How I Use the Ruth Niles Bottlestopper Mandrel System in the Workshop
- David Condon
- Mar 27
- 10 min read
I’ve been turning for a good number of years now and, like most woodturners, I’ve tried more than a few bottlestopper systems along the way. Some worked well enough, some didn’t, and a couple caused more frustration than they were worth, blanks running out of true, threads not seating properly, and pieces that just didn’t feel right on the lathe.
After going through the different types, I eventually settled on the Ruth Niles bottlestopper mandrel system, and it’s the one I continue to use in the workshop today.
I made a brief overhead video a few years back showing how I use the system, and I’ll be honest, it’s not great. At the time I was still finding my feet with video, the camera didn’t always capture the important details, and working without a script meant I skipped over things that actually matter.
Rather than re-shoot the video which I may never get to do, I thought it would be more useful to explain those missing pieces properly here.
If you watch the video first and then stay with me, I’ll clear up the details that weren’t obvious on camera and explain a few choices I make that might save you time, frustration, and ruined blanks.
What is a Bottlestopper Mandrel?
For any beginners out there, a bottlestopper mandrel is a threaded mounting system used in woodturning to securely hold a wooden blank while shaping it on the lathe. It ensures the blank runs true and allows you to cut clean internal threads that match the stainless steel stopper.
Why a Good Mandrel Matters
A good mandrel system makes a bigger difference than most people realise.
With a poor setup, even if your turning is good, you can still end up with:
● Blanks running slightly out of true
● Weak threads inside the wood
● Excess vibration while turning
● A poorer overall finish
The mandrel is the foundation of the whole process. If that foundation isn’t solid, everything that follows becomes more difficult.
What I found over time is that consistency matters more than anything. A system that centres properly and holds securely allows you to focus on shaping the wood rather than fighting the setup.
If you’re still getting comfortable with your setup, I’ve covered the basics in my Woodturning Guides & Articles section, including how small setup details can affect your results more than you might expect.
What the Video Doesn’t Show Well
One of the things the video doesn’t really show clearly is the importance of alignment before you ever start turning. At around 0:30, I’m using an M33 × 3.5 adaptor, which can be surprisingly hard to find online. I use this setup so I can mount the chuck in the tailstock, which greatly reduces the chance of the blank moving off true while initially threading it onto the mandrel. Start wrong, continue wrong!
This might seem like a small detail, but it makes a noticeable difference to how cleanly the bottlestopper runs later on.
Why alignment matters
Good alignment at this stage helps prevent the wood tearing off centre inside the drilled hole. If that happens, the threads won’t seat cleanly, the grip will be weaker, and you’re more likely to run into problems later. Once the blank is out of true, you’re also forced to remove more material just to get it running properly again.
Getting this right early saves time and preserves strength in the finished piece. Small errors at this stage tend to carry all the way through the piece.
It’s very similar to what happens when processing your own wood, small mistakes early on tend to show up later. I go into that in more detail in How to Process Logs for Woodturning.
Poor blank preparation
Blank preparation matters more than people realise. Wood with defects, or drilling with the blank poorly held, will almost always cause trouble later. A bottlestopper is a small object, but it’s meant to make a statement, so there’s no point starting with poor material.
I prefer to drill on another lathe rather than using a drill press. That’s simply my preference, but it gives me better control and consistency. You can still tap the blank and skip this method if you wish, but I know this approach works. Even then, blanks can occasionally go slightly askew, which is why I always allow a little extra material when preparing them.
The Bits People Get Wrong
Common beginner mistakes
One of the most common issues I see is people using their hands without any fixed reference points. That makes it very easy to start threading off the line of the drilled hole. The result is a bottlestopper body that runs out of true as soon as the lathe starts.
At that point, you’re fighting the piece instead of turning it, and the final stopper ends up weaker than it should be.
At 1:05 I start winding the quill and using the headstock wheel at the same speed. This equates to a slow tap but with absolute control.
Why things loosen or run out of true
Some woods are naturally softer than others, and if your setup is careless, the grip around the threaded section can be compromised from the start. Once that happens, vibration and cutting pressure will only make things worse.
This is one of the reasons I’m careful about how much pressure I apply and how cleanly everything lines up before turning.
At 1:14, I stop winding at about 5mm (1/4'') and remove the chuck. At this point, The wood is in line with the drill hole. Using my hand, resting on the tailstock for support I can start winding the wood closer to the mandrel seat.
Overtightening
It’s very tempting to overtighten the blank onto the mandrel, but this is a mistake. Stripping the threads weakens the grip significantly and can lead to failures later on. Firm is enough, tight is not better.
At 2:00, there is a plastic washer on the mandrel that separates the metal from the wood. I normally wind until this area is hand tight and then stop. I must make sure the plastic mandrel is centred properly before being happy that the wood is fully mounted, centred and hand tight.
The Tailstock Helper
Many people turn without the aid of the tailstock but one little catch is enough to damage the internal threads and have you out of true.
At 2:40, what is not clear in the video is the is a small hole in the pen mandrel head and when I clean up the end of the blank I actually create a small plug that fits snuggly into this hole when the tailstock engages the wood. This really gives you a firm support when removing the bulk of the waste material to find your shape.
Speed Control
Speed control plays a bigger role than people think, especially with smaller pieces like this. Lathe Speed should be appropriate to the size of the piece and the presence of tailstock support. When the tailstock is engaged, you have a bit more stability and can run slightly higher speeds if everything is balanced. Once it’s removed, you’re relying fully on the mandrel and threads, so backing off the speed helps reduce vibration and protects the integrity of the piece. Keeping things controlled rather than pushing for speed will nearly always give you a better finish and fewer problems.
The First Time Touch
At 2:57, in the video I touch the tailstock in place and then switch on the lathe. I then disengage and re-engage the tailstock before locking it in. The reason I do this is based on experience. I found in the early days that the wood sometimes moved when I first connected and this on/off method cured that more often than not.
Clearing the Threads
At 3:19, I mention threading the finished piece on the mandrel again by hand. This clears any remaining debris and sets the threads for connecting the stainless steel bottlestopper. It also will tell you if the threads are loose or overly tight. If still too tight, use the mandrel again. If loose, add a tiny spray of sanding sealer; once dried it will firm things up.
Finding Your First Thread
At 3:38, I start threading the bottlestopper but in reverse (anti clockwise). I do this until the stopper falls off the first thread and I know that is where I should start threading clockwise. If you just thread in, you may cut in the middle of a thread and now you are stuck on a new path which is going to be wrong.
To Glue or Not to Glue
I don't use any glue at all and prefer hand tight only. Again it's a personal preference for me. You can use a dab of superglue, no need for a lot of it. You just need enough so that it won't start to undo during use. You can also use sanding sealer like I described above.
Customer Instructions
Many people assume a bottlestopper needs to be forced into the neck of a bottle to create a good seal. In reality, hammering a stopper in can damage both the stopper and the internal threads. A light wetting of the O-ring seals, with a drop of liquid, followed by a gentle quarter-turn clockwise is more than enough to create an airtight seal.
I wouldn’t advise turning the bottle upside down, as bottlestoppers aren’t designed for that type of use. In most cases, a bottle that has just been poured will already be wet enough for the seals to engage properly. If not, a small dab of water around the O-rings works perfectly well.
Safety Notes
Like all woodturning tasks, turning bottlestoppers carries some small risks. Drilling on a lathe, make sure you hold the quill mounted drill mandrel while drilling and clear the waste from the hole as you go.
Use responsible speeds when Turning the bottlestopper, it is not as secure as between centres or a compressed dovetail in a chuck.
On a broader safety note, I’ve written a couple of posts that are well worth reading if you have your own workshop. Dust is one of the most underestimated hazards in woodturning, and my post Is Wood Dust Dangerous? explains why it shouldn’t be ignored, even during tasks that don’t look particularly risky.
Safety in woodturning isn’t just about the moment you’re turning, it’s about the overall environment you’re working in.
I also cover general setup and awareness in 8 Things New Woodturners Forget When Setting Up Space for a Lathe, which highlights a few common oversights that can quietly cause problems over time.
Common Problems with Cheaper Mandrels
Before settling on this system, I tried a number of cheaper alternatives.
Some worked reasonably well, but most had small issues that became frustrating over time.
The most common problems were:
● Slight movement or flex in the mandrel
● Blanks running out of true even when mounted carefully
● Threads not seating cleanly
● Poor quality fittings that wore out over time
None of these are major on their own, but they all add up. Instead of focusing on the shape and finish, you end up constantly adjusting and correcting.
That’s ultimately why I moved to the Ruth Niles system. It removed those small issues and made the whole process more predictable.
Quick Summary
● A solid mandrel system improves accuracy and finish
● Alignment at the start is critical
● Don’t over-tighten the blank
● Use tailstock support to protect wood threads
● Cheap mandrels often introduce small but frustrating issues
Final Thoughts
There are plenty of cheap alternative bottlestoppers out there so if you are happy with what you are using, by all means stick with it.
If you'd like to use a more upmarket product that makes your end product look more professional, the Ruth Niles products are the business. They sit lower/closer to the neck of the bottle so you see the wood more than the metal. Cheaper alternatives will show the rubber and some of the brass or silver plating and the balance can be off. These versions can flake over time. The Niles bottlestoppers are solid stainless steel.
There’s no single “right” way to turn a bottlestopper, but there are plenty of ways to make life harder than it needs to be. Most of the issues people run into with mandrel systems come down to alignment, preparation, and rushing the early stages. Get those right and the rest of the process becomes far more predictable.
Thanks for Reading,
David
About the Author
I’m David Condon, a woodturner and small business owner based in Tralee, Co. Kerry. I’ve been working with wood for most of my life at this stage — 11 years as a carpenter and over a decade running my own woodturning business.
Over the years, I’ve learned that woodturning is as much about patience and problem-solving as it is about tools and technique. I work mainly with Irish hardwoods, teach woodturning full-time, and spend most days learning something new in the workshop myself. On this site, I share the same practical knowledge I pass on to my students, shaped by experience, mistakes, and time spent at the lathe.
© David Condon Woodcraft – All Rights Reserved.
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