Has anyone ever waterproofed their cheap panniers (nashbar MTB) with a painted on coating? I ruined a cell phone on one of our 50 milers in the rain and was curious if anyone had attempted it. Auto undercoat spray, or acrylic paint?
I know putting them inside ortlieb and using trash bags will work but I wanted to know if it has been done successfully in the manner I am thinking about.

Just line the non-waterproof panniers with heavy-duty garbage bags. If the tour is long enough, bring a couple of spare bags along. Problem Solved.

They sell waterproofing spray meant for jackets and tents. You could try that, I guess. I have no experience to say if it would work or not. But my husband just bought a bottle of it for his rain jacket, if we have leftovers I may just try it on the panniers!

seems to me that waterproof "outers" that are available nowadays fairly cheaply would work better, they sell them at MEC so must be readily available in the States too.
plus some bags inside for good measure if rain still could get in from the wheel side where the cover might not go over the whole thing.

https://www.mec.ca/Products/product_d...34374302693397

just seems like a messy job, and the stuff could crack or whatever, and might look godawful too...

The few things I carry in my panniers that would be ruined by rain go in a double-bagged Ziploc. Don't cheap out, get Ziploc brand. Done.

I have used an industrial polyurethane, coating , solvents quite noxious,
so the organic solvents safety mask , or at least a stiff breeze, was part of the tools.

it saturated fabric that was just lightly coated, on the roll, before sewing.

I suggest , Zip lock freezer bags, and heavy duty trash bags for , Liners
since buying a $100. a gallon chemical is probably not what you are thinking of.

Waterproofing treatments all wear off fairly soon.
Waterproof covers can collect water in the bottom underneath the pannier
Trash bags last a week or so of touring before getting torn.

The best solution I have found are dry-bags. You dont need the Ortleib-style welded canoe bags, just a waterproof nylon version will do the job. I keep some stuff inside the drybag and other stuff outside within the pannier.

that has certainly been my experience canoe camping using the old style non waterproof canoe packs, as well as bike touring before I had waterproof ones.

too bad for covers collecting water, but I still see them as an easy cheap alternative, to keep on using non waterproof bags, espeically with a toughish plastic bag at least for the bottom of the inside of the bag to keep stuff dry there even if you have what you are mentioning.

For water proof covers, I wonder if anyone has tried putting grommets in the bottom of the covers? I don't have covers for my panniers, but that seems like a quick, easy solution to the pooling water issue.

Also on the thrifty side, but addressing the durability issue, some people recommend trash compactor bags rather than plain, old trash bags. Tougher then your standard kitchen bag, but still cheap enough that you won't cry when it rips.

Waterproofing sprays won't work. Most panniers are made of waterproof material, but it's the seams that leak. You can try sealing the seams with goop from an outdoor store. I wouldn't trust it for anything important to you like a sleeping bag or your spare clothes if you are camping.

Rain covers don't protect the backside of the bags that get wet from the wheels. The garbage bag liner idea has merit as does using ziplock bags.

I just use waterproof panniers now so all of this is academic as my stuff just doesn't get wet. I started with non-waterproof panniers and got tired of the bagging hassles and inevitable gear wetness when they failed.

ditto

Rob, I like the Wallace idea, that was my first thought as well.
As for the backside, I figure it would be fairly easy to rig up something to make just that flat section much more waterproof (spray, attached plactic, I dunno) Which goes back to if someone had a pair of panniers given to them, or didnt want to pay more for waterproof ones, covers and some improvising would make a fairly decent fix for not much money.
(also uuuuuuuuusually on a trip we dont get rained on for toooooo much time on the trot--touch wood touch wood, so the methods discussed would certainly be better than nothing and would do a reasonable jol. (that said, as Vik say...once you get waterproof ones, in my case I dont really want to go back, especially for the commuting I do)

Since cheap nylon drybags costs about the same as a set of pannier covers and do a much better job, give the a try.
I carried my sleeping bag in one on the rack-top through several days of torrential rain in Norway with no leakage.

McNett tent floor sealant will fix them,even if the old crap is peeling off.It's about $15 a bottle and you'll at least need 2 bottles.(4 panniers)

You can seal seams on any material with Mcnett seal grip.Once it's on,it will never come off,even if you want it too.

You'll have to wash them twice in a machine,rinse them until no soap remains,remove any loose old waterproofing,then your ready for waterproofing.Still with me? It can be done,is it worth it? If you really like them or there old Kelty or Rhode Gear stuff it might be.

For about twice that and alot less work,you can find 4 new Axiom Transit panniers online.There about $30-$35 a PAIR.

I don't like the one-big-garbage-bag-inside-the-pannier option as it's hard to pack. We just packed our stuff in normal plastic grocery bags and then put those bags in the panniers. We end an endless supply of grocery bags (except in some places in Argentina where they were banned!) so when they started wearing out we just got new ones. The stuff that we didn't use often got stashed in a grocery bag at the bottom of the pannier and the stuff we used a lot was at the top. It was easy.

Ziploc bags are great, but they do wear out over time. We found that, after a couple years on the road, that we didn't use Ziplocs at all - had some ditty bags and then used plastic grocery bags to keep them dry.

I'm with guitarrick, large ZipLocs - problem solved. Plastic grocery bags are getting banned a lot of places and it is a good thing. Use the ZipLoc or other heavy plastic shopping bag until it wears out, recycle and start with another.

My experience is with backpacking so far. Bike touring will be this summer. In hauling weight on my back, I prefer the pack to be simple with few additional "features". Closure should be foolproof as well as light and simple, say roll top or drawstring. The only items that need to be dry are clothing and sleeping bag. These are kept dry in siliconized, waterproof stuff sacks which are available in sizes and shapes from about one liter to several gallons and weigh an ounce or two. The fabric is indeed waterproof and the seams sealed with silicon sealer available for tent seams. These actually hold air and you can blow them up like a balloon. Trash bags I've found, like others, to be delicate and don't last. What I have had good durability with is trash compactor bags which are much sturdier than plain trash bags. My most used backpack has had the same compactor bag for over a year. This pack has not had daily use for that period of time, such as in a trans-continental tour, but it has had many days of use.

Just go to a camping store and buy a couple waterproof stuff sacks.