Woodworm

[Michael4]

Attending to some woodworm using Cuprinol Woodworm Killer (the only one I can find).

Underneath of old deck...

It seems to enjoy old untreated ply and gnaws its way along the internal plies leaving little evidence of its existence apart from fine dust and the occasional hole.

Am I right to assume that it will not eat wood that has been painted/treated/varnished etc? Does a salt environment kill it off? Anything else I should do?

[Ed]

It won't eat its way into a painted surface.....but it might well eat its way out...

You need to just try and work out whether it is active woodworm or just old woodworm. If active you need to try and kill it, although I wound be tempted to remove it and burn it before it gets into other boats. It is much more likely to be old woodworm and in which case you can just paint it over with a very thin wood primer like eposeal, CPES or whatever and ignore it.

I have had found it a few times. As you say, it attacks the inner layer of ply or especially the inner softer layer of Agba in a Fairey hull and can really eat it out, without making any apparent damage to the exterior. But doesn't seem to make a great deal of difference to strength either, so as long as it is dead, I reckon you just fill the holes and get on with it.

Of course if the woodworm is in something structural, there may well be more to worry about. Luckily never had that yet.

Best

eib

[Michael Brigg]

Woodworm in its own way is a kind of predator.

Like any other predator it's best chance of a kill is to choose a victim that is already weak.

Make the woodworm your friend and use its skill to find the weaknesses to your advantage!

Even if its dead, the wood it has been in will already be weakened perhaps by exposure to damp and then frost. Unless it is a non structural part of the boat, or an essential part of the boats history / personality I wouldn't trust it.

(That being said, the old wooden i14 mast from "Blue Moon" is currently in my attic and I have noticed it hass tell tale signs I have several piles of dust accumulating under some of the eves, and the roof is Cedar Shingles. Nonetheless my Roof maintenance man from Rentokill says I have nothing to worry about. I don't think he sails though.

One of the Cowhorn tiller extentions from my IC 10m, Torment also has several holes and feels ominously light and makes suspicious cracking noises when stressed. I have made a new ones as I do not trust it one inch

We have of course been here recently when discussing a similar issue on Antifouling and treatments (like Cuprinol) to prevent future rot. I recall referencing another sailors lament that (with increasing regulation of what is good for us) there will soon be no paints capable of killing anything! We have come a long way from 1935 (when the yachting magazines, believe it or not were advertising a "new" German product called Z**** "B" as a de infestant for sailing boats!) Of course I am not advocating the use of Cyanide as a common household cleaner, but I think we would all sometimes appreciate for example a more effective stripper (Dichloromethane banned by the EEC as it "might" cause liver Cancer, never mind its extensive continuing use to make Instant Coffee, and its ongoing availability for "Industrial" use.)

[trebor]

Perhaps their is a wood that is more attractive to woodworm? use it to attract worms then burn, fit a fresh piece, burn, repeat, job done
More environmentally friendly.

[Michael4]

I'm reasonably deaf now so won't hear the munching...I'll subject the suspect area to the sharp screwdriver test and if it passes slosh something nasty on it then seal it all in leaving me plenty of time to worry about something else...

[JimC]

... it attacks the inner layer of ply or especially the inner softer layer of Agba in a Fairey hull and can really eat it out, without making any apparent damage to the exterior. But doesn't seem to make a great deal of difference to strength either,

Well, no, what you're ending up with is a typical sandwich construction in which the middle layer simply needs enough strength to keep the outer structural layers the appropriate distance apart... So all we need are trained woodworm which bore appropriately aligned and distributed tunnels and we have a new lightweight building material... I wonder if our great-grandchildren will have genetically engineered woodworm which secrete shellac onto the tunnel walls to waterproof them?