[vet_boy77]

(sorry about prev post, this should have been a new topic)
I'm looking to salvage a tank that is a week or so into the making. Here's my delima:

I made a Great Stuff background and covered it with a bark/coco fiber mixed with Ace Concrete primer/Bonding Adhesive. The background dried hard and looks great. However, there will be a water feature in this tank. The waterfall will be going down a piece of cork bark, so long term term water exposure is ok. However, I'm concerned about the concrete primer dissolving from the high moisture over time.

Now I'm looking to bail myself out, without having to scrap and redo the tank.
Any ideas on something I can coat the whole background to seal and protect it? Please let me know.
Thanks
John

 

[Guest]

the concrete might be a bit acidic for a water feature. Concrete shouldn't break down for quite a few years and even then will u still want this particular tank? Just cover the whole back with silicon, that sould work by the time it really needs to be replaced.

 

[Blort]

John,

Did you get the MSDS from the Ace Primer? It is something that I have been meaning to do, but haven't gotten around to. At any rate, I have a ton of books on plastics right now that I checked out from the university's library and have done a fair amount of reading about this. So, if you send me the MSDS, I can look it up.

Initially, the Ace Primer looks pretty close to the Flevopol being used in the Netherlands. They have been using this stuff for some time with apparently little ill effects. It is probably PVA (polyvinyl acetate) AKA Elmer's Glue, Weldbond, etc. I posted recently about this around here somewhere and in some detail on Frog Net. IMHO, next to silicone PVA is something that I would lump together as "least concern" for me. Compared to PVC commonly used with its chlorine molecule and Great Stuff with its very long MDI polymers and possible halogenated molecules, I would be more wary of the other polymers in your background. PVA will break down eventually and is more permeable to water than other polymers. However, it seems to be less of a problem environmentally and would probably still last about 5-7 years. You could coat it with epoxy, but just a read a couple of pages on Bisphenol-A (most common epoxy component) on the EPA's and FDA's websites and its possible effects as a endocrine disruptor/carcinogen and you will probably find much, much more to be concerned about.

$0.02,

Marcos

 

[vet_boy77]

Thanks for your input. I know it's debatable, but my impression is that these things are safe for use in a frog tank. However, for now, my greatest concern is that under high moisture, or splash from the wather feature, the primer loosens and then my nice dirt background melts away or falls apart? Any thoughts on keeping it together longer? The section I tested (after allowing ample time to dry) did seem to loosen significantly after I gave it a heavy spray- enough so that I could start wiping away loose coco fiber.
John

 

[Blort]

John,

There was some good information here:
http://www.poison-frogs.nl/e030223.html

I can't get the page to come up except on Google's cache, but here is his recipe:

Here the full benefit was taken from a Dutch development in tropical vivarium construction, which is also explained in the website of George Cramer. Flevopol is an emulsion of a hydrophilic network forming polymer ( like glue ) which is used in the construction industry to improve concrete floors and structures. It is a Dutch product but there should be enough similar materials around in the world that perform identical. Since the experience in Holland lasts already several years and no bad effects have been seen on the frogs in these vivaria. The mixture i used contained :

1 part of concentrated flevopol
1 part of water
4 parts of milled peat, regular garden grade
4 parts of so-called coco-peat, milled cocos fibres sold as potting material.
First the water and the flevopol were blended, followed by 1 part of peat and 1 part of coco-peat, then blending again. The last part was repeated 4 times until the right substance was reached that was sticky but stable and strong. The cocos fibres provide a lot of structure. As a blender a regular plaster blender was used put in a battery operated drill.
I used 1 litre glass pots as the size of 1 part, at the end about 10 litres of peat paste is made this way.
The application is easy and self explanatory. It sticks to a lots of stuff, one can apply this with gloves, or with a spatulum. Structures can be kneaded and one can cover pipes and wires. When the surface is very smooth the material slids away, therefore some structure is required.
Drying is slow and takes a 4 days to a week. With the mixture i used there was a large part of shrinkage which resulted in cracks of the layers, which gives quite a natural look at the end. Parts were the PUR foam became visible again were filled up several days later.
This sounds like a lot of work, but it was very nice to do !!!

Also of interest is:
http://imageevent.com/audiomaster/40gallonhexagon

There is an email there for someone who has messed with the stuff, so perhaps they could provide some input. If they do, it would be great if you could post it.

Next, you could try to contact George Cramer:
http://www.georgecramer.com/backgrounds3.html

I've heard that he is a very nice guy.

Also, I think bbrock has experimented with the stuff. There is quite a bit of information about it on Frog Net see this post for information and links:
http://www.dendroboard.com/phpBB2/viewt ... sc&start=0

Even when you hear people talk about silicone and coco-fiber, many talk about some of the fiber coming off initially. From the websites above, it seems that multiple layers are involved and pretty thoroughly mixed into a slurry containing several components. Bear in mind that Great Stuff, silicone, and PVA probably aren't ideal as far as bonding to each other since bonding polymers to other polymers is tricky business. If you have the time, I would set up a waterfall directly on the background and run it for a while to see if the results are satisfactory. Also, contacting some of those folks on the websites cited above may give you some 1st hand advice on reducing the amount of fiber that comes off when in contact with moisture.

Best,

Marcos

 

[bbrock]

Just to clarify something. Concrete is alkaline, not acidic. But what we are talking about here is a plastic concrete additive, not the concrete itself. I only have two tanks with the Ace primer mix as backgrounds which have been set up about a year now. From what I can see, this stuff is pretty impervious to water once it cures. One of my tanks has standing water in the bottom in constant contact with the cured bonding background. No signs of softening or degradation there at all. I know the bottle on the primer says something about not being waterproof or similar but remember that those instructions are for the products intended purpose as a concrete primer/bonding agent. We aren't using this stuff for its intended purpose.

I did look up the MSD on this stuff once and didn't see anything that caused any alarm but then again, I'm far more relaxed about such things than many other people.

 

[vet_boy77]

Thanks for all the comments and helpful advice. I think I will continue with viv as is, and place a direct final coat of the Ace concrete primer on the areas that will get a lot of splash, and probably sprinkle with coco fiber to season. Another alternative is to do a final coat of weldbond.
Success or failure, I will write up a nice construction journal with pictures once all this is finished.
Thanks again.
John

 

[Blort]

Here is a snip for an article published today on the BBC website:

A team from Washington State University has produced evidence that some inherited diseases may be caused by poisons polluting the womb.

Research on rats suggests man-made environmental toxins may alter genetic activity, giving rise to diseases that pass down at least four generations.

http://news.bbc.co.uk/2/hi/health/4605847.stm

It will be interesting to see what comes out of this research especially if Bisphenol-B the primary compound in many epoxy mixes is classified as an endocrine disruptor in the ongoing EPA/FDA studies.

 

[Ryan]

I used concrete primar recipe to make my fake tree, the roots go into the water, and have yet to notice any problemsand it has shrimp which are sensitive to chemicals in the water. Has been in there almost a year.

Ryan

 

[Blort]

I don't think concrete primer has any suspected endocrine disruptors in it. The primary concern is some other polymers, primarly epoxies.

 

[Tony Kim]

I've been working on one of my other tanks, I created a stony background with a mixture of ultra lightweight spackling with plaster paris that was very moldable and let that dry for a day and half, then I painted with deco-art acrylic paint (non-toxic), let that dry for 8 hours. I sealed it with a clear gloss polyurthane, that dried for 2 days. I tested by filling the tank up with water and watching for bubbles there were none. So I drained it and placed the plants and moss in. I'm in the process of testing in extreme humidity and checking for chemical odors and degrading. But so far I think the polyurthane is going to be a good sealant for my experiment. I'm going to broaden my creativity when this all works out on my next tank. In a week, I'll post the results here to let you know if it's good or bad.
Tony