KMDSI is currently shipping KMB 18/28 hoods that may either be black or blue in color inside the hood. These colors are due to the different manufacturers rubber we are using in the hoods. There is absolutely no difference in performance or quality of the final product.
The foam face seal inside the hood is considered a consumable item. These face seals will degrade in time and need to be replaced (part # 510-505). This is a fairly simple procedure which can be performed either by the end user or a KMDSI authorized dealer.
Due to the many variables in use and maintenance of these hoods and face seals, KMDSI cannot assign a specific life span for them.
As noted in the KMB 18/28 Operations and Maintenance Manual Troubleshooting Section 3.5 Demand Regulator Malfunction: a leak of any type in the face seal will cause the regulator to free flow. This includes holes and/or leaks caused by the face seal separating from the hood. This can be due to rough handling of the hood, chemical contamination or simply the aging of the product.
It is extremely important that a good glue joint is maintained between the face seal rubber and the hood. Any leaks in this area will cause the regulator to have a slight steady flow of gas which will escape through the faulty glue joint.
If the seal separates from the hood, and the rubber is still in good condition, it can be repaired simply by turning the hood inside out and running a layer of wetsuit glue in the seam, following the instructions for gluing set by the glue manufacturer. Press the face seal and hood together to ensure a good bond with the glue.
If the Hood rubber or face seal foam is weakened or deteriorating due to material aging, KMDSI recommends that the hood be replaced. Repairs to aged rubber have a very short life span.