concrete sealants

[Russell Peters]

If you use muriatic acid to lower your pH, the effects will only be temporary. Once the acid has been exhausted or cancelled out, then your pH will bounce back. You then need to add more acid. The problem with this is that the up and down fluctuations wioll stress out your Koi. Don't do it!!!
There are other ways to lower your pH without using any acid based products that have long term affects.

[Minster49]

Does this means that limestone blocks should not be used for ponds?

[Russell Peters]

Good question, I am afraid i don't know. I think the lyme in concrete is different than limestone rock as a solid.

[xiaohuang7]

I struggled with the concrete sealer question...

and finally bit the bullet, literally. It tooks weeks for CIM 1061 to come off of my friend Jason and myself. It was like shedding black danruff, even after taking almost a shower in paint thinner. We didn't wear rubber gloves the first time. That was a big mistake.

Very hard to apply, it starts out thick, and progressively gets thicker and harder to spead after the 10 or 15 minute mark. After the 20 minute mark we end up pushing it around with our hands. The hardest was not "painting" (if you can call it that) our pond, it was the fliter chambers and settlement tank. Since everything's sloped, it is really hard to mov around, and hard to get out. Plus CIM tends to run, so if you use it make sure to super cover your drian pipes and take into account the pooling in the low areas (or it'll mess up your nice concrete slope to the drains).

So when you apply it, it's definitely a race against time. Beforehand, cover everything in plastic. Including the patio/walking areas, and even the chairs you'll flop down after applying, exhausted. Sticky as all heck, can't use typical paint rollers, use the stuff for adhesives (even that gets pulled off by the CIM as you pass the 20 minute mark). Wear shoes that can be thrown away.

- paid $190 bucks for each 5 gallon bucket
- FDA approved for human food service contact
- used in some municipal potable water tanks
- needs at close to 5 days to dry (not 1 like the instructions say)
- produces foamy substance upon filling with water (kinda looking like soap)
- foam goes somewhere else after a week or two
- sealing is very good

Here are some pictures, it was worse (my friend and I both slipped and fell in the chambers). I had the stuff on my butt for a month.

John

[danzcool]

You asked about sealants and you have some decent answers already, there is another option that should be mentioned and that is polyurea. Polyurea is definitely not the cheapest option, but it is probably the longest lasting solution in regards to sealing cracked concrete. It's not a do-it-yourself solution, requires special equipment so you have to hire someone who specializes in it... but it cures very fast and you can fill it the same day. Don't know if it fits your situation, but it might be an alternative to look at.

[Rich L]

Danzcool is right on.

Aged concrete and DIY applications are seldom cheaper than polyurea, in the long run. The need to apply the coating properly cause too many pond coatings to fail over the years. Failures occur from six months to ten years and then have to scraped clean and retreated in the problem spots. Polyurea is far better at sealing a pond that's developing cracks. The cracks won't stop and nothing stretches and flexes like polyurea to guarantee the cracks won't impact the seal.

There is an excellent comparison chart and discussion on all the coatings popular today posted on this board or on koiphen. It compares real costs of installation, reliability and other information that will certainly narrow down your choices for you and will help you to make your final decision in an informed way.

As far as harming you koi, if you're only dealing with a small pond, remove the fish until the job is done. On the other hand, if your pond is massive, remove the fish until the job is done.

It’s too much trouble to isolate the koi from harm while you're working on the pond and too easy for a mishap to be deadly.

[Steve Nguyen]

just curious, what's the cost of using polyurea?

Steve

Quote: Originally Posted by danzcool You asked about sealants and you have some decent answers already, there is another option that should be mentioned and that is polyurea. Polyurea is definitely not the cheapest option, but it is probably the longest lasting solution in regards to sealing cracked concrete. It's not a do-it-yourself solution, requires special equipment so you have to hire someone who specializes in it... but it cures very fast and you can fill it the same day. Don't know if it fits your situation, but it might be an alternative to look at.

[Rich L]

Hi Steve,

Jeff charges about $12 a suqare foot. That's a flat charge with all the additional work to do the job included. Some others charge less but that may not be turn key.

If you know anyone in the area who's interested, Jeff or I can drop over and work up an extimate.