This fall season I bought a Amigo mio turnout sheet, it is waterproof and really dirty right now.. when I put her winter blanket on I want to get the sheet washed and keep it for spring.. but it is waterproof and I heard if you wash them they are no longer waterproof... is there anything to "re-waterproof" a blanket ?? any suggestions
Yep. Clean it and then use Camp Dry (an aeresol spray you can get at most sports or camp supply stores) to waterproof it again.
Just washing the sheet should not destroy its waterproofing. Follow the manufacturer's instructions for washing it (usually cold water with a recommended cleaner). IIRC putting a waterproof turnout in the dryer will almost always render them not-waterproof any more.
You can re-waterproof turnouts with several products; I leave that up to the pros, as I cannot even easily wash mine at home, so I just send them off to the blanket cleaners to be cleaned and waterproofed if necessary. It's ~$17 to get a turnout washed and they come back looking brand new. Definitely worth the money, IMO (but I'm only blanketing one horse).
I recently got this stuff called "ReviveX" by McNett... It's a wash-in waterproofer meant for human outerwear, Gore-Tex, etc., all waterproof/breathable fabrics, and safe for home washing machines.
I followed the directions to the letter for Horsie's turn-out sheet-- washed it first in their own brand of synthetic fabric cleaner, then the waterproofer, soak for 10 minutes but don't rinse, then dry on high for the recommended period of time. (The directions are very specific, not just wash-&-go.)
I can't say enough good things about it... that sheet is so waterproof, MUD isn't even sticking to it. I plan to do the same to his heavier-weight RAMBO this weekend too, so we're all set for winter.