The only sure way of killing woodworms is putting the clock case in a freezer.

After much research, I found that even the best chemical treatments are not 100% a sure thing and the cost for fumigating a grandfather clock would be $500 to $700.

You cannot buy these lethal chemical. The chemicals you can buy will not do the job. Surface treatmants won't reach into the wood deep enough and the critters will live on. Even the professional and highly regulated folks that do this for a living will not guarantee 100% effective treatment.

If you are treating a house, you have no choice, there is no way to suddenly freeze the whole house. Tent fumigation is all you can do.

I purchased a German Grandfather clock and discovered the wood worms after I brought it home to my log cabin.

What we ended up doing is taking our chest freezer lid off, putting a new insulated top on it, used a Radio Shack remote thermometer to monitor temperature, and in went the clock, wrapped in plastic garbage bags to protect from condensation.

Interestingly, the freezer had no problem getting below zero in a few hours and maintaining that temp all week. Killed em dead. The bugs cannot adjust to the sudden winter conditions.


The photos are in reverse order. Since we never did this before and developed the method as we went along, it was easier to take the photos at the end of the freeze cycle as the grandfather clock was removed.

The 2 inch foam was wrapped with shipping wrap, don't remember what it is called, its like Glad Wrap on a 300 foot by 6 inch roll.

The duct tape was used to hold it together prior to the plastic wrap.

The foam to freezer area was sealed with some pipe fiberglass (?) wrap to keep the cold in and heat out.

The thin white wire it the Radio Shack indoor outdoor electronic thermometer. It even told us the warmest coldest cycle in any given period. Freezer never went above 0 degrees. We could of set it warmer or colder.

Available light photo. The Grandfather Clock in the back ground is not the "problem clock"

We took the insulated top off and we are about ready to lift the clock out of the freezer.

This is not a big freezer, about 50 inches wide.

Note! The movement was removed as well as the doors. Close inspection revealed no wood worm attack in those areas. It also made the clock lighter. Of course, if needed, the doors could of gone in separately.

March 1, 2002 © Jim MIrek


Additonal Links on this subject.

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