Mock Rock! - Tutorial Part 1 The Recipe


Afraid of Exorcism
Ok, there's been a lot of talk about home courses and indoor tracks lately. Many different techniques are being used from styrofoam to chicken wire and wood to create the basic structures. The following is a proven formula for a very durable, lightweight surface that can be manipulated to look like any rock or concrete surface.

This recipe may be the perfect solution for the top/final layer.


Many people decide to make hypertufa faux rocks because they find real ones are quite expensive. Though this project isn't too terribly challenging, be aware that this is not an easy 1-2-3 "you're done!" type of procedure. It also requires some creativity on your part.

Suggestions are:
* Study what rocks/boulders "look" like, meaning the pitting, crevices, etc. naturally found. The challenge with this project is obviously trying to simulate the real stuff.

* Get all your materials ready. Have more of the hypertufa recipe ingredients on hand than you anticipate needing. Allow yourself a workspace that can remain a "workspace" for awhile. Again, this project is not an overnight thing.

* If the rock is going to be large and too heavy and/or awkward to move ... cast it in the spot where it will reside.

1. Create your mold/form using styrofoam, wood, chicken wire, etc. An armature might have to be built for structural support on larger rocks or boulders. Reinforce smaller forms, if necessary, to prevent them from collapsing. For example, you can stuff a chicken wire form with wadded up plastic grocery store bags.
2. Refer to this article below for the recipe: Hypertufa Faux Rock Recipe. Be sure to apply your mixture AT LEAST 3" thick to the entire mold.
3. You may begin sculpting at this stage. Many folks use a point trowel for rock veins and a large, highly porous sea sponge for the overall texture.
4. Cure it properly or your rock won't last! Refer to this article below: Hypertufa Curing Guidelines
5. After the initial curing stage, you may want to further enhance your rock by rubbing its surface with a REAL rock that is very rough. Scrape and scrape; wash down your faux rock when done; and allow it to dry thoroughly.
6. Now you can apply a stain, painted finish, etc. to further enhance a realistic appearance.
7. Apply concrete sealer to protect the color and texture for years to come.

If you want to make super tough artificial rocks use this no-fail faux rock recipe:

Hypertufa Faux Rock Recipe
1 part portland cement
1 part builders sand
2 parts peat moss
Acrylic fortifying additive
Optional: Concrete dye colorants
Enough water to make a mud-pie consistency

The acrylic fortifying additive is a "must do" as it helps make the rocks stronger. This product should be readily available wherever you are purchasing your Portland cement. (Quikrete's brand is called "Concrete Acrylic Fortifier" and comes in 1 quart and 1 gallon bottles.)

If you are planning on using your faux rocks around a pond's edge, MAKE SURE you carefully follow this information: How to Properly Cure Hypertufa. You DO NOT want any leaching of lime into your pond's water. Lime is very detrimental to plants and fish!

Make sure you've read this information on how to properly mix hypertufa ingredients. As with any 'tufa project, a successful outcome when mixing up this faux rock recipe is dependent upon the proper ratio of ingredients: Hypertufa Mixing Guidelines: Tips to Help You Avoid Unnecessary Mistakes (see below)

Part 2 on the way, stay tuned...
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Afraid of Exorcism
Mock Rock - Tutorial Part 2 - Mixing Guidelines

Guidelines for mixing Hypertufa
Helpful Tips To Avoid Hypertufa Recipe Mixing Mishaps

There is a procedure for correctly combining your hypertufa recipe's ingredients.

There is no sense in making mistakes during the mixing process. I want you to avoid unnecessary guesswork so that your 'tufa garden art project turns out a success.

To give you an idea of "how much hypertufa does it take to make a …?" Alright, here is a loose rule-of-thumb:

* 30 lbs. of Portland cement
* 1 cubic foot compressed peat moss
* and 1.5 cubic feet of perlite

... should yield enough mixture to make an 8-inch x 12-inch x 12-inch trough.

If you're mixing up a large quantity of one of these hypertufa recipes, divide the mixture into smaller batches to make it easier to blend.

- Measure the dry ingredients into a large container such as a wheelbarrow. Use a shovel, concrete trowel, garden hand trowel or similar for mixing.
- Make sure all ingredients are thoroughly blended before adding water. Mix and blend more than you think you need to!

How Much Water Is Enough ... Or Not Enough?
Add The Water Slowly ... You Can Always Add More

How do you know what is enough or not enough water? There is a pretty good test you can do and I'll get to that in a second. I just want to mention this for your benefit:

There are many variables that will affect the amount of water needed for each hypertufa recipe. It might be that the peat moss you're using on a current project is much drier than what you used on a previous project. The humidity may be much lower/higher than the last time you did a project.

The APPROXIMATE amount of water needed MAY or MAY NOT be 1 to 1-1/2 parts water (in relation to the dry ingredients "parts"). Be on the safe side, slowly add your water to your thoroughly blended dry mix. Add water until you have a damp mixture. One that is not crumbly but also not oozing with water.

Next, take a 10 minute break from the whole mixing process. Let the water "soak in" a bit.

After your 10 minute break, begin to blend and stir everything again. Make sure your hypertufa recipe is equally moistened.

Test your mixture for the proper consistency by taking a handful of mix. Squeeze it into a ball that will hold together when you open your hand. A little bit of water can slightly ooze between your fingers. Remember that this mixture must be able to cling to your mold and stay put and not start sagging.

Part 3 on the way ...
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Afraid of Exorcism
Mock Rock - Tutorial Part 3 - Curing Guidelines


Don't Rush This Step or You'll End Up With a Disaster On Your Hands!

Many people have had the sad experience of having their project start to crack, crumble or not even set solid. It just starts falling to pieces soon after it starts to cure. And many remain baffled as to why it happened.

They followed the recipe to a "T", but after they applied the mixture to the mold, everything seemed to start going downhill from there. Although it's said that making hypertufa is almost as easy as making a "mud-pie", there are some important facts to know that will greatly increase the odds that all your 'tufa projects will be successful.

Even a few minutes without the right level of moisture can cause severe cracking
and the loss of many hours of work.

Unfortunately, even a slight breeze in your workspace can rob enough moisture from your mixture to cause it to fail. The less air movement around you, the more moisture you'll keep in. Avoid breezes while you are working. Sorry, you definitely don't want to have a fan pointed at yourself to stay cool while you're working on your project!

If you are doing your hypertufa project outside, dealing with breezes can be frustrating. Mother Nature isn't very accommodating in letting us know when a breeze or gust of wind will happen. Try to find a sheltered spot you can work in.

The Mixture is Applied and Your Object is Ready … Now What?

You've applied all the hypertufa mixture and are happy with your garden art object so far. Great … you're moving along in the right direction.

Here's your next step: carefully place your object into a large black plastic trash bag (or similar) and seal it up tightly. (If your object is too heavy to lift, then do your best to cover with black plastic. Keep in mind you are trying to retain moisture to help the object dry slowly.) Plastic trash bags, plastic roll sheeting, anything that is air and moisture tight will also do the job.

* Additional step: many 'tufa makers will thoroughly mist the object with water before sealing up the bag. There is no exact science to anything regarding hypertufa. That includes the "best way" to cure it. It's frustrating, but the truth is while one technique may work for one 'tufa maker, that same technique may not be successful for another. Trial and error will show you what works for you.

Seal the bag as air tight as possible. You may want to inflate it a little to help keep it from touching (and possibly making an unwanted impression on) your object's surface.

SUN OR SHADE for the Best Cure?

Two Options That Will Work In All Types of Climates

Two Options: Place It in Direct Sunlight or
Keep It In The Shade ... Either Will Work

Here we go again … one hypertufa maker swears by one method, and another says "I've never had to do that. My pieces always come out great". OK, take your pick. Try it either way. These both work, and depending upon how large an object you've made, the spot you are able to leave it undisturbed during the curing process and other factors like these, will determine which method you will use or have to use. It's up to you.

If you cannot place your project where it will receive direct sunlight, fine. Your next step will be to periodically open the bag, mist the surface to keep it moist, and reclose (or recover your larger object) after misting.

If you can place it where it will receive direct sunlight, that's fine, too. Try to put it where it will get as much direct sun as possible. Because the bag is sealed, it creates a very hot environment. The heat will cause a lot of moisture to be released from the hydrating cement. The moisture will condense on the inside of the sealed black plastic bag and now you have an "automatic" water supply that will help keep your object properly hydrated while curing. A built in "mister".

This First Stage of Curing Lasts About 2 to 4 Days
How long does it take a hypertufa project to dry? It depends upon the humidity and temperature. And … the recipe you used; also how thickly you applied the 'tufa to the mold. This is why making hypertufa is not a set of cut and dry rules. Experience in experimenting with recipes and different types of projects brings you the expertise.

After approximately 24 hours you will want to test your new, and still curing, hypertufa object. Carefully open the bag (or uncover) and see if your fingernail can scratch off any 'tufa. If you can, seal it back up and wait another 12-36 hours. When you can't really scratch any off (without some difficulty), you're ready to unmold your object. Your object is still a bit fragile! Remove from the mold carefully.

* If you want to add texture to the object's surface, you need to do that now before you move on to the next step.

Caution: when handling damp pieces you should wear your gloves! Your hands need to be protected.


You Can't Rush The Cure So Relax! Give Your Project The Rest It Needs :-)

Gingerly place your object back into the plastic bag and seal tightly. You can now keep your object at room temperature. Continue to keep it moist, misting occasionally if needed. Allow it to cure for at least another week but the longer it can slowly cure in a moist environment, the better.

At this point, most 'tufa makers will keep the object bagged up for a month or more. (I've seen it written that a one month cure time can result in 25% stronger 'tufa). You need to be patient. The longer and more slowly it can cure in a moist environment, the stronger your hypertufa will be. Curing will also take longer at cooler temperatures.

Alright, now you're ready to get rid of that black plastic bag! Your new garden art object can be removed and left until it is completely dried ... you'll know if it sounds hollow when tapped.

You're not quite done yet. There is one more important thing to consider ...

Cured Hypertufa is Very Alkaline
Due to the Portland cement, the 'tufa ends up being very alkaline. If you have ever seen a white powdery residue on new cement, that is the free lime leaching out. This lime causes the alkalinity. Most agree that the lime is toxic to most plants and therefore needs to be leached from the object if you are going to use it as a planter.

You can find many varying methods on leaching out the lime. Follow an easy method: Soak 'tufa in a larger container of fresh water. Change the water every day for 3 days. It is plant safe by then.

Note: The lime can still burn your skin so wear your gloves. If the planter is too large to fit into another container, I'll hose it down once or twice a day for 3-5 days.

Other recommendations are to leave the planter outside for 1 or up to 2 months, allowing it to weather naturally by being rained upon. I've even read of leaching baths concocted from various chemicals -- and chemicals that are not very user friendly. I've read of others spraying down the hypertufa with household vinegar. I wouldn't consider the chemical or vinegar suggestions as satisfactory methods.
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Supporting Member
The build up at the house starts June 22nd.
I plan on taking lots of pics and adding to the tutorial as we go. After seeing Martina create flower pots with this stuff, I know its super lite and durrable.


Holy moly, if you two are building a rock "garden", this is gonna be amazing....It looks like less work to haul twenty tons of rock and dump it in the backyard out of a pickup bed.

Tell you what, we'll start building yard courses at the same time and I'll do it the real rock way and you guys build it and see who gets done faster!



Supporting Member
I agree dumping a pile of rocks in place is much easier but there are advantages to building structures like this. I'd say most of all is the fact that they're potentially portable. In a situation like ours there will be a 40' x 20' area dedicated to RC, however when we decide to sell, not every potential buyer may want a RC proving ground in the yard (I would but...) This may also work well for Hobby Shop owners, indoor events or even Condo dwellers.

Either way, I'm down for another competition, possible the Home Course Throwdown next?


I shall Throwdown a rock garden commencing on the 22 June, Two Thousand and Eight. With pics. :lurk:


mock rock

now that looks like fun ..and when your finished you can crawl on it ..i think this is perfect for apartment balconies a such ..good idea mutha

home coarse throw down has a nice ring to it..


Supporting Member
Holly crap, we've got ourselves a duel!
This why I stopped doing dares! LOL
We'll start another thread for it so we don't mess with MB's thread, she's shaking her head at me!


New member
I made a few rocks a little over a year ago and the largest one is showing some fine cracks. So I have a couple questions as I want to add another large rock . Granted the cracks aren't large or unsightly but I would prefer they didn't grow.
1. Is there a different mix I can use to resurface and stabilize the surface with?
2. with large rocks, is there a different mix or curing process?
Thank you in advance.



Supporting Member
I'm honestly not sure, the pots Martina made are still intact but I can't speak for my old crawler course as we sold the house 3 yrs ago. Wish I had more advise for you.... nice lookin rocks though!


New member
Thanks, I'm hope there's a Mason in the group who has an idea or two. I would like to figure it out before I start another large one ( a bit larger than the last ) but with a better driving surfaces.