In the previous article, I wrote about three factors that reduce water repellency, and in this article, I would like to consider how to restore the water repellency that has been reduced.
Since there are three factors that cause the decline in water repellency, there are countermeasures for each of them. In other words, appropriate measures must be taken for each of the three factors.
(1) When dirt adheres to the surface
Remove the dirt. In other words, washing is all that is needed.
This is why regular laundering is the key to maintaining water repellency.
Washing also prevents chemical deterioration of the adhesive surfaces of seam tapes and rain jacket membranes, which in turn prolongs the life of the garment.
On the other hand, we know that some people are concerned about the loss of water repellency due to washing. I would like to describe the deterioration of water repellency due to washing in detail in another article, but the following measures may be helpful.
(2) In the case that it has become accustomed to water
The method to be tried after implementing (1) is the method described in this article. If the water has become accustomed to the material, simply remove the water and leave the material in place. However, leaving it at room temperature will take time, so the key is to apply heat in order to accelerate the process. The easiest way is to put them in the dryer. The key point is that heat needs to be applied while the garment is still dry. If water remains in the garment, energy will be used to evaporate the water and will not be used for heat as the key acceleration factor.
(3) If it is removed by abrasion
In the case where both (1) and (2)have been tried but still no luck, in other words, the coating has been removed, so neither (1) nor (2) will recover (strictly speaking, there is a limit to how to deal with (2)).
In this case, what is necessary is to re-coat, in other words, to perform Re-DWR. I will write about the quality of DWR in another article. It is not enough to re-coat any DWR, but if the DWR is not of high quality, it will soon lose its effectiveness.
As described in (1) through (3), there are different ways to deal with each of the decline factors. Since it is usually impossible to distinguish between these factors at home, (1) and (2) should be implemented in order. And if that does not work, implement (3).