Tech Tip: Baking tape for restoration
Recently I’ve been working to restore some 25 year old 1/4″ tape to bring it back to playable condition. We have several boxes of 25 year old (or thereabouts) 1/4″ tape that has not been touched in years. Part of the goal is to be able to bring some of this old recorded material back to life with the hopes to be able to present some of it as part of CJAM-FM’s 35 years on FM celibrations.
For those who don’t know, the way they made audio tape in the 70’s and 80’s used a glue to hold the iron oxide to the plastic tape which over time breaks down and becomes sticky. If you try and play a tape once it has become sticky the results can be disastrous. It can cause the iron oxide to come off the tape, stick to the rollers and tape heads on your reel to reel or even the back of the tape. The result is something that not only doesn’t sound right but also destroys the original.
The answer is to bake your tape before playing. Baking it at a low heat – between 130 to 140 degrees fahrenheit for between 4 to 8 hours can “re-bond” the glue, making it hold again and removing moisture so you can safely play the tape without damaging it.
For years I’ve searched for a good solution for this. Using an oven has never been a good option – at low temperatures most ovens have difficulty maintaining a steady temperature. And definitely don’t use a gas oven. While gas ovens are great for baking food, they don’t work well for baking tape.
About 15 years ago I made a tape baker in an empty file cabinet drawer, a 100 watt light bulb, and a small fan. It worked but wasn’t the most efficient and was difficult to regulate the temperature. For this project I wanted to find something better.
I’ve read about people using food dehydrators to bake tape, and I decided to look into this option. I managed to find the Salton VitaPro food dehydrator. Very reasonably priced
and comes with 5 trays, the trays are just the perfect size to hold 10.5″ Ampex reels. Loading it up with an empty tray between each reel I can bake 3 reels of tape at a time. It has a temperature control which is surprisingly accurate – setting the temp to 135 degrees and checking with a thermometer it was able to maintain a temperature within 3 degrees. I’m sure there are other food dehydrators on the market that would also work just as well, this just happens to be the model they had at the store I was in.
It is working well and so I thought I’d pass on the tip to this list – for anyone looking for a good way to restore those old “gems” that have been in the storage closet for 20+ years. Of course the other part of the task is to have a working reel to reel.