DIY Silicone Heat Blanket

[sir.orange]

Is this the right dimmer?? http://www.ebay.com/itm/POWER-REGULATOR ... 2213wt_982

for heating application i think you d be better with at least 2000VA = Watts Output, that one you found is more for electric motors it says only a maximum of 600VA = 600Watt Output at 110V

[troublemaker]

Will

[troublemaker]

BTW... I have about 2000 feet of NiChrome wire, 25 gauge 2.06 ohm per/foot. In my blanket I'm using about 100' of wire so I will have alot left over. Total wattage of mine is going to be somewhere around 1400w. So I will for sure share the wealth!

[sir.orange]

what 40000V can "create" depends on amperage, one without the other is nothing (U*I=P) but for our application the voltage rating isn t that much interesting....

will it work? it depends how your wires are connected: is it just ONE wire or are wires connected in a parallel curcuit, how many parallel rows?

check on the web how resistances in parallel circuits work:

with the info "total resitance" and "voltage" u can calculate/estimate power and amperage.

i think 2,06Ohm is much too less, im using wire with 19Ohm per meter, (working on 220V)depends on what voltage you work,110V?

if you ll post your calculations here, we can check them very easily, only results are hardly comprehensible.

[troublemaker]

Well my blanket has 4 parallel circuits which are 51.4199 ohms each, 12.854975 total ohms, 110VAC = 1414w. Or somewhere around there, I can always add another circuit and change the wattage.

[sir.orange]

12.854975 total ohms, 110VAC = 1414w.

makes 941W in my calculation, am i wrong?

what temperature are you aiming?

[troublemaker]

You are correct! I had a brain fart!

[vol]

blanket surface looks spotty, whether these bumping is not transmissible to bottom after lamination? maybe would be nice to put some plastic on top then some board and make some pressure when silicon cure?

[chrismp]

i use 2mm thick aluminum sheets for my cassettes and i get no indentations from the blankets.

[troublemaker]

messed up stand by

[troublemaker]

1326 watts, 11.2 amps, 194*f, takes about 5 minutes to get to full temp pluged directly into the wall.

[MontuckyMadman]

Woooo blue... please share details...
nice. Silicon? Nice work.

[troublemaker]

First off who ever said they used 1KG of silicone for a complete mat was a little bit off! I used about 2.5 KG. I bought 2KG of silicone off Ebay for around $80 shipped, mold making stuff high temp 600*f 50a hardness. Then I used 2.3oz chopped strand fiberglass mat for backing. If I make anymore blankets I will use 2oz cloth instead. This blanket is 15"x78" 76" useable lenght. To get the silicone to flow out smooth I placed some wax paper on the top then a piece of masonite on top of that then placed my summer tires off of my jetta for weight, silicone set up in about 3 hours. Flipped the mat over and laid out the grid of finishing nails. Placed nails 3/4" apart making 5 circuits all wired in parallel. The neat thing I did was use buss bars, one on each side of the mat. I poked holes in the mat to run the five wire ends to the other side buss bar. Then I drilled two 1mm holes per wire in the buss bar for a connection point weaved the wire through the holes twisted back onto them self, good tight connection. The wire I used was some Hott Watts brand NiChrome 25 gauge wire (2.03 ohms per foot) from Ebay. (I have alot left so if anybody needs some just ask!) Then I crimped on a high temp ring terminal onto the lead wire and hand hammered rivet it to the buss bar, low profile and very strong. Oh, BTW the buss bar is .032 aluminum scrap I had laying around. Then I applied a layer of silicone on top of everything then another layer of chop strand. I left the nails in the whole time during the process, pulled them out just before the silicone set then rubbed the spots down with my finger to fill the holes. Then I flipped the mat again to attach the other buss bar and negitive lead wire then covered with more silicone and fiberglass. The lead wire is 12 gauge outdoor lighting wire, could of used 14 gauge and been fine. Well thats about it, take a look at the pictures below for more info.

[troublemaker]

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[troublemaker]

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