Cool tip from tv DIY show. To water proof maps spray with thomsons water seal for decks and concrete. Spray both sides let dry waterproof map!
I tried that with some maps I printed on an inkjet printer. The Thompsons blurred those to the point of being unreadable. But they were waterproof.
I expect it would work with commercially printed maps, maybe even ones off a laser printer?
Several years ago I used Thompson's Waterseal from a gallon can to waterproof paper maps. It worked great by painting it on in a light coat. When the gallon I had ran out, I bought another. It was terrible stuff. It darkened the paper and stayed tacky without ever really drying. Totally unusable. Obviously Thompson's changed the formula.
So I then tried inexpensive waterproof spray cans I found at Walmart. I sprayed 95 printed color map pages with my planned race route on the Yukon River. Some pages were laser printed and some were inkjet, both on regular plain computer paper. Spraying just one side of the paper placed flat on cardboard was enough to saturate the whole page through. Two cans did the whole 95 page job and it dried in a couple of hours. No discoloration at all, no smearing of the ink, the paper became tear resistant, and completely waterproof enough to twice survive getting wet while on Yukon 1000 mile canoe races.
I see that Thompson's now offers aerosol spray cans of the product. It may or may not work, but I'm happy with the inexpensive stuff I found at discount. Be sure to try some on test paper before large scale use.
what I have done is to use clear contact paper - cut the map into whatever sized pieces you want and leave a slight gap between the pieces so that you can fold the map easier. I think they still make the stuff.
or you could take your map to a commercial place and have it laminated
Clear shelf liner works fairly well if
you can find it.
Go to a Kinkos/FedEx-type office store and use the laminating machine. They’ll show you how to use it. About $1 a page, as I recall.
Does laminating make the paper un foldable?
Can’t fold after lamination.
Can’t fold, but you can roll
One option is to get a shipping tube (it’s sort of like a paper-towel tube, but heavy duty), then roll the maps and put them inside. They’ll be well protected for storing in a pack, but with no creases.
Clear packing tape
First I make a copy of the map (to preserve the original) then piece together and tape the copied sections to a table using small pieces of basic house hold wrapping tape. Once in place I pull out lengths of clear box packing tape and place over the map. Overlap each strip of tape by about ½ inch, and make sure the tape extends past the border of the map by about ½ inch. After one side is done, flip the map and do the same on the other side. Once complete on both sides I cut the ½ inch border overlap. After that I rub the whole thing with a plastic spackling knife for good adhesion and press out any bubbles.
Note that this is not foolproof, sometimes water does find a way in at a few small areas. No biggie, I just make another one from the original.
ink jet printer problem
Most art store sell spray fixative to keep graphite and ink drawings from smudging. It can also be used over ink jet. It is somewhat waterproof, but could be sprayed over with a water sealer.