...rocklike.  This will make the edges much harder to dent when you're moving stuff around.  Still be careful, though.  

Next, prime the cabinet with Kilz primer (or Zinzzer...your choice).  I used latex (water based) since it's easier to clean up off brushes and doesn't stink.  My cab has 2 coats of primer using a smooth knap roller and a good brush (I only use Purdy brushes).

It took a good number of days for my primer to dry, but that's because it was very humid out when I was doing all this.  A day or so should be good if it's dry where you are.



For paint, the best I've found is the Rustoleum Painter's Touch Ultra Cover latex...  After about 4 coats, it looks like a melamine finish...just a touch of texture.  Here's the non-ultra cover...

http://www.homedepot.com/Blacks/h_d1/N-25ecodZ5yc1vZ1z1409i/R-100208855/h_d2/ProductDisplay?catalogId=10053&langId=-1&keyword=painter%22s+touch&storeId=10051

Here's the hint of texture...this is a VERY closeup picture.  




Just make sure you buy roller covers for the smoothest finish you can afford.  I don't like the foam ones though..

I used just under 2 quarts of paint on my cab...and I painted the inside.  Just make sure you use a new or cleaned and *DRY* roller for each new coat.  A good brush helps too.  



AJ

Those pine strips would have been a great idea but I already have a few 2 x 4's laying around now. Couldn't i just cut them down to size?
For an addon question what kind of paint should I use on the MDF. Any kind of spray paint or bucket paint that is preferred? I've heard that MDF is tricky to paint.

[crumptinite]

So did you paint the cabinet when it was already assembled or did you take it apart?

[mcseforsale]

No.  I wasn't able to.  There's a couple of reasons.

1.)  all the wheeled crap that 3 kids come with doesn't allow me the room.  basically, during the day, I'd have to move stuff out of the garage, then make my cuts in the driveway, do some assembly in the garage and then move the stuff back in at night.
B.) being in Ga., my garage floor is sloped by code.  So, I was fighting a sloped garage floor and once I got it all built into a cabinet that was square and plumb, I didn't want to mess with it.  Especially since this is my first woodworking project (other than stuff like swingsets and fences). 

To paint the inside, I put it back up on it's side on the workhorsen and painted as much as I could, then flipped it over and did it again.  That allowed me to get inside the marquee area and in most of the other spots.  For the bottom of the inside, I just got in there and painted. 

AJ

So did you paint the cabinet when it was already assembled or did you take it apart?

[Mental]

True 1" solid maple is cheap and comparable to steel as far as strength goes. The screws will rip out of your MDF before the maple fails.

[eds1275]

I'd recommend gluing your supports as well as screwing them in. Glue is stronger anyways, basically the screws just hold them in place until the glue dries without spending a fortune on clamps. I ended up just using my brad nailer to nail them in place once the glue was applied.

[yaksplat]

I'd recommend gluing your supports as well as screwing them in. Glue is stronger anyways, basically the screws just hold them in place until the glue dries without spending a fortune on clamps. I ended up just using my brad nailer to nail them in place once the glue was applied.

+1 Glue and screw everything that you never plan on taking apart.  I like to use construction adhesive and torx screws.  The bit won't slip if you can't get a lot of pressure on the screw, and you can even use a ratchet with the bit in a 1/4" socket without slipping.

[mcseforsale]

Yes.  Glue and screw.  I used Gorilla wood glue on the all of the stuff that won't get moved. 

Not sure about construction adhesive on MDF, though.  The paper and "wood" would tear before the wood glue breaks loose, so construction adhesive might be overkill.

AJ