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The bracket in the first image is holding a frame onto the bottom of a (Stiga) table tennis table. The other one (and some others) have broken off the table. I need to repair the chipboard as shown in the second image. How can I repair this so that the screw does not break out again?

The table tennis top is 5/8" thick.

I think that the top (the chipboard) is beginning to warp which is pulling it away from the frame and causing these screws to come out.

working

broken

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    You should be able to make a permanent or long-lasting repair to this using filled epoxy. Do you have some mixed wood dust (from power tools) and/or fine sanding dust? You can use just a fine powder like sanding dust (on a large scale they use wood flour) but I believe you get a slightly stronger fix if you use a mixture of particle sizes, as long as there are no particularly large flakes. The repair I mention here I used a mixture. – Graphus Nov 20 '20 at 8:58
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    @Graphus answers go below! – FreeMan Nov 20 '20 at 16:53
  • @FreeMan, yes indeed they do ^_^ ........ but Answers don't contain questions for the OP. – Graphus Nov 20 '20 at 19:34
  • @Graphus - yes I often have wood dust from other projects. I'll try that. I have the 5 minute epoxy but I should be able to mix and fill in that time limit. – Guy Nov 21 '20 at 1:21
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You should be able to make a long-lasting, possibly permanent, repair to this using filled epoxy.

As outlined in previous Answers, you can mix epoxy with nearly any dust to make it a thicker and ultimately stronger material (as well as to modify its working characteristics, e.g. with the addition of talc to improve sandability).

Normally when filling epoxy you just use fine powders. However in this case a mixture of wood dust and coarser stuff, but no large flakes, may give the best results. A mixture of particle sizes results in an 'aggregate' system (similar to concrete) which gives a stronger material than if just dust (or sand alone) would produce.

Because you're using 5-min epoxy as clarified in the Comments, I would suggest doing perhaps two of the divots at a time, so you don't run the risk of trying to work with epoxy that has begun to set up. If you find it necessary do the holes one at a time, there's no downside other than the tedium!

In addition to the epoxy, wood dusts and a mixing tool1 you also want a drill and to have a hair dryer/heat gun on hand if possible.

Here's the entire procedure outlined:

  • drill out the ragged holes to make larger, more-easily-filled holes.
  • Blow out all loose material with compressed air or through a straw/empty ballpoint tube.
  • Pre-mix your wood dust and any coarser stuff into a single pile so you can add it into the already mixed epoxy without wasting time; you will be under the clock every time you mix.
  • Heat the hole or holes — not the epoxy — well with the hair dryer or heat gun.
  • Mix a small batch of your epoxy, but before you blend with your powders quickly add a small amount to the hole. You'll see that the epoxy will liquefy noticeably when it contacts the heated wood, and more easily soak into the chipboard. Then blend epoxy and wood dusts to a 'stiff batter' consistency approximately — you want something less than a stiff paste; still slightly fluid and able to drip off the end of your application tools.
  • When all the holes are filled now you wait much longer than you're expecting for the epoxy to fully cure. I would suggest waiting at least overnight (yes, even with 5-minute epoxy2).
  • Mark the positions for the screws and then drill your pilot holes as normal for solid wood, then carefully drive the screws home. I would strongly recommend not power-driving them, unless you have absolute confidence in the clutch on your driver. This is just a few small screws, do them by hand and don't Popeye them3.

You can aim to fill each divot flush by using just the right amount of filler each time but this is a tricky thing to judge. I think it's a better idea to slightly overfill, then flush after setting using a block plane, careful sanding or filing.


1 Note that you'll probably want a stronger mixing paddle than you typically use for straight epoxy (such as the small plastic one included in many epoxy packets). Filled epoxy is much stiffer and harder to manipulate, especially at the consistency you're aiming for here to hold screws.

2 While the packaging of 5-min epoxies may typically state they're cured in an hour the small print may go on to specify that it takes 12 or 16 hours to reach full bond strength at e.g. 24°C (75°F).

3 By this I mean resist the temptation to go "one grunt past tight" :-)

2

One option you have is to drill out a suitably sized hole for a threaded insert.

threaded insert

The above image is from Amazon, but many sources will have this type or similar inserts. You'd have to switch your screws to machine screws and ensure to match the insert to the desired thread size.

  • For something like a gaming surface, where you might want to take it apart to store or repair, this would be ideal. – jdv Nov 21 '20 at 14:15
  • The holes are already torn out and ragged, and the material is chipboard. Do you not think this argues against these being a viable alternative? The holes in the brackets are presumably quite small so the OP can't go up in size by much to allow for all the broken-out material to be taken care of by drilling. So some reinforcement of the material might be in order.... like with epoxy. And if you're mixing epoxy anyway..... – Graphus Nov 22 '20 at 7:25
  • with sufficient depth to the insert, it would distribute the forces applied near the surface to the entire thickness. Additionally, a shorter insert deeper into the crater would require only a longer bolt. I like the drill-out and glue-dowels answer, mostly because I have a ton of dowel scrap. – fred_dot_u Nov 22 '20 at 12:59
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Drill out the blown out screw holes with a 3/8ths drill bit.

Use wood glue to glue in some short pieces of 3/8ths dowels.

Use a flush cut saw or oscillating saw to cut off the excess dowel and sand smooth.

Now you can drill new pilot holes for your screws

  • As an added bonus, the screws will hold better in solid wood than they did in the particle board. – FreeMan Nov 20 '20 at 23:57
  • This almost standard fix for torn-out screw holes isn't really suitable here (and isn't actually the no. 1 choice at the best of times anyway). – Graphus Nov 22 '20 at 7:25
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Instead of trying to fix the existing holes:

Move the bracket 6 inches1 left or right, screwing into fresh particle board, leaving the old holes as lost.

Consider using threaded inserts as described in Fred's answer specifically designed for use in particle board, then replace the wood screws with appropriate machine screws.

Don't try to put a new pair of holes between the existing sets - it will be more likely to break out again.


1Or more than a half bracket's width if 6" seems too far from where support is needed. You don't want the new holes ending up too close to the blown out edges of the old ones.

  • Ooo, I love this Answer! Good thinking dude. Only problem I foresee is that the brackets appear to interact with machine screws at specific locations — see slot in bracket in photo #1, and projecting screw in photo #2. – Graphus Nov 24 '20 at 8:24
  • Excellent point, @Graphus. I believe those are limit screws to ensure the legs don't fold/unfold too far. If there's at least one other bracket/limit screw pair on this leg, it should be OK. TBH, though, it may be worth moving that limit screw to the new bracket location. – FreeMan Nov 24 '20 at 11:35
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    Well... you could get a Tap & Die set and make new holes for the limit screws. Why keep it simple and cheap when you can make it complicated and expensive with so little effort? This is woodworking after all, right? – Greg Nickoloff Nov 25 '20 at 14:54
  • Or, @GregNickoloff if the limit screw does need to move, drill a new hole & run a self tapping sheet metal screw in. I doubt that screw needs to be used, just a screw. Heck, you could probably epoxy on a little bit of metal bar to do the trick... – FreeMan Nov 25 '20 at 15:59

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