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- From: vancleef@netcom.com (Hank van Cleef)
- Subject: Rec.antiques.radio+phono Cosmetic and Cabinet Questions(FAQ: 6/9)
- Message-ID: <antique-radio+phono-faq-6-845766911@netcom.com>
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- Organization: Bluebonnet Firebottle Works
- References: <antique-radio+phono-faq-1-845766911@netcom.com>
- Date: Sat, 19 Oct 1996 23:15:31 GMT
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- Posted-By: auto-faq 3.1.1.2
- Archive-name: antiques/radio+phono/faq/part6
-
- Rec.antiques.radio+phono Frequently Asked Questions (Part 6)
-
- Revision Date Notes
-
- 1.0 Oct. 15, '95 New section
-
- Part 6 - Cosmetic and cabinet finish questions
- ------------------------------------------------------------------------------
- FAQ editor: Hank van Cleef. Email vancleef@netcom.com
-
- This is a regular posting of frequently-asked questions (FAQ) about
- antique radios and electronic phonographs. It is intended to summarize
- some common questions on old home entertainment audio equipment and
- provide answers to these questions.
-
- This section discusses some of the methods that can be used to clean and
- restore items in acoustic phonos antique radios, and other items. While
- the internal construction of phonos may be quite different than that of
- electronic devices, many of the cleaning issues are quite similar.
- Almost any old device requires a fairly standard cleanup involving
- removal of dust and dirt, internally as well as externally. The first
- step in restoring an harmonium (reed organ) or a piano, as well as a
- phonograph, music box, or radio, is to clean the item thoroughly, inside
- and out, and assess its condition. Very often, all that is needed is a
- good vacuuming, with the help of some small paintbrushes to loosen dirt,
- and a soap-and-water cleanup. Clockwork mechanisms, small electric
- motor mechanisms, and electric phono turntable, wire recorder, and
- similar mechanical transport mechanism generally need to have old
- "petrified" lubricants cleaned off, and reassembly with new lubricants.
-
- Cabinet restoration depends on the method of cabinet construction and
- finishing. Items built in the 19th and early 20th centuries generally
- had wood "furniture" cases, finished with a shellac process. The
- introduction of synthetic varnishes in the 1920's meant a rapid change
- to use of synthetics for wood finishes, and shellac finish on a home
- entertainment device becomes rare through the 1925-40 period. Post WWII
- wood finishes are most commonly one of the urethane synthetics.
-
- Plastics that could be formed by casting and injection molding processes
- became available at the end of WW I, and many home entertainment devices
- made in the 1920's have visible parts made of "Bakelite," a phenolic
- resin with an inert filler that can be injection molded. By 1940, there
- were a variety of thermoplastic (i.e., melts when heated) and
- thermosetting (i.e., cures under heat and does not remelt) resins were
- commonly used in construction of molded radio cabinets, knobs, and
- decorative trim items. Many of the plastics used in the later pre-WW II
- period were not stable over long periods. Ultraviolet from strong
- sunlight and heat above human body temperature would accelerate
- distortion and discoloring, for which there generally is no repair other
- than replacement of the affected part. Items in good condition should
- be cleaned up and positioned where they will not be subjected to strong
- sunlight or heat.
-
- Various metals are used both in internal construction and in cabinetry.
- Painted steel plates and cabinets are commonly found. Also stamped
- brass decorative parts. One very common process was to use steel and to
- electroplate it with a brass finish. Die cast white metal parts are
- commonly found. The zinc alloys used in the 1910-35 period produced
- excellent parts, but are subject to aging and corrosion breakdown.
- Typically, they will become larger, then become extremely brittle and
- crumble. Once again, the only "repair" solution is replacement of the
- affected part. There is a long-standing myth that white metal parts were
- made of "floor sweepings" and scrap, and the term "pot metal" is
- sometimes used in the US to denote the material. This is not accurate.
- Zinc precision die casting technology uses specific alloys and
- processes, and produces excellent results. Some manufacturers used
- die-cast or sand-cast aluminum alloys after the mid-1920's. These
- should not be confused with zinc alloys. Die casting processes for both
- zinc and aluminum produce high dimensional accuracy, but require
- creation of an expensive metal mold set, so are generally associated
- with high-volume parts. The tooling required for sand casting is much
- simpler and less expensive, but the as-cast parts require machining of
- critical dimensions.
-
- This is a very cursory overview of materials and processes, and the
- reader who wishes more information should search out and study some of
- the literature written for engineers and crafts people who work with
- these technologies. In particular, "Machinery's Handbook" and (in the
- US) the SAE Handbook (Society of Automobile Engineers) have extensive
- information on metals and manufacturing processes.
-
- Your FAQ editor has some strong feelings about some of the techniques
- for cleaning and restoration that have been discussed on various
- newsgroups. There is no question that many restorable items have been
- ruined beyond repair by use of inappropriate chemicals and cleaning
- methodologies. Beyond this there are considerations of "kitchen
- chemistry." Almost any solvent or process has safety considerations to
- consider. And almost any solvent or process will damage something in a
- device. You may want to use it over here on this metal part, but if you
- get it on that plastic part or electronic component, in may destroy it.
- Additionally, there are issues of fire hazards, fumes, violent reactions
- with other chemicals, and safe storage to consider. Know your products,
- and know your processes. A kitchen is a place for food preparation, not
- chemistry experiments or industrial processes. Be very careful to keep
- solvents where they cannot contaminate foods or anything used for food
- preparation. Store chemicals separate from food items, and away from
- the inquiring hands of small children. Also keep in mind that many of
- the preparations sold in grocery stores for kitchen cleaning purposes
- are, in reality, very strong chemicals, and may have very little
- information on the chemical content or processes. When writing this, I
- checked a can of Dow brand oven cleaner. It acknowledges 4% sodium
- hydroxide as an active ingredient, and gives a litany of safety
- precautions in use. This stuff is more violent than most of the
- industrial cleaning processes I've used. Many of the spray can cleaning
- products are very easy to use----just spray them on your valuable
- antique and watch it dissolve before your very eyes. Remember that
- these are proprietary products, and while the labels may disclose a few
- "active ingredients," it is often not all that is in there that will
- wreak havoc. There is a steady stream of notes in the antique groups
- from people who tried a spray can kitchen product and discovered, too
- late, that it took markings, finishes, etc. off along with the dirt.
-
- There are two manufacturers who make chemical products specifically for
- use around electronics equipment. Caig Laboratories makes "DeOxit,"
- which is considered by many people to be about the best contact cleaner
- around. They make a number of other chemical products for various
- electronics uses, and provide good and specific application and use
- notes for their products. GC Electronics, formerly General Cement, make
- a variety of products for various uses. These include a good electronic
- coil dope, a chemical wire insulation stripper for stripping the enamel
- from magnet wire, and a variety of cleaning products and adhesives.
-
- One "easy cleaning" method that gets tried regularly is use of a
- household dishwasher to clean things. Don't do it. Almost all
- dishwashers use high temperatures in their washing cycle, and the
- detergents used are a strong caustic solution. They may wash dishes
- well, but for other cleaning, have almost all the attributes and
- drawbacks of a hot caustic tank (see "lye," below) with few of the
- virtues. I've had the unpleasant experience of spending a day with
- precision machine tools reworking the castings in an automotive power
- steering pump that were put through a good household dishwasher.
-
- General purpose solvents that are generally mild and easy and effective
- to use are:
-
- 1. Water, with or without soap. Water is actually the most universal
- solvent. A little bit of soap or detergent will increase its ability to
- wet the surface. More soap will make an alkaline solution. Safe on
- most things, but may dissolve inks used on dial markings, and should be
- used with care around electronic components, particularly iron core
- chokes and transformers. One of the better detergents to use is a
- generic-type dishwashing detergent such as Octagon brand.
-
- 2. Household ammonia. This should be the clear non-sudsing type, with
- no additives like lemon sent. Straight ammonia is a strong alkali, and
- will dissolve shellac very quickly. A mild ammonia solution generally
- does a good job of dissolving dirt on painted and metal surfaces. A
- plain ammonia solution without additives will dry without leaving a
- residue, and may be preferable to a soap/detergent solution for many
- applications where a thorough water rinse is not used.
-
- 3. 3M adhesive cleaner (an automotive product). This is a petroleum
- product sold for removing adhesive residue, road oil, etc. from
- automobile painted surfaces. It is safe on most plastics. Excellent
- for removing the residue left by old masking tape, cellophane tape, and
- removing adhesive labels and their residue. It's made by the principal
- makers of several adhesives, so is formulated for removing residues from
- their adhesive products.
-
- 4. Isopropyl alcohol. Generally sold as "rubbing alcohol." This is an
- alcohol/water mix, and sold in various concentrations. What I use is a
- 70% solution. Alcohol will attack marking inks and painted surfaces,
- but will sometimes cut adhesives and things like chewing gum that the 3M
- products have difficulty with.
-
- 5. Diesel fuel. Excellent for dissolving petrified lubricants and
- other petroleum products. It is not as quick as gasoline for this
- purpose, but has the advantages of being much less flammable, and leaves
- an oily coat in the part surface for several weeks, which will protect
- against immediate rusting. Generally safe with plastics and slow to
- attack painted surfaces. Diesel fuel is an excellent choice for
- cleaning spring phono motor parts.
-
- All of the above are fairly safe and easy to handle. Except for soap
- solutions, all have distinctive odors. Ammonia generally requires
- ventilation or outdoor use, and diesel fuel leaves a strong "perfume"
- that is very slow to dissipate.
-
- Noxious and violent chemicals that are excellent for some controlled
- applications. All of these require care and precaution in use and
- handling, and present serious safety hazards if not used properly.
-
- 1. Automotive lacquer thinner. This stuff will cut right through many
- things. It is also extremely flammable. Excellent for cleaning
- petroleum and oily residues off metal parts to leave them absolutely
- clean. Cuts almost all thermoplastics instantly, and will damage paint
- surfaces. Removes most marking inks very quickly as well.
-
- 2. Lye. As a commercial cleaner, this is generally used in heated
- tanks and called "hot caustic." It is always used as a dip tank
- solution. You can make a small "hot tank" by dissolving lye in a
- coffee can, placing it in a large frying pan, filling the frying pan
- with water, and heating to around 60C (160F). Do not heat directly or
- bring to the boiling point. Room temperature lye is a very strong soap,
- and should not be allowed to contact skin for any period of time.
- Heated it is very aggressive. Lye will dissolve the white metals,
- aluminum and zinc, and should not be used to clean them. It will remove
- petroleum residues, paint, and a variety of other things. One very good
- application of a hot caustic tank, which will illustrate what it can do,
- is in cleaning steel automotive engine blocks and cylinder heads, where
- it is extremely good at removing carbon deposits, cooling passage scale,
- and oil passage residues. Hot caustic tanks are often used for paint
- removal tasks.
-
- 3. Chlorinated hydrocarbons. These include carbon tetrachoride,
- trichlorethane, and various "freon" cleaning solutions. While most of
- these are good cleaners, they have a lot of undesirable characteristics.
- Many of them are no longer available. GC Electronics sells
- trichlorethane in small quantities, but I have not seen it clean things
- that didn't clean just as well with other solvents.
-
- 4. Strong acids. Hydrochloric, nitric, sulfuric, and phosphoric acids
- all have good industrial applications. "Oil of vitriol" and "muriatic
- acid" are colloquial names for sulfuric and hydrochloric acid. All of
- them are extremely agressive and difficult to handle. A mild phosphoric
- acid product with good applicability for rust removal is sold as "Naval
- Jelly." Other than this, these chemicals are poor choices for use in
- antique restoration.
-
- Solvent application methodologies:
-
- The best methodology for using any of the above solvents is controlled
- application, to assure that only the parts to be cleaned by the solvent
- come in contact with it. In most cases, soft cloths and Q-tips work
- well. The best soft cloths were cloth baby diapers, which have been
- largely displaced over the past thirty years by disposable diapers.
- Start by vacuuming off the loose dust. A small paintbrush and some
- smaller brushes, such as those sold for basting poultry, can help in
- loosing dirt. Follow up with a mild soap and water solution applied
- with a rag. A soft toothbrush can reach into inaccessible places and is
- particularly valuable in cleaning up knurled metal parts and fluted
- knobs. Use Q-tips moistened with solvent to reach into inaccessible
- areas and to "spot clean" specific areas.
-
- (this area under construction)
-