Clay in Newfoundland

Hi My name is Dave
From Newfoundland

    I am very new to this ( and I am a little nervous here ) but REALLY want to build a rocket stove this year.
What I am hoping to find here today is someone from this area that could give me a few hints.. Someone that may have done this before.

  I am trying to find a source for clay in the Avalon area.  I found some red looking soil and put it in a jar of water, but it look too sandy.

Thank you for your time.
 Dave

Hi Dave,   I am not from Newfoundland but when it comes to finding your own clay, there are some basics that I'm sure would apply to any area.
As for the jar test, after all the soil is well saturated with water (no clumps) and you shake it one last time, how long does it take to settle out? If it all settles out in lets say 10 minutes then probably no clay. Adding about a teaspoon of salt to a mason jar sized sample reduces the settling time considerably.
After a rain is when I go looking for new clay sources -  try the 'worm' test by rolling a small amount of soil in your hand and then make a knot with it...how well does it hold together before breaking? The more clay there is, the more it will stay together and be very pliable.
Any soil where the rain pools and stays for several days afterwards is a good indicator of clay. When this same pool area dries up, does it have many fissures and cracks indicating clay?
Clay also has a dull sheen to it when moist and of course is sticky when wet and hard when dry. Road cuts or any exposed subsoils are good places to look as it helps eliminate the need for too much digging past the topsoil layer.
For building a rocket stove, you won't need a large percentage of clay in the soil (from 10 to 30 percent - depends on your soil) but sometimes you need to mix two soils together to get the right mix. Test bricks will help with this once you get going.
Of course there are many videos, books and info out there you can research as well but thought I'd throw a few pointers out to get you started.

Thank You, Gerry, for your quick reply.


Yes the jar of water settled in less than 10 mins with about 1 1/4" of sand with about 3/8" of light brown stuff at the top.
So is it correct to say that if you remove the top soil and under it very hard gray or red dirt  ( not sand or gravel ) then it more than likely clay?

We are not from here we moved here about 12 years ago and as you know many of the terms are different ( Newfinese ) so anyone I try to ask about clay they think I mean potting soil.
I may also have trouble finding straw as there are not many farms here. Hay yes I can find this everywhere, but I don't know if it would be a suitable alternative.

I believe I can use most anything for the mass storage bench as long as it doesn't have insulative property, ( packed dirt or fine pebbles ) but can I use refractory cement to hold the fire bricks in place? If I can't source clay?

I do have "the rocket mass heater builder's guide" book that I am slowly making my way threw.

So is it correct to say that if you remove the top soil and under it very hard gray or red dirt  ( not sand or gravel ) then it more than likely clay?  

I don't know any foolproof way just by sight or description alone that will prove a soil has clay in it. It could also be silt which is very fine sand. Use the characteristics of clay to prove itself to you by performing the tests I mentioned earlier. Another test I just remembered is to grab a handful of fairly wet soil and squeeze. Does it extrude between your fingers in fairly nice ribbons (presence of clay) or just kind of crumble and fall apart? (little or no clay)

I may also have trouble finding straw as there are not many farms here. Hay yes I can find this everywhere, but I don't know if it would be a suitable alternative.  

Hay is not used in cob or as a building material as it is very likely to mold and deteriorate quickly. If you can't find a source for straw, while you are out on your clay finding walk, you could test various grasses and fibrous plants along the way (dead from last year - again, no green or fresh plants as they will deteriorate as well) by grabbing a small handful and pulling and twisting. If they break easily move onto the next candidate. I have collected dead plant matter either in the fall or early spring. Summer is usually not a good time as last years dead plants have usually decomposed too much to be strong enough for tensile strength. Last year I found some reeds that worked really well for me.

I believe I can use most anything for the mass storage bench as long as it doesn't have insulative property, ( packed dirt or fine pebbles ) but can I use refractory cement to hold the fire bricks in place? If I can't source clay?  

Refractory cement is but one way to go, just make sure its rated for very high temperatures say (2000 F +) . You could also buy a bag of fire clay which will work as well. With clay, its much easier to take your stove apart to try other brick configurations without having to chip off the cement and possibly damage your bricks.

I do have "the rocket mass heater builder's guide" book that I am slowly making my way threw.

My first book was Rocket Mass Heaters  -Superefficient Woodstoves YOU Can Build by Ianto Evans, Cob Cottage Company. I would recommend this book as well. More aimed towards building with what you have or can get for free or cheaply.