Seven Ways to Get Rid of Woodworm

[JonE]

https://museumpests.net/solutions-low-te...treatment/
Consultants will charge you to advise that the freezer will need to be slightly larger than the object to be low temperature controlled. Clever stuff.

[Colin Morgan]

So, it wouldn't be out of the question to save a rare Seven - say a vintage Swallow or Mulliner saloon - with woodworm in the frame by renting a refrigerated container for a couple of weeks? (Just remember to drain the water out of the radiator.)

[Mike Costigan]

My grandfather said he used a razor blade to slice off their heads whenever they popped out of the hole... well, so he claimed 

[Bob Culver]

Judging by its expecial appetite for one or two local timbers the local borer is possibly not the same as whatever in UK. However the colleague of a colleague restores old clocks. He places the wooden cases in a plastic bag in the freezer for a protracted spell. Also had A Ford Y seriously infested. Arranged to place in a cooler store freezer over Xmas closedown for apparent cure. 
Some ply very susceptible. Often the inner layer is almost gone.

[Peter Naulls]

I was feeling rather smug having always used proprietary woodworm treatment and never had any recurrence of the problem. Then I read on and began to wonder whether it's because my garage is cold enough to freeze the pests to death!

Seriously though, a good saturation of treatment, leave it to dry thoroughly and then give the wood several coats of yacht varnish or spirit-based paint (not cellulose). They don't like surface finishes.

I have often wondered why woodworm choose certain pieces of wood; one piece can be turned to dust whilst an adjacent one is untouched. Density perhaps? sapwood versus heartwood?

[Nick Lettington]

I must try to remember that next winter... how long do I need to leave the car in bits in the garden for Jon?

[Bob Culver]

Local borer certainly favour certain timbers. Rimu is a long lived local with quite dense sapwood. Borer love it.  Not native pine is much softer but not so favoured. Very long lived local kauri, very sought  for boatbuilding when it was still available, is similar pine but not severely attacked. Dunno if the parents carry a recogniton chart or taste the timber before laying eggs in exposed end grain, or the "babies" choke if in  the wrong species. I think they tap on the walls and ceiling of tunnels to determine how thick, as they tunnel parallel. Makes for patterns like o 1920s railyards when old floors are sanded.
Apparently in old clocks the borer dust clogs the mechanism!

[Hedd_Jones]

Peter

I have seen woodworm in oak, but always in the sapwood. 

On a rack bench when planking an old log the good heartwood soon appears and is alway unaffected.

[Peter Sweeney]

I have seen large Oak house timbers over a foot square reduced to dust and the next jointed section un affected. The little blighters seem quite fussy. As said before some plywood can have only odd plys attacked. Treatment of new timber is only as good as the method used. I had a 6" Tanallised gatepost put in 15 years ago the whole 2 foot below the ground rotted. Outside our gate there's a telegraph pole which when tested recently it was found to be perfectly sound. It was put in in1947 so the same age as me. It had been treated by laying a long time in a vat of Creosote. Not allowed now. Penetration is the key as its the grubs tunneling inside that do the damage. Painting the surface with chemicals only penetrates a little way Soaking or injection is better. Ideally soaking under a vacuum but not practical at home.

[Reckless Rat]

Here in southern France, Holm oak or Chestnut are the popular choices of wood used for load bearing timbers in older houses (long before the advent of pressure treated factory formed trusses) - due to the warm climate wood is particularly susceptible to wood borers, such as woodworm, termites and longhorn beetle. They prevent infestations by charring the wood before installation. Seems to do the trick.