DIY Silicone Heat Blanket
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
never know what you find out there.
Last edited by MontuckyMadman on Tue Apr 05, 2011 7:20 pm, edited 1 time in total.
sammer wrote: I'm still a tang on top guy.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
So i am finding out I am all screwed up.
Doing all my clacs in metric and ordering materials in standard measurements has finally bit me in the ass.
The sample I got was 1/16 inch. Way to thick.
But I thought it was 1/32". Doh.
So I ordered 1/64" which will be like paper. fack.
I may nave some 1/64" silicon sheet 7 feet long for sale for a song.
I paid 60 but will sell for half most likely assuming its too thin.
Testing...is expensive.
Doing all my clacs in metric and ordering materials in standard measurements has finally bit me in the ass.
The sample I got was 1/16 inch. Way to thick.
But I thought it was 1/32". Doh.
So I ordered 1/64" which will be like paper. fack.
I may nave some 1/64" silicon sheet 7 feet long for sale for a song.
I paid 60 but will sell for half most likely assuming its too thin.
Testing...is expensive.
sammer wrote: I'm still a tang on top guy.
like brazen said, i think you'll be fine with 1/64.
only disadvantage would be that thinner material tends to rip easier, but these blankets don't have to take a lot of tearing forces.
insulation should be fine.
after reading about all the problems you're having, i'm starting to think i was just lucky with the materials i used.
only disadvantage would be that thinner material tends to rip easier, but these blankets don't have to take a lot of tearing forces.
insulation should be fine.
after reading about all the problems you're having, i'm starting to think i was just lucky with the materials i used.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
sweet we will see. I think I will sandwich 2 layers of the 9 oz glass between the sheets.
They did email me and tell me I can return the piece I ordered for credit if I ordered wrong. Thats pretty cool, guess they just melt er down.
I just call and talk to a different person every time and eventually someone will email or call me. I email several of them as well.
Being a small consumer with a large distributor is tough, shouldn't have to be, but it is.
Now that I actually put an order in, they are very responsive.
In retrospect I could use a slight bit more of that durometer rtv around 1300 grams but I didn't like the wet layup factor, I found I was having to really work the rubber into the glass and was moving the wires around.
this sheet lamination should be easy, maybe, and super smooth.
They did email me and tell me I can return the piece I ordered for credit if I ordered wrong. Thats pretty cool, guess they just melt er down.
I just call and talk to a different person every time and eventually someone will email or call me. I email several of them as well.
Being a small consumer with a large distributor is tough, shouldn't have to be, but it is.
Now that I actually put an order in, they are very responsive.
In retrospect I could use a slight bit more of that durometer rtv around 1300 grams but I didn't like the wet layup factor, I found I was having to really work the rubber into the glass and was moving the wires around.
this sheet lamination should be easy, maybe, and super smooth.
sammer wrote: I'm still a tang on top guy.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
Alright. I got my shit and ran my tests.
1/64 with 9 oz glass will work well I think. Very flexible and strong
I pressed a sample at like 2 psi but I don’t think that is even necessary.
I am just gonna lay some extra sheets of mdf and or melamine on there.
You can peel the rubber sheet off but you really have to peeeel at it.
That stuff is covered in talc so I had to wash it all, easier said than done. The talc or whatever was hydrophobic so I had to soap and wash it with a sponge.
I may run a stitch all the way around when done just to prevent the possibility of peeling later on but this will go in the press and not move most likely.
This has taken a long time and I still don’t know if my circuit designs will deliver enough wattage and or blow out my breaker.
12.5 amps is what I got with 10 parallel resisters and a 30awg nicrome wire and 120V.
Perhaps my connection points will generate more resistance at the lead wires? I don’t know how to account for this or how much it would be. I am forgoing the screw connectors and will just wrap the resistance wire around the bare lead wire. In my tests you would have to pull pretty damn hard to get these connections to come apart. I will have my lead wire connections out of the pressing area. Making it long for safety's sake.
Fingers crossed, may know more mon.
1/64 with 9 oz glass will work well I think. Very flexible and strong
I pressed a sample at like 2 psi but I don’t think that is even necessary.
I am just gonna lay some extra sheets of mdf and or melamine on there.
You can peel the rubber sheet off but you really have to peeeel at it.
That stuff is covered in talc so I had to wash it all, easier said than done. The talc or whatever was hydrophobic so I had to soap and wash it with a sponge.
I may run a stitch all the way around when done just to prevent the possibility of peeling later on but this will go in the press and not move most likely.
This has taken a long time and I still don’t know if my circuit designs will deliver enough wattage and or blow out my breaker.
12.5 amps is what I got with 10 parallel resisters and a 30awg nicrome wire and 120V.
Perhaps my connection points will generate more resistance at the lead wires? I don’t know how to account for this or how much it would be. I am forgoing the screw connectors and will just wrap the resistance wire around the bare lead wire. In my tests you would have to pull pretty damn hard to get these connections to come apart. I will have my lead wire connections out of the pressing area. Making it long for safety's sake.
Fingers crossed, may know more mon.
sammer wrote: I'm still a tang on top guy.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
so I am the only one to post here.
sweet success, mostly.
It cooks very well to temp under pressure, 60psi.
it is a little wrinkly, just on the bottom, the top is totally smooth. This will be the top one.
We jostled it getting into the press and I didn't actually press it under pressure except for a heavy mold and sheets of mdf and osb on it.
What happened is being as though I had to wash the talc off to get it to bond with the rtv it also made it very sticky and it wrinkled up on the bottom because it stuck to the AL skin and we fumbled it a bit I think.
I think it wrinkled and got stuck in wrinkles putting it in the press.
Next time I will have each sheet: one side clean for bonding and talc on one side so it can slip and not bind up on the AL skin/cassette.
Total cost $220 for one blanket. That's half price from what I understand.
Perhaps I could get away with less RTV but i used 500g and wasted 250g on several tests.
Thanks for the help Chris I would have never been able to do this without those sites and calc tables i think.
We have a Sparkey coming in to check it out and actually give me a wattage and an amperage, I think, or at least tell us what the whole line draws.
this thing actually gets to temp faster and more evenly then the mei one I have, mostly because it is the whole width of the AL skin but I don't know anything else. I think the wrinkles press flat as the whole material is rather malleable its not the glass that bunches just the rubber I think.
total thickness 1.37mm so pretty damn thin.
This is a pic on the wrinkly bottom, it actually makes it look much worse than it is, shadows or somthin.
sweet success, mostly.
It cooks very well to temp under pressure, 60psi.
it is a little wrinkly, just on the bottom, the top is totally smooth. This will be the top one.
We jostled it getting into the press and I didn't actually press it under pressure except for a heavy mold and sheets of mdf and osb on it.
What happened is being as though I had to wash the talc off to get it to bond with the rtv it also made it very sticky and it wrinkled up on the bottom because it stuck to the AL skin and we fumbled it a bit I think.
I think it wrinkled and got stuck in wrinkles putting it in the press.
Next time I will have each sheet: one side clean for bonding and talc on one side so it can slip and not bind up on the AL skin/cassette.
Total cost $220 for one blanket. That's half price from what I understand.
Perhaps I could get away with less RTV but i used 500g and wasted 250g on several tests.
Thanks for the help Chris I would have never been able to do this without those sites and calc tables i think.
We have a Sparkey coming in to check it out and actually give me a wattage and an amperage, I think, or at least tell us what the whole line draws.
this thing actually gets to temp faster and more evenly then the mei one I have, mostly because it is the whole width of the AL skin but I don't know anything else. I think the wrinkles press flat as the whole material is rather malleable its not the glass that bunches just the rubber I think.
total thickness 1.37mm so pretty damn thin.
This is a pic on the wrinkly bottom, it actually makes it look much worse than it is, shadows or somthin.
sammer wrote: I'm still a tang on top guy.
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MontuckyMadman
- Posts: 2395
- Joined: Fri Jun 20, 2008 9:41 pm
I learned some cool new stuff, the blanket draws 11.9 amps at load on the controller, it cycles but tops at 11.9.
I said 12.5 but the calc was actually 12.3 so I was a bit high. Whatever, I am stoked.
So now I build another one for the bottom.
I don't know the wattage but it seemed sufficient to get it hot in moderate time when we ran it.
The entire shed we are in with both blankets and all the stuff with the radio and heat ON would or could be 36amps. There is only a 10 ga wire running to the shed with 5, 20 amp circuits on a 100 amp breaker. You want to max at 80% of the possible load, in this case being 30amps.
so we will try and not burn down the shed.
I said 12.5 but the calc was actually 12.3 so I was a bit high. Whatever, I am stoked.
So now I build another one for the bottom.
I don't know the wattage but it seemed sufficient to get it hot in moderate time when we ran it.
The entire shed we are in with both blankets and all the stuff with the radio and heat ON would or could be 36amps. There is only a 10 ga wire running to the shed with 5, 20 amp circuits on a 100 amp breaker. You want to max at 80% of the possible load, in this case being 30amps.
so we will try and not burn down the shed.
sammer wrote: I'm still a tang on top guy.