Epoxy School Blog


Metallic epoxies - the smiling contractors!

For a brief change of pace, imagine for a minute you were handed application notes by a manufacturer that included Step 1: Start smiling!

It just so happens that I was reading the instructions on a bottle of calming bath foam (my wife's by the way) and the usage instructions kicked off with this rather unusual request. I couldn’t help but laugh when considering what sort of reaction the same instruction would get in the typically dour epoxy industry. Everyone would probably think the manufacturer had gone mad!

When I thought about this idea a little further, there’s only ever been one epoxy field I thought could legitimately include smiling as part of the instructions. In fact, I actually saw grown men turn giddy like school kids during a training course I was conducting!

Industrial epoxy contractors weren't smiling

Before I go into details, I’ll firstly say that I’ve worked with a lot of different contractors over the years and many were in the ugly end of industrial flooring. I’m talking about aggressive chemicals, horribly corroded concrete and demanding conditions with high-pressure shutdowns. The only time I saw an industrial epoxy contractor come close to a smile during these times was when they got paid for the job. I must say, I didn’t find too much to smile about myself when doing that sort of work!

Metallic epoxy contractors were smiling

Anyway, all this changed when we entered the decorative field and started conducting epoxy training courses for our metallic epoxies. For the first time ever I had contractors hanging on my every word and eager to give absolutely everything a try. I don't know if it was because they could see themselves doing something other than boring, thankless grey floors or what? Maybe they had some untapped artistic talent buried deep down and this was their chance to finally let it out. Whatever the reason, these guys became genuinely excited and were beaming the whole day.

Industrial contractors learning metallic epoxies.

Chase your smile!

This experience was a real mind-opener for me personally on the wider topic of job satisfaction and enjoyment. Despite what the industrial field had previously taught me, watching the transformation that came over the participants that day proved there’s no reason why epoxy contractors can’t love what they do as well – it doesn’t have to be all doom and gloom.

In my opinion, the key is to keep learning and keep trying new things. From what I’ve seen in my epoxy training courses, metallic epoxies tend to have a similar affect on everyone and bring out a real creative passion that can border on addictive. Of course, it doesn’t necessarily mean it’ll be the same for you; you might even love the nitty gritty stuff. The point is, if you’re not smiling with the work you’re currently doing, you’ve simply got to get out there and find a better fit. Who knows, you too might be able to start work every day with a smile.

Note: I’ve converted the same metallic epoxy training course that made these guys so enthusiastic into modules in the Epoxy School shop. If you’re interesting in learning a new skill with metallic epoxies, please take a look.

Take care and talk to you later,

Jack

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Epoxy secrets revealed - environmentally friendly epoxies or "Greenwash"?

With environmentally friendly attached to so many products these days, I can’t help but wonder whether it’s become just another meaningless buzz word for marketers.

Taking a step back, green products aren’t about feel-good “tree hugging” in my opinion. There’s absolutely no point making an oven cleaner that doesn't clean your oven, so I see the green product movement as the search for better performance while being safer for both man and environment. With numerous raw materials and manufacturing practices proven undesirable in this regard, the epoxy industry is the perfect candidate for a push toward environmentally friendly products and momentum has been slowly gathering.

The environmentally friendly response

In response to trends like this, you find that coating manufacturers tend to do one of two things. Some go for Option 1, which is to spend their time and money developing new technology, in this case environmentally friendly epoxies, aimed at the future market. When the surge in demand inevitably comes, these manufacturers have proven, genuine technology ready to offer a hungry market. On the other hand, some go for Option 2. These manufacturers see an opportunity to cash in immediately on the budding trend by promoting their existing products as compliant in any way they possibly can. This is called Greenwash and it’s a problem we need to look at.

What Greenwash looks like

Greenwash occurs because, to put it bluntly, some companies take the easy way and just make their products sound green. For example, I recall a manufacturer that reduced their solvent content from 20% to 10% and pumped it up as environmentally friendly. Another did a similar thing to gain green certification with one product, yet sneakily promoted their entire range fell into line. These might be steps in the right direction, but a joke if you’re serious about making green products that are safer for both man and environment.

What makes that kind of practice even worse is the fact these “green products” only address higher profile dangers like solvents. There are all sorts of unpleasant chemicals and wasteful manufacturing processes that conveniently get ignored when the easy option is taken. These all have an impact on the environment and have to be considered in order to offer genuine environmentally friendly epoxies.

In addition to all that, we’ve also learnt from exposure to asbestos that it’s pointless just looking at the front end of product usage. We need to measure the entire lifecycle, including the removal, recycling and/or disposal.

How to avoid Greenwash

So, how can you tip-toe through the marketing to find genuine environmentally friendly epoxies? The answer is the same with any form of marketing: don't believe popular product perceptions or the manufacturer’s spiel unless the claims can be fully supported. One way to do this is to look for green products that have been independently audited under an internationally recognised standard. Even then, it pays to do a bit of research on what the standard is about because they’re not all equal as far as testing is concerned. Failing that, you could even ask the manufacturer if they have an environmental disclosure statement, but, once again, look for those that have been independently verified.

GECA logo - a program that looks to certify environmentally friendly epoxies.

Take care and talk to you later,

Jack

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Solvents - their purpose in solventless epoxies

Solventless epoxy means without solvents, doesn't it? So why would I need solvents when using them?

In floor coatings, organic solvents are used to thin the resin so it applies easily and forms an even film. Some products require more than others depending on how thick the resin is to begin with and what else is added.

With solventless products, they’re formulated with a lower viscosity so they can be used without the addition of solvents. That being said, they can still play an important part in solventless epoxy application.

Vinegar in a bottle - can be used for epoxy clean up but not epoxy thinning.

Solvents for epoxy clean up

Most manufacturers talk about “epoxy thinners” as a general term for solvents, however I like to be a bit more specific. When talking about solvents for epoxy clean up, I talk about two separate stages.

The first is when the product is still fresh and within working time, the other when it’s gelling. My preference for epoxy clean up in the first phase is methylated spirits (or denatured alcohol). The smell isn’t strong, it’s readily available and, most importantly, it’s not as nasty as some of the more aggressive solvents.

Once the product has entered the second phase, I look for acetone or methyl ethyl ketone (MEK) as they’re more powerful solvents than methylated spirits. There are plenty of other solvents on the market that’ll do the same job, but I tend to stay clear of options like methylene chloride and xylene because of safety concerns.

At this point it is worth stating the number one rule with respect to epoxy clean up: do not use a solvent on your skin. Yes the solvent will break down the epoxy and remove it from your skin, but breaking it down also helps your skin absorb it more efficiently, which isn’t good news. Only ever use warm, soapy water to clean epoxies off your skin.

Solvents for epoxy thinning

The purpose of epoxy thinning when it comes to solventless epoxies is generally for spraying or making the product easier to roll in cooler conditions. It’s worth noting that a small amount of solvent has a big impact on a solventless product, so 2-4% by weight is typically enough and certainly no more than 10%.

Solvents for extending pot life

Acetone and MEK belong to a group of solvents called ketones that extend pot life by blocking the crosslinking reaction with the amine. By adding a small amount in the bucket you can extend pot life dramatically and give yourself more time for application. Once the product has been rolled out, the reaction reverses and the solvent evaporates off as it normally would, which means this little trick doesn’t extend the working time as much.

Water as a solvent

Water doesn’t mix with epoxy naturally, however there are a number of ways formulators get around that to create water-borne epoxies. Most people assume these coatings are the ultimate in safety and environmental friendliness because they contain only water, however the fact is many have organic “co-solvents” to help the products flow and form a nice film. Next time you open a bucket of water-borne paint, pay attention to the smell. It’s definitely not just water in there!

Take care and talk to you later,

Jack

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Epoxy product selection - Technical Data Sheets and MSDS

When it comes to epoxy product selection, everything is not always as it seems.

A product may sound like it hits the spot – it may have the right speed, viscosity, hardness etc. – but behind this ideal exterior there can lay some important fine print not all salespeople like to talk about. Knowing your way around a couple of key documents will help unearth these potential sticking points yourself and make sure it’s the product you want to be dealing with.

Let's start by looking at a Technical Data Sheet (TDS).

Technical Data Sheet clues

When searching for certain products, you’re typically drawn to things like speed, gloss levels, chemical resistance etc. If you’ve been handed a Technical Data Sheet by sales person, the chances are these will all check out ok. It’s in other places, however, that you should look a little more closely. Personally, I always head to the Limitations section on Technical Data Sheets first because you learn more about the product here than anywhere else, particularly its quality and overall suitability for you.

A classic example in this sense is the mention of an induction time. Letting a product sit for 10 minutes before application is there to control blushing and is a legacy of older curing agent technology, both of which mean you can probably find a better alternative elsewhere. What else could show up on a Technical Data Sheet and make you think twice? There are plenty, but warnings on using the product below certain temperatures or above certain humidity are common, so are the appearance of surface haze in some conditions. The point is this section is usually full of information you’ll want to know when going through the epoxy product selection process.

Material Safety Data Sheet clues

The next key document I rely on for epoxy product selection is the Material Safety Data Sheet (MSDS). The regulations controlling what has to be declared on a MSDS vary from country to country and manufacturers will mostly reveal only what they have to. Despite this, reading the MSDS can, at the very least, give users an idea of some risks that could influence epoxy product selection. Covering all of these is a large topic well beyond the scope of this post, however I’ll highlight a couple of epoxy users might want to consider. 

Firstly, there’s the corrosivity rating. While there are a few non-corrosive curing agents on the market, the remainder tend to be lumped together in a generic classification for transport purposes and that can be dangerous in my opinion. The alarming fact is there can be big differences in the degree of corrosivity from one curing agent to the next, even if the MSDS has them all listed as a Class 8.

If working with extremely corrosive materials isn’t your cup of tea, how can you tell from an MSDS if something is acceptable or not? The key is to read what the product does with respect to skin contact. On the lower end of the scale are irritants, meaning skin contact can lead to temporary irritation, usually in the form of a mild rash. Then there are sensitisers, meaning increased sensitivity to the product can be experienced over time if exposure continues. On the harshest end are the corrosive materials, which can cause chemical burns when in contact with your skin. Taking a look at what you’re dealing with in this way will quickly tell you what you need to know.

The second area users should consider with epoxy product selection is toxicity because some components are toxic in very small doses. Hopefully no-one ingests (drinks) these materials, but the risk of breathing in vapour or ongoing skin contact is very real, especially over the long term, and has to come into the equation when deciding if a product is one you want to work with.

A few of the hazard symbols that can be found on the MSDS of epoxies.

The take home message from this post is that reading just some basic information in Technical Data Sheets and Material Safety Data Sheets can help you make the right choices when it comes to epoxy product selection. For those wanting to learn more about this topic, there is a training module in the Epoxy School shop that goes into much greater detail (click here).

Take care and talk to you later,

Jack

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Epoxy troubleshooting - inter-coat delamination

I think one of the worst nightmares in floor coatings is inter-coat delamination, or in simple terms, one coat failing to stick to another.

Not only is there the immediate problem of removing the failed coating, but the even bigger concern of why it didn’t bond in the first place. After all, if you can’t get to the bottom of why it happened now you’ll almost certainly have a second failure on your hands!

So, what are the typical causes of inter-coat delamination with two-pack epoxy coatings and how can you prevent it from happening?

Product re-coat window and coating adhesion

When most two-pack epoxy products cure, they form a smooth, hard film that isn’t the easiest to stick to. To get around this, manufacturers talk about applying following coats within the re-coat window – a period where the film hasn’t fully reacted yet and can therefore form strong chemical bonds with coat on top. If this re-coat window is missed, you’ll need to rely more on physical bonding by sanding the film and establishing a mechanical profile for the next coat to cling to.

A TDS showing the re-coat window of an epoxy coating.

Amine blush and coating adhesion

I have already written a post on amine blushing in this blog (Epoxy troubleshooting – amine blush), so please have a read of that for a more comprehensive discussion of this problem. For now I’ll just say that the waxy film created through the blushing reaction can be a powerful barrier to epoxy adhesion.

Incompatibilities and coating adhesion

Incompatibility can occur in several ways. For instance, some products may contain additives or modifiers that interfere with coating adhesion in general. In other cases it might be more specific, such as incompatibilities between two products or even two technologies. Some of these incompatibilities are well known, while others aren’t. For example, I’ve seen plenty of contractors caught out by using cement-based levellers under impermeable coatings and experiencing coating adhesion troubles because they didn’t allow sufficient time for drying.

Solvent entrapment and coating adhesion

This topic can get a little complicated and I’ll cover it in more detail in post shortly. Briefly, solvent entrapment can occur when another film is applied before all the solvent (organic solvents or water) in the first film has had a chance to evaporate. In this situation the solvent can become permanently trapped, which often leads to soft spots, blisters and inter-coat delamination.

Contamination and coating adhesion

Even though the period between coats is typically a matter of several hours, contamination and the impact it can have on coating adhesion is definitely still something to be wary of. Off the top of my head, I can think of a couple of instances where contamination between coats led to substantial coating adhesion problems. The first was a cool room floor in a meat processing plant that had condensation run off the walls and sneakily deposit a load of oil and fat that wreaked havoc. The second also involved oil, however this time it was a very untimely crack in a pipe that left an uncured floor completely immersed. Contamination can also, of course, be air-borne so be aware of anything that could land on the floor in between coats as well. 

I’ve never personally been a part of a project where the two-pack epoxy coating came off in large sheets, however it is definitely possible because I’ve heard from contractors that have. Rest assured they didn’t have fond memories! The threat is very real and you’ve got to make sure you’re aware of the potential causes of epoxy adhesion issues to avoid such a disaster.

Take care and talk to you later,

Jack

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Selling epoxies - epoxy contractors and follow-up calls

Ok, hands up. How many of you regularly go to the trouble of quoting with epoxies, but don't follow up?

Some would say, “I'm too busy”, while others push the old line, “I wait until they call so I know they’re serious.” From my experience, the most successful epoxy contractors – and business people in general – are the ones that take the initiative and follow up after the quote has been submitted. The difference is that simple!

An epoxy contractor selling epoxies and waiting for the phone to ring.

Selling epoxies - the power of the follow up


Why is it so powerful? The epoxy contractors doing it will tell you a follow-up call, or courtesy call as I like to say, actually does a number of things –

  • It tells you the client got the quote rather than simply assuming they did. A wrong assumption here can not only cost you the immediate epoxy project, it can potentially damage your reputation if the client thinks you didn’t bother to respond.
  • It shows the client you’re willing to go above and beyond standard levels of service.
  • It gives you the chance to address any information you might’ve missed or left out by accident, thus avoiding being overlooked because of an incomplete quote.
  • It gives you a second chance. You can explain what you’re doing again and why you priced it the way you did. You can even discover what the opposition are offering and modify accordingly.
  • It keeps you in touch with the epoxy project. If the client is just getting prices at this point, you can get a better idea of their timeline and get back in front of them closer to the start date.

Selling epoxies - you owe it to yourself!


With all the benefits of a post-quote follow-up call in mind, the point is that you really owe it to yourself to start making them. Think about it for a second. Think about all the time and effort that goes into a quoting an epoxy project in the first place. You go out to site and take a look; you might talk to a manufacturer or two and nut out a solution; you work through all the materials and costs; you stew about logistics and how it’s all going to fit into your schedule. At the end of the day, quoting with epoxies is a big exercise and deserves every chance of success. A follow-up call is a quick and easy way to give those chances a huge boost!

I’m such a big fan of these phone calls that I schedule in another even if I don’t win the work. Calling up when your quote wasn’t successful is a tremendous learning experience because you can find out why and improve your chances for next time. In addition to that, if something goes wrong with the original epoxy contractor then you’ll be the next in line.

Selling epoxies - but I really am too busy


OK, so what if you are genuinely too busy to make these calls? What if you already win enough work and don’t need to bother with this extra hassle? Well, I think the follow-up call can still play an important role by improving the jobs you win. Think of it this way: rather than win all sorts of bits and pieces that come your way, wouldn’t it be better if you targeted the epoxy projects you actually wanted to be involved in? The follow-up call in this situation can help busy epoxy contractors buried in troublesome, unrewarding projects to drag themselves away and start chasing better opportunities.

As a final thought on this topic, I think it helps to put yourself in the shoes of the customer and consider how you like to be treated when receiving a quote. If you’re anything like me you like punctual, courteous, professional responses. In fact, if I get good service from a company in this regard then I’m often happy to pay more because they’re trying harder to win my work and they’ll try harder to satisfy me on the job too. Why would it be any different when it comes to epoxy contractors and epoxy projects?

Take care and talk to you later,

Jack

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Epoxy secrets revealed - do UV-stable and non-yellowing epoxies exist?

UV-stable epoxies, low-yellowing epoxies, non-yellowing hardeners...do they actually exist?

In the epoxy flooring field especially, so many products sound similar that marketing experts are always trying to find ways to distinguish themselves from the opposition.

(Note: the reason why lots of products sound the same is there are more distributors than genuine manufacturers, but that's a topic for another time.)

For as long as they’ve have been used, the Holy Grail has been to find one that doesn’t yellow in sunlight. Plenty of formulators have tried, including myself, however we don’t seem to be there just yet. Because such a product would instantly become a best seller, manufacturers are pushing hard to cash in on whatever yellowing benefits they can offer. New terms like “low-yellowing epoxies” or “non-yellowing hardeners” have crept into promotional material and it can be quite persuasive. You can forgive a contractor for thinking, “Maybe these guys have figured it out after all!”

The real story with epoxy yellowing


In my humble opinion, most of the claims based on UV-stable epoxies aren’t very accurate for a few very good reasons –

  • All resins will discolour over time. Epoxy, polyurethane, acrylic, whatever...they’ll all break down eventually with UV exposure. Some will be much quicker than others, but nothing lasts forever.
  • The severity of UV varies depending on the country and the project. For instance, the UV intensity in Australia is much worse than other countries. I’ve seen UV-stable epoxies or low-yellowing epoxies sold in other parts of the world discolour within months under Australian conditions.
  • Coming back to epoxies, the epoxy resin itself (Part A) has an aromatic chemical structure, which in simple terms means it doesn’t like UV. Some will put stabilisers and absorbers into the resins to slow the epoxy yellowing, but these materials themselves have a limited lifespan. Once they expire, the epoxy yellowing will occur. Also, I personally feel there’s a question mark on the stability of these additives as I’ve seen drastic colour changes when products have been in storage for 6 months or more.
  • Even those with aliphatic amines in Part B, which are supposed to be better off as far as UV goes, are often modified with benzyl alcohol or nonyl phenol – aromatic compounds that aren’t any good and counterproductive as far as non-yellowing epoxies go.

An image showing how UV tests yellow both epoxy and PU samples.

Genuine low-yellowing epoxies


Once again, in my opinion, until a manufacturer can make a 100% solids aliphatic version, epoxy resins will discolour and genuine low-yellowing epoxies won’t exist. I should clarify that I’m only really talking about epoxy flooring in this context. Aliphatic epoxies have been used for other applications, however formulating one suitable for the demands of flooring is proving a more elusive task.

In closing, I know some manufacturers may well be cringing as they read this post, but I prefer to tell it how it is than deceive people and cause problems down the track.

Take care and talk to you later,

Jack

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Epoxy troubleshooting - amine blush

Have you ever seen a waxy, often whitish haze form on the film of a two-pack epoxy?

The chances are it was something called amine blush, which is caused by a reaction involving the curing agent with moisture and carbon dioxide in the atmosphere.  Sometimes it can also show up as a surface oiliness or stickiness and, although it can be removed with some all-purpose soap and a stiff brush or scotchbrite pad, it’s definitely not what you want to see.

What amine blush looks like on an epoxy film.

The dangers of amine blushing

Amine blushing is bad news on a couple of levels because it can interfere with numerous properties and lead to poor adhesion, poor gloss and difficulty in re-coating.

Practically speaking, amine blushing on your basecoat means you raise the risk of developing issues such as crawling in the second coat. You could also end up with large scale delamination as the amine blush essentially acts like a strong adhesion barrier across the affected surface. If, on the other hand, your topcoat develops amine blush then you’ll end up with visual defects and the surface will pick up dirt more easily from the stickiness.

How to avoid amine blushing

As noted before, amine blushing is the result of the amine in the epoxy hardener reacting with carbon dioxide and moisture. Some amines are more prone to the problem than others and, as a rule of thumb, those that aren’t soluble in water have less risk. In my own experience, I’ve found epoxy hardeners based on isophorone diamine (IPD) – a very common curing agent due to the fact it’s highly reactive, very thin and cheap – particularly susceptible to amine blushing and one to be wary of in this sense.

Obviously the conditions play a big part in whether a curing agent will blush or not as well, with cool, humid conditions the biggest concern. In this case there is plenty of moisture in the air and curing is slowed dramatically, giving the reaction plenty of time to take place. In warmer weather where the curing cycle is shortened, amine blushing tends to happen more inconsistently and I’ve seen products misbehave after going down perfectly in identical circumstances the day before.

Some other recommendations on amine blushing

To finish up, there are a few other things I’d suggest when it comes to amine blushing.

Firstly, not many people consider the carbon dioxide part of the equation when experiencing amine blushing problems. A common source for elevated carbon dioxide is the gas-fired heaters used to heat rooms and reduce curing times. If you’re using a curing agent prone to blushing then heating the room might not be an option. Secondly, the easiest way to check the blushing potential of any product is through the technical data sheet (TDS). Check the product limitations and see what the manufacturer says about humidity and temperature requirements before you use it. If in doubt, simply ask the manufacturer directly.

Most contractors that have been doing epoxy floors for a while have seen some form of amine blushing. Have you? What did you do?

Take care and talk to you later,

Jack

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Epoxy troubleshooting - soft patches or "hot spots"

Have you ever seen a solventless, two-pack epoxy floor coating cure hard except for a couple of soft patches, or “hot spots” as they’re sometimes called?

Do you know why something like this might happen? There are a few reasons, however one of the most common causes for mistakes like this is simply a failure to mix the coating correctly.

Soft spots, or soft patches, create a dirty looking floor.

Mixing well isn't enough

OK, you may have beaten the product with a drill mixer for five minutes, but unfortunately that doesn’t mean you mixed it well. The fact is you will always have areas within your bucket that do not mix well naturally – namely, the sides – and if you don’t pay attention to these then hot spots can occur.

I see and hear about it all the time; a contractor has mixed the product in a bucket and scraped the sides or left the bucket sitting upside down to get as much out as possible. There’s nothing wrong with trying to minimise losses this way, however to avoid soft epoxy patches you must be sure these regions are mixed properly as well. The only way to do this is to scrape the sides of the bucket during the mixing process to lift the stagnant product and draw it into the middle. It becomes even more important during cooler temperatures or if using a thicker product that doesn’t flow as easily.   

What about larger soft spots?


The hot spots created by poor mixing practices with solventless epoxies are usually small in size, so what might be the cause of larger soft spots?  If you have large soft spots, i.e. covering a full kit or more, then I would be asking questions about the mix ratio or, heaven forbid, forgetting to add the curing agent at all. Don't laugh, it does happen! If the coating was a solvent-borne or water-borne product (or even if solvent was added to a solventless product) then something called solvent entrapment might be in play and I’ll get around to that in another post.

How can I fix soft spots?

Unfortunately there are no quick fixes for soft spots. You can’t simply roll some curing agent into the mix and hope it magically hardens into the perfect film you originally intended. Instead, you have to take your medicine, so to speak, look to remove the defective film and go again. On most occasions this will involve scraping up the soft epoxy and solvent wiping away any residue. Once the solvent has evaporated you can patch the area or overcoat it. Be aware though, if you go back to bare concrete with your solvent wipe then you should patch that immediate area first before over-coating otherwise you could end up seeing it through the topcoat.

Take care and talk to you later,

Jack

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Surface preparation - should I use a primer or sealer?

Some call them primers and some call them sealers, but are these terms interchangeable?

For me, the answer is no. An epoxy primer serves a different purpose to an epoxy sealer and if you’re not careful making that distinction it could come back to bite you. The fact is, primers won't always be suitable for sealing and sealers won't always be suitable for priming. The key to avoiding problems is simply asking why you are priming or sealing in the first place.

Primers increase adhesion


In my opinion, a primer is used for its adhesive qualities, meaning the next coat doesn’t have sufficient adhesion or is not compatible with the surface it’s bonding to. An everyday example would be using a primer before trowelling a 6:1 mix of resin and sand. At 6 parts sand to 1 part resin, there’s barely enough resin to hold the sand together let alone provide a good adhesive layer and priming would therefore be beneficial.

Sealers are for sealing


A sealer, on the other hand, serves the purpose of closing off the substrate before you apply the first coat. You can apply a sealer for a number of reasons, including the prevention of defects like pinholes or to improve the finish of subsequent coats.

Another difference between the two is that you tend to only require a single primer coat whereas you can require multiple sealer coats. For example, you apply the first sealer coat and notice it looks sealed/glossy in some areas, but bone dry in others. If I was concerned about defects, I’d want to see a consistently sealed surface before the first coat went down.

Sealing a concrete slab with a clear epoxy sealer.

Do I have to prime or seal?


A big question that comes into play on this topic is whether you always need to prime or seal. Once again, the answer is
no. You can buy primerless products that are resin rich enough and surface tolerant enough to be applied directly onto the substrate, eliminating the extra labour and product required to apply a primer. You can also get surfaces that aren’t weak or porous and won’t need a sealer to bring them up to scratch.

Finally, is it worth priming and/or sealing “just in case” to guarantee better results? You guessed it – no, not always. I can give you an example where sealing actually caused the trouble. In this case the contractor wanted a sealer to strengthen porous concrete, however in doing so they compromised the adhesion and caused some big headaches for themselves. It’s a very interesting story that I’ll have to cover in more detail at another time.

Take care and talk to you later,

Jack

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