I discovered few 10-15 holes on one of my oak plans I use to build a table. How can I assure that there are no worm left alive to ruin my future table. I cannot plane them.oak with woodworm signs

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    You cannot be sure the board has no active 'worm' inside, regardless of whether the bore/exit holes you see are all obviously old. And unfortunately pesticides can be the least effective method to eradicate, since they often can't reach the larvae deep in the wood and when applied to the surface to prevent re-infestation there is incredibly shallow penetration (as there is with almost everything we apply to wood). – Graphus Jul 30 '18 at 11:24
  • As one smart guys said there are only two things certain in the world: death and taxes ;) I am looking for a common sense approach. I am afraid that I do not have access to a large freezer or kiln. – sorin Jul 30 '18 at 12:42
  • Well what seems to make sense will vary from person to person. I've brought small pieces of wood that I knew had active woodworm into my own home, knowing I'd be using the microwave or freezer to be absolutely certain to kill off remaining larvae, but I know many experienced woodworkers take the position that if there's the least chance a piece of wood has a current infestation and the piece is too big to freeze it's burned as firewood or thrown away, they just won't take the risk of it spreading. – Graphus Jul 30 '18 at 14:52
  • All holes were dark which makes me believe they were old, before the wood was kiln dried. I guess I will take the risk and apply treatment and expect for the best. I could mark them and check if I see new one every 6 month (Alexa set a reminder to check table for new holes” ;) – sorin Jul 30 '18 at 16:35
  • "I could mark them and check if I see new one every 6 month" Yes that's something you can do. Others fill all current holes (doesn't have to be a hard filler, just coloured wax will do) then they know if they spot a hole anywhere down the line it's definitely new activity. – Graphus Jul 30 '18 at 18:01

Most likely the bugs are already gone. (Bugs only stick around for a few years* - the holes they leave last forever) If you clean the board up and leave it for a while and see no further evidence of new holes or dust you can be reasonably safe in assuming they have gone.

(* See Graphus' comment on possible life spans)

If you think they are still alive, then you have three main options:

  1. Heating
  2. Cooling
  3. Pesticides


If you have a big enough oven, or access to a kiln, heating to wood to a moderate temperature (ie about 56°C) will kill pretty much everything inside, very reliably


If you have access to walk-in freezer, putting the boards in a plastic bag (optional - for humidity) and leaving them in there for several weeks will also kill most bugs.


Probably the most reasonable option available - you can buy pyrethrin spray designed for wood bugs that has a very fine tip applicator that can fit into the holes. Each hole needs to be sprayed. This can be time consuming, but I've found it very effective.

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  • Can I use a heatgun? I already have one. Good part is that total number of holes is around 8 after bit more planning. If not In get some spray. Thanks. – sorin Jul 30 '18 at 6:23
  • @sorin - no chance of heating the inside of the board up to temp without charring the outside with a heat gun. Spray would be the way to go i think – Dave Smylie Jul 30 '18 at 7:31
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    What we generically refer to as woodworm is the attack by a number of wood-boring insect pests, which each have slightly different breeding cycles. The rest of your Answer is dead on but I think you should edit the first paragraph because it is by no means true that they only stick around for a yea — 2-5 years is the figure most often quoted. Additionally any of the three or four most common species can re-infest the same wood generation after generation, which is how you get boards or pieces of ply that are half gone inside. – Graphus Jul 30 '18 at 11:21
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    @graphus - fair enough. Edited post – Dave Smylie Jul 31 '18 at 2:20
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    @Joe, no. Finishing is considered a good preventative against reinfestation however because wood-borers like to lay eggs on unfinished wood. – Graphus Aug 1 '18 at 11:40

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