|We've worked with the type of lava called "feather rock" for many years now. We find it very interesting and easy to work with if you're patient. Although feather rock is available in many parts of the US, you may have to do a little research to find it and a little traveling to purchase it. Large landscape suppliers are starting to carry it more and more, though it is likely to be a seasonal item. So if you plan on playing with it during the winter, better pick up your supply while it's available in the spring and summer. |
All lava rock is not feather rock. Our friends in Hawaii have tried to carve and drill the lava there and it is very hard and brittle. Feather rock is very porous, which is part of the reason it's so easy to carve.
Before starting work on your feather rock, we can't say enough about safety. Goggles are imperative, as are gloves. Chips and slivers of dry feather rock are like glass... and getting even a small piece in your eyes could be disasterous. Getting it in your hands isn't fun either.
One way to cut down on flying debris is to soak the rock you intend to carve completely immersed in water for an hour or more. Doing this also makes the rock easier to work with.
Almost any sharp object can be used to carve feather rock. Our favorite tool is a chipping hammer. It is a chisel like tool with two different chisel points and a shock absorbing handle. You can also use masonry bits to drill and carve holes and caves. We mainly use the chipping hammer because you can chip lightly and accurately, not taking too much rock off at a time.
When we find a rock we like ( or we break one off of the large boulders we purchase) we find it's best side and drill a 5/8" hole all the way through it with a 10-12" masonry bit and an electric or cordless drill. Then we mount our rock on a pvc stand.
We look for the most natural places in the rock to build and chip out pools, spill ways and stairs... Patience is the keyword here... chip slowly. If you need to, attach a pump to the rock ( we use 1/2 ID, 5/8" OD tubing, set it in water and watch how the water flows. Are there places in the rock where if you carved them out you would have a pond?
Is there enough rock to have two pools, one spilling into another?
Running water over the rock will give you an idea of what to do with it using its natural shape.
All feather rock has natural faults in it. It's a good idea to look a rock over carefully before you start carving. Decide what you want to do with it and try to use the natural make up of the rock to help you decide where and how the best place to carve into the rock is. Once in a while a rock may completely break in half or more pieces when being carved. This may have been a result of banging too hard on the rock causing it to break at a weak spot. The softer the rock, the more faults it will have.
If you have an opportunity to choose your rock from a large pile, pick up a few pieces and look at them from all angles. You will notice that some of it is heavier. These heavier pieces will be harder and take more time to carve, but will be less likely to break in the process. The lighter pieces of rock will carve a lot easier, but you will need to be more careful with your chipping...it will break easier. If you see rock with pink streaks in it and this is your first project, avoid it. The pink rock is almost impossible to drill through, and if you're trying to drill a hole for tubing, the pink layer will cause you great grief.
Make a mistake? Chip off a large piece that you didn't want to or put a hole where you wanted to have a pool? Use silicone or E-6000 to glue the pieces together. For holes, use clear plastic, such a piece of a sandwich bag, make a patch, glue it to the rock. When it's cured, cut off the excess, spread more E-6000 over the plastic where it will be visible and sprinkle the material on the E-6000 until you can't see the patch. Use loose material that has fallen from your carving that is the same color of the rock where you're making the repair
Well... if you've been wanting to try working with feather rock, you should be able to get started now. Go out and buy a few pieces and practice carving. Don't forget the glasses and gloves.