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What do F-16's, F-18's and baby carrots have in common? They have all landed on CCS Patch, Nosing, Slurry Binder (PNSB).
What is the role of the aggregates? Depending on the size distribution, shape, hardness and quantity used, they can dramatically affect the placement properties, strength, wear, impact resistance and thermal behavior of the grout. It's possible to achieve workable mixes that are only ~10% epoxy with excellent working properties. And unlike cementitious patches, there's rarely a bonding problem and in most cases, priming isn't necessary. So what's the deal about baby carrots? Well, we can't reveal secrets of our best customers. We can tell you that baby carrots are formed from larger carrots that have been cut and ground. The longest-lived grinding wheels are made with a high mod epoxy and a low mod epoxy in a special combination. Similar wheels handle even harder tasks like pistachio nut hulls.  Top of page
StripSEAL: Tips for Guys Used to Epoxies
StripSEAL is different than epoxy surface seals since it's a polyurea. The trouble is, some field techs use it the same way as an epoxy, which may lead to frustration.If your guys are open-minded and do a couple of things differently, they'll be very happy with its performance—otherwise it wouldn't be one of our top sellers. Biggest reasons to use StripSEAL are:
Ratio: Cartridges are preferred over bulk (in cans) by 5:1. Why? The convenience factor and the cartridges help achieve the proper proportional ratio. As a polyurea, accuracy to the proper 1:1 ratio is more critical for StripSEAL than for epoxies. Some of our customers buy in the cartridges but throw away the static mixers—they use the cartridge for correct proportioning onto a mixer board where they mix just the right amount. Manual Gun: An aid in achieving the proper ratio is a good dual component gun. After trying about 10 different models, we found a U.S. patented manual gun that is extremely good at 2 critical actions: 1) excellent ratio control and 2) rapid product acceleration throughout the squeeze action. The patent covers the use of a special spring-action, which aids mixing by applying residual pressure and improves hand leverage. The best bet for large jobs is an electric or air driven gun because they generally are very heavy duty, get the best ratio and provide instant acceleration of product through the static mixer, which helps eliminate unmixed material spots that don't cure. These guns don't get tired like operator hands so the first cartridge gets mixed the same as the last. Mixing: StripSEAL in bulk must be ratioed very close to 1:1 or it won't work consistently. Some people use disposable paper cups to get the volume correct. After you get equal volumes, you must mix it for about 30 seconds after you first start to observe the uniform gray color. The extra mixing helps compensate for the fast reaction time. For cartridges, a good dual-component gun like the model we sell, is essential. Bad guns don't provide sufficient mechanical advantage (you need at least 4 or 5:1 ratio) in the squeeze grip to allow the instantaneous acceleration through the static mixer that helps eliminate insufficiently mixed material. Partial cartridge: Using a cartridge until empty without stopping will yield the best performance. If you stop more than 2 minutes part way through the cartridge, you should remix the first couple of static mixer quantities on a piece of cardboard with a trowel or simply throw it away. This semi-mixed material in the static mixer is partly reacted and won't set up properly without further manual mixing. Pressure and time: We suggest that injection pressures be kept below 150 psi for StripSEAL (the lower the better). You can usually inject within about 35-40 minutes, but if you are going to use higher pressures (>100 psi), wait an hour. Surface prep: StripSEAL has a peel strength up to 400 psi so it should be able to withstand relatively high pressures if you leave sufficient thickness on the surface to offset its flexibility. If your surface is relatively smooth, you should roughen it with a very mild grind or wire brush to give it a toothier profile. Surface ports: If instead of taped ports, you use glued-on ports, apply the StripSEAL more thickly around the base of the port than with epoxy because it is more flexible and if too thin may allow a bit of weeping. Our surface ports are made with either ABS or nylon (your choice) and work fine with StripSEAL, but in some applications you may need to support them with wire, a toothpick or a cocktail straw. Blowouts and Stripping: Many field techs apply epoxy seals very thinly. StripSEAL is ineffective if applied this way. It will blow out under higher pressures due to its flexibility. For good containment and easy removal, StripSEAL be applied at a minimum of 1/8" thick and about 1" width. If you observe mostly well sealed areas with a few pesky soft areas, there are three likely causes:
Wet substrate: StripSEAL doesn't perform well on damp or wet substrates. The iso "A" side wants to react with the water before it bonds. Epoxies should be used under these conditions unless you can get the surface temporarily dry with a hot air gun. Moisture after application doesn't affect the seal. Top of page
Find answers to questions you didn't ask Could you use a free training program to refresh or upgrade your field crews' skills in structural concrete repair or crack injection? Call us—we might be able to help. Assuming we have room geographically in our Kemko applicator program to fit your company, we can plan a practical, hands-on training session of about a day and a half with little lead-time. Tired of submitting old copies of CCS product data sheets and MSDs? We just completed a complete overhaul of both items. Email or call for a complete set of updated information on CD. Yep, thanks to Brian we finally beat the curse of some prehistoric software (politely called legacy software) that didn't work on a computer born after 1978 (like Wolfgang's). Want to save a few bucks? Just combine your epoxy needs to a total of 60 gallons or more and you will qualify for a minimum of a 3% discount. Spend the savings on your lovely wife. Performing a crack injection job requiring surface ports? Give the Kemko ports a try. We now carry ports fabricated in your choice of 2 materials: ABS (black) and nylon (cream translucent). Both port materials feature a base flange with superior bonding compared to ports made of polyethylene (i.e., ours won't blow off like poly). If you are also looking for a good source of the wedge shaped golf tees for use as port plugs, we can help there too. Your normally safe crewman just poured epoxy on his shirt or pants leg; what should he do? No matter what article of clothing, the best response is to remove it quickly. With short-term dermal exposure to our products, there is usually little harm as long as the skin is washed thoroughly and completely with lots of soap and water. Long term exposure to some part B's may cause alkali chemical burns. Last piece of advice: don't wear the dirty clothing home. Top of page
If you occasionally encounter a challenging repair task that requires an epoxy or polyurea product not found in the ChemCo catalog, don't despair. Call us with your challenge and let us tell you whether we can make something. The ideal product could already be listed and tested in our extensive R&D files (watch out for our dusty old records). We produce special orders for customers at all times throughout the year. In many cases, we have all of the raw materials in stock and can produce just the quantity you need with a few days warning. Top of page
View our company history in PDF format (requires Adobe Acrobat Reader, a free download). Previous newsletters: 2001 | 2000-1 | 2000-2 | 2000-3 | 1999 Old news from AE days: 8 page Zip file of all previous news | Page 1 (PDF) | Page 2 (PDF) | Page 3 (PDF) | Page 4 (PDF) | Page 5 (PDF) | Page 6 (PDF) | Page 7 (PDF) | Page 8 (PDF) Top of page
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| Toll Free: 800.757.6773 Tel: 650.261.3790 Email: email@chemcosystems.com
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PNSB is our popular lo-mod binder for use in repairing joints and spalls, often located in very tough applications like Navy and Air Force runways, municipal refuse handling facility floors, large vehicle repair shops, machine shops and food processing machines. Often, PNSB is extended with 4-8 volumes of gap-graded aggregates to provide a durable (5000 psi) surface that is highly resistant to chipping, impacts, point loads and large temperature swings. When used as an extended binder, it has a useful working life of up to 45 minutes at 72°F, so there is time for your best trowelers to properly place the entire batch you just mixed in the mortar mixer.
