Alchatek Blog

Here it is. My favorite topic. Why? Because I have seen and heard some really stupid things concerning this. It is my pet peeve. It separates the technicians who care from those who are only going through the motions. And quite frankly, it can be the difference between a successful outcome and dismal failure - or at the very least an expensive call back.

When you drill holes you create concrete dust. The hammer drill bit literally chews up the concrete. Most of it comes out of the hole and falls on the floor. However, a lot of dust is left behind inside the hole. If it is not properly flushed out then it will mix with your polyurethane injection resin and make a thick paste. This thick paste can be forced into the crack and prevent the clean resin from reaching deep into the crack where it is needed. Most of the time you won’t even realize you have a problem. But there it is nonetheless. Waiting for the right conditions to allow water to seep back through the crack you thought you fixed.

How to avoid this? Simple - flush the hole out from the back using a very cheap flexible hose that attaches to your flush pump (you did bring a separate flush pump didn’t you?). Start at the highest hole and work your way down until clean water is flowing out of each hole.

Spraying water at the face of the holes may make it look clean, but it is not. There is still dust deep in the hole. Filling a water bottle up and squeezing it so that water shoots part way up the hole is not good enough. You have to have the water exit your hose at the back of the hole. This is the only way.

Exceptions? Of course there are. If you pull the drill bit out of the hole and water gushes out behind it in a steady stream you can skip this step. Otherwise, make sure you bring a flush hose with you. It has to be small enough to fit inside your drill hole. We make it easy for you. We make one and sell it for cheap (so don’t blame us if you get to your jobsite and don’t have one).

This is so basic it is silly. However, I have seen experienced technicians do the water bottle trick and try to explain that it is sufficient. I’m happy to report that those guys are working for your competitors now. Just make sure your guys don’t get lulled into laziness and skip what just might be the most important of these five basic steps:

1. Drill the hole
2. Flush the hole
3. Install the ports
4. Flush the crack
5. Inject the resin

Next up, installing the ports!

Click below to read the previous articles in this series if you missed them:
5 Steps of Concrete Crack Injection - Overview
5 Steps of Concrete Crack Injection - 1. Drilling Holes
5 Steps of Concrete Crack Injection – 1. Drilling Holes (Continued)

Click below to read next articles in this series:
5 Steps of Concrete Crack Injection – 3. Installing the Ports
5 Steps of Concrete Crack Injection – 4. Flushing the Cracks
5 Steps of Concrete Crack Injection – 5. Injecting the Resin

Want in-depth info on crack injection procedures and products?

Let’s face it, most of the structures you drill through will be full of rebar. Rebar is the steel reinforcement that gives the structure its strength. Concrete protects the rebar by shielding it from moisture, and the high pH of concrete keeps the rebar from rusting. However, once a crack forms it allows more water and environmental gasses to reach the area surrounding the rebar. Carbonation of the concrete can now occur which causes the pH to drop and the corrosion process to begin. The rust expands and takes up 15 times the volume of the un-corroded steel which causes tensile forces to work against the concrete eventually resulting in additional cracking and spalling. Hopefully, you will be called in to fix the leaks before much of this damage occurs.

Once you are on the jobsite, this slow process of decay does not really affect you (unless the concrete is spalling off as you drill). Your issue with the rebar is that it will stop your drill bit from penetrating the crack. The cracks will often follow the rebar, especially if there is not an adequate coverage of concrete over the rebar. Shallow rebar is a huge contributing factor to cracks in concrete.

At this point, all you care about are two things. First, how do you know if you have hit rebar? Second, if you have hit it, what in tarnation do you do now?

After drilling many thousands of holes like I have over my career, you pretty much know when you have hit rebar. Here are a few things to lookout for:

1. Forward progress of drilling has stopped.
2. The sound of the drilling changes.
3. The quantity of drilling dust is reduced.
4. If you are not sure, put your hand out to catch some of the drilling dust coming out of the drill hole. Observe it for metal shavings.

1. Move further away from the crack and try again (adjust your drilling angle).
2. Move closer to the crack and try again (adjust your drilling angle).
3. Move parallel to the crack and try again.
4. Move to the other side of the crack and try again.
5. As a last resort, drill straight into the crack. This is not the ideal situation, but if you can drill deep enough to get an injection port installed, then you might be able to successfully seal the leak.

Now that the surface of your concrete looks like Swiss cheese, it is time to go get that bag of fast set hydraulic cement you brought along for just this purpose. Try to patch it up before you begin injection because some of those abandoned holes are libel to have hit pay dirt. If you don’t seal them up then you will have foam or resin leaking out of the holes.

Hitting rebar is not fun and can be frustrating. The key is to expect it and try to think three dimensionally. See if you can visualize what is going on behind the concrete. This is one of the keys to becoming a really good injection technician.

Click below to read the previous articles in this series if you missed them:
5 Steps of Concrete Crack Injection - Overview
5 Steps of Concrete Crack Injection - 1. Drilling Holes

Click below to read next articles in this series:
5 Steps of Concrete Crack Injection – 2. Flushing the Holes
5 Steps of Concrete Crack Injection – 3. Installing the Ports
5 Steps of Concrete Crack Injection – 4. Flushing the Cracks
5 Steps of Concrete Crack Injection – 5. Injecting the Resin

Want in-depth info on crack injection procedures and products?

I remember my first day on the job back in June of 1985. We were working nights in the MARTA subway tunnels in Atlanta, sealing leaks in the ceiling. They handed me a 30 pound hammer drill and told me to drill holes in the ceiling at a 45 degree angle. Sure, what the heck is a 45 degree angle? I put on a lot of muscle that summer drilling overhead and hauling 50 pound pails of resin all over the Southeastern U.S.

Drilling holes into concrete seems like a straight forward process. However, it must be done correctly or everything you do afterward is a waste of time. Often, contractors put their least experienced technician on the job because it is manual labor and can be taught quickly. Knowing a few of the basics can help a newbie drill like an expert.

First, you have to understand that the beginning of the hole is where the injection port makes its seal against up to 3,000 pounds per square inch of injection pressure. It is important that the hole stay round, especially when using hammer in type ports. That means you have to keep the drill bit in a straight line.

Why a 45 degree angle? This is the best way to intersect the crack halfway through the structure (which is your goal). On a 10” thick wall, come off the crack 5”, drill at a 45 degree angle and you should hit your target. Just start with your drill bit straight into the wall, give the trigger a few bumps to make an indention in the concrete with the bit, and rotate your drill so that the angle is half way between your starting position and the wall.

How far apart to space your holes? It depends on the width of the crack. Tighter cracks need tighter spacing because the resin won’t travel as far. Wider cracks can have wider spacing because the resin will travel with ease. A rule of thumb is to drill your holes no farther apart than the thickness of the concrete. Drill, flush and pump a test hole with water to give you an idea of how far the resin will travel.

Be sure to pull your drill bit out every four or five inches of penetration to clean out the drilling dust. Otherwise you are likely to bind up your drill bit, which is not fun to try to remove.

Sometimes you will have to drill straight into the crack. I always try to angle drill first, but with extremely tight cracks you may have to compromise and drill straight in. Go as deep as you can, but make sure you don’t go all the way through.

Another tip: If you stagger your holes from one side of the crack to another, be sure not to intersect a hole you already drilled. This causes all kinds of problems.

We will talk about flushing drilling dust out of your holes later, but I can’t repeat it enough. If you want a successful injection job you have to flush the drilling dust out of the holes from the back. Otherwise, the dust will form a paste that gets forced into the crack and blocks your resin from getting where it needs to be. Splashing water on the front of the hole doesn’t really help. Be sure to get a small hose to the back of the hole and flush it with clean water.

In the next article I will talk about what to do when you inevitably hit the injection contractors nemesis...rebar!

Click here to read the first article in this series if you missed it:
5 Steps of Concrete Crack Injection - Overview

Want in-depth info on crack injection procedures and products?

There are five basic steps to be done when injecting a crack in concrete that is leaking water. This is crack injection 101. Learn these steps and you will be well on your way to understanding what it takes to seal a water leak in concrete with products such as Spetec PUR F400, Spetec PUR F1000 and AP Seal 500. In future articles, we will explore every one of these steps in more detail and address the multitude of options (such as port selection, hole spacing, depth, what to do when you hit rebar, etc.) But for right now, we are going to discuss the most basic steps.

Step 1: Drill holes. Use a hammer drill to drill holes in the concrete that intersects the crack. These holes are usually drilled at a 45 degree angle to intersect the crack halfway through the structure so that the resin is forced towards the front and back of the crack.

Step 2: Flush the holes. When you drill, you create concrete dust. If you don’t flush this dust out of the holes, it will be forced into the crack during injection and may clog the crack, preventing resin from getting where it needs to go. Put a flexible hose all the way to the back of the hole so that water flushes the dust from the back of the hole to the surface of the concrete. Flush until clean water is flowing.

Step 3: Install your injection port. The port is what seals the hole and gives the injection pump a direct connection to the crack.

Step 4: Flush the crack. Unless water is pouring out of the crack, you will need to inject clean water through the injection port and into the crack. This serves several purposes:

• Cleans the crack of dirt and other contaminants to allow resin to flow freely.
• Gives you an idea of how far and how easily the resin will flow into the crack when you start injecting the foam.
• Helps to open areas that the resin wouldn’t otherwise flow. Water is thinner than resin and will penetrate deeper and into tighter areas.
• Ensures the resin will have enough moisture to react with.

Step 5: Inject the resin. Always use the lowest pressure that will continuously feed resin into the crack. Slowly turn up the pressure as necessary to get the resin flowing. My rule of thumb is to keep injecting even if resin starts to flow out of the crack. As long as more resin is going in than is coming out, you are improving your chances of success. When the resin isn’t moving further along the crack, move to the next port.

Sounds simple, right? Well it is and it isn’t, as we will discover in the next several chapters of this blog series...

Click below to read next articles in this series:
5 Steps of Concrete Crack Injection - 1. Drilling Holes
5 Steps of Concrete Crack Injection – 1. Drilling Holes (Continued)
5 Steps of Concrete Crack Injection – 2. Flushing the Holes
5 Steps of Concrete Crack Injection – 3. Installing the Ports
5 Steps of Concrete Crack Injection – 4. Flushing the Cracks
5 Steps of Concrete Crack Injection – 5. Injecting the Resin

Want in-depth info on crack injection procedures and products?

Giving lunch and learn presentations at engineering firms can be a great way for contractors to develop relationships with engineers, get recommended for jobs, etc. But you have to do it right. Let's take a closer look...

You schedule your lunch and learn, get your lunch delivery receipt, wrestle with the inevitable obscure HDMI/VGA/laptop technical difficulty, and present to a team of design professionals on your product line. The presentation goes well, with a couple of the subject matter experts engaging with relevant project challenges and case study feedback. In all estimations, the presentation went well, you gather your sign-in sheet, business cards, and laptop, and head to your next meeting.

What was the takeaway for this lunch and learn with the team you just left? What value was added to their day? (Of course, a good lunch is always of value!) But, did they go back to their desk immediately immersed in the 15 emails they missed during the presentation, or did they walk away with a true impression of the value your company would bring to their job sites? We all like to think that our presentations are well-curated and sharp, delivering relevance and technical insight highlighting quantifiable job site benefits. But, the truth is they are sometimes not. If they were all great, we wouldn’t realize when we saw an exceptional one.

To the engineering community who may be reading this post: what were one or two of the unique aspects that stood out to you in the last exceptional lunch and learn you saw? And perhaps more importantly, what are some of the mundane items that most lunch and learns could leave on the cutting room floor? On the supplier side, I think we could all use this valuable feedback to improve our lunch and learn efforts (and those of our contractor customers). If you found this article through a link on a social media post, go back and post your replies there. If not, please call me at 404-618-0438 with your feedback, so we can further assist our contractor customers with their presentations.

To the contractors out there: would you like help finding engineers and preparing your lunch and learn presentation? Call us now at 404-618-0438 and ask for a technical consultant!

Want more information on Alchemy-Spetec products?

You meet someone for the first time, have a productive and promising conversation, exchange business cards, rinse, and repeat. As I’m sure the case is with many of you reading this, I’ve had this exchange with hundreds of people during this tradeshow season, and sincerely wonder if the connections that were made in the exhibit hall were carried through optimally.

As I read through daily posts on social media, it’s clear to me that there are some very creative, driven, and competent sales professionals in my network. After reading a particularly interesting LinkedIn post on leadership culture, a lightbulb went off. Why don’t we ask more questions in our posts? There’s a very good chance that a lot of us are thinking and pondering over the same basic sales and marketing challenges.

So, I raise these questions to those who found this post via social media (our posts are shared on LInkedIn, Twitter, Facebook, Instagram, Pinterest and Google Plus). What are some of the creative ways you have personally followed up with trade show contacts? Or perhaps you could share how a vendor has creatively followed up with you. And what is the best way to follow up these days? Phone calls, emails, social media, etc? I would love to hear some of your trade show follow up strategies. I know some of you have some great ideas. If you found this article via a link in one of our social media posts, please go back to that post and reply with your thoughts!

Want more information on Alchemy-Spetec products?

The Spetec Re-Injectable Tube System is a primary waterstop in cold joints and pipe joints. When used with acrylates like Spetec AG 200, it can be flushed with water at a pre-determined set time, creating a clean tube ready for subsequent use. It can also function as a standard single-use injection tube system with polyurethane injection resins like Spetec PUR H100 and Spetec PUR F400. The Spetec R-ITS is compatible with combination grouting techniques involving microfine cements.

Procedure:

Spetec R-ITS Application:

1. Tube to be set in maximum runs of 30’ (10m).
2. Terminal ends to overlap to avoid discontinuity in coverage.
3. Must have flush connection with substrate free of rubble and large debris.
4. In conditions with uneven substrate profiles, consider use of Spetec WT400 to fill in imperfections or used as sole waterstop.
5. S-curve technique to be used at hori­zontal-vertical transitions.
6. R-ITS single or dual terminal boxes provide thread for zerk or button head fitting connection.
7. Make a cup test to clearly note reaction time of polyacrylate gel mix.
8. Continue pumping to generate pressure, and achieve penetration through desired profile and substrate. Pump for maximum 75% of reaction time established in cup test, then remove zerk plug, and flush line with water.
9. Reinstall zerk plugs to prevent any unwanted substances in the re-inject­able tube.

Applications:

• Primary waterstop systems.
• Cold Joints.
• Expansion Joints.
• Replacement for traditional PVC waterstops.
• Combination grouting techniques.
• Tunnel crowns, slurry walls, and details.
• Stabilization/permeation combination grouting.

Advantages:

• Re-injectable functionality.
• Monolithic waterstop seal.
• Effective in applications with honeycomb concrete.
• Will not fold or crush with concrete weight.
• Can be injected under flowing water.
• Chemical resistance once injected.
• With NSF approved resin, can be installed in a potable water application.
• Dynamic valve behavior accordingly to pressure.

Want more information on Alchemy-Spetec waterstop products?

When it comes to leaking cracks, Spetec PUR F400 is an excellent solution. This product is free of solvents and phthalates, which is much safer for our contractors to use. It's also NSF/ANSI 61 approved for use with potable drinking water. This allows contractors to fix leaking wall or floor cracks at water treatment plants. Spetec PUR F400 is also safe for use around water containing fish and other wildlife.

Spetec PUR F400 is designed to shut down leaks in concrete, brickwork, concrete sewers pipes and precast concrete. This product works very well with leaking hairline cracks due to its low viscosity. Spetec PUR F400 is very flexible after it sets up, which allows it to retain its bond if the concrete shifts or moves due to freeze/thaw cycles. When the concrete shifts, the grout continues to bridge the crack.

Want more information on Alchemy-Spetec leak seal products?

Today is our last day exhibiting at the No-Dig Show!  Visit us at booth #146!

Watch this video to preview a couple Alchemy-Spetec product demos!

Want more information on Alchemy-Spetec products?

Spetec PUR GT350 is an MDI based hydrophilic one component flexible polyurethane grout. It is used for many things, most commonly for leaking cracks, soil grouting and joint leaks.  This highly flexible grout works very well in wet moving cracks.  The flexibility of this grout allows it to bridge cracks if they're still moving.  Spetec PUR GT350 works very well in the soils behind leaking walls.  This product has a quick reaction time.  With very heavy water flows, Spetec PUR H100 Accelerator can be used for faster set times.

One of our customers did a big project with Spetec PUR GT350 for the city of Beaumont, TX. They had 200 manholes that had leaking joints and cracks. The contractor soaked backer rod with Spetec PUR GT350 polyurethane grout to fix the leaking manhole joints. Crack injection was also done on the precast structures. If you're a leak seal contractor, consider going after these very profitable types of large scale municipal jobs. If you'd like assistance in that matter (or any others), call us now at 404-618-0438.

Want more information on Alchemy-Spetec leak seal products?