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Old 14th Nov 2012, 9:48 am   #21
ekcopyephilips
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Default Re: Killing woodworm

Think I'll (ill) try the freezer trick. I've(Ive) managed to peel off the fabric covering and wash it. So will X-rays kill the eggs (if any). I work in a hospital and have access to Xray equipment. How long an exposure time are we talking just out of interest?

Incidently this is going slightly off topic, but I've (ive) noticed the ply on this AW87 (from the 30's) is less affected by worm than 50's produced ply. I was told it was down to the glue used between layers.

Mike
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Old 14th Nov 2012, 11:21 am   #22
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Default Re: Killing woodworm

The 1930's Invicta I've got was pretty infested when I rescued it from some stables, so 1930's ply is attractive to some it seems. I gave it a good soak with Cuprinol woodworm killer and filled all the holes with coloured wax and I haven't seen any little piles of sawdust or new holes since.
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Old 14th Nov 2012, 12:59 pm   #23
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Default Re: Killing woodworm

Quote:
Originally Posted by ekcopyephilips View Post
I work in a hospital and have access to Xray equipment. How long an exposure time are we talking just out of interest?
Diagnostic X-ray equipment is specifically designed to use low exposures and I don't think it would have any effect. It might be possible to use radiotherapy equipment designed for cancer treatment.
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Old 14th Nov 2012, 4:01 pm   #24
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Default Re: Killing woodworm

Quote:
Originally Posted by Billy T View Post
Quote:
Originally Posted by ThePillenwerfer View Post
If it'd fit you could microwave the little blighters. - Joe
Has anybody tried that? I seem to remember reading somehere that small critters are unaffected by microwaves, possibly because the wavelength is great in proportion to their body size. The wavelength at 2.4 GHz is just under 5 inches so it might not be very effective, I've seen ants happily crawling around in a microwave on full power.

Might kill them with indirect heat if the wood was cooperative though.

Cheers

Billy
If we are talking microwave ovens, then the microwave frequency is targeted to excite water molecules - heating then up. Anything that contains water will be heated, whether living or inanimate. So it would cook any woodworm.

The problem with microwave ovens is that there are dead spots inside so the heating effect is uneven, which is why they have turntables. If the woodworm (or ants) get lucky and are in a dead spot then they don't get cooked.
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Old 14th Nov 2012, 6:05 pm   #25
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Quote:
I work in a hospital and have access to Xray equipment. It might be possible to use radiotherapy equipment designed for cancer treatment.
And if you use the Colbolt 40 source it doesn't cost anything to run.
 
Old 14th Nov 2012, 6:05 pm   #26
brenellic2000
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Default Re: Killing woodworm

This subject crops up often! My knowledge of electronics is zilch, but I do know about timber, sawmilling and pressure treatment of timber.

The beetle will lay its eggs in a crack or crevice so they can't roll away; it will chose damp timber and sapwood because the cellulose will be digestible; it does not seek dry, seasoned timber. The egg can remain dormant for many years until the right humidity.

The larva will then eat into the moist cellulose and leave in its trail, its excreta - a hard or dusty plug. That is the first sign of trouble. They love old plywood because it uses an edible animal glue - and sap wood is full of lovely sugars. The larvae will eat away and finally emerge some years later from a flight hole - then it's gone!

Pouring woodwork killer down flight hole serves no purpose! Pouring it into plug of excreta will also serve no purpose as the volatile carrier (white spirit for example) will evaporate before the nerve agent can penetrate into the dry plug! It will never reach the larva!

Yes, you can paint woodworm killer onto freshly sawn timber (it will penetrate the cell walls by osmosis) but it will never, ever be more than a thin surface treatment on dry timber as osmosis cannot occur. Water based insecticides have a marginallly better chance - but they use water only because is not a volatile hydrocarbon.

This week end, get a dry piece of softwood batten 6"x2"x1" and one of hardwood. Soak (steep) both in a bucket of wood preservative. Monday morning, cleave the timber - the only penetration will be along the sap carrying veins from end to end (end grain); there will be hardly any penetration at the sides! So labouriously painting preservatives onto a planed timber surface serves very little purpose. It is superficial!

To properly treat timber against insect attack needs genuine Creosote - absolutely nothing beats it! But! You can only penetrate into the sapwood cells by high pressure (we used the Bethell process). The dead heartwood of oak, chestnut etc is impenetrable - but it is still edible, if damp! This process costs money - which no one wants to pay - yet they will spend a fortune on after market woodworm killer!

Keep your timber/cabinets dry to avoid woodworm and brush out all corners and crevices regularly. Nature will always win over mankind's complacency! End of story!

Barry
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Old 14th Nov 2012, 6:24 pm   #27
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Default Re: Killing woodworm

Unfortunately Creosote was made illegal for DIY use from 2003.
A further EU directive is about to make its professional use even harder.

But I'm not sure anyone would want to use Creosote on their radios would they?
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Old 14th Nov 2012, 8:29 pm   #28
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Default Re: Killing woodworm

Excellent post, Barry - thank you

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Old 14th Nov 2012, 11:53 pm   #29
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Default Re: Killing woodworm

I suppose that if the ants are crawling on the metal base of the oven, they could be OK, as the metal surface will be at earth potential and the field strength adjacent the surface could be relatively low. An ant crawling on the rotating glass platform might not be so lucky as it would be exposed to the full field strength. I recall when designing lumped component RF amps in the 400MHz and 1.5 GHz bands, of about 20W power, observing that a greenfly that had found its way between the turns of one of the coils making up the output impedance matching network, speeded up dramatically when power was applied!

Some more info extracted from the more comprehensive treatment of the subject in Melville & Gordon. I have highlighted the passage that explains the advantage of injecting into flight holes on painted timber.
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File Type: rtf melville.rtf (6.5 KB, 189 views)

Last edited by emeritus; 14th Nov 2012 at 11:56 pm. Reason: typo correction
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Old 15th Nov 2012, 1:48 am   #30
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Default Re: Killing woodworm

I can see two problems with using microwave ovens:

1. As mentioned in post #24, the microwave energy is distributed very unevenly within the oven cavity, and even with a turntable there will be dead spots which aren't heated enough to kill larvae and eggs.

2. The microwave energy will boil water within the wood, and this may cause damage (lifting veneer, weakening plywood etc).

Microwave ovens cook food largely by steaming it. The direct microwave energy doesn't do very much apart from make steam.
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Old 15th Nov 2012, 10:02 am   #31
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Default Re: Killing woodworm

I've had reasonable success by soaking the cabinet in Rentokil or similar, tying it up tightly in a bin bag and leaving it in the garage for six months or so.
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Old 15th Nov 2012, 10:32 am   #32
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Default Re: Killing woodworm

If the wood is not veneered then dump it in bath of good old fairy liquid with a hint of caustic soda for a day. So not only do the holes soak up hostile chemicals and loosen insect debris but it also comes out lovely and clean also.
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Old 15th Nov 2012, 2:54 pm   #33
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Default Re: Killing woodworm

How about stopping the beetles laying eggs on your radios in the first place by encouraging them to use 'traps' instead?
This is only an idea, but it would entail having small blocks of their favourite wood (with saw cuts in them) lying nearby.
Hopefully any beetles flying about will choose these rather that your prized wireless sets.
Then once a year at Christmas you can burn them in a fire!

Andy
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Old 15th Nov 2012, 3:05 pm   #34
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Default Re: Killing woodworm

GMB is quite correct that creosote is only available to licenced operators and even they are being encouraged by EU legislation to use waterborne salts. But the fact remains that nothing beats creosote - because it is a 100% natural distillation - and that is why the EU banned it! Modern replacements are proving ineffective and many have already been banned by the EU!

Even a creosoted shed can get woodworm - not because the creosote doesn't work but because it is only a superificial surface treatment - ie. the larva gets indigestion as it eats the first layer of treated cells. The next layer of cells are untouched by the insecticide UNLESS a full vacuum and pressure impregnation is used as in the Bethell process or by osmosis of salts in pre-seasoned timber. Telegraph poles and sleepers last 100 years because they use the Bethell process!

Surface treatments do not and cannot last without retreatment!

To avoid woodworm, keep your timber/furniture well dry and well aired. There is no other cure for insect or fungal attack other than a naturally resistant, or pressure treated timber... no matter what is says on the tin! You pay for cheap timber and cheap wooden products by choice!

Barry

Last edited by brenellic2000; 15th Nov 2012 at 3:20 pm.
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Old 15th Nov 2012, 4:56 pm   #35
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Default Re: Killing woodworm

Question, is modern ply more woodworm resistant because of the synthetic glues used?

And a bit OT modern 'green' glues without hydrocarbon solvents don't stick as well.
 
Old 15th Nov 2012, 5:27 pm   #36
brenellic2000
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Default Re: Killing woodworm

Yes to the resin-glue. Pre-1950s plies used Scotch glue - rendered animal or fish products, which are edible.

The timber in modern ply is still edible if damp, though much depends on the specie of timber. Birch ply - the finest ply for aviation and furniture is rich in natural sugars (you can make wine from the sap) but resinous teaks etc are generally resistant. But the modern ply veneers are only 0.5mm thick on an iffy core!

Solvents are just a vehicle to carry the glue or resin - just as water does with an emulsion paint. They are designed to evaporate. Water causes the grain to rise - which you don't want!

The main reason why hydrocarbon solvents are being banned is both Health & Safety (carncinogenic) and need for political control by a supranational EU state. EU officials have no idea what is in creosote, so they can't licence the ingrediants and thus cannot exercise the controls which they can on a manufactured preservative - one which does not even approach creosote in its effectiveness! It makes you mad!

Barry
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Old 15th Nov 2012, 6:23 pm   #37
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Default Re: Killing woodworm

Thanks for all that info Barry. Paul (S) mentioned paraffin in post 7-still available I believe. I have used this in the past (despite or perhaps because of the smell). Does it compare with creosote in your opinion?

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Old 16th Nov 2012, 12:55 pm   #38
brenellic2000
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Default Re: Killing woodworm

Liquid paraffin is not a recognised or recommended insecticide or fungicide, but was widely used to protect timber from attack by chemical or mineral oils (as a barrier) to prevent structural softening and 'rot'. Old engine oil will rot timber due to its acid content.

Paraffin wax is used as an end grain filler to retard seasoning checks. It is edible! You'll find it in processed food!

Turpentine (NOT white spirit or Turps Substitute) is a natural antiseptic, insecticide/fungicide derived from timber resins and is very effective indeed. It is readily absorbed into dry cells. The spirit in insecticides evaporates far too quickly.

The crux of the matter is that painting preservative onto timber is only ever 'skin deep'. A sawn board stood vertically does not rot as water runs off it. Laid horizontally and it rots as water gets trapped in the grain which opens and closes with the seasons - thus the cells become soft, edible and support life.

Crucial to preventing decay is the preserving of the wet/dry contact areas (eg ground level, condensation etc) which supports life. Yet people spend a fortune on protecting what doesn't decay - and totally ignoring what does!! Its complicted!

TTFN
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Old 16th Nov 2012, 9:56 pm   #39
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Default Re: Killing woodworm

I really think you ought to consider the implications of stuffing a wooden box full of hydrocarbons that will be enclosed and full of warm electrical circuits.
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Old 17th Nov 2012, 2:20 am   #40
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Default Re: Killing woodworm

I have found that whit spirit is pretty good for most vermin including black ants.
Woodworm killer could be applied after it has been allowed to partly dry out and then "chase" it in with white spirit.
That is no substitute for what they did with telephone poles in central Europe many years ago.
They cut the tree and stood the trunk up with i think the root end at the top and sealed a trough on the end and kept it topped up with copper sulphate for a few months until it dripped out at the other end
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