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COATED ELECTRODES

Re-drying of Electrodes Customers are recommended to redry low hydrogen electrodes before use whenever there are application requirements relating to weld metal hydrogen content and / or radiographic soundness. This information is given on the box label for the individual electrodes. Failure to follow these recommendations may produce pores and weld failure. Unitor Minidryer-350 (094-637827) 100–350 °C (212–662 °F) can be used for this purpose.

Recommended re-drying temperatures, holding time two hours, for Unitor electrodes: GPO-302 N GPR-300 H SPECIAL- 303 N LH- 314 N LHH-314 H LHV-316 N LHT-318 N LHL-319 N LHR-320 N TENSILE-328 N IMPACT-329 S WEARMAX-327 18/8-321 N 23/14-322 N DUPLEX-325 N NIFE-334 N NICKEL-333 N TINBRO-341 ALBRONZE-344 ALUMIN-351 N CH-2-382 ACA-384

Normally no need for re-drying Normally no need for re-drying 300 °C (572 °F) 350 °C (662 °F) 350 °C (662 °F) 350°C (662 °F) 350 °C (662 °F) 350 °C (662 °F) 350 °C (662 °F)

250 °C (482 °F)

250 °C (482 °F) 1 hour 250 °C (482 °F) 1 hour 350 °C (662 °F) 350 °C (662 °F) 350 °C (662 °F) 200 °C (392 °F)

200 °C (392 °F)

200 °C (392 °F) 1 hour 250 °C (482 °F) 1 hour 80 °C (176 °F) 1 hour 120°C (248 °F) 1 hour 180°C (356 °F) 10 hours*

Re-drying time is measured from the point at which the re-drying temperature has been reached. After re-drying, the electrodes can be returned to a heating cabinet and kept at a minimum temperature of 70 °C (158 °F).

Unitor Heating Cabinet-85 (094-637850) 85 °C (185 °F) can be used for this purpose.

Mild steel rutile and rutile / organic electrodes such as GPO-302 N normally need no re-drying Re-drying covered electrodes more than three times is not recommended. * The copper coating will oxidize during the process, butt this will not influence the performance of the product.

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