By L. Craig Keoun
Proper repair of the fiberglass components of an aerial manlift unit requires special expertise, testing equipment, and product liability insurance. It is critical that any user of such equipment makes sure that the company chosen to do this work is competent and well-equipped.
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While a body shop or a custom molder of fiberglass parts may have capable and skilled craftsmen who can make a repair look good, it will likely not have people with the specific, detailed knowledge needed to make aerial lift components truly safe (to protect the lineman) nor will it have the product liability insurance (to protect the company).
Some of the special considerations involved in fiberglass repairs and rebuilds of aerial manlift components include:
- The requirements for insulating capabilities of upper booms and lower boom insulators and what affects those insulating capabilities;
- The structural strength requirements for fiberglass upper booms and lower boom insulators in view of the special stresses to which these items are subjected;
- The real insulating capabilities provided by the fiberglass bucket itself, although the bucket isn"t officially recognized for insulating capability by ANSI A92.2;
- and The requirements for structurally sound mounting of the bucket to secure its attachment to the boom.
Evaluation of Capabilities
The following questions should be asked of any company being considered for aerial manlift fiberglass work:
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- Does the company carry product liability insurance?
- Does the company’s product liability insurance carrier know that it is doing repair or replacement work on aerial manlift components?
- Are the company’s personnel technically competent for this type of work? For example, are any of its people certified by the American Composites
Manufacturing Association as Certified Composites Technicians? Also, is the company familiar with the special needs of fiberglass components in aerial man lift units? - Does the company have a copy of ANSI A92.2-2001 or Canadian Standard C225-M4000, and are its people familiar with its requirements?
- Does the company have the capability to do dielectric testing in accordance with the applicable specification or to otherwise ensure that its products are dielectrically sound?
- How does the company satisfy itself as to the structural aspects of its work? That is, what types of testing and analysis equipment does it own and use?
Examples of Specific Component Repair/Rebuild Issues and How the Repair Company Should Handle Them
Example # 1: It receives an upper boom in fairly good condition for surface refinishing and rehabilitation. The first thing that should be done is to visually examine the boom for any evidence of damage. Any such evidence should be compared with boom damage criteria shown in the manufacturer"s manual. Any problems require the action indicated in the manual. If the boom is dirty inside, the shop should call and ask permission to pressure wash the inside. After cleaning, the boom should be dielectrically tested to make sure that it is still dielectrically sound. If there is a dielectric problem, the boom should be analyzed with a conductivity meter and/or an ultrasonic tester to identify the problem. If the analysis reveals a problem, the company should call the owner and discuss the steps needed to solve it. If there are no additional problems, the boom should be cosmetically repaired and refinished as needed. Then, the boom should be dielectrically tested again and structurally tested at a load of more than double its rated load. If no flaws are found, the boom should be waxed with the proper material and shipped back to the owner in a secure package along with certificates showing the results of the dielectric and structural strength tests.
Example # 2: An upper boom with some apparent cracks is received for evaluation. The cracks should be reviewed using both the manufacturer"s repair manual guidelines and the repair company’s judgment and experience. It will probably be necessary to sand the coating off the boom to evaluate the cracks. If the cracks are judged to be repairable, the repairer should quote the cost of the repair so that the owner can compare that to the cost of a new boom. If repair is approved, the repair company should do the structural repairs using the proper reinforcement and resin, let the repairs cure, then do a structural test on the boom to make sure that the repair procedures worked. If the repairs are acceptable, the boom should then be cosmetically refinished and dielectrically tested and returned to the owner.
Example # 3: A bucket is received for repair. The bucket mount consists of a number of studs protruding from the bucket wall. One of the studs is coming out of the wall. The bucket probably should not be repaired because of concerns about the possibility of the bucket later coming loose from the boom.
Example # 4: A bucket is received for repair. The bucket mount consists of vertical fiberglass ribs protruding from one side of the bucket. In examining the mounting holes in the ribs, it is determined that there are cracks in the ribs at the location of the holes. The bucket probably should not be repaired.
Example # 5: A bucket is received for repair. The mount side is not damaged, but the front corners are cracked through. With proper techniques and materials, the bucket can be repaired. The repairer should determine whether the customer just wants the bucket repaired structurally or wants the bucket to also be refinished to a like-new condition. In most cases, the latter option is chosen. A quotation for the cost of the repair should then be given to the customer, and then the appropriate repair action should be taken.
Plastic Composites Company— Background and Repair Capabilities
An executive with PCC worked with an executive from Mobile Aerial Towers, Inc. in 1959 to design and build the electric utility industry’s first fully insulated upper boom and then later its first insulated lower boom. These became the booms for the Hi-Ranger, the industry’s first insulated bucket truck. PCC then made all of the Hi-Ranger fiberglass and did all of the Hi-Ranger fiberglass repairs for 33 years, until Telelect bought the Hi-Ranger operations. The Hi-Ranger was always known for the quality of its fiberglass. Telelect had its own fiberglass operations, so PCC went into the business of making aftermarket fiberglass parts for the Hi-Ranger and, later, for most brands of bucket trucks.
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PCC also continued and expanded its repair operations for bucket truck fiberglass. It is probably not surprising that PCC answers “ yes” to all of the questions listed above under the “ Evaluation of Capabilities” heading.
Plastic Composites Company— Replacement Products, Bucket Liners, and Accessories.
PCC now makes replacement buckets, booms and guards for most brands of bucket trucks. Although dielectric testing is no longer required for buckets, PCC still tests its buckets because PCC believes that test ensures the quality of its buckets. PCC has tested used buckets of other manufacturers and seldom finds one that will pass the PCC test.
In addition to its fiberglass parts, PCC makes and sells polyethylene bucket liners and a wide variety of safety and efficiency accessories for bucket truck work.
For more information about PCC, its products and its capabilities, see www.buckettruckparts.com.
About the Author:
L. Craig Keoun is president, Plastic Composites Company.
