Replies

1. 
   GRW | May 10, 2005 08:38pm | #1

   Toolfreak,

   My $.02..

   Use screws instead of brads. I don't think  an  MDF glued joint will be as strong as a natural wood glued joint. I'd add 2" screws from the outside/through the dato/ and into the MDF shelf.  

2. 
   BG | May 10, 2005 08:45pm | #2

   toolfreak,
   Your not going to have very much shelf strength with the mdf..it'll bend easily. However, the only reason I can see to add brads is to avoid clamping...the extra holding power(compared to the glue) is negligible.

    

3. 
   ring | May 10, 2005 09:34pm | #3

   I think the brads are entirely uneccessary in the first place.  If the MDF shelf is a tight fit in the dado, and assuming that it is short enough so as not to bend, the glued joint is all you need.  Use convex cauls to apply pressure to the middle of the joints as well as the edges when glueing up.

   If you want to use fasteners anyway, maybe consider this:  Screw the whole thing together from the outside, then add a second MDF sheet (doubling the wall) from the outside, which will hide all the screws and give you a heavier vertical wall.  Make the face frame wider for the verticals as necessary.  The added cost of the MDF is probably not a factor.

   DR

4. 
   Kent_F | May 10, 2005 10:14pm | #4

   I agree - no need to nail dado joints.

   You didn't by any chance get this idea from a certain woodworking TV personality, did you?  : )

1. 
   Toolfreak | May 10, 2005 10:54pm | #5

   Actually, yes. I've seen Norm use a brad nailer to toenail on the inside near the dado joint. Would I want to do this if I were using regular lumber?- Toolfreak

1. 
   notDusty | May 11, 2005 08:19am | #6

                Hi Toolfreak ,

                            You are building an mdf bookcase , and not a piece of fine furniture . In theory the fasteners only need to be there until the glue dries , if they were then removed no strength would be lost , in theory . Given the same materials and the same bookcase to put together personally I would use fasteners . The finish nails brads or screws will not hurt or weaken your task . If this were solid exotic hardwood and the best work of your life then , by all means use no fasteners . I build furniture and do case work , I build a lot of boxes and typically the finished ends do get pin nailed through the dadoes , but few nails go through the face of my work , instead I glue and clamp the faces on . In real furniture I was taught there is no place for nails .Be realistic and flexible go with the flow of each application and project . A purist who says under no circumstances use nails , probably would not build out of MDF , what do you think ?

                               good            luck            dusty

2. 
   Kent_F | May 11, 2005 05:34pm | #7

   To my mind, it's not a question of purism or the materials used. I just don't see the point of adding nails to a joint unecessarily. Maybe I'm just lousy with a brad gun, but the risk of blowing a nail thrugh the side, splitting the end of a shelf, or leaving a brad head sticking up seems to outweigh the convenience of tacking the parts "just until the glue dries."

5. 
   Ricks503 | May 12, 2005 03:56am | #8

   If you are building it out of MDF go ahead and use the nails to hod it togetger while the glue dries. You will probably be painting it, so just fill the holes.  If you want to add strengtht to the shelves, add a 1x2 along the front of the shelf .  You can cut the shelf 3/4" less in width and the 1x2 will sit flush with the front. If you want, pin that with nail at each end.  This is going to be a utility bookcase, not a Duncan Phyfe repro.  Go with what will work and be fast - save your time for the better stuff.

    

    

   1 - measure the board twice

   2 - cut it once

   3 - measure the space where it is supposed to go

   4 - get a new board and go back to step 1