Polishing stones is a fun hobby that leads to beautiful results! You can do it by hand with little equipment or invest a little money in a stone sifter, which allows you to polish dozens of pieces at a time. When finished, you can arrange the stones around the house to show off your new skill!
Steps
Method 1 of 2: Polish the stones with sandpaper
Step 1. Choose the right stone
You can polish any stone you want, but there are some features that make one piece more suitable than another. If you want a material that is easy to polish, go for something soft, like onyx, calcite, or limestone. Very hard stones need a longer process, nevertheless they become much brighter than softer ones.
- To understand if a stone is soft, scratch it with another stone; if you get an engraving with a plaster-like texture, the stone is soft.
- You can also choose a stone with a rounded shape without protrusions or notches.
Step 2. Wash the material
If the stone is dirty, clean it carefully using soap and water. Get a brush to get rid of stubborn dirt and debris; when finished, dry the surface by dabbing it.
Step 3. Model the stone
If you want it to be rounder, use a small hammer or chisel to remove a few pieces of material. Wear safety goggles to protect your eyes from splinters and use gloves if you wish. Remove any protrusions or sections that protrude.
- If you are happy with the shape of the stone, don't worry about shaping it.
- You can also rub it over a cast of concrete to remove any bumps.
Step 4. Sand the stone with 50 grit sandpaper
This is the rougher type of sandpaper and is perfect for further shaping the material. Rub the sandpaper over any bumps or bumps you want to smooth out. If you are happy with the natural shape of the stone, sand it all over with 50 grit sandpaper to even it out.
Step 5. Use 150 grit sandpaper to remove scratches
Take the stone and smooth it with this type of paper. You will have noticed that the previous emery paper (the 50 grit paper) left some scratches; works the surface to smooth it and erase these marks.
Step 6. Switch to 300 to 600 grit sandpaper
Smooth the entire surface of the stone, focusing in particular on the scratches left by the previous processing. This type of emery paper is very fine and leaves no scratches, but allows you to correct the imperfections left by the rougher ones.
Step 7. Rub the stone with a piece of leather and polish
When you have finished the sanding phase, make the stone shiny with a leather cloth and a tube of polishing product. Both of these materials are available at home improvement stores if you don't already have them. Put some product on the leather and spread it on the stone; by now, it should have become beautiful and shiny.
Be careful not to buy a colored polish, otherwise you run the risk of staining the stone
Method 2 of 2: Using a Tumbler
Step 1. Purchase a sifter and abrasive sand
These tools are perfect for polishing stones, because they give a more defined shine than working by hand and can hold several pieces at a time. You can buy a stone tumbler online at websites like Amazon. Remember that the price is extremely variable, so buy a model that meets your needs. You can also choose a tool that uses a medium (220), fine (400) or very rough (80) grit medium.
A cheap plastic sifter is a good option if you only want to use it occasionally. Consider spending a little more if you plan to turn stone polishing into a new hobby
Step 2. Choose and select the stones
Before polishing them, divide them to insert batches of homogeneous hardness and shape into the tumbler.
- You do not have to put stones of different hardness in the cylinder, because the more resistant ones can wear and scratch the softer ones. You should also avoid working with very different shaped elements in a single session, such as round stones with other jagged ones, because those with an irregular shape polish at a slower pace than the rounded ones.
- Try to put stones of varying sizes in the tumbler; in this way, the pieces reach a more uniform shape.
Step 3. Fill the tool half or of its capacity with rocks
First, wash the pieces with soap and water, then put those with similar hardness and shape into the sifter. Take them out of the cylinder again, weigh them and put them back inside.
Step 4. Run the tool after inserting abrasive sand
Weigh 45g of abrasive material for every 450g of stones you put in the cylinder; afterwards, add water until its level reaches the base of the upper layer of stones. Secure the instrument cover and start the engine; leave the tumbler in action for 24 hours and then open it to check the process; then put the lid back on and turn it on again.
- Let the tumbling process go on for 3-7 days, monitoring it every 24 hours to make sure it is proceeding as expected.
- Rough abrasive sand shapes the stones. If these are rounded enough, 3 days of processing are enough; if they are quite irregular, you will need to leave them in the cylinder for up to 7 days to get an even result.
- Checking every 24 hours allows you to evaluate your progress. After the inspection, you can decide if the stones are ready for the next step or if you need to work them for another day.
Step 5. Remove the stones from the tumbler
After 3-7 days, you can take them out of the tool and transfer them to a pan. Remove the sand residue from the stones and clean the inside of the cylinder. Do not throw the abrasive material down the sink drain, as it solidifies and causes obstructions; throw it in the trash instead.
Thoroughly wash the stones and the tumbler until they no longer have any stains. Even the smallest residue of abrasive material can ruin the next part of the process
Step 6. Operate the cylinder after adding medium grit abrasive sand
Fill in the same amount of abrasive that you used earlier. Pour the water until its level reaches the base of the top layer of stones. Seal the lid and start the sifter; leave it in action for 4-5 days checking it every 24 hours.
- After 4-5 days, stop the car and check its interior. Transfer the stones to another container and discard the abrasive medium.
- Also at this stage, you need to make sure that both the tumbler and the stones are perfectly clean and that you throw the sand in the garbage, not the drains.
Step 7. Run the tool with the fine abrasive sand
Put the clean rocks in the cylinder, always add the same amount of fine sand and pour the water until its level reaches the base of the lower layer of stones. Close the machine with its lid and leave it in action for 7 days. Check the processing every 24 hours.
This is the last step in which the abrasive medium is used, so do not reduce the duration of the processing until you are satisfied with the result both in terms of brightness and the texture of the surface. During the checks it may be necessary to clean the stones, to evaluate their brilliance
Step 8. Clean the barrel and rocks
Be thorough in this task; make sure you have removed all the sand from the cracks, otherwise the tool may not perform at its best in the future. When you remove the sand from the stones, you will notice that they are shiny and shiny!
Step 9. Perform the final polish
Sometimes, soft stones don't get as shiny as you would like with tumbling alone. Add the finishing touches to those pieces that need some shine, using a leather cloth and some polish. Put some polishing substance on the cloth and scrub the entire surface of the stone. Give the stone the brilliance you want!
Advice
- To find stones to polish, go to the beach or buy some semi-precious gems.
- Remember to clean the tumbler thoroughly, otherwise it will get full of debris and will not work properly.
