chrisc%gold.gvg.tek.com@RELAY.CS.NET (Chris Christensen) (11/02/90)
The solution to the tape problems that have been discussed over the past few weeks is presented here. I am not being presumptuous just refering to an article that was published in Mix May 1990. 1. The black goo that is building up on the tape guides and heads is the oxide and not the lubricant! 2. Please don't bake tapes in an oven at 200 degrees F. 3. Don't shuttle the tapes back and forth to build up a layer of air. 4. Don't use any cleaner that is water based to clean audio tape. 5. Silicone impregnated may so more damage than good because it will encourage any dust or shedding oxide to build up on the metal parts of the tape path that has been directly or indirectly treated. If you have a tape that squeels read on. The problem is binder break down or lubricant breakdown. This is no new news but read on it does get better. The binder problen is the most prevelant and the lubricant problem is relatively rare. The lubricant breakdown manifests it's setf with a whitish deposit on the guides and heads. The binder breakdown is a dark gummy residue. The binder breakdown is due mainly to moisture being absorbed by the binder and causing the binder to migrate to the surface of the tape. The article that I am extracting my information from is the May 1990 issue of Mix. The Author is Philip De Lancie. The article talks about the binder problem and offers a solution. A sidebar also describes what AGFA is doing about the problem. Also this article is written by a professional audio engineer in the business of rereleasing "classic" recordings recorded at 15 and 30 ips. AGFA has a service that will restore 2500 foot reel recorded at 15ips for $280 to 350. The following is the basic process as extracted from the article, there is no guarantee expressed or implied. If you are unclear or indoubt about this process than consult a professional. Step 1. Inspect the tape and any splices. This would best be done on a deck that has only roller guides and no heads. After you are sure that the tape hasn't stuck to the layers beneath it and that any splices haven't stuck or dried out, etc. move on to step two. Step 2. A physical cleaning of the tape with a non-abrasive cloth or some of the materials that have been described in detail in rec.audio.high-end can be used to remove any loose oxide. Remember here that when you remove oxide you are removing the recording!. The material used here should be clean, lintfree and have no chemicals. Step 3. Pack the tape on the reel HEADS OUT. If you are doing more that one reel at a time, seperate the reels by an inch or so when stacking them in your oven (more about that later). Step 4. Bake the tape in a temperature controlled oven at 130 degrees F. Don't do this in a gas oven as a by product of burning gas is moisture, the main culprit that got you into this mess. Bake 1/4 " tapes for about four hours. Allow the tape to return to room temperature on it's own accord after the blow dryer is turned off. With this treatment the tape will be playable only for a short period of time, a few hours to a week or two. Ovens that are designed for cooking don't usually maintain the recommended + or - 10 degree range. Also it is desireable to have good airflow through the oven to cary away the process gasses. The article that I read suggested a cardboard box set on top of a wire shelf that was spaced off of the table top (3") with blocks of wood . The graphic showed a blow dryer inserted into the side of the box near the top and several inches above the the top of the reels stacked in the box. It also shows a thermometer in the box to monitor the temperature. The author further suggests that since the homemade oven isn't thermostatically controlled it will be necessary to experiment with the set up to to insure a maintainable 130 degrees F. Use the blow dryer on a low heat, low speed settind and vary the box-to-table height to get the temperature right. The ideal oven would be thermostatically controlled with the heating elements electrostatically shelded from the tape compartment. A convection oven that has a continous flow of air and can operate at 130 + or - 10 degrees F may be able to be made into a suitable tape oven. Good Luck.