Technical Bulletin TB036 - CHANGES IN THE HEATER REBUILD AND RECOAT SERVICE OFFERINGS

Transcription

1 Technical Bulletin TB036 - CHANGES IN THE HEATER REBUILD AND RECOAT SERVICE OFFERINGS To: All McElroy Manufacturing Fusion Distributors Over the years McElroy Manufacturing, Inc. has supported your recoat needs through the direct use of MMI manufacturing capacity. However, the logistical challenges related to the service offering, coupled with the growth in availability of DuPont Licensed recoat vendors has led to a decision by McElroy Manufacturing to discontinue direct involvement in any recoat applications. This would include requests to recoat butt plates, heater adapters and/or any other request to recoat MMI or other manufacturer s items. The decision to take this course of action was not an easy one, so in an effort to mitigate any disruption to your business, MMI s engineering department reviewed commercially available (DuPont Licensed) vendors that could serve the recoat needs of MMI distributors. As a result of this research and followup interaction with the vendors, including the distribution of McElroy s recoat specifications (McElroy Engineering Standard #ES005A - Attachment C), MMI prepared a list of geographically diverse vendors that are available to support your recoat needs. While the following list (Attachment A) is not an endorsement of the vendors by MMI, it does present you with a DuPont Licensed alternative to support your recoat needs. Additionally, and concurrent with the change mentioned above, McElroy Manufacturing, Inc. will cease its heater re-build service offering. MMI has offered a limited heater rebuild service offering for several years again using existing manufacturing capacity. The demand for this service has diminished and MMI has developed numerous rebuild kits (Attachment B) that make it possible for the Authorized Service Centers to easily rebuild the existing range of MMI heater products. As for the timing of these actions, we want to give you ample time to contact a recoat vendor and to make arrangements to cover your ongoing recoat and heater repair needs; therefore we will continue to accept orders for these services until March 1, All orders for the services received after March 1, 2005 will be refused. Page 1 of 6

2 Attachment A DuPont Licensed Industrial Applicators The following is a list of Dupont Licensed Industrial Applicators in your area that are available to support your recoating needs. Recoating must be performed in accordance with McElroy Engineering Standard ES005A using Dupont Teflon Primer and Dupont Teflon PTFE Topcoat. California California Denmac Industries Inc. Crest Coatings, Inc E. Rosecrans Avenue 1361 S. Allec Street P.O. Box 2144 Anaheim, CA Paramount, CA sales@crestcoating.com denmac@ix.netcom.com Web site: Web site: (714) (562) (714) fax (562) fax Georgia Maryland Impreglon, Inc. Applied Coating Systems 220 Fairburn Industrial Blvd Wilmarco Avenue Fairburn, GA Baltimore, MD Web site: svogt@appliedcoatingsystems.com (770) Web site: ( fax toll-free (410) (410) Fax Massachusetts Ohio Applied Plastics Co., Inc. E. L. Stone Company, Inc. 25-T Endicott Street 2998 Eastern Road P.O. Box 128 Barberton, OH Norwood, MA elstone@elstone.com appplastics@earthlink.net Web site: Web site: (330) (781) (330) fax (781) fax Texas Hitemco Southwest 7134 Satsuma Houston, TX info@hitemco.com Web site: fax Page 2 of 6

3 Attachment B McElroy Heater Rebuild Kits Group A. The following kits will rebuild 8 through T500II (non-coach) heaters with microprocessor control or older heaters with the control box mounted to the heater bag frame: GROUP A MMI Part Number A A T Kit Description V HEATER HANDLE/CONTROLLER REBUILD KIT 8-120V HEATER HANDLE/CONTROLLER REBUILD KT T500II - 240V HEATER HANDLE/CONTROLLER REPLACEMENT Group B. The following kits will rebuild 2 or 4 heaters with microprocessor control or older heaters with thermo switch control (wood handles): GROUP B MMI Part Number A A A A Kit Description 2-120V HEATER HANDLE/CONTROLLER REBUILD KIT 2-240V HEATER HANDLE/CONTROLLER REBUILD KIT 4-120V HEATER HANDLE/CONTROLLER REBUILD KIT 4-240V HEATER HANDLE/CONTROLLER REBUILD KIT Group C. The following kits will convert 2 or 4 heaters with microprocessor control from the long handle to the shorter handle design: MMI Part Number A A GROUP C Kit Description 2 - HEATER LONG HANDLE TO SHORT HANDLE CONVERSION KIT 4 - HEATER LONG HANDLE TO SHORT HANDLE CONVERSION KIT Page 3 of 6

4 Attachment C McElroy Manufacturing, Inc. ENGINEERING STANDARD NUMBER: ES005A DATE: 10/11/2004 DESCRIPTION: Heater and Heater Adapter Re-Coating Specification using Dupont Teflon PTFE Coating ALL ITEMS SHOULD BE EXAMINED PRIOR TO RE-COAT Heater and heater adapter surfaces with nicks, gouges and other fusion surface defects, that are not removed in the surface preparation process, or heater adapters with distorted serrations should not be re-coated and should be replaced with new McElroy factory replacement parts. All heater butt plates should be examined for flatness prior to re-coating. Plates that are not flat or will not draw flat when installed on a heater body will not provided proper heat transfer. These items should not be re-coated and should be replaced with new McElroy factory replacement parts. SURFACE PREPARATION 1. Sand blast all parts with glass bead or 80 grit aluminum oxide at 80 PSI. Note: Care must be taken to avoid warping flat plates during sand blasting. Heavy blasting to remove deep nicks or gouges is not permitted. Blow all parts with compressed air to remove sand residue from interior cavities. 2. Handle parts on edges or surfaces not to be coated. PRIMER APPLICATION Apply Dupont Teflon Premixed Acid Primer/One Coat per Dupont Specifications only. 1. Prepare primer for spraying per DuPont Coating Fact Sheet. Roll material approximately 30 RPM for 30 minutes. 2. Coat parts with DuPont primer approximately mils thick. 3. Bake parts at 450 degrees Fahrenheit for minutes. This is part temperature and not oven temperature. Page 4 of 6

5 Attachment C TOPCOAT APPLICATION Apply Dupont Teflon PTFE Topcoat per Dupont Specifications only. 1. Prepare topcoat for spraying per DuPont Coating Fact Sheet. Roll material approximately 30 RPM for 30 minutes. 2. After baking primer, cool the part to degrees Fahrenheit before applying topcoat. 3. Coat parts with DuPont topcoat approximately 1-2 mil thick. Serrated heater adapters require a very light topcoat layer to prevent mudding. 4. Bake parts at 750 degrees Fahrenheit for 30 minutes. This is part temperature and not oven temperature. After parts are baked at 750 Degrees Fahrenheit, another layer of topcoat cannot be added. QUALITY TESTING OF COATING a. Fingernail Scratch Test Use fingernail to test scratch coating for adhesion. No material should be lifted from any coated surface. Examine coating for uniformity of color and texture. b. Coating Thickness Test Using an electronic thickness gauge, verify the film thickness is within the specified range for primer and top coated items. c. Cross Hatch Test Materials: Single edge razor blades, transparent Bordens Mystik 6400 tape and metal edge ruler or template. Scribe the film with one corner of the blade, held at right angles to the film, in a series of eleven parallel cuts approximately 3/32 (2.4mm) apart. Repeat at right angles to form 100 squares. A strip of transparent tape is pressed over the scribed area and rubbed firmly with the fingernail to obtain maximum contact. Pull off the tape at about 90 degrees firmly and rapidly, but do not jerk the tape. Rotate the area 90 degrees and repeat tape test. Film with good adhesion should show no squares removed (slight lifting at the edges of the squares is not counted), but 20% of the film removed is considered gross failure. If 1 (2.54cm) tape is not available, two strips of narrow tape may be used. On aluminum substrates several tests may be made with one blade. On frit coated metal, Stainless steel, etc.., a new blade should be used for each test because the blade becomes burred and ragged films edges result. MAINTAINING STOCK SUPPLY Primer material should be degrees Fahrenheit. Topcoat material should be degrees Fahrenheit to preserve shelf life. All stock should be rotated when replenished to ensure that the oldest stock is used first. Page 5 of 6

6 Attachment C SURFACE COATING REQUIREMENTS Page 6 of 6