A sales rep job is to sell you something that their store stocks / carries.
While their intentions are good and noble, sometimes their product knowledge is not quite accurate. We have seen a few sales reps recommend products and materials that could actually damage the ovens. For example, one rep recommended rubbing axle grease all over the Mattone Barile foam form so it could easily be removed and used again. Axle Grease…
Recently, we have had two customers that built their Mattone Barile ovens with premixed High-Temp mortar that was water soluble. Both customers went to their local supply store to purchase materials to mix their own high-temp mortar, but their sales reps talked them into buying “Brand X” premixed mortar. Unfortunately, the premix was water soluble and both customers called (in near tears) as some of their mortar joints were starting to crumble.
IT IS VERY, VERY, VERY IMPORTANT THAT YOU ONLY USE DRY / BAGGED NON-WATER SOLUBLE MORTAR!
If you are in doubt, call the manufacturer of the product and ask to speak to a sales rep or product engineer. DO NOT rely on the receptionist for product verification! Only speak with a trained manufacturers representative - that’s why they get paid the big bucks!