Has anybody tried applying durable water repellent to their street clothes?

I tried an experiment on Sunday, spraying a pair of cargo pants down with Granger's, drying them to "activate" it, and then biking about 25 miles. The result: it didn't rain. This stuff is great! They've been predicting nothing but rain for the next week in the Pacific Northwet, and the clouds were so frightened, they didn't release any water... Or maybe the forecast was wrong. It rained a bit yesterday, but as timing would have it, I was indoors the whole time.

I had some intimate contact with the lake, and managed to stay dry, but that's a long story. When I got home, I wet my hands and "shook" the drops at the pants, to act more like rain; as expected, the water beaded up like mercury, and rolled off.

But I've only tried that one pair of pants, and can't wear them every day. So I haven't been able to really test this idea. Has anybody else tried DWR'ing the stuff they ride in?

I have the same problem. Bought a nifty rain jacket for the spring and it's drizzled maybe once while I was commuting. I'm guessing I'll need to buy some sun block if it's ever gonna rain enough to try out my jacket.

that is funny

A buddy washed a jacket with some kind of wash in waterproofing, don't know if it was DWR, didn't realize a pair of his wife's pantyhose was in there as well. When he pulled them out, they were holding about a gallon and a half of water!

If I leave the house with an umbrella it won't rain. If I lose the umbrella on the way home, it'll be a monsoon. Go figure.

I hope the DWR works when the clouds forget about your threatening behaviour. I'm guessing the DWR will wash out when you put them thru the wash cycle. Let us know how it works. This might turn out to be a neat experiment.

Well...I have never heard of DWR but it seems like I have been lucky with rain this season so far. I generally carry a cheap "re-usable" plastic poncho in case it starts to rain while I am riding. The last 2 days it has rained I have managed to ride in between rain showers. For instance yesterday we had a massive downpour maybe 30 mins before I was due to start riding. I think I am going to have to either walk or take a bus and even get the umbrella out. All of a sudden a few minutes before I leave it stops raining and I had enough time to ride to work before it started to rain again.

This DWR stuff does sound interesting though....

Not on clothes,but I've had to spray my Courierware bag twice with Kiwi Camp Dry. It works quite well,I get about a year's wear until it needs a recoat.

DWR (definition hidden in OP) just stands for Durable Water Repellent, and it's the standard fabric tech used on all camping and cycling gear advertised as "breathable". A tight weave fabric (usually nylon) is coated with a water repellent solution. The weave of the fabric is supposedly designed such that vapor (evaporating sweat) can escape through the micropores, but droplets (rain) are too large and have too high a surface tension to pass through the pores/coating.

The advantages over a non-breathable garment are simple: You don't get all fouled up in your own sweat.
The disadvantages are less obvious:
- Over long exposure and heavy saturation, DWR will soak through. Eventually the wicking action of accumulated sweat inside and beaded water outside will allow 2-way permeability of the fabric.
- DWR is suceptible to dirt. Micro-abrasion of the coating wears down the effectivity.
- DWR is suceptible to detergents and laundering. Use a DWR-safe tech wash and delicate setting when laundering DWR garments.
- DWR is suceptible to abusive handling. Repeat crumpling of the fabric wears down the coating effectivity.

On the upside, you can re-coat DWR fabrics and usually renew them back to original functionality. Nikwax makes a great wash-in re-coating solution I've used on my hiking gear.
Spray on solutions too often contain silanizing compounds, which stink to high heaven and can cause allergic reactions in many people due to the suspending agents.
If I were to make a pair of "street pants" into water repellent ride gear, I'd look at a pair of tight-weave mid-weight pants (light denim or other canvas-like fabric) and use Filson's Oil Finish Wax (for reproofing their Tin Cloth field garments).

So it's time for a follow up, partly because I had an opportunity for a real test ( with mixed results ), and partly because I think rain is a pretty important issue for bike commuters. We can go out for an evening ride, get soaked, and come home to a warm shower and a change of clothes ... but that's not usually the case at work.

Last night, I spent about an hour and a half, cycling in the ( sometimes driving ) rain. The pants ultimately soaked through, although this took about 20 minutes longer than normal for the situation. My jacket, however, is not waterproof, but comes with a healthy DWR treatment, and didn't let a drop of water through over the entire ride. At first, the water did indeed bead up, however, the beads were too small to roll off. Also, while I sprayed the front and back of the pants, the insides of the thighs twist out a little bit when I sit down, so my lap hadn't got any DWR love, and soaked much more quickly. Also, I wonder if 30 minutes in the dryer was long enough to fully "activate" the treatment? I'll do more testing and let people know if/when I hit on the right combination.

Now for some Q&A:

In theory, a coat of Granger's is supposed to be good for 10 washes. For things like jackets, you're generally supposed to apply a new treatment once a year. I wash my pants a lot more often than that, of course!

Clifton brings up a good point. I have some Stoic wool base layers, which all come with a Nikwax treatment, and a few Arc'teryx jackets and pants, which use and recommend Granger's. These work very differently ( both of them work well ), and I'm not certain Nikwax is technically DWR? I know Nikwax is actually a wax coating, which obviously repels water, while Granger's and other DWRs coat your clothing with some type of fluoride molecules, and then use heat to bind to the clothes. This increases the surface tension of water, making it much more difficult to soak into the fabric face. I've always heard recommendations to avoid the wash-in types, because they'll coat the inside of your clothes, making them repel the sweat you're trying to shed.