Probably the most important layer of clothing when hiking is the waterproof layer, it keeps you dry and comfortable when the weather turns against you. They normally perform really well when new but performance deteriorates as they get older. Hopefully this blog will explain why this is and what easy steps can be taken to breathe new life into your waterproofs and make them last longer!
How Do They Work?
Without getting into too much technical detail you can split waterproof clothing into two groups “shells” and “analogy”. They are both designed to keep you dry from the elements and regulate condensation/perspiration built up from within.
In the “shells” group the waterproof clothing will either have an internal coating (PU or similar) or a membrane/laminate (Gore Tex, Event, Pertex or similar) the function of this is to create a barrier in order to stop water getting in and to a degree allow moisture out.
In the “analogy” group we have Paramo clothing which is designed to mimic animal fur with the use of a “pump” liner which is designed to push moisture outwards to protect you from rain, condensation and perspiration.
To do their job effectively they both have one thing in common, a Durable Water Repellency (DWR) coating on the outside that makes water bead. This coating is the key for the waterproof clothing performance as it has a massive impact on the breathability.
As I said above DWR is the “beading” performance of the waterproof clothing, the better the beading the better the DWR performance. If clothing is no longer beading but becoming saturated with water the DWR coating has become less effective. There are two main causes that reduce the effectiveness of the DWR coating:
- Contamination from mud/dirt, detergent, smoke and alcohol
- Abrasion from wear and tear, abrasive surfaces and friction
It was interesting to see an experiment where a word written on a coat with a finger dipped in alcohol gel completely removed the DWR ability to bead water! Very apt during this COVID-19 time!
The good news, it is easy to reinvigorate the DWR and therefore restore the performance of your waterproof clothing!
First thing to do is clean your waterproof clothing following the instructions on the clothing label. Please note, one of the contaminates for DWR is detergent so there are specialised washing products like Nikwax and Grangers designed to clean without damaging the DWR coating. In addition if you are using a washing machine make sure that the detergent/conditioner drawers are clean of residue.
The obvious time to wash waterproof clothing is when it’s visibly dirty or if you notice it doesn’t bead as well as it should. More often than not washing waterproof clothing is all that is needed to reactivate the DWR.
I normally wash my waterproof coat and trousers together, closing all zips and fastenings. I wash my leg gaiters separately as they have aggressive velcro fastenings, which can damage the DWR on the coat and trousers through abrasion.
Reproofing clothes is no longer a chore with solutions like Nikwax Tx Direct Wash-In, simply apply through a wash cycle in your washing machine. Reproofer should be applied to clean clothes so best to do after a wash cycle.
I would normally reproof on every other wash cycle. Your clothing will tell you if reproofing is needed i.e. if it’s beading well but just a bit mucky a wash will do, if water is not beading and rain is soaking in then it will need reproofing.
Is Tumble dry or apply heat still a requirement?
Instructions used to say “apply heat” to reinvigorate the waterproof coating after washing/reproofing and people still do as a matter of habit – I for one still put my waterproof clothing through a tumble dryer!
This was due to the chemicals previously used in the DWR coating that needed heat to reinvigorate the performance. Modern DWR coatings no longer use these chemicals, therefore the requirement to tumble dry or apply heat is no longer required. In addition reproofing solutions like Nikwax TX Direct Wash-In do not require heat to activate.
My thoughts are to follow the clothing care instructions, if it states you can tumble dry and you have the ability to do so there is no harm in putting it through the tumble dryer!
Which Care Product is Best?
This is down to personal preference, however, first check the manufacturers care instructions as guarantees may be invalidated if the wrong product is used or performance may only be guaranteed with the use of certain products….
Personally, I tend to use Nikwax products as they are easy to use, perform well, environmentally friendly and I can buy 5 litre bottles of the stuff!