MDF how to edge joint

[Zahid Naqvi]

What is the best way to edge joint MDF. I am going to build a shoe rack to put in the garage, so I grabbed a couple boards of laminated MDF to avoid painting the finished product. What do you think is the best way of making a T joint with MDF for both pieces. I can always put a wood strip under the joint and use it to hold screws but I see several joints in my closet where the MDF is joined in a T and there is no additional support used. The joints seem to be pretty strong.

[Chris Padilla]

Zahid,

I'm confused what you want: Are you looking for a good way to edge-joint (glue) two pieces of MDF?

I'm not clear exactly what a T-joint is: Do you want to dado a piece of MDF into another piece to create a shelf?

Sorry, just confused.

[Dennis McDonaugh]

It sounds like you just want to join two mdf boards together and not joint an edge on an mdf board.

Normally I'd use a dado to the the cross of the T to capture the the shaft of the T. It'll make a stronger joint. However, if the mdf is screwed to the wall such as in a closet, I don't think it'll matter because act of screwing it to the wall adds a lot of strength too.

[Bob Hoffmann]

The simpliest way to connect an MDF edge to the middle on another board -- a "T" joint -- is to use MDF screws. They use a special bit to drill a steped hole that fits the screw. These are special designed screws to hold in MDF -- normal screws do not do a very good job.

McFeely carries a package with screws and bit. Since it is in a garage, the screw hole is probably not a problem, but you can also get round covers for them that fit over the hole.

[Zahid Naqvi]

Dennis and Bob, got what I was leaning to. So if I cut a dadoo in the cross of the T to capture the shaft do I need nails or screws or glue is enough. I've read about the special MDF screws, but it seems too much trouble for a shoe rack which will be kept in the garage (and will probably house muddy soccer shoes as well).

[Dennis Peacock]

Z,

I use a hardwood spline to edge join MDF. Increases the glue surface area and makes for a nice strong joint. Use Poly glue to keep the joint from swelling due to the water content of the PVA glues.

[Zahid Naqvi]

Zahid,

I'm confused what you want: Are you looking for a good way to edge-joint (glue) two pieces of MDF?

I'm not clear exactly what a T-joint is: Do you want to dado a piece of MDF into another piece to create a shelf?

Sorry, just confused.

I used the T joint phrase to literally use the letter T as a visual example of what the joint looks like. Consider it like a middle shelf in a bookcase. How would you join the shelf to the sides if both were MDF.

[Zahid Naqvi]

Z,

I use a hardwood spline to edge join MDF. Increases the glue surface area and makes for a nice strong joint. Use Poly glue to keep the joint from swelling due to the water content of the PVA glues.

Aha! now that is something I can pull off with my extensive collection of shop tools. The only problem is I didn't describe the question very well, the bookshelf example is probably closer to what I wanted to say. Edge of one MDF board connecting to the middle of the other, literally like the letter T

[Dennis Peacock]

3/8" deep dado joint and some coarse thread screws from the outside into each shelf.

[Charles McKinley]

Hi Zahid,

There are a couple of fast and very easy ways to od what you want. Pocket hole screws + glue or biscuits + glue would work fine. It you do not have the tools to do one of these operations you could rabbit the face piece and clamp and glue it to the shelf or use dowels. There are many ways to do it. Pick one and have fun! Someone here has the qiote line,"Experience is what we call our mistakes."

[Zahid Naqvi]

3/8" deep dado joint and some coarse thread screws from the outside into each shelf.

There you go, now you're talkin b'ness :D

[Dennis Peacock]

There you go, now you're talkin b'ness :D

Do you need some Poly glue? I got some you can borrow if you like.

[JayStPeter]

Aha! now that is something I can pull off with my extensive collection of shop tools. The only problem is I didn't describe the question very well, the bookshelf example is probably closer to what I wanted to say. Edge of one MDF board connecting to the middle of the other, literally like the letter T

Sounds like a use for buscuits to me. That's what I'd do.

Jay