Yes, I'd agree with the others, just use acrylic water based paints, then I'd seal it with Krylon Clear. Should work fine. By the way, I read a good tip recently for anyone wanting to paint on glass or glossy ceramic pieces. Spray them FIRST with Krylon Clear MATTE Sealer, then paint will adhere fine to them. Then seal with whatever you want. hugs, Karen

Unfortunately as we are all well aware, there is theory and there is practice. I didn't want to muck this up with details LOL more than I already did. When I mention 90% reflectivity for the best white paints and kitchen aluminum foil, that's theory. That 10% of conductive heat that comes in from the the aluminum foil that bothers me is thus also theory. Let's talk mylar and foil and departures from theory since that discussion is now necessary to compare the two. In practice, the aluminum is probably providing only about 70% reflectivity and 30% of the heat is going in. Aluminium deposited on mylar new also gives about 90% radiant reflectivity in the best case too. On the surface it would seem a builder's option. First, Grizz you are talking about quality space blankets. This is not really quality, but considering economics it might scrape by: HD Medical Space Blanket Many of the cheap Chinese mfgrd space blankets are quite transparent although they don't appear so from a distance. Aside: Perhaps double layering will work, the outher layer will take the brunt of UV and random tear damage and could be glued only along the bottom which would effectively add airspace between them. Or for that matter the bottom layer could be foil or paint. The mylar will last about three months in the bright sun before it starts yellowing significantly. This is why I have been looking for info on whether anyone has used a UV protective clear coat hard shell finish on top - would likely solve the problem. Aluminum foil on the other hand until damaged will continue to block light completely... although polished 90% aluminum very quiclkly formas a microscopic oxide layer which cuts this to about 80%, and then it can corrode usually into a white, not very reflective oxide which is only 1/7 as heat conductive as aluminum. As far as conductive values (not speaking of reflection for anyone else following this) of mylar in just single layer, it is 1/4 as conductive as PVC but twice as much as air. It still suffers from the same problem as the aluminum in alumimum foil from the reflective surface (put for us on the outside instead of using like a space blanket to keep heat in where it faces inside) in that the aluminum will heat up and conduct the same for all the energy that goes unreflected. Where mylar beats that though is that the incredibly fine layer has no foil backing to pass the heat since the same radiance is hitting it, there is very little capacity to hold heat for transfer which is a slower process, the deposited Al simply reaches temperature quicker and transfers it out more quickly. It would be a ratio of 2/3 of the non-reflected head going into the pipe and 1/3 going into the air but the chemical microthin deposition will dump the heat back out in the convective air currently much more quickly. On a microscopic level what is happening is say the mylar goes up say 10 degrees and even though the plastic backing interface feels this, the actual heat flow is stymied because you get an even gradient on the plastic side while on the air side the full 10 degree difference is maintained (heat flow rate is in direct proportion to the temperature difference, so conductivity is obviously not the only thing to consider in a microscopic deposited layer like this). In summary the mylar plastic will suck up 2 X the heat in dead still air (=1X) (Vs thicker foil which does 7 X), but the slightest infinitesimal breeze will double or triple the interface temperature difference between aluminum and air vs. what is being experience on the plastic side. Having triple the temperature difference in this example will triple the heat flow into the air. A good point to remember was your advice to Rio when he suggested using Heavy duty foil, and you said for yourself the cheapest stuff was best. You also have the same physics supporting you. HD Al would significantly add to the internal temperature of the pipes as in full metal jacket. Imagine the temp if the channels were made from aluminum with a PE liner... Here, I could cook eggs on them in Summer. I mentioned all the above to sort of show IMO how it will be hard to get hard numbers to compare for these reasons. However it is absolutely clear from this that new mylar will cut down the transmitted heat by a factor of anything from 1/3 of foil to for our purposes all of it. 3-month old mylar ... I have the suspicion that as we reupolster we will be wondering why we didn't KIS with the foil. That's why I think a two layer mylar with a sacrificial exterior might help. Clearly there are engineering issues with all of these things but until someone actually has done a little enthusiastic tinkering I think that is about as far a ledge I can walk out on ! Aluminum is not without its problems. By the time it is well broken in (but not torn up), that 30% turns completely into heat, so this is the drawback of aging foil cald channels. The mylar will drop down to 70% or even less, for argument's sake as well. There is no clear winner unless you don't like having to do frequent reupholstering. This post was edited by PupillaCharites on Thu, Sep 26, 13 at 16:47

I'm just seeing this thread and perhaps the decission has already been made, but, my experience with Krylon for plastic was not good at all. The stuff started peeling off before one season was over. Of course I didn't use a primer, I don't remember reading anything on the can about using primer. I don't care for the color choices either. kfainf, thanks for the info on Rusteoleum! Rach

would't you love to be the one paid for naming paint colors? I always use names just to remember which ones may work, after that they are forgotten. And write the room name on the can. But you are right, they never put them on the can, just the code for mixing. Most likely because the names change depending upon the market, but actual color may remain. There are many paint experts here that have posted great thoughts regarding your point on color names, psychological response, etc. I hated the sliding doors on my closets. Mirrors didn't make me feel like the room was larger, they seemed more like a huge "thing" in the rooms. The first change made when moving in was adding interior doors to the closets. They are even with the edge of the trim. Easy to install, but ripping out the sliding hardware was a pain. When done the closets actually felt larger and gives you an area on the back of door for hanging things if wanted. Plus the rooms look so much better now. You didn't say what the size of openings are, not sure if this would work for you. If your doors are 3 mirrors or 2 large, the doors might swing open too far. And I'm sure there are better slider doors around if you need to stay with them. I used one mirror door for the back of my bedroom door. The other one has a thin overlay with chalkboard paint to use in the art/office area. You can now get chalkboard film to do this if there was a use for one in your home. A corkboard overlay would work too...for me.