[Doublej]

I need some advice on how to attempt repair a coffee table. From what I can tell even though the table was not Ikea priced, it is cheaply made.

A guest sat on the left front corner of the table. This caused the following:
1.   The bottom drawer frame rail has separated from the leg.
2.   The Philips screw that fastened the rail to the leg went through its hole.
3.   The bottom drawer frame rail has developed a hairline crack on the front.
4.   The rectangular tenon joint on the rail is chewed up.
5.   The area where the screw went into the leg is no longer in tact.

When I removed the Phillips screw and disassembled that area, I found a squarish headed screw in the leg that I cannot figure out the purpose of. Based on my limited knowledge, I was going to try to use a mending plate screwed to the front face of the leg and frame rail to hold things together.

What do you think? Is there a better way to attempt a repair? I put a bunch of pictures of the situation in my gallery. Here's one.

[WGH]

Looks like the tenon broke off but since the entire table looks like it is paper veneered particle board there was no structural strength in it anyway. There is no way to replace the tenon so you will have to rely on the screws to hold it together. The quick and dirty fix would be to run a couple of 3" screws through the leg into the frame rail, pre-drill first or you will split the frame. A couple of 3/8" plugs on top of the countersunk screws, shaved flush and stained completes the repair. Otherwise you will have to fill the old screw holes with toothpicks and glue then re-drill.

Is there room on the inside for a block of wood? Even a 1/4" plywood scrap glued and clamped would work. You will have to scrape off the lacquer to reveal bare wood or glue won't stick

A mending plate will give the table the sought after rustic trailer trash look, I prefer the "T" brackets from Home Depot or Ace Hardware spray painted black. An "L" bracket under the frame would work too.

[Doublej]

Thanks WGH. For the trailer trash L bracket under the frame look what length screws should I use if the rail is 1 1/2" tall?

[WGH]

1" is good, wrap a piece of tape around the drill bit at the 1" point so you know where to stop.

Wood screws don't work very well in MDF because the threads are shallow compared to the shank and only part the shank is threaded


Look for a deep thread or coarse thread screw with threads the entire length of the shank


The pilot hole should be the same size or slightly smaller than the shank


Although some people say the threads are only for the screws removal and they are inserted using a big hammer.

[Brettio]

In the table leg I’m assuming there’s are two ‘holes’, one where the tenon slid in and another below it where the screw was screwed in, but pulled out.  I think if it were me  I’d fill the screw hole in the leg with some good quality wood filler and let it dry.  In the cross piece screw hole I’d glue a small wood plug from a wood dowel (cut it short enough to hide the screw head).  After all that is dry I’d pour a good quality wood glue in the tenon hole, slide the tenon in (I realize there isn’t much but I think there’s enough to get some bite) then screw it together.  I agree a screw with full length threads is important. 

I know this isn’t saying much, but the wood glue connection will likely be stronger than the partical board that it’s holding.

Brett

[brj]

Spax makes an MDF specific screw, though it has the partial threading that WGH first recommended against:

SPAX® MDF/HARDWOOD SCREWS

These screws use a Torx drive, which is far less likely to cam out than your standard Philips or flat head, but I'd still be tempted to pre-drill despite the 'self drilling' claim.

(I have a box of their very similar 'multi purpose construction screws' (though the Spax website lists them as cabinet screws) that differ visually only in that they have a pan head instead of the milling head.  They are waiting to have their heads painted black for a subwoofer project involving MDF cabinets - purchased after one of the oh-so-commonly recommended dry wall screws sheared off in the superglue reinforced hole.  Grrr....)