Many woodworkers are making holiday gifts in their shops. Are you one of them? Please remember to exercise caution with rags used to apply the finish.
What is the safety issue?
Varnish used in the shop in some cases will self-ignite, given proper conditions. Why? As a varnish containing linseed oil, or Danish and tung oil dries, it generates a LOT of heat. Unvented, this can cause the “goop” left in the rags to self-ignite – to spontaneously burn. This can cause your shop, your home, to come down in flames.
The following is key: Hang out your laundry
Whatever you do, PLEASE unroll the rags, and hang them to dry with plenty of air circulation to take away the heat.
The thought of someone failing to follow this simple procedure invaded my skull while doing a tiny bit of finishing today. As I applied Waterlox to a small piece of sycamore, it hit me that not everyone may be thinking about hazards lurking in the shadows. For example, can you figure out the potential problem in the following photo?
Prior to leaving the shop I lay out all the rags I use, with plenty of air circulation:
What do you do?
I wonder how many times I ignored the basic rule of applying varnish with a cloth. How about you? Have YOU ever had an incident such as a fire due to carelessness? Or have you heard of someone in the family losing possessions due to a fire started with rags used to apply a varnish?
Please leave your story in the Comments section. Thanks!
— Al Navas
About Al Navas
Good tip Al! One that needs refreshing from time to time.
The worst culprit in the finishes we use are the oils, linseed oil in particular. Oily rags MUST be either spread out to dry (for potential reuse), or immersed in water until they can be squeezed dry and burnt. There are no other choices. Put them in the trash can and you might have a fire in the can. Leave them out for the trash removal people and you might have a fire in their truck.
While visiting my daughter’s family in Austria we heard fire sirens one evening. My son-in-law, who works at a hospital came home the next day with the story. A workshop had caught fire. An elderly couple who lived n an apartment above the workshop perished. Cause: an apprentice didn’t know the hazard of oily rags and left them wadded up in a trash can inside the shop. …more here…
Bob,
Thanks for expanding and explaining further on my tip! I recall reading on your blog about the incident in Austria – a sad story, with a sad ending. This is a very real threat.
To my readers: I encourage you to follow the link to Bob’s blog, where he provided the details in the case earlier this year. It will be worth reading.
I have some definite rules in my shop and one is hanging all finishing rags on a make-shift clothes line outside the shop. Usually the paper towels and rags hang there to dry for about a week, ie, from rubbish day to rubbish day. I have not personally had any issues but I have read stories of others. This is a precaution that everyone should follow.
Al Gotowka
Al,
Thanks for sharing your experience. The idea of a clothes line close to the shop is terrific! I might do that, too!