Hi Woofie.

>> And then there were the heat mats I got for cheap from Harbor Freight.

>> I had to prop the flats up nearly an inch above them.

I wonder how many watts they were!

>> Another downside of them was that the covering on the mats appears to be somewhat porous, so I'm very careful with them.

They hardly even sound lawyer-tolerant. I stand corrected!

In all fairness, I've been using those Harbor Freight mats for about 3 years now with no problems. I do put a bit of a barrier between them and the styrofoam, though, because they are definitely warmer and tend to stick a bit. They do work great for starting corn indoors, if you're inclined to try that sort of thing.

Love your dog photo - he/she looks as though s/he's sharing a joke with you...

Ever since I read about people using oddball heaters to make DIY heat mats, I've been keeping my eyes open for some large box I could insulate, to heat 4+ trays. It would have an air space to diffuse the heat ...

But I don't really need it. And after I made it, I would have to find a place to store it 8-10 months of the year.

I do have one commercial heat mat that has some thick rubberized coating. It looks identical to every heat mat I've seen advertised.

Even so, I lay plastic film over it to help keep water away.

I've used the Hydrofarm heat mats (both single and double) for several years without a thermostat. If you find it a little too hot, and drying out your seed-starting mix too much, just raise your trays a bit (4 milk-jug covers, 1 in each corner provides about 1/4" airspace).

I have 3 different brands now (6 mats) and I think the Hydro Farm is the best quality. Regarding Thermostats - I have one, but consider that it was a waste of money. Cost more than a heat mat.

I would not buy some cheap no-name heat mat. Even to save money.

Thanks for the tip about starting corn inside.. Woofie.. we are going to give them a try this year

I started them in the square peat pots, the ones that are 3 or 4 inch. That worked out well, because you can just bury the whole pot when it's time to set them out. Anyone know how long seed corn keeps?

I've started corn indoors, too. Otherwise, the rabbits seem to get it as soon as it sprouts. Sigh....

woofie said:I started them in the square peat pots, the ones that are 3 or 4 inch. That worked out well, because you can just bury the whole pot when it's time to set them out. Anyone know how long seed corn keeps?

IIRC, 1 - 3 seasons depending on how/where it is stored.

I have several windowsill heat mats like this for my lighted shelves. They work well for me, no thermostat. They raise the temp just enough to make the seeds "pop".

I found this at Google images
http://parkseed.com/images/l/0...

Karen

those look nice