Sword tipping has become a highly topical conversation recently, and many people have been discussing it and asking my opinion about both whether and how to tip your sword. Over in the HEMA discord I was asked about how and when we expect plastic tips to fail, which prompted a very long comment about the common ways tips fail and how to mitigate these issues by making tips well and regularly inspecting and maintaining them. I’m making this post to share my experience more widely as I believe a lot of people might start making thermoplastic tips soon. At the end I’ll summarise the advice about how making better tips and regular maintenance and inspection can help reduce all of the failure risks I describe, and some other issues.
Why should you tip your sword?
If you’re here, you probably already know about the Safety Tips projects . If you’re not, the study found that of the common sword tipping options we tried, PCL Thermoplastic was by far the safest option (you can read about it here: Safety Tips: Phase 1 Project Results) – drastically reducing the risk of puncturing while also not sticking to a mask. All other options were worse for one or both of these risks. Since then, I have taken to tipping all of my swords (not just rapier). This is partly to understand what other factors we might want to test in future studies, but also because at present I have found no drawbacks and only the benefit of being less likely to injury my friends.
How Tips Fail & How to Mitigate it
As mentioned, the material we used is a type of Thermoplastic called Polycaprolactone, or PCL. The community has largely taken to referring to this a “thermoplastic” (which is partly my fault), which is technically true but PCL is only one kind of thermoplastic (other examples include Kydex, Nylon and many others). Technically all “thermoplastic” means is that it softens when heated and hardens when cooled – many plastics do this, not all. The reason we use PCL is that it’s melting point is around 60°C, and is very easy to work into whatever shape you want at around 80-100°C. At this temperature is putty-like without being sticky, and the material is a poor conductor with low heat capacity allowing you to mould by hand without gloves even at this high temperature. This makes it very easy to make it into whatever shape you want – allowing you to easily tip any kind of sword quickly.
The downside is that this means most people are making their own tips, and because even the most avid sword collectors amongst of only have a few dozen swords, often people do not have much experience in making them. Mistakes will be made that will lead to less durable and also less safe tips than is ideal.
Even before the study, PCL was the preferred material for the Wessex League & Albion Cup tournaments, which I am involved in running. As these were the first large tournaments in the UK, most of the UK also copies the equipment standards we set. Many competitors would show up and need their swords re-tipped last minute which was highly inconvenient, as the main issue with PCL is it needs to thoroughly cool after you have formed it before you can use it – this is not something you can do in the 10 minutes before your pool starts. This prompted me to make the video below to show people how to make it.
Since this video, I have probably made 50 tips, as well as closely examined hundreds of tips during the Wessex kit check process, including several that failed across around 10 events and 4 years of personal use. The below advice is not quite “scientific” but is based upon extensive experience and experimentation with different options.
Over the years I have observed 5 ways that these tips might fail:
- The sword point puncturing through the tip
- Cracks in a poorly made tip splitting and breaking or loosening the tip
- Impact damage and dents from cutting and the tip striking the sword
- Internal imperfections creating weak points that split
- The tip coming off during use
All of these can be heavily mitigated with regular inspection and by making the tip well – I’ll describe both in detail below, and summarise the main recommendations at the end – skip to the end if you just want that.
1. Sword Point Puncture Through the Plastic
This is exactly what it sounds like – the sword point may eventually work its way through the thermoplastic material after repeated strikes. I’ve had two tips fail this way: one was the first tip I ever made (failed after about 2 years), the other was in the Safety Tips pre-tests where it slammed with far more force than a fencer would apply into a chip board target (I don’t consider this a realistic situation.
During Wessex kit checks in 2024, about 5 swords out of hundreds were rejected because of this. In all cases, the sword was only slightly through the plastic, with a small piece of metal visible, so this was caught before it became dangerous – but the tips needed to be replaced.
Catching Early: Regularly inspecting the tip is essential. Frankly, I would do it after every training session, sparring bout or tournament match. A quick visual inspection is enough and will take only a few seconds. Usually the point is slightly showing rather than completely punctured through making it easy to catch. A tip that started off fitting very tightly and that has become loose may also indicated this issue is starting, but I wouldn’t immediately replace it at that point just keep a closer eye on it. It could also be one of the other issues described below.
Prevention Method: It’s important to always ensure at least 1cm of material covers the sword point when forming your tip. When pushing the tip on the sword it can be quite easy to go too far – if you hold it up to the light you should be able to see how much material is present over the tip. If you went too far, take it off, heat it up again, and start over.
2. Manufacturing Cracks During Formation
Any cracks in the tip will be weak points that eventually lead to failure. When this happens it will split along the crack – this might lead to the tip coming off, or to splitting making it easier for a tip to punch through. The cracks typically appear at the base of the tip on the blade when the tip was first made. This is usually the last part that you shape, and with the hot plastic touching the cool metal, the PCL cools unevenly meaning the two parts may not fuse properly together.
Catching Early: Again, regular inspection of the base is important. This should at minimum be done immediately after making the tip (and can be fixed without remaking the tip – see below). If you’ve had to tape the tip on (see issue 5), you should remove the tape and reapply periodically, inspecting the base when you do.
Prevention methods: The most important part when making the tip is to ensure the plastic you use is smooth and hot. After forming your initial ball of material, return it to hot water multiple times. Take it out, smooth it, and when it’s ready put it back in the hot water for at least 30 seconds before trying to apply it to make sure it is thoroughly hot. Using water that is close to boiling also helps. If it’s hot when you start, the cooling issue matters less. Do also make sure to firmly press the base of the tip – it’s probably a good idea to do this early in the process, as you will likely have thinner material there so it will cool faster. This is also more likely to happen on thinner material, so having a larger base is a good idea.
Fixing: Whether this occurs in the making process or later, it is easily fixable without needing to remake the tip using a heatgun. I recommend getting a heatgun that has variable temperature and can be put down stably on a table during use. The best way to explain this is: you can toast it like a marshmallow, heating up the bits you need to heat up, and then pressing them together. I set mine to 100°C (because air transfers less heat than water). If the cracks appear later, the same process works – note that I specifically do not recommend using this for the the first issue.
3. Impact Damage from Cutting Practice
This is an issue that I have experienced with swords where cutting is more prevalent. Cuts that just barely reach your opponent can result in the tip striking hard parts of the opponent’s sword, like the crossguard or blade. This can cause dents and cracks in the thermoplastic. If the damage is severe enough, it could compromise the tip’s integrity or make it more likely to come off. There are couple factors at play.
Material quality matters: When searching for a brand of red thermoplastic (because I wanted to improve the look), I tried a few different brands and discovered that not all PCL brands perform equally. Some are significantly softer and more prone to impact damage making particularly this issue (and likely the others) worse. Cheaper brands may be mixed with starch as a bulking agent that also softens the plastic. The brand that I can recommend with confidence is Thermoworx, which in the UK is sold under the names “Whitemorph” and “Colourmorph”. I have not done a full review of other brands and there may well be others that are perfectly fine so if you’re happy with what you have, stick with it – but if you tried something and it sucked try a different brand.
Prevention methods: The main thing to mitigate this when making your tip is to make sure there is sufficient material over the edges, which is where the strikes are likely to occur. I make sure there’s about 2-4mm of material – you don’t need as much as over the tip – covering the edge.
Fixing: This issue is perfectly fine to fix with a heat gun. The dents are often small: just heat them up and smooth the material over the dent, and it will be fine. This will mean it’s not a weak point in future. If it’s cut clean through, it will also still be fine to fix with the heat gun – but you may want to just remake it if it’s very destroyed (perhaps changing brands). I’d recommend erring on the side of retipping if you are unsure. You can also move move material to the edges to make this less likely to happen at the same time
4. Internal Air Bubbles
Air bubbles trapped within the plastic create also creates weak points that can lead to splitting and exacerbate all other failure modes. You can spot these by holding your formed tip up to bright light where they should become visible – I would do this on the plastic ball before shaping it to the sword. Small bubbles <1mm are unlikely to cause an issue, but large ones will. The location also matters: above the point or on the edge is a problem, along the flat less so.
Prevention methods: Make sure there are no large air bubbles in the ball before you push it to the tip. Compress and reform the ball (bursting the bubble with a toothpick or similar if needed), and return it to the hot water and repeat as much as you need. Alternatively, you can push the sword point on directly through the bubble and then compress the plastic tightly to the sword – this should remove the air gap entirely. Holding the sword up to the light will tell you if it succeeded. If the bubble is in a location not likely to be struck you can just accept it as well.
5. Complete Tip Detachment
Tips coming off – particularly if they aren’t noticed – is an obvious drawback of relying on adding tips rather than relying on the point built in to the sword. This issue is actually much rarer with PCL than with alternatives that come in a predetermined shape (especially if that shape was not intended for a sword), because PCL provides a superior fit around the blade. Bright colours also mean that if it does come off it is usually more obvious that other tip options, or even compared to a broken point on an untipped sword.
If your sword has an enlarged tip (flared, rolled etc) this is basically impossible as the plastic will be tightly formed to it – I haven’t even bothered to tape my longsword because the fit is so good. For swords without enlarged tips, you can still get a very tight fit that mitigates this issue – although it is still possible for these swords for it to come off. The tips below are all completely secure to the sword without tape, even with the damage.
Prevention methods: The main prevention is to ensure as tight a fit as possible. Whatever shape of sword you have, pinch the tip along the flat of the blade during formation will ensure it fits snugly. This also moves excess material from where it is least important (the flat) to the edge and tip where it matters more. If you do have an expanded tip, make sure to pinch at the base of whatever expansion there to make that a tight fit as well.
Taping is the obvious other important factor – and the tape is far more likely to fail than the tip. I use electrical tape as a preference because it can be removed and reapplied without leaving a residue – there may be other better tapes (if you think you have one, let me know). The bright colours are an added bonus. Note: I have found that duct-tape does not take a hit well and leaves a sticky mess, I don’t recommend it. Regularly inspect the tape and reapply it periodically – it will break long before the tip does. Wrap it in several layers to make it more durable. Even if you have a securely fitting tip, adding tape is still a good idea.
General Advice on Making & Maintaining Tips
You probably noticed that a lot of the mitigation strategies are the same for each problem – so the good news is this means by doing a few small things differently, you can get better life out of your tips and lower the chance of it failing at the wrong moment.
Making Good Tips
The most important starting point is to begin with a smooth, even ball at the right temperature. Return the ball as many times as you need to the hot water, smoothing out imperfections and holding it up to the light to look for internal issues. Before applying it to the sword, return it to the hot water for at least 30 seconds before taking it out and thoroughly drying it.
When shaping to the point, ensure you have enough material over the point (1cm) and edges (2-4cm). This will likely end with a relatively straight taper when viewed from the flat. Ensure a good fit by pressing tightly on the flat, and at the base of any natural flared tip the sword may have. You will likely have to do many small adjustment, pushing material to where you need it then correcting parts that have become too thin – be patient.
You can hold it up to the light while it’s still warm to check you have good coverage and no internal issues. If you need to adjust it and it’s already cooled, use the heat gun to heat up whichever part you need to fix.
After it cools, inspect the base for cracks – they will be more obvious after cooling. If there are any, use the heat gun to fill them exactly as you would with a repair (see below).
Regular Inspection & Maintenance
Regardless of how well made your tip is, I recommend inspecting the tip of your sword at least after every practice session. As a reminder you’re looking for:
- The point of the sword poking through
- If the tip has become loose
- Cracks and deep dents forming at the base or on the sides
- Tape being damaged, cut or simply coming loose
Maintenance is pretty simple. The most useful tool for this is a heat gun set to 100°c.
If the point of the sword is poking through, take the tip off and make a new one. While in theory maybe you could heat up the end and add another layer, this will likely just be a fracture point because you fused the parts together after the fact – just take it off. This is the only part that can result in catastrophic failure, it’s not worth risking it You can even use the same material if you linke, although it will longer to heat evenly than if you use fresh material. If the sword has an expanded tip of any kind you will likely need to use the heat gun to take the tip off – if not it should slide off easily enough.
In the images below I heat up the crack at the base and use a butter knife to gradually expand it until I can take off the tip.
Cracks and dents can be heated up using the heat gun and pushed closed by hand. Do make sure to use the heat gun for a while so that the plastic is nice and hot – if it’s transparent, it’s hot. If the plastic isn’t heated all the way through then the two parts might not fuse together and it may happen again. If you do it well, you’ll probably find cracks occur less frequently over time. You can also use this to move material from places it isn’t needed towards the edge or the tip.
If tape is the issue, I assume you are smart enough to have worked out that you need to put new tape on it. Unless you’re in a rush (e.g. this is mid tournament bout and you’ve just been called) it’s better to take the old tape off and put fresh stuff on.
A note on heating methods
There are different opinions about the best way to heat PCL. Most manufactures recommend using hot water to heat it up, and this is my preferred option. Water transfers heat very efficiently to the plastic making it heat up quickly and evenly, and it’s easy to quickly return the plastic to the water to heat up before shaping. 80-100°c is also the ideal temperature – if it’s hotter, the PCL becomes sticky and harder to shape, and at this temperature the low thermal conductivity of the plastic means you can shape it by hand without gloves.
The downside of water is of course that we’re putting it on a steel sword, and steel rusts. When you first make your tip it is very important to dry the plastic thoroughly before you apply it: use a cloth rather than paper towel (honestly? I generally use the t-shirt I’m wearing). This is also why I will use water for the initial formation, but switch to a heat gun for repairs. If you do have a heat gun you can also use it like a hair-dryer on the plastic ballto get a nice dry piece of hot plastic before you start if you’re very worried, although mostly I just use cloth.
If you want to avoid water entirely, unfortunately the heat gun is not useful for initially melting the pellets: they are too small and light and will just be blown around. Some people prefer to use a microwave – I do not, as this leads to uneven heating and often overheats parts and underheats others exactly like a microwave dinner. If you do use a microwave instead of hot water, I strongly recommend wearing washing up gloves. PCL gets stickier the hotter it gets, and the one time I tried the microwave it stuck to the gloves and was hot enough to be painful even through the gloves. If it does get stuck to you go run it under a cold tap immediately so it cools and can be removed.
Conclusion
PCL Thermoplastic tips will most likely fail, eventually, if you don’t look after them. Understanding how they fail and making and maintaining them correctly will reduce the risk of this happening at the wrong moment. Regular inspection, quality materials, proper technique, and prompt repair of any damage will keep your tip safe and tournament-ready. Well made tips should last you many months of hard use – most of my rapier tips have lasted for several years (I’ve not been tipping the others long enough to reach that point) – but a poorly made tip or one using weaker plastic may only last a few months.
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