Joining and gluing MDF

[tim walker]

I am about to make a picture frame with MDF and will then paint it.

Since it will be painted and I can use joint compound, should I even bother with mitering the corners and just go with butt joints? I have the capability to biscuit join or use pocket holes for actual joining.

And since MDF doesn't like moisture so much, will a tite-bond type glue work or should I try some other glue.

And finally, for MDF, if pocket hole screws are an option, would the fine or course work better? Seems logical to me that the course would be better but never worked with it in MDF.

Thanks all and Happy Holidays.

[Todd Burch]

Miter, biscuit, yellow glue.

Todd

[Mike Heidrick]

Coarse Kreg screws work in MDF most of the time.

[Yonak Hawkins]

tim, if you're planning on hiding the joint anyway I don't see why you can't use any type of joint you feel will hold, including a butt joint, if desired. I use yellow glue all the time on MDF with good success .. it would require some help, however, for a simple butt joint, such as a biscuit or spline. Screws, however, while they hold quite well going through the sheets, hold less well going into the edges.

[Michael Mahan]

seal well with shellack based primer before you paint the joint lines will show later on if you don't
edges of MDF swell very easy

[Justin Rapp]

I used 3/4 MDF to do paint-grade built-in shelves for both of my kids room's. I use tite-bond II with no issues. All joints were set into 1/4 dado's and then a 1" staple through the side into the shelf. The staples recessed just below the surface, which then got wood filler and sanded.

Another option to hide the joint is to use wood filler on the joint. After you cut your miters, use a chamfer bit and take a small edge off the miter joint. When you put the joint together you will have a V notch which can then be filled with wood filler, sanded smooth and you will never see the joint after it's painted!

[Harvey Melvin Richards]

Another option would be to make the frame solid. Route out the picture pocket.