Treating woodworm in wooden type

Hello everyone,
First of all my apologies if this discussion is on the wrong board or has been posted before.
I’ve recently acquired a font of wood type that has been stored in a shed for some time. As a result, several of the pieces are slightly damp and others seem to have been visited by woodworm. I’m unsure if the woodworm is still active though I assume (perhaps wrongly) that if it was more of the type would have been affected.
Could anyone who has any experience of treating these issues could give me some advice? Ultimately i’d like to get the type printing again, preferably filling in the holes left by the woodworm if possible.
Thanks in advance for your help!

Log in to reply   21 replies so far

It would be my guess that this is what you have, not a worm:

If you google topics like “control of powder post beetle” or “how to get rid of powder post beetles” you will get more information. Even a Youtube video comes up:

I don’t know if, (or how well), any of this works, so I can’t make any guarantees, but I wish you luck!

Hope this helps, Geoff

two or three possibilities, but only from U.K. point of view,?
Woodworm treatment(s) generally/here, come in the form of small dispenser tubes with fine nozzle for (admittedely tedious) but effective, squirt into every hole, BUT be careful the crafty little B*****S some times bore in and come back out in a bolt hole, protective glasses/caution,
In the event that the product only comes in the form of a larger can(ister) with no applicator, the use of a modern disposable/plastic Hypodermic syringe from the drug store, usually in sterile packs 5-10 etc, once again fiddly but very precise, and virtually no waste, the author has done it.
Filling the holes,?? 2 or 3 listed on the Web but mostly seem to be disguise rather than strengthening, i.e. Beeswax and turpentine, injected in… .Authors own, *on off* remedy to repair, a very beautiful complex wood engraving, to print from, utilised a *Wanner,* High pressure Grease Gun perfectly clean, with a small amount of 2 pack Chemical Wood repair compound, filled the holes that were the biggest, and most important for impression, did the job on 10, 12, impressions, never again, massive headache. (had to acquire a Needle point nozzle for the Gun.!!!)
Cure the damp,?? Suggest, hypothetically, and if possible with the use of a Nipping press or Blocking press, layers of wood type, interleaved with sheets, for example, plywood, clamped gently, tweeked occasionally, for as long as possible/practical, as in natural curing in the saw mills, just a thought. Good Luck.

Pint of petrol and a match .

Put all the type in a container of white spirit, weight all the wood type on the bottom and drown the little blighters.

You think you’ve got problems with the wood type mite.

I would worry about the risk of it getting into the cases as well as the beams of where ever its kept !!
Wood worm is a pain and despite popular belief very difficult to completely eradicate . soaking in a noxious substance will kill off the present lifeform but doesnt stop its cycle of life you have to keep treating over a period of time as the loft space where i stay proves !!

Would two weeks in the freezer in ziplock bags do it?


For holes in type I have had luck with auto body glazing compound. It is used by painters to fill small imperfections before painting. It comes in a tube ready to use. Get it from an automotive paint store.

My 2 cents
- get them into a dry ventilated environment. Woodworm like damp wood and fetid air. Allow to dry slowly, or they will crack
- squirt woodworm treatment in the holes. The holes are the exit holes, so they may have had their fill and gone, but it makes me feel better
- shellac/french polishing stick to fill the holes
- lingering smells - I tried bicarbonate of soda, but UNLIT scented Christmas candles seem to work better
Nothing guaranteed, obviously, but so far so good

The freezer idea is a great thought, but I don’t think it will work. I had a piece of old farm equipment out in the barn and the worms had gotten into the wooden legs. It deteriorated more and more over several years until I removed and burned it. It gets well below zero in the winter out in the barn, so they must have the ability to hibernate through the cold.


Hi everyone,
Thanks very much for all the comments and advice - even those advocating the more extreme, flame based measures!

After reading up on Powderpost beetles as recommended by Geoff I think i’ve found my pest. The hole sizes are about right. I’ll need to look for powdery residue inside the blocks to see if the infection is still active.

It sounds like Mick and Etinink’s suggestion of applying the woodworm killer with a syringe would be the best starting point - i’ll attempt to do this at the weekend and see what happens.

As for filling the blocks - Sharecropper’s suggestion of car grazing compound is an interesting one - can anyone suggest a brand name so I that can attempt to find it in the UK?

Finally, The Arm NYC’s suggestion of the ziplock bag in the freezer really caught my interest, despite Foolproof546’s justified misgivings I may be tempted to try it out on a piece!

Thanks again for all the help and I shall post results when I have them!


John, gRazing is, I believe, a typo. It should be gLazing compound, I think. Look for glazing putty at any well-stocked automotive supply store.

Michael Hurley
Titivilus Press
Memphis, TN

‘tis glazing compound - I’ve edited the original post. It works to fill pits in photopolymer plates as well.

If automotive glazing putty is anything like the glazing putty used for house windows it would seem to me not a good choice — one quality of glazing putty I know of is it never dries completely, and thus stays flexible and keeps sealing — but also would compress or move under pressure of printing. Another automotive material to try would be Bondo, a 2-part epoxy-like body filler which cures hard and is quite strong, but easily scraped or sanded to shape after it cures. You could mix a small batch at a time and repair a few letters. Comes in quarts and gallons.


What A load of Crap, MAINLY???. . My original post was offered in response to the original question, (now there,s a funny thing in itself???)…In no particular order, UNLESS you are going to blanket cover every part of every item, the only way to treat individual holes is to treat INDIVIDUAL holes, why else would you have dispenser cans with fine nozzles, my *hypo* was just a refinement to contain the excess as much as possible. (When the beams are treated in a dwelling, yes Blanket coverage is the order of the day, but with protective clothing, breathing masks etc etc)
Total immersion in ANY Liquid, highly unlikely, WHY?? any liquid must surely, permeate the item in selective fashion, i.e.following the lines of least resistance, through the fibers of the wood.!!! Does childlike logic, not say, that it will expand in a haphazard way, and subsequently, contract in the same haphazard way and probably crack anyway.?? Although my last paragraph was conjecture only, was based on the Methods, as seen for Many Many years, for initially drying out virgin timber, I. E. interleaved with cross braces and clamped to insure even air flow, and avert warping, hence the nipping press etc..
. .
LOOK UP (possibly) the methods for immersing Drum Skins. Banjo Skins, Motorcycle Clutch corks in water and translate into the effects on/for Wood Type treated the same way.??

As I post along with 2 or 3 others, am experimenting with, reproducing Poster Type,!!
Just possible that I may have an idea, rather than quoting from the Web.???
HOLES, all blind EXIT Only, not quite, hardly My Dear, Immaculate conception, or as simple as they bored their way in and out, not always the same way I.E. bolt holes/emergency exits, YES!! have frequently studied a particular piece of heavily infested material, whereby soft, 3 ply is used next to and with, for example, Oak for the main frame, SPECIFICALLY, in full height case racks (printers Of course) where the little S***S have munched away for many years, on the back panel of the frame, through the ply, when they have reached the oak, it went something like this, *B****R IT, Too Hard, do a *U* turn, bore out of this layer of ply, skip one layer, going the wrong way, and munch through the next one, for a year or two.?*

I call to the stand, your own *BROOKE BENTON,S The Boll Weevil Song* May Corroborate!!!

Blind Holes, Not always, which gave rise to my, Protective Goggles etc, learned the hard way, at least 50 yrs ago. Copped an eye full and it STUNG.!!

FILLING The Holes with *X* *Y* or *Z* compound, also a virtual non starter, if the hole be a crescent or a *U* turn yes/possibly, but still only possible to persuade any substance to traverse the complete length of the hole, once you fill one end it is physically impossible, to pump anything in the other end?? trapped air has good compressive capabilities and will reject any intrusions, with luck you may retain 1/16” down the hole, air compression will reject anything further?? try it,!! knife any thing, (Glazing Putty, Chemical Wood, 2 Pack Epoxy Resin, etc) into a 1/16” blind hole, and watch it self eject, disguise YES, repair Unlikely. ????

Rubbish out of the authors archives NO!! Trawl the Net, and see how this very principle was used to excellent effect on the AIR COMPRESSION ARRESTORS on MANY Big Cylinders to eject the Bed for its return stroke, in essence exactly the same, but in Giant Form.???
Which is also why, my quoted (above) high pressure Gun and needle point nozzle, was reasonably successful by leeching the air, out, through the wood, and allowing the filler in, (up to a point)…
Even tried, unsuccessfully, to solve the problem with Old, Old, fashioned genuine Carpenters, Wood Glue, BOILED UP from (well documented) Horse Bones etc. Complete failure, even as hot as possible, with just gravity it would not enter the holes more than a few Thou.!! Solidified too quick, AND it stunk, like a Yankee SKUNK, I used a genuine Printers/Bookbinding Glue pot, admittedly with a little extra blow torch heat.

Current museum practice is to wrap in polythene / place in ziplock bags (depending on size of object) if there are surface finishes liable to be damaged by damp (not applicable to woodletter), and place in a commercial freezer that goes to a lower temperature than most domestic freezers, remove from the freezer for a week and allow to return to normal temperature, and then repeat once more.

As metal type is unaffected, wormy cases can be loaded into freezers complet with type.

Female woodwrom (seems from comments upthread you have something different?) are idel critters that do not usually exit the holes to surface. Instead, the males exit and fly arolund and locate females at entrances of holes to procreate. The females then re-enter the holes to lay eggs.

Eggs laid on the surface of timber hatch out tiny woodworm whose entry holes are microscopic and hence extremely difficult to find to inject chemicals. Many exit holes will be from males and hence injecting chemicals into thse holes will achieve little.

Chemical treatments vary in effectiveness; also the density of the timber hugely affects how deeply the chemicals penetrate the bulk of the object. Unfortunately woodletter was usually manufactured from dense timbers and was often satuated in oil to maxime stability. Both these factors would tend to limit penetration of chemicals.

Freezing as described above should kill existing woodworm and eggs, but will confer no lasting protection and hence re-infestation is possible. After throughly cleaning all ‘frass’ (dust from the holes), the objects and their surroundings should be periodically inspected for fresh frass which would indicate re-infestation.

Hope this is useful.

Seems I heard at one time that a quick freeze will kill some types of bugs/larvae because, while they can adapt their bodies to withstand freezing temperatures during the course of the slow change of the seasons, they cannot adapt to rapid changes in temperature, such as if they were warm for a long period of time, and then suddely thrust into freezing conditions.

Hi everyone,

Thanks very much for all of the additional comments.
At the weekend I bought some woodworm killer with an applicator and injected into each of the holes. Afterwards I gave an all over application to the entire alphabet, including letters without exit holes. These were then left to dry superficially before being brought into the house to dry fully.

I’m hoping this will have worked however i think it will be difficult to tell! Apart from new new holes and the appearance of frass are there any additional symptoms to look for?

I’m quite intrigued by The Free Presse and Geoffrey’s comments regarding freezing. Does anyone have an idea of the temparature that would need to be achieved for this method to be effective? Unfortunately I only have access to a normal chest freezer but i’m tempted to try it all the same (providing I can do it without the girlfriend noticing)

My only concerns with the freezing method would be the possibility of the type splitting after being exposed to such drastically varying temperatures, or it developing damp after spending a week in ice. Has anyone who has ever tried this method had either of these problems?

Nope - apart from fresh holes and fresh frass, there are no other warning signs of renewed worm activity. Remember that frass can fall out of old holes and hence can give false cause for alarm. Usually firmly tapping the objects will dislodge old frass; once you’ve done this you can be reasonably confident that if you see further frass, that you have a fresh problem.

Chemical treatments only penetrate to a limited depth, dependent on the species of timber. Also, the oil that woodtype is impregnated with by the manufacturers will limit the depth of penetration, and any old ink or ink-removong chemicals that have soaked into the woodtype will limt penetration (though the latter may well help kill off worm!)

I’ll ask some museum conservators I know about what tempetatures you should aim for and pos their advice. If you have qualms about damage then place the woodtype in ziplock bags Musuems routinely freeze wooden objects ranging in size from type-sized to large of furniture. However, if you have qualms, then try a few pieces first.

I’m just catching up on this thread. I’m expecting delivery of a set of type that has woodworm. Seller has treated with a a chemical, I’d still like to use freezing or heat to kill. I’ve read that freezing quickly below -20 F or heating above 150 F will take care of any insect.

Free Presse - I’m curious how the methods you described worked. What did you end up doing? Did the woodworm re-emerge?

Others - curious about other ideas here. How many would take the challenge of quarantine/treatment given a unique set of type? I’m especially curious to hear from anyone who had an infestation re-emerge or killed known live bugs. Or am I overthinking this?


would heating in an oven to 175F, for 45 minutes then dropping into a cooler or chest freezer with “dry ice”, FrozenCO2, be possible for your problem. keep adding blocks of the dry ice for 24 hours?

I seem to know (from don’t ask me where), that bugs can adapt to gradual changes in temperature, such as from summer to fall to winter. However, they cannot adapt to rapid changes, such as from room temperature into a freezer for a week or so. For instance, I think one way to get rid of bed bugs in winter is to wait for a very cold day and then shut the bedroom door and throw all the windows open long enough so that everything in the room freezes for a period of time.