matt69olds

I’m kinda in the doghouse. Many relationship experts have said women really don’t want solutions to problems, just for someone to listen. My inner MyGuyver won’t allow that.

My wife has a large assortment of holiday blow molds. In an effort to cut down on the daily repositioning after the wind blows them around, I put a little concrete in the bottom of each one. Which leads to my question.

Does kwikcrete style concrete get heavier once water is added? I bought 4 40 pound bags of concrete and poured what SHOULD have been 20 pounds in each one. Which brings up my question.

If I put half of a 40 pound bag of concrete down each blow mold, I ASSUMED once the water evaporated I would have roughly 20 pounds of concrete in each. That is clearly not the case. These things weigh much more than 20 pounds!!!

On the positive, theft is not going to be an issue. Unfortunately, putting out decorations is now much more involved.

Wonder what Bob Vila would say?

66_Jetstar

Whenever I work with concrete I ask the old lady if she wants a new pair of shoes.

75 W-30 H/O

4R5

The water does not evaporate but mixes with the cement to start the chemical process to form concrete. I'm no chemist or Chem Engr, and I don't know how much water is added to the 20lbs dry cement, but water is about 8lbs per gallon so yes the final mix weight will be more.

Olds64

You gotta post some pics.

allyolds68

As previously noted, the water does not evaporate, it is consumed in a chemical reaction.....

jaunty75

Yes. In fact this is why, in dry climates or on a hot summer day, where the water in the freshly-poured concrete might evaporate before the concrete can cure, you'll sometimes see the fresh concrete being watered with a sprinkler like you would with your front lawn. It's to keep the concrete wet long enough for the curing reaction to complete.

Wet concrete does not "dry." It hardens.

z11375ss

I had to look up what the heck a blow mold was. With your expert tinkering these blow molds are going nowhere in ANY kind of weather. What's not to like? I saw my neighbor's molds on their azzes the other day after some wind. Who's right? You are!

VC455

Here, in round numbers, is the armchair version of the concrete process...

1. To make cement (the active component of concrete), limestone is heated in a kiln to drive off carbon dioxide, leaving calcium oxide. This kiln product is mixed with gypsum and ground to a fine powder.

2. Cement is mixed with sand, gravel, and stones. The cement comprises about 15% of the total weight of the mix. This is the dry concrete mixture.

3. Water is added to the concrete mixture at 1/2 pound water per pound of cement (100 pounds dry concrete plus 8 pounds of water).

4. About 7 out of the 8 pounds of added water chemically combines with each hundred pounds of dry concrete mix to produce set concrete.

5. With time, about a pound of uninvolved water evaporates, leaving 107 pounds of set concrete.

Conclusion... There is some increase in weight of set concrete due to water addition. Not as much as we might think.

BangScreech4-4-2

What's a "blow mold"? It's not what I think it is, is it?

z11375ss

No! Even the Presidential version has changed definitions these days! The one nowadays you put UP your nose.

jackedolds

We have blow molded decorations also. I’ve tried weights if all sorts also. My final solution was to get 1/4” smooth round rod. Cut sections about 24” long (adjust as needed per decoration) . I drilled 9/32 dia holes in the decorations to allow pushing the rod through (so each rod goes through a hole in the side, then the bottom and into the ground). The rods cross so the decoration is pinned to the ground and non-rotatable (like a board toenailed from each side). when it’s time to remove them a vice grip on the rod, twist/twist/pull and they come out of frozen ground. Mine now have no weight inside and reliably stay in place. Good luck with the wife and the concrete!

matt69olds

This is a blow mold.

More examples

matt69olds

My wife has collected blow molds for probably 20 years, unfortunately they have become collectible over the last few years. The days of finding them in garage sales for a buck are unfortunately long gone. We have stated to run out of room for spring them, so now she has to more selective when she does find them.

matt69olds

That explains what I already know. Obviously, the concrete is there to stay now, i definitely won’t make that mistake again.