4 replies to this topic

[noebl1]

I've been trying to help Kevin with an issue with Hydrostone that I'm not seeing, and not sure what I am missing.  In 2016 I purchased from The Plaster Guys on eBay supposedly "Hydrostone", and have been using it for the last couple of years.  He also purchased from the same store, but I don't believe it's as old. I keep mine stored in it's original double bag it came in, and I clip it shut (so not overly air tight.) 

 

When I pour hydrostone, I find it gets warm (not terribly hot) typically as I am massaging the bag of the mix.

 

Kevin and I are both using BoxBox containers, and he's finding when he pours, the hydrostone tends to expand and warp the same BoxBox containers I am using.  It's sometimes also is cracking for him I believe.  He mentioned he's read some posts from Drew saying he's had to deal with expansion with hydrostone.

 

Here's what I do:

 

1.  With a new container, I add the powder to get a rough measurement of the level I want (Usually do this once and note it down to repeat later)

2.  I put a baggy on the scale, zero it out, and add the hydrostone powder out I just measured to the bag and weigh it
3.  I divide that value by 3 to get the water weight needed
4.  I put a cup on the scale, zero it out and add that weight of water
5.  I add the water to the baggy with the powder and mix in the bag for a couple of minutes
6.  When evenly mixed (kinda gooey like batter, but pours), I cut the end off the bag, and pour it into the container. At this point it's slightly viscous, so I can tip the container back and forth to make sure the bottom is covered, but I can also make one side higher than the other by just tilting it in the air for a moment (so it's not propped up.) 
7.  After about 5 minutes, I add the test tubes to add their notches for later placement.  At this stage, often a thin film of water has raised to the top
8.  I wait until it dries, pop the test tubes out and done, maybe a bit of clean up if I spilled on the sides (which wipes off in pieces if really thin)

 

I don't see any problems with warping or expansion as it sets after 20mins or so.  I have inadvertently added too much water by messing up my weighted cups, but I didn't see any warping, just took a lot longer to cure.   I also find if I pour a bit thicker into the box (maybe 1/3 of an inch), I can see thru the clear bottom the thicker areas may take up to 24hrs to fully dry.

 

I am trying to figure out if I really got Hydrostone, if the age of my Hydrostone is affecting my results, how much hydrostone I am adding, or something else I am doing is making it work well for me and not for Kevin.  I appreciate any insights from others who have worked with Hydrostone may have.

 

Thanks!

Edited by noebl1, June 19 2018 - 7:16 AM.

[YsTheAnt]

Perhaps he is putting too much? I remember somewhere Drew mentioned he only puts 1/8 of an inch of hydrostone at the bottom of the containers.

I believe Drew also said that he put masking tape around the container before pouring the hydrostone to prevent warping.

[noebl1]

That's the weird part, I put in about 1/4" of an inch at times as I've been playing with levels to find one I like, and never had an issue.  It's weird.  Making me doubting they sent me the right stuff

[Kevin]

As Drew has said to me previously he uses 1/16" for the hydrostone floors (if I recall correctly), and squeezes the sides of the container together then tapes them while the hydrostone cures. This prevents it from bowing too far outwards while the curing takes placed.

 

Unfortunately, this does not always work for me and there is often a small enough gap for some ants to escape, or come close to escaping (squished in the side of the boxbox lid). When I pour the hydrostone thin enough, the bowing does not occur but the hydrostone warps upwards and cracks if you put any downwards pressure on it. I find it may take up to a week for the warped floor to occur and the hydrostone may be level for days after curing. The gap left between the bottom of the plastic container and hydrostone floor is enough for ants to nest in if there is a hole or crack in the floor. If I pour the hydrostone thicker, it doesn't have this warping effect but bows the plastic container as previously mentioned.

 

The whole matter is very annoying to deal with and I may switch to another gypsum cement or other casting materials for outworld flooring - like resin. Although resin is another whole book of problems including it's toxicity to small ants.

Edited by Kevin, June 19 2018 - 12:39 PM.

[nick2253]

That does sound like an annoying problem!

 

I'm struggling a little bit to understand some of the details.  Based on my experience with hydrostone, I would expect it to expand no matter how little you pour.  If you have a strong enough container (or reinforce the container appropriately) or a small enough amount of hydrostone, you can avoid any container bowing.  But it will still expand to some degree.  I'm wondering if your hydrostone is not drying evenly, causing the warping.

 

My confusion comes from:  how are you getting a gap at all? I would think the only way you're getting a gap is that you're compressing the sides more than they would be "naturally", and when you release that compression, you're creating the gap.  One strategy that you might try is just adding some tape or rubber bands (or some similar reinforcement) to the container prior to pouring the hydrostone.  Don't try to compress the container, just reinforce it.  Then, if all is good, you should get a slight amount of expansion that will be mostly contained by the reinforcement, so if the sides are pushed out, it's only slightly, and you should have no gap.

 

Another solution to the gap is to pour some additional hydrostone around the edge to fill the gap, after the first layer has dried.

 

On the warping problem, have you tried some controlled drying?  If your oven can go cold enough, that's a good way to dry.  You could also try a hair dryer.  I would also double check your mixing ratio.  You might see if you can get away with slightly less water.  Another strategy that I've used in the past to both improve strength and improve looks is adding some sand and/cement to the mix.  This might also help with your warping issue, especially the sand if the problem is related to drying.