Sometimes concrete ponds are constructed and virtually no thought is given to how the surface should be in regards to it being able to accept a waterproofing coating later.  Sometime the surface is either too smooth or too rough and needs to be corrected prior to applying the coating.

I have seen people use brick in the ponds also.  Now brick is a funny material.  It is either too porous or ultra smooth.  Porous brick is not usually an issue because the pore can be filled, but ultra smooth brick can cause future delaminating if it is not properly surfaced prior to coating.  The techniques to handle this type of brick would be the same as with concrete to be explained here.

I find that one of the easiest ways to make a smooth surface more rough is to sand blast it.  Of course sand blasting has its pros and cons.  For one thing, it most certainly will clean a surface pretty well and give a nice texture to accept a coating, but it also makes a serious mess.  You’ll end up with sand everywhere and it will be there until your surrounding yard assimilates that which couldn’t be cleaned up.

Also with sand blasting, you’ll have to hire someone to do it.  It’s not likely you own the equipment necessary and probably do not have the skills either.  That’s ok though, because there is at least one other way to accomplish this.

My favorite way is to use a large 8” angle grinder.  Suit up in protective eyewear and a face mask and you can go to town with a tool like this and either smooth out the concrete or rough it up as needed.  They work wonders.  Let me explain.

If you use a flexible sanding disc on an 8” angle grinder it allows you to cut away imperfections in the concrete while at the same time protects the concrete from you accidentally gouging to some degree.  This means you can float the grinder over the surface and follow the natural contours more closely without cutting away too much concrete.

You should use a 24 grit sanding disc for the process as it will leave a more desired surface afterwards.  Not to mention it will last longer since it is coarser.  Be sure to aim the spin of the grinder away from yourself.  There’s no sense in directing debris right at yourself.  It not only hinders your sight but the flying debris can injure you as well.

Take Gunite for instance.  Usually a Gunite installer will assume that you plan to apply a plaster coating to the new pool or pond and he or she will normally apply a broomed finish to the Gunite surface.  That’s fine and dandy for a plaster surface, but no good for applying a coating.  If you apply the coating to a surface like that, you’re likely to waste a bunch of material just trying to fill in-between the broomed gaps.

Finally, as I said before, this scenario works fine for smooth brick too.  If you can just give the brick a new surfacing, it will give the coating much more to grab hold of during the application process, which will give you a longer life with the coating.

Keep in mind that this process will also be helpful when smoothing out mortar joints too.  Sometimes masons can get a little slopping with their joints and there’s no reason to just coat over them as is.  Clean them up first.

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If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST

Over time concrete can crack.  Ground movement, concrete shrinkage, freeze/thaw conditions can all play a part in possible cracks forming in your pond.  The trouble is that when they happen, you have to go out there and fix the problem.

So how do you go about fixing a crack in a pond?  Well that all depends upon the type of crack as well as the size of the crack.  Cracks can be anything from small hairline cracks up to large fissures that go right through the entire structure.

The simplest of cracks is just a hairline crack.  A crack like this can be easily repaired using the right materials.  However, using the wrong materials can easily lead to that hairline crack turning into something far worse.

Far worse simply means more resources to affect the repair.  Cash and time are things everyone wants to avoid dumping into repairs so taking your time to think the situation through is very important.

Let’s say you have a crack.  The first thing you should try and do is determine how bad the structure has been affected.  If it’s a hairline crack, it probably does not go through the entire structure, which is good for you.

If the crack goes through the structure you might have your work cut out for you.  In severe cases there isn’t a lot of repair that can be done.  But those instances are pretty rare if the structure was made using all of the proper elements needed for good, sound construction.

There are several types of materials that can be used for repairing concrete, including, more concrete, concrete strengthening additives, bonding agents, rebar, steel mesh, epoxy (like Pond Shield epoxy) and fiberglass.

Most people tend to lean towards applying some sort of rubberized caulk into the crack.  The problem there is that rubberized coatings or caulks do not bond very well to concrete and can peel. 

You also end up with a crack repair that continues to move and can eventually fail again.  You really need to shore up the concrete so that it acts just like it was when the crack did not exist.

For hair line cracks, an epoxy like Pond Shield can be used to coat over the crack.  Coating over a crack will give you the most minimal resistance to the crack reappearing.  I suggest that you use a grinder with a cutting wheel to groove the crack and THEN fill it in with Pond Shield.

What you end up with at that repair is essentially a concrete stitch.  The epoxy holds the crack from both facing sides as well as across the top of the crack.  Pond Shield tensile bond strength (that exceeds the internal strength of concrete) combined with its elongation break strength of 9,500 psi will pull and hold the concrete as though it were once piece.

For larger cracks, like those that are a half inch or so wide, you’ll have to consider more drastic measures.  You may find yourself cleaning up the crack quite a bit by actually removing portions of concrete so that you can place new concrete into the affected area.

If you cut through rebar or steel mesh, you will have to put new rebar or steel mesh back in.  Rebar and mesh help strengthen concrete as a whole.  If you have to replace pieces of rebar, you can drill into through both sides of the crack at an angle so that you might glue new rebar in place.

After the stitch is in place, you can use concrete to fill in the crack.  You concrete can have fibrous additives in it that will act as a strengthener.  Be sure to use a good bonding agent on concrete before filling it in.  This will aid in the adhesion between the old concrete and the new concrete.

Once the concrete has set up and cured properly, cut the rebar off that is sticking out of the concrete.  Make sure to try and cut it lower than the surface of the concrete.  Then apply your epoxy to seal the rebar and prevent any corrosion.

Because concrete is porous, I recommend that you coat the entire surface that will be submerged in water.  This will keep the water from soaking through the concrete and reaching the rebar beneath where it can corrode there too.

For added strength, you can also apply a strip of fiberglass over the crack as well.  Just apply the strip while the Pond Shield is still wet and saturate it out completely.  Once cured, the complete repair ought to be much stronger than the original concrete was.

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If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST

Did you know salt water was corrosive?  It is.  In fact it is a problem that engineers have been faced with for some time in regards to larger concrete structures like sea walls.  Of course sea walls are corroded by much more than salt, such as sand and gravel kicked up and splashed against the concrete.

Salt water itself contains magnesium chloride, sulfate ions and hydrogen carbonation ions that will essentially attack concrete to a certain degree, but what really starts to corrode in a concrete structure is any of the steel substructure within.

Concrete contains an alkaline environment that provides some protection against corrosion. The steel inside the concrete that is used for reinforcement will react with the concrete and form film that protects the steel.

This is where salt water works against that process.  The chloride and sulfate ions will weaken that film as the water soaks into the concrete.  Once the film is breached, then the corrosion process begins to work on the steel itself.

Have you ever seen rust stains coming out of concrete?  Usually these stains appear around a small fissure or crack.  The fissure or crack would have been the most likely place for the salt water to enter.

Because concrete is a type of porous material, oxygen and humidity can be present at the point the salt water has come into contact with the film.  This is when the corrosion process of the steel will begin.  This is also the point where things can go bad.

Now granted, this is not an over night process.  Generally this process is gradual, but environmental conditions can accelerate the process.  Building a holding tank for saltwater aquaria risks this sort of corrosion if not properly protected.

Going back to the steel in the concrete, this being wire mesh of rebar, this normally just a simple carbon steel.  When carbon steel corrodes, it expands.  Have you ever found something old that’s made of steel that has become all rusty?  You recognize the item, but it’s usually a lot bigger than it was when it was new. 

The problem with the steel inside your concrete tank is that as it expands, forces will be applied to the concrete structure that causes it to crack.  This in turn, leads to more of the corrosion process to begin.  At some point, if not cared for, the concrete will totally fail.

As I said earlier, corrosion of this sort will surely destroy concrete over time unless it is properly protected.  You need a barrier between the concrete and the salt water that will stop water, chlorides and oxygen from reaching the inner working of the structure.

Pond Shield epoxy has been formulated to do just that.  It has been tested in a variety of corrosive environments, including salt water to ensure that it is capable of performing this important task of protecting the concrete.

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If you’re looking for a non toxic solution to water proofing your pond, fountain or water feature, please visit the Pond Armor site. If you have any questions regarding the products Pond Armor manufactures, please contact us at 800-716-1545 M-F 8:30am to 4:30pm PST