Tuesday, October 2, 2012

Pitch

A gentleman from England sent me this image of the interior of his fire bucket and asks, "what is this odd looking stuff ?". Answer; Pitch.

Pitch is a viscous substance derived by rendering either bituminous or resinous organic material. Bituminous pitch is a type of raw petroleum tar that can be found throughout the entire world oozing up from the ground. Perhaps the most famous of oozings is the La Brea Tar Pits in California. Another source and a different type of pitch is that which is rendered from the sap of resinous trees such as the Pitch Pine.

The use of all forms of pitch has an ancient history and has been utilized by man since prehistoric times for a plethora of applications. In association with leather drinking vessels and fire buckets, pitch was applied to their interiors as a water-proofing agent. The application process is simple; heat the pitch in a tin melting pot over some coals (or a 5th burner), taking care not to get it too hot as it is combustible. Once the pitch is at its melting point (if its smoking it's too hot) it can be poured directly into the leather bucket. When the pitch touches the leather it cools instantly and adheres. Just a thin coating is all that is needed so when I pitch, I quickly roll the bucket and pour the remaining hot liquid pitch back into the melting pot. It's a juggling act to do it neatly. I do not recommend this for the novice...an accident can leave you badly burnt. In ancient times, melted pitch was poured down from castle walls onto attackers with great effectiveness!

In it's raw state, pitch requires some amount of rendering to remove the unwanted volatiles. Once the volatiles are rendered off the remaining pitch can be very brittle, to return it to a plastic state I add approximately 10-15% beeswax. However, even with the addition of wax, pitch can break if the bucket is dropped on a cool day. Ah, here is the brilliant quality of pitch, it can be repaired even by the most feckless of clods! The easiest way is to add more hot pitch but if you're fresh out of pitch, a lit candle passed over the crack can reseal the break...it won't look very tidy but it can be made serviceable again. And this my good fellow is why the interior of your bucket in the photo above looks like such a blubbery mess, it's the result of  many repairs over the past centuries....and it looks just like it should.

You may visit a museum someday and be told that fire buckets were kept filled with sand or water (or both)at all times. If you are told this, the correct response should be to give the docent a sound swat to the back of their head as this information is 100% incorrect. (No, don't swat, I'm only joking...keep in mind they only make minimum wage and it's not their fault, it's the museums fault for not properly training their interpreters). If you want to know the entire story of how fire buckets were used, someone must ask me, (you may use the comment section here on the blog).