You are currently logged off.

NP1: The MasterSeal

NP1 from MasterSeal is a one-component, high performance, non-priming, gun-grade,  elastomeric polyurethane sealant.

NP1 from MasterSeal is a one-component, high performance, non-priming, gun-grade, elastomeric polyurethane sealant.

Now that the weather has finally improved, those projects have started piling up, and there’s no better time to get to them!   

This week’s article will be going over MasterSeal NP1 sealant, its uses, and its features and benefits.  MasterSeal NP1 is put out by Master Builders Solutions (BASF), who have over 100 years experience in the construction business, so you know that this sealant is going to be nothing less than the best.  Sealant, or caulking, is used to seal joints or seams in various building materials, applications and settings.  Its major function is to provide insulation, prevent water intrusion, and can be used to temper noise levels.  NP1 can be used as a sealant, as a grout, or as an adhesive.  Using sealants is a cost-effective, and easy way to save money and improve the appearance and longevity of any residential or commercial structure.  Sealants are a major part of the construction process, and there is no better time to finish those sealing projects than right now, because when the weather gets nasty again, you will want your sealant to already be in place and ready to go.

“Using sealants is a cost-effective, and easy way to
save money and improve the appearance and 
longevity of any residential or commercial structure.”


With the versatility of sealants like NP1, it’s easy to see why the demand for them is so high.  NP1 is an indoor and outdoor sealant that can be used in water-immersed environments, expansion joints, panel walls, precast units, and so much more.  Contractors frequently use NP1 sealants for building projects like window installation/insulation, vinyl sidings, and for storefront assemblies.  Its joint movement capability of ±35% provides excellent flexibility for caulking windows and keeping moving joints weather-tight, and it bonds extremely well to metal and non-metal roofing, and even brick cast without priming.  Its uses really are endless.  The Consumer Federation of America claims that sealing seams and preventing leaks  can be a great way to drastically decrease energy costs, improve efficiency levels and also reduce your carbon footprint. So using sealants is not only good for wallet, but good for the earth too.  Applying sealants to cracks and crevices around homes and commercial buildings also puts less strain on HVAC systems and can save time, money and hassle by reducing the need or frequency of major repairs.  Before using a sealant, it’s a good idea to prep that application area a bit, even though priming isn’t typically required before using NP1.  It’s important that the surfaces are sound, fully cured, clean and dry, and free of any loose particles or debris. When applying to concrete, stone, or other masonry, you will want to use an abrasive to prime the area before sealing.  Before applying a sealant to wood or metal you will want to scrape away any paint, rust/scale, or coatings first.  With coatings in particular, its recommended to test the adhesive first, to make sure that the sealant will work properly, which will be explained in more detail later on.

One of 12 color options to choose from!
One of 12 color options to choose from!

MasterSeal NP1 is so popular, because of its durability, dependability, and it’s multitude of great features.  NP1 is a one-component, high- performance, gun-grade, elastomeric polyurethane sealant, that requires no mixing, produces long-lasting weather-tight seals, and typically requires no priming.  It’s used primarily for sealing all types of exterior construction joints, on multiple materials, and is suitable for all climates.  Along with concrete and masonry, NP1 also has the ability to bond to metal roofing and brick cast, which makes it very popular with various industries.  Having a urethane-based sealant allows for its movement capability of ±35%, its flexibility keeps moving joints tight, and reduces peeling or cracking in metal joints.  NP1 is ready to use, so it doesn’t require mixing, and as mentioned before, priming the application area is not usually required before using.  Again, in special circumstances or substrates (like with copper, stainless, and galvanized) it may be required to prime an area before using NP1.  It’s suggested to apply a light, even coat of primer with a brush or clean cloth.  Make sure to allow primer to dry before applying NP1.  Depending on temperature and humidity, primer will be tack free in 15 to 120 minutes.  Now, as you may know, when applying NP1 the user should apply the sealant with a caulking gun, and should fill joints from the deepest point, to the outer point, by holding a properly sized nozzle against the back of the joint.  Dry tooling is recommended, which is smoothing the applied sealant area with a  dry spatula (or similar tool). Tooling results in correct bead shape, a neat joint, and maximum adhesion.  It’s also important to know that you should never use your dry finger to smooth the sealant.  If you are going to smooth the sealant you should be using either dry tooling, or some prefer to don a latex or nitrile glove and then wet a fingertip with Isopropyl alcohol which they then gently run over the caulked joint to smooth it out.  Using alcohol on your finger allows you to smooth the sealant with ease because the alcohol briefly reduces the NP1’s surface tack.  It is very important to note that if you do smooth the caulked joint, make sure the sealant is set deeply enough so as not to interfere with the sealants adhesion.

“NP1 is available in 12 different colors, so you can match
the sealant to a wide variety of common substrates.”


As with most things, when it comes to applying sealants, you want to make sure you are taking proper safety precautions.  It may seem silly for this type of product and its corresponding applications, but things happen, and we want to make sure they don’t happen to you.  First off, you want to make sure you are wearing proper eye protection, and protective clothing as needed.  These will ensure that no product touches your skin, and of course when doing any construction work always protect your eyes with safety glasses or goggles.  When using NP1 it’s important to make sure that alcohol-based materials and/or solvents do not come into prolonged contact with the sealant, before it has been properly set and dried.  NP1 should also not come in contact with oil-base caulking, uncured silicone sealants, polysulfides, or fillers saturated with oil, asphalt, or tar.  Noted previously, NP1 can be painted, so long as it has been fully cured and its surface is clean.  Even though NP1 can be used in water-immersed environments, it is not to be used for continuous immersion in water.  The same is also said for intense U.V. exposure, which can result in discoloration.  Discoloration can be a problem if you are using white sealant. We recommend using Ultra sealant or Sonoclastic as an alternative for applications requiring a white sealant that can not discolor.  However, on top of being able to be painted, NP1 is also available in 12 different colors, so you can match the sealant to a wide variety of common substrates.  So if you’re worried about discoloration, keep in mind you can find different colors to use, or you can paint over the sealant.  If you are painting over NP1, remember that it is elastomeric, so you should use a paint that is also elastomeric.  As mentioned before, if you are going to smooth the sealant with your finger, make sure you do so with some alcohol sprayed onto your gloved finger, or use a dry tool like a spatula.  The sealant is too sticky to smooth with your bare finger.  

It's recommended to dry tool with a spatula, or similar tool, after using a sealant to smooth the area.
It’s recommended to dry tool with a spatula, or similar tool, after using a sealant to smooth the area.


So where does that leave you?  Well, if you find yourself in the midst of multiple sealing/caulking jobs around the house, or on the work site, and need to find a great sealant, look no further than NP1 from MasterSeal.  It’s versatility alone will give you the most bang for your buck, and you know, that with the proper placement, you will have a dependable seal every time.  As far as stretching your dollar, a sealant is a good way to go.  Using sealants around the house, for window sealing, expansion joints, roofing projects, etc.  will help to increase your energy efficiency, which will ultimately help save you money on heating costs in the long run.  After the past few winters we’ve had here in New England, saving money on heating sounds pretty appealing!  During springtime, sealants are crucial in protecting masonry joints from the damage of the freeze/thaw cycle, so avoiding water damage repairs and costs is also going to be a huge advantage!  But again, with the weather only getting better, it’s a good idea to get a head start on your sealing projects.  Because when that bad weather comes back, you don’t have to think twice about whether you’re prepared for it or not.  So start your sealing projects off right, and use NP1, MasterSeal’s leading, interior/exterior, elastomeric polyurethane sealant.  Don’t get caught using anything else!  Be sure to check out the KL Jack website for our complete collection of NP1 products!

Work Better, with NP1 and KL Jack & Co.