Can waterproof spray work?

[RGM]

I'm going to Ireland soon and I hope someone could help me with this question. I have a decent pair of Merrell hiking shoes. They are not waterproof. If I buy a waterproof spray for suede and synrlthetic, will this help? Ireland is known for its pop of rain. I hate to have to buy all new waterproof hikers.

[jay]

I have backpacked in the Highlands of Scotland and can relate to that.  In my experience, sprays can work temporarily.  Most that I have tried, however, don't last much past one or 2 good soakings.  Others here might have some better ideas than I do on this, but I usually try to carry plenty of extra socks and air my feet out whenever I can.

One thing I learned about waterproof boots tho, if water gets in them, it doesn't come out.  I got caught in a storm and had my pants tucked into my boots.  Water ended up soaking thru my pants and running into my boots.

[Aaron Zagrodnick]

I've used DWR and other water repellent treatments on boots and shoes, but only on footwear with a waterproof liner already. The main reason was re-treatment of the leather or fabrics just to keep them from soaking up too much water which adds weight / increases dry times / reduces any breathability a waterproof / breathable membrane might offer. I would agree with jay that most treatments are pretty temporary when it comes to shoes or boots, with as much abrasion that they're subjected to, whether brush, snow, rocks, etc. anything wears off really quickly compared to most other gear. Depending on the weather I would suggest going with either an all waterproof system complete with gaiters or go entirely the other direction by going as breathable as possible. I wrote more on hiking footwear choices here (arranged by season) as well in case it helps!