Cold water swimming balm: a stiff barrier that survives salt, chlorine and neoprene
A cold water swimming balm at 22 percent beeswax and 25 percent lanolin, in a 100 g tin poured at 78 to 84 C, with neoprene notes and the warmth claim refused.
Swimming balm is a friction product sold in a category that keeps implying it is a warmth product. What it actually has to do is stay on skin that is submerged, moving, salted and rubbed by a neoprene collar for an hour, which is a much harder brief than any balm designed for a bathroom shelf. This page gives a formula built for that, the temperatures to make it at, and the one claim you must not put on the tin.
22 percent beeswax, 25 percent anhydrous lanolin and 15 percent cocoa butter, with castor and jojoba for cling, poured at 78 to 84 C into a wide 100 g tin and cured 48 hours. Apply 2 to 4 g to dry skin at the neck, chin and underarms before the suit goes on. It does not slow heat loss in cold water.
What the film has to survive
Every other balm on this site sits on dry skin in still air. This one does not, and the difference sets every percentage that follows. Immersion first. A film under water is not evaporating, so the usual measure of a balm's job, the reduction in transepidermal water loss, is not what is happening. The film is doing mechanical work: holding a low friction layer between skin and whatever rubs it. That is the problem addressed in anti chafe balm, with the added complication that moving water is washing the layer the whole time.
Then shear. At 55 to 70 strokes a minute a wetsuit collar crosses the same 2 cm of neck skin 3,000 to 4,000 times in an hour. No film survives that as a continuous coat. A good one survives as a smeared layer that keeps reflowing into the contact patch, which is a property of a soft, tacky, high viscosity material rather than a hard one.
Salt and chlorine matter less than people expect: neither dissolves wax or triglycerides, so neither strips the balm chemically. Cold matters more. Skin at 8 C is stiff, and so is a tin left in a car boot at 3 C, so a formula that spreads beautifully indoors can be unusable at the water's edge.
The warmth claim, and the arithmetic that refuses it
Grease has been associated with cold water swimming since the earliest Channel attempts, and the association has always implied insulation. The physiology work on Channel swimmers from the 1950s onward did not support it, and the arithmetic shows why it never could.
Thermal resistance of a layer is its thickness divided by its thermal conductivity. A generous balm application of 10 mg per square centimetre, five times the usual cosmetic film, sets at a density near 0.92 g per cubic centimetre, giving a layer about 110 micrometres thick. Wax and fat conduct heat at roughly 0.2 W per metre per kelvin. That is a thermal resistance of about 0.0006 square metres kelvin per watt. Three millimetres of neoprene comes to roughly 0.06, a hundred times more, and a swimmer's own subcutaneous fat and vasoconstricted skin supply more again. Water itself conducts heat about 25 times better than air, which is the whole reason cold water is dangerous.
The balm therefore supplies well under one percent of the insulation in the system, and it is the part rubbed off first. It cannot alter cold shock in the first three minutes, swim failure in the following half hour, or the rate of core cooling after that. Thickness does not rescue it: even a deliberately heavy 1 mm grease layer is an order of magnitude behind a thin wetsuit, and it does not stay 1 mm thick past the first hundred strokes.
Do not describe this product as thermal protection, insulation, warming, or anything that implies it makes cold water safer. In the UK and EU a cosmetic claim must be substantiated under the common criteria in Regulation (EU) No 655/2013, and there is no evidence to substantiate this one. A claim to protect a person from a physical hazard also pushes the product out of the cosmetic definition, towards protective equipment or, if you attach it to hypothermia, a medicinal presentation. Work the wording through cosmetic versus drug claims first. Acceptable copy: protects skin at rub points, conditions skin exposed to salt water, water resistant barrier balm.
The formula
Weight percent of the total batch, adding to exactly 100. The 550 g batch fills five 100 g tins with a working overage.
| Phase and ingredient | % | 100 g (g) | 550 g (g) | What it does |
|---|---|---|---|---|
| A: beeswax, cosmetic grade | 22 | 22.0 | 121.0 | Holds the film together under shear |
| A: anhydrous lanolin | 25 | 25.0 | 137.5 | Tack, water uptake, cling when wet |
| A: cocoa butter | 15 | 15.0 | 82.5 | Body, slow melt, stops slump |
| A: castor oil | 12 | 12.0 | 66.0 | Adhesion to damp skin |
| A: jojoba oil | 10 | 10.0 | 55.0 | Slip, oxidative stability |
| A: high-oleic sunflower oil | 15.9 | 15.9 | 87.5 | Bulk emollient, spreadability |
| B: mixed tocopherols | 0.1 | 0.10 | 0.55 | Antioxidant, added below 60 C |
| Total | 100 | 100.0 | 550.0 | Fills five 100 g tins |
The tin matters as much as the contents. Use a shallow, wide tin of about 120 ml filled to 100 g rather than a tall pot: set balm runs near 0.92 g per millilitre, so 100 g occupies about 109 ml, and a wide face is one numb fingers can drag across. Scale other batch sizes in the batch calculator rather than by hand.
Why each number is what it is
22 percent beeswax is roughly double a body balm and 50 percent above a lip balm. The reason is not hardness for its own sake but resistance to being wiped off: a wax network at that loading gives the film a yield stress high enough that stroke pressure deforms it rather than displacing it, the mechanism set out in rheology and yield stress. Below about 18 percent the film wipes clear at the collar within twenty minutes. Above about 26 percent it stops being spreadable with cold hands, which is a worse failure because it happens on the beach.
25 percent lanolin is why the formula works wet rather than dry. Lanolin is built from sterol and wax esters rather than triglycerides, it melts at 38 to 44 C so it stays soft and mobile at skin temperature, and pharmacopoeial grades must take up at least twice their own weight in water. The film therefore hydrates in place instead of beading and lifting when water reaches it. That is the property the classic swimmers' grease was after, bought at the price of a sticky feel that would sink a face balm and is irrelevant here.
15 percent cocoa butter rather than shea, because cocoa is the harder butter at roughly a third stearic acid and holds body at 25 C in a tin sitting on a summer beach. 12 percent castor oil is there because ricinoleic acid carries a hydroxyl group on the chain, making castor unusually polar for a vegetable oil, so it wets damp skin better than anything else in the list. Above about 20 percent it turns stringy and hard to apply through a wetsuit sleeve.
Jojoba at 10 percent is a liquid wax ester rather than a triglyceride, so it resists oxidation and buys the tin a long life in a bag that is repeatedly warmed and cooled. High-oleic sunflower is the cheap workhorse that makes the whole thing spread. Tocopherol at 0.1 percent sits in the usual 0.05 to 0.2 percent working range, where more is not better.
Method, pour and cure
- Weigh phase A into one jug. Weigh lanolin warm. Cold anhydrous lanolin is a stringy paste and you will lose a gram or two to the spatula if you fight it straight from a cold store.
- Melt at 78 to 85 C. A water bath, held until completely clear with no cocoa butter haze on the spatula. This formula is 62 percent solids by weight and takes longer to clear than a lip balm, typically 20 to 30 minutes.
- Cool to below 60 C and add phase B. Stir in the tocopherol off the heat. If you scent the batch at all, do it here and keep it low.
- Return to 78 to 84 C and pour. Yes, this is above the normal tin window. See the note below.
- Let the dish form, then top up. After 15 to 20 minutes the surface has set and the centre has sunk. Pour a thin second layer from a jug kept warm to give a flat face.
- Chill briefly, then cure. Twenty minutes in a fridge to drive cocoa butter through its crystallisation quickly, then two hours at room temperature uncapped, then 48 hours capped before you judge the hardness or label anything.
The site default for tins is 60 to 68 C, set out at pour temperatures, assumes 8 to 14 percent wax. At 22 percent beeswax with 15 percent cocoa butter the melt thickens into a slurry within a couple of degrees of the beeswax clear point, and a cool pour into a wide tin sets against the cold wall before it reaches the rim, leaving a scaly ring and a layered product. This formula is therefore a deliberate exception: pour at 78 to 84 C, accept a deeper shrinkage dish, fix it with the top up. Never hold above 85 C. If the tins are cold, warming them to 30 to 35 C on a tray helps more than another five degrees in the jug.
Neoprene, swimsuits and pool water
The usual worry, that balm rots a wetsuit, is half right and aimed at the wrong material. The elastomer is polychloroprene foam, and published compatibility data rates it well against animal and vegetable fats and only fairly against petroleum oils, which swell it over repeated exposure. Swelling of a rubber in a liquid is measurable, by mass and volume change after immersion under ASTM D471, and it is slow. The parts that actually suffer are the ones nobody thinks about.
| Material | What contact does | Rule |
|---|---|---|
| Polychloroprene foam | Slow swelling with hydrocarbon oils, little effect from wax and triglyceride | Fat based balm is the safer choice, rinse the suit in fresh water after every swim |
| Nylon or polyester jersey lining | Absorbs and holds the balm, which later oxidises and smells | Wash the collar with a wetsuit cleaner, not detergent, every few swims |
| Glued and taped seams | Contact adhesive softens with prolonged oil soak, and the neck seam is the highest stress one | Apply to skin, not to the suit, and keep the dose off the seam line |
| Smoothskin rubber collars | Turns slick, then collects grit that abrades the surface | A thin film only, wipe the collar clean after use |
| Elastane swimwear | Beeswax and lanolin mark pale fabric yellow and the mark sets with heat | Rinse cold and never tumble dry a marked suit |
| Silicone goggle seals and caps | Any oil breaks the seal and the goggles leak or fog | Never apply near the eye socket, and wash hands before touching goggles |
On petrolatum: the traditional swimmers' grease is a mix of wool fat and petroleum jelly and it is genuinely good at the job, being the most occlusive material in common use, inert, cheap and effectively non sensitising, as set out in petrolatum and mineral oil. Its two disadvantages here are that it is the material class neoprene tolerates least and that it is close to impossible to wash out of a suit lining. The head to head is at lanolin versus petroleum jelly. Swimming in skins, petrolatum is a reasonable choice. Swimming in a wetsuit, use the fat based version.
Pools are a separate matter. A greasy balm floats off, contributes to the scum line at the tile and loads the filter, and many pools prohibit it in their conditions of entry. For a pool session use a fraction of a gram at the two or three points that actually rub, applied ten minutes before entry so the film has set on the skin, or skip it.
Where to put it, and how much
Applying balm everywhere is the commonest waste. Chafe happens where a hard edge crosses a soft crease repeatedly, and there are only a handful of those.
| Site | Dose per swim | Why it rubs |
|---|---|---|
| Back and sides of the neck | 1.0 to 1.5 g | The collar moves across it on every breath and turn |
| Under the jaw and chin | 0.5 g | Front collar edge, worse in a high necked suit |
| Armpit and inner upper arm | 0.5 to 1.0 g each side | Sleeve seam through the recovery phase of the stroke |
| Behind the ears | 0.2 g | Cap edge and goggle strap |
| Inner thigh and groin | 0.5 g | Skins swimmers in briefs, or a suit leg opening |
That comes to 2 to 4 g per swim, so a 100 g tin covers 25 to 50 swims. Apply to dry skin before the suit goes on, because a film spread on wet skin sits on a water layer and slides off with it. Rub it in until it stops looking white, then stop: a visible white smear is product that will be in the water within five minutes. General dosing logic is at how much balm to apply.
At 5 C air temperature a 22 percent wax balm is close to unspreadable and cold fingers have no fine control. Carry the tin inside a jacket against your body on the walk down, and roll a scoop between your palms for 20 to 30 seconds before it touches skin: palm heat at 33 C takes the surface of the scoop through the cocoa butter softening range in under a minute. If you regularly swim below 5 C ambient, make a winter tin at 18 percent beeswax, giving the difference to sunflower oil, and accept that it wears off sooner.
The vegan version, and what it costs
There is no plant material that reproduces lanolin. The substitution therefore rebuilds the film out of a harder wax plus a much higher polar oil load, which gets you most of the structure and less of the wet cling. Total structurant rises to 24 percent, made up of candelilla and castor wax in place of 22 percent beeswax, while castor oil and hydrogenated castor replace the lanolin.
| Ingredient | % | 100 g (g) | 550 g (g) | Replaces |
|---|---|---|---|---|
| Candelilla wax | 14 | 14.0 | 77.0 | Most of the beeswax structure |
| Castor wax (hydrogenated castor oil) | 10 | 10.0 | 55.0 | The rest, plus some lanolin body |
| Cocoa butter | 15 | 15.0 | 82.5 | Unchanged |
| Castor oil | 18 | 18.0 | 99.0 | Lanolin's tack, partly |
| Jojoba oil | 12 | 12.0 | 66.0 | Slip and stability |
| High-oleic sunflower oil | 30.9 | 30.9 | 170.0 | Bulk |
| Mixed tocopherols | 0.1 | 0.10 | 0.55 | Antioxidant |
| Total | 100 | 100.0 | 550.0 |
Quantify the loss honestly. Lanolin must take up at least twice its own weight in water to meet the pharmacopoeias, so the 25 g in a 100 g tin can hold around 50 g of water in the film without it breaking. The vegan version takes up essentially none, so water displaces the film rather than being absorbed into it. Candelilla also clears at 68 to 73 C and builds a harder, more brittle network than beeswax, so under collar shear it fractures instead of smearing back together. As a Trebalm working estimate rather than a measured retention figure, plan on reapplying at about half the interval and expect noticeably less protection past 45 minutes. Pour 2 to 3 C hotter, at 80 to 86 C, because candelilla sets earlier. The same conversion applied to a much lighter product is on vegan lip balm.
Failure modes
| Symptom | Mechanism | Fix |
|---|---|---|
| Will not spread at 5 C on the beach | Wax network and cocoa butter both below their softening range | Warm the tin against the body, roll between palms, or drop to 18 percent beeswax for winter |
| Gone within twenty minutes | Applied too thin, or applied to wet skin so it floated off with the water layer | Dry the skin, use the doses in the table above, reapply at the neck for long swims |
| Gritty tin after a week | Cocoa butter crystallising slowly into coarse crystals | Hold the melt to a clear point, then chill the filled tins fast. Mechanism at grainy shea butter |
| Scum and complaints at the pool | Product floats off into the water and loads the filter | Fractional doses at two sites, ten minutes before entry, or nothing at all |
| Itchy red band at the collar line | Could be lanolin, could be the thiourea and thiazole accelerators used in neoprene, which are established contact allergens | Patch test the balm alone before blaming it. See how to patch test a balm |
| Tin smells stale by the end of a season | Salt water and wet fingers carried into the tin, plus repeated warm and cold cycling in a kit bag | Scoop with dry fingers or a spatula. See water contamination in balm |
| Oil beading on the surface | Liquid oil exceeding what the wax network holds, usually after a hot car | Store below 25 C, and raise beeswax a point if it recurs |
Who should not use it, and what to print
Lanolin contact allergy runs at roughly 0.4 percent in the general population and much higher among people with long standing eczema or chronically broken skin, and at 25 percent this is a high exposure product. Anyone with a known wool alcohol allergy should not use it; the full picture is at lanolin allergy explained. It is also wrong for skin that is already broken: an open chafe wound at the neck needs covering and a rest from the suit, not a barrier balm spread over it.
The decision rule is simple. If your problem is chafe, this formula is worth making and will do the job for a season of swimming. If your problem is cold, the answer is neoprene thickness, exposure time, acclimatisation and getting dry fast afterwards, in that order, and no balm belongs anywhere in that list. Skin care after cold exposure, which is a real and separate issue, is covered at cold weather skin. Print on the tin: intact skin only, avoid the eye area, keep below 25 C, contains lanolin (wool wax alcohols). Print nothing about warmth.
Frequently asked questions
Does swimming balm keep you warm in cold water?
No. A heavy application is roughly 100 micrometres thick and contributes under one percent of the thermal resistance in the system, against a wetsuit or the swimmer's own subcutaneous fat. It cannot change cold shock, swim failure or the rate of core cooling. The grease traditionally used by marathon swimmers is a chafe barrier that acquired a reputation it never earned.
Will balm damage my wetsuit?
A wax and vegetable fat balm is the lower risk option, because polychloroprene tolerates animal and vegetable fats better than petroleum oils. What actually suffers is the nylon lining, which soaks up the balm and later smells, and the glued neck seam. Apply to skin rather than to the suit, rinse in fresh water after every swim, and wash the collar periodically with a wetsuit cleaner.
Where should I put swimming balm before an open water swim?
Back and sides of the neck first, since the collar rubs there on every breath, then under the jaw, the armpits and inner upper arms, behind the ears where the cap and goggle strap sit, and the inner thigh if you swim in briefs. That is 2 to 4 g in total. Apply to dry skin before the suit goes on, and keep it away from goggle seals.
Can I use petroleum jelly instead?
For skins swimming, yes, and it is very effective, inert and cheap. For wetsuit swimming it is the material class neoprene tolerates least, and it is very hard to wash out of a suit lining. A beeswax and lanolin balm gives comparable cling with less risk to the suit and washes out more readily.
How much beeswax does a swimming balm need?
20 to 24 percent by weight, roughly double a body balm. That gives a film with enough yield stress to deform rather than wipe away under a collar. Below 18 percent it clears from the neck within about twenty minutes. Above 26 percent it becomes unspreadable with cold hands at the water's edge, which is the worse of the two failures.
Can I make a version without lanolin?
Yes, using 14 percent candelilla wax, 10 percent castor wax and a raised castor oil load, but be clear about the trade. Lanolin takes up at least twice its weight in water, so the film hydrates and stays tacky when immersed; the plant based version absorbs none and is displaced by water instead. Expect to reapply about twice as often.
Sources and further reading
- Pugh L.G.C. and Edholm O.G., The physiology of Channel swimmers, The Lancet, 1955.
- Tipton M.J., Collier N., Massey H., Corbett J. and Harper M., Cold water immersion: kill or cure?, Experimental Physiology, 2017.
- ASTM International, ASTM D471, Standard Test Method for Rubber Property: Effect of Liquids, West Conshohocken.
- United States Pharmacopeial Convention, USP monograph: Lanolin, including the water absorption requirement.
- European Commission, Regulation (EU) No 655/2013 laying down common criteria for the justification of claims used in relation to cosmetic products, EUR-Lex.
- Medicines and Healthcare products Regulatory Agency, A guide to what is a medicinal product (Guidance Note 8), GOV.UK.
Reviewed and updated 6 September 2026. Spotted an error? Tell us and we will fix and log it.