Mdf

[john worrell]

How is the best way to attach MDF? Glue with screws or glue with nails. Somewhere I read that they have specific screws to be use with MDF to keep it from splitting. I think glue and nails would do it???

[Prashun Patel]

Describe your joint. IMHO, it depends.

For shelves, I prefer to use dados and glue or shelf pins.

Pocket screws or dowels can work nicely too.

[Terry Clark]

John,

To date I've mostly used glue and course threaded drywall screws for 3/4 mdf. My drill has a ratcheting chuck and I set it low to set the screw without spliting the material. I've also used pocket holes with washer head screws. The problem I had with them is it's easy to over tighten and route out the hole. For 1/2 material I've used glue and brads. Hope this helps.

Terry

[john worrell]

I am building some squaring blocks to help in case alignment, etc. and some jigs...will be utilizing butt joints mostly. Thanks for the input.

John

[Joe Chritz]

If you are talking about but joints (i.e. Cabinet carcasses) then the "best" method is probably dowels. Those are kinda slow and hard to align with equipment available to most small shops. Confirmat screws are basically a threaded dowel and are used by many cabinet shops for MDF and melamine carcasses.

I have butt jointed Melamine cabs (PB core but I doubt that matters) with assembly screws. Simply a #8 2" screw with a nib head (for countersink) and a #17 cutting point. They are available at all the usual suspects under different names.

Line up the sides, pop a brad or staple on each end, drive the screws, wash, rinse, repeat.

Joe

[Per Swenson]

Hi all,

Firm believer in Confirmat (http://www.rockler.com/ecom7/product_details.cfm?sku=652&filter=confirmat&cookietest=1) screws and tite bond.
Or dado and Titebond.

Per

[tyler emrick]

For my butt joints I like to use tite bond and 18 gauge brads to hold it. Then use a #8 countersink with 1 1/4 to 1 1/2 coarse drywall screws.

[Matthew Henderson]

I just built a table saw stand for a delta contractor saw with 3/4 MDF. All joints were dadoed. Then tite bond and 15 gage nails from a gun. No splitting and the thing is as solid as a tank. Weighs almost as much too! I used to build speaker boxes with MDF. Again, glue and brads and I never had a problem. One thing that worked for me was to not nail within 1.5 inches of an edge.

-Matt

[Russ Kay]

I got a conformat screw kit from McFeeley specifically for working with MDF, and I've not been really happy with it. As set up, the drill doesn't go deep enough (and I've been unable to loosen and readjust the stop collar), so driving in the special conformat screw ends up splitting the MDF. Nowadays I use the special step drill, then extend the pilot hole with a regular drill bit, and everything works. But it's an extra step, and a PITA.

On the other hand, I've also used regular flathead screws from McFeeley for the same purposes, and they have worked just fine too. I like the idea of the conformat screws; they've worked well in inexpensive commercial small cabinets I've bought; but making them work for me doesn't seem worth the extra expense.

-- Russ

[Per Swenson]

Russ,

When using confirmats, you want the three step drill.
Not the one with the collar. They are available from twenty to thirty
dollars around the intertubes. Here is a example. (https://www.true32.com/ProductDetail.jsp?LISTID=23D0000-1132433345)
It is my opinion the the other style is just gas in a bath tub.

Per

[Ray Schafer]

I use confirmat screws, Spax mdf screws or just titebond glue. Biscuites are an option, also. Dowels can work fine, but they are much simpler if you have the Dowelmax.