MasterSealNP-1 Polyurethane Sealant Caulking 10.1 oz tube

Not sure why whomever posted this product didn't include the color (of which there are quite a few - this one light grey (see image - I used it to seal a small hole / rusted area on the top of a repurposed metal sea / land container)). I recently had a hard time finding this product at the local big box building supply stores - it's a fantastic roofing sealer (et al) which sticks to almost everything but it MUST be a dry surface for proper adhesion. I have had the same results as others that have commented about one persistent problem regarding this product - sometimes it dries out inside the tube before it's first use rendering it worthless (I usually squeeze the tube before I purchase it but of course that can't be done with an online purchase). I use it on everything needing an incredibly strong but flexible and waterproof bonding / gap filler.

I purchased for work in my sealed crawlspace. I checked the date code before using and was about 7 months old. Worked great for me.

My Primary use is for Caulking the Metal Brackets that Hold the Roofing material to the Brick Parapet Walls.but, It's handy to have for Caulking Mortar , Concrete, Cement, etc.When I need to add a Product to get Free Shipping, this NP1 caulk is always a possibility if I need it in inventory.

I ordered two tubes of caulking and when they arrived, both tubes were fairly stiff when I squeeze the casing. After cutting the nozzle and puncturing the seal, the caulk would not flow out of the tube when I used the caulking gun. It was already dried out and solidified in the tube. Unfortunately, I lost a few days in my schedule and still need to go to the store to pick up usable product. Will never order "shelf life sensitive" materials on line again.

Good stuff been using it for years, be sure to check the production date "see pic". Product seems to be good in the tube for one year.

I have a modular home and the wood siding expands with temperature changes. NP-1 is the best I've found and it lasts years...wonderful product.

Arrived stiffened and unusable

In my opinion, NP-1 Is simply the best caulking i have ever used. I wish it didn't have a shelf life. But, oh well.