I had my MHP wrapped in a pillow case & plastic wrap. In an attempt to get as close as possible to the MHP, the chicks were tearing the plastic wrap and getting stuck inside.
I had to remove the plastic wrap.
ETA: Can some of you post suggestions/pics how to covering & protecting your heat pad? I'm sure there are some in this threat, but that's a lot of post to sort through. Thanks!
P.S. I have zero ability or equipment to sew. lol
Yes plastic wrap will not at all work. The stuff some of the other folks are using are some kind of heat-cling wrap or something. They will have to speak to that. [I see that Blooie has now responded but I'll go ahead and post what I've written here about what I did.]
This is what I did, and I'm sorry but I have no photos to show you:
1. Take a flannel pillowcase that you don't care about-- you can often get them at thrift stores, or you could cut a piece from an old flannel sheet-- and cover the heating pad, letting the cord come out one corner of the open end. Fold the pillowcase over the pad so that the extra material is on top (so only 1 layer of fabric between the bottom side and pad). Orient the pad so that the "warm" side is the down-facing side, that is, the smooth side that will face the chicks. (Some pads get warmer on one side than another.) The pad I used, the recommended Sunbeam model, comes with an integrated flannel cover already, so you only want 1 layer added to that on the chick-side.
2, Then I took a needle and thread and sewed the pillowcase to itself to close up all openings-- I just made big stitches to close it up on the top, where the folds come together. But as Blooie just noted, you can just fold it and not sew it. When you attach the P+P, the folds will be held tight (see next step).
3. The P+P gets tucked into the UNDERSIDE of your wire frame (like the inside of a bowl)-- make sure your wire frame is strong. You connect the P+P to the wire frame with the tiny, thin bungee cords you can buy-- 3 or 4 of the cords hooked across the short way. This puts the P+P close to the chicks and they can't get trapped between the P+P and the wire frame (as has happened to folks when they put P+P on top of the wire frame). Place the P+P into the wire frame in such a way that the cord sticks out where you need it to go in order to plug it in.
4. Take your wire frame, now with the P+P attached, and turn it over into its correct orientation. What you have is a wire frame exposed with the P+P attached underneath. The P+P should be firmly attached. I then covered the wire frame with a hand-towel sized towel laid flat, with an overhang over the front edge as most people's photos will show. I just changed the towel as needed. So no iron-on plastic required. I also put straw on the top, as many photos show. As the chicks started exploring, they would scratch the straw off the top-- I changed out that straw, and towel, as needed to keep the whole space clean.
NOTES:
a. I guess if there was a determined chick they might crawl UNDER the towel on top, but the good thing is that towel is not connected to anything so if they kept crawling they will come out the other side. I did 2 batches of MHP, 1 with chicks and one with guinea keets, and neither time did any chicks crawl under the towel on top.
b. I did lose a guinea keet when the wire frame collapsed from the weight of the keets on top. The keets are extremely tiny when born and I had flattened out the frame so that their backs could touch the pad (as is correct), but my wire didn't have enough spring in it (strength) once it was flattened that far. In my case I wound up putting a couple wooden blocks into place so that the frame couldn't collapse, and increased the curve into the frame again as soon as possible with the growth of the keets. Ideally no blocks would be used since that creates an obstacle under MHP. This was not an issue with the chicks (chickens) because they are born larger and the frame was perfectly strong for them.
This is probably more information than you actually needed, but I decided to write it out anyway.
--Victoria