Using a lathe for woodturning or metalworking is lots of fun. But over time, your lathe tools will get dull. Dull tools make cutting more difficult and can leave rough finishes on your work.
The good news is that sharpening lathe tools is a skill you can learn! With some basic tools and practice, you’ll be able to keep your lathe tools razor-sharp.
In this article, we’ll teach you everything you need to know as a beginner about sharpening lathe tools by hand. We’ll explain why sharp tools matter, walk through the sharpening process step-by-step, give tips for success, and answer common questions. Let’s get started!
Why Bother Sharpening Lathe Tools?
When you’re excited to get turning or machining, it can be a pain to stop and sharpen tools. So why bother spending the time and effort? There are 4 big benefits:
1. Your Tools Will Cut Better
Think about trying to cut paper with a dull pair of scissors versus a sharp pair – big difference! The sharper the edge, the easier it slices through whatever you’re cutting. Same goes for your lathe tools. Sharp edges let your tools remove material faster and with less force required by you.
2. You’ll Get Better Results
Dull tools are more likely to tear out chunks or leave scratches and rough areas. When your tools are razor sharp, they cut through the wood or metal cleanly without grabbing. This leaves a smooth flawless surface. The sharper the tool, the finer polished cuts you can achieve.
3. It’s Safer
Trying to force a dull tool through dense wood or metal increases the risk of it catching or binding. This can cause the tool to jerk out of your hands or break. Very dangerous! Sharp tools cut cleanly with less sticktion reducing the chance of accidents.
4. Your Tools Will Last Longer
Using dull tools requires applying extra pressure. This strains the metal and causes faster wear and tear. Regular sharpening reverses the damage from use, extending your tool’s lifespan significantly. The less wear your tools incur, the longer they’ll last.
So in summary, keeping your lathe tools razor sharp makes cutting easier, gives better results, reduces safety risk, and keeps your tools lasting longer. That’s why it’s worth taking the time to sharpen properly!
Sharpening Equipment You’ll Need
To sharpen your lathe tools at home, you’ll need just a few important items:
Grinders use abrasive wheels to reshape and grind away metal on the lathe tool’s edges. This quickly repairs damaged edges or changes the angle. For lathe tools, you’ll want:
- Bench grinder – A stationary grinder with a motor that spins the wheels. Look for a model with adjustable tool rests.
- Angle grinder – A handheld grinder that’s useful for sharpening awkward shaped tools.
- Grinding wheels – Replaceable wheels for grinding metal. You’ll need coarse grit for heavy grinding and fine grit for final sharpening.
After grinding your tools, you’ll use a sharpening stone to hone and polish the edges. Some good options are:
- Diamond stones – Plates coated with industrial diamonds that cut aggressively. Use medium then fine grits.
- Arkansas stones – Natural quarried stones that give a smooth polished edge. Progress from coarse to hard/translucent.
- Diamond cards – Small credit card sized files with diamond coating for portability.
- Stropping compound – Abrasive paste applied to leather for final polishing.
Angle Measurement Tools
To replicate existing edge angles when sharpening gouges or skews, you’ll need:
- Protractor – For measuring and reproducing existing bevel angles.
- Wolverine jig – Holds tools at preset angles. Popular accessory for grinders.
- Angle blocks – Precise blocks for checking angles.
Some other useful items include:
- Magnification – Like an optivisor, headset magnifier, or loupe for inspecting edges.
- Edge radius gauges – Templates for checking/matching the edge roundover.
- Cutting fluid – Used when grinding to prevent overheating that damages the metal’s temper.
- Leather stropping paddle – For applying stropping compound to polish edges.
Step-by-Step Sharpening Instructions
Now that you understand why it’s important to sharpen and have the needed gear, let’s walk through the actual process in 6 key steps:
Step 1 – Clean Your Tool
Before sharpening, its important to remove any debris, sap, grease or rust from your lathe tool. Here’s how:
- For wood turning tools, use acetone or mineral spirits to remove buildup.
- For metalworking tools, remove rust with a wire brush or steel wool.
- For any tool, scrub with dish soap and warm water then fully dry.
Proper cleaning exposes the metal and helps the sharpening be more effective.
Step 2 – Examine the Edges
Next, carefully eyeball and feel the edges of your tool to check for:
- Rolled over edges that need grinding to repair
- Large chips or gouges in the metal
- Cracks near the edge that require grinding past
Use magnification to get a really close look at the edge. Know what needs addressed before you start sharpening.
Step 3 – Re-shape on a Grinder
If your tool is very dull, has damage, or you want to change the geometry, you’ll need to re-shape it using a grinder:
- For a bench grinder, ensure the tool rest is secured near the wheel and properly adjusted.
- Position tool against the rest and gently move side to side through the grinding wheel at an existing or new angle.
- Apply cutting fluid or dip in water to avoid overheating the metal.
- Grind evenly until original shape is restored. Match angles of existing bevels.
Go slowly and check often. Follow jig angles if needed. This step removes a lot of metal.
Step 4 – Refine the Edges
Next, refine and polish the edges using a fine grit grinding wheel, diamond stone, or hard Arkansas stone:
- On a grinder, use a fine 120-180 grit wheel to straighten and smooth edges.
- With a stone, use medium then fine grit progressive grades. Lubricate the stone with water or oil.
- Scrub stone back and forth along the bevel using even, consistent pressure.
- Remove all previous scratches, and blend together new bevels.
- Deburr edges by drawing the blade across the stone trailing edge first.
Step 5 – Micro Bevel With Finishing Stones
The final step is adding an extra-fine “micro bevel” along the very edge:
- Use a leather strop charged with polishing compound.
- Or an extra fine 800-1200 grit ceramic stone or translucent Arkansas stone.
- Lightly sweep tool along stone using the existing bevel angle, just barely raising it.
- This micro bevel strengthens the razor edge and polishes to a mirror-like shine.
- Remove any burr by gently dragging edge trailing across leather or stone.
- Clean tool and inspect edge under magnification. Repeat steps if needed.
Step 6 – Verify Sharpness
The final check is verifying the edge is freshly sharpened and razor sharp:
- Carefully run a finger perpendicular across the edge to feel for a burr or roughness
- Slice through paper or shave a bit of soft wood
- Visually inspect for reflective shine indicating a polished, honed edge
Now your tool is ready to use! Follow this process whenever your lathe tools need some TLC.
Tips for Successful Sharpening
With practice, you’ll develop skills and confidence sharpening lathe tools by hand. Here are some tips to help you along the way:
- Permanent marker – Use a marker to blacken edges first. Makes it easy to see where metal is being removed.
- Cutting fluid – Dip tools often in water or cutting fluid when grinding to prevent damaging steel from overheating.
- Grind evenly – Alternate grinding evenly side to side to avoid uneven bevel angles.
- Diamond card – Use this for touch ups between full sharpening sessions.
- Burr removal – Draw blade edge trailing across stones and leather to remove any burr.
- Freehand – Try freehand sharpening for speed but use guides and jigs if needed for consistency.
- Take notes – Document what works to replicate results and improve each time.
Be patient with learning this skill. With some effort, you’ll soon be able to quickly restore ultra sharp edges. Your tools and projects will thank you!
Frequently Asked Questions
Here are answers to some common beginner questions about sharpening lathe tools:
What sharpening stones should I get?
Start with a medium 300-600 grit diamond stone for major sharpening. Add a fine 800-1200 grit ceramic or Arkansas stone for final honing. A leather strop with compound is also highly recommended.
Can I use sandpaper instead?
Yes, but it wears out quickly. Silicon carbide wet/dry paper around 400-800 grit is a low cost option that works in a pinch. Get the highest quality you can.
How often should I be sharpening tools?
A rough guideline is to sharpen roughing gouges after 1-2 hours of use. Finishing gouges may go 4-6 hours between sharpening. Scraper and parting tools should be touched up as soon as any dulling is noticed.
What are the signs a tool needs sharpening?
Needing extra downward pressure, rough/torn finishes, or needing to run lathe slower are all signs a tool should be sharpened. Doing it before tools get really dull saves time.
What causes lathe tools to get dull quickly?
Cutting dense exotic woods, using abrasive additives, too high lathe RPMs, dull tools to start with, and cutting dry can all accelerate dulling. Proper lubrication and tools helps.
Any final tips?
- Make sure to wear eye and hand protection when grinding
- Invest in quality jigs and fixtures to guide tools
- Master your grinder tool rest adjustment and alignment
- Take your time and regularly inspect edges
- Enjoy the process – sharp tools are so much nicer to use!
Let me know if you have any other lathe tool sharpening questions!
The ability to effectively sharpen your lathe tools by hand is a valuable skill. With some basic equipment, a systematic process, and regular practice you’ll be able to keep your chisels and gouges razor sharp.
Remember these key points:
- Sharp lathe tools are safer, easier to use, and leave cleaner finishes
- Grinding repairs edges, while honing and stropping refines them
- Match angles and use progressive finer grits
- Establish a routine sharpening schedule for each tool
- Master freehand techniques but use jigs when needed
It may take some trial and error to get comfortable with sharpening by hand. Stick with it and you’ll soon be rewarded with tools that cut like butter and leave flawless surfaces! Let those lathe chips fly!