DIY Silicone Heat Blanket

[MadRussian]

MR - It sounds like you are making just the one blanket and the guys are quoting in terms of two.

I don't think so
Of course I want to make two blankets.

We have 1400 watt blankets they draw 12amps each at 120v.

[MadRussian]

Depends how fast and at what pressure u want to laminate.
We have 1400 watt blankets they draw 12amps each at 120v.
We press at 60 psi but laminate pressure is higher. It takes about 15 min to get to 180f if we start at 80f and then 30 min to cook the laminate.
If you press at a higher psi, you may want to cook the laminate faster to avoid pressing out too much resin.
It all depends on the viscosity of your resin sytem and the glass transition of your resin. And speed of cure.
You can press a ski at 125psi if you cook the whole thing in 15min flat, but i wouldnt recommend it in yoir home.
Around 2-3 watts per inch is very suficient for your blanket, 2000 watts will do very well.

well I definitely don't want to a raise temperature fast. my goal to get gradual expansion of components under heat. Epoxy will be Entropy so I don't have to deal with toxic vapors and solvents for clean up. 60 PSI is what I want the press at. Also cassettes will be steel with insulation under bottom blanket and above top blanket which will reduce heat loss. This also should reduce needy of power right?

How much power? You need enough power to reach the final cure temperature. A ramp rate of between 1 and 2 degrees C/ minute appears to be OK. Ramp up too quickly and depending on where your temp probe is located, the body of the ski may start to over-heat or the tips may lag behind. The goal is an even cure, so above a rate of 1.5 degrees C/per minute and you may need a cooling system or a press design that compensates for this issue or both.

MM blanket at 1400 W bringing temperature 0.4°C in 1 min. This way if I even make it blanket around 1600 to 1700 W should be well under 1.5°C rate

[MontuckyMadman]

Entropy does put out toxic vapors at heat cure fyi.

[MontuckyMadman]

Entropy does put out toxic vapors at heat cure fyi.

[MadRussian]

my wife give me ideas this morning. why bus have to be inside the blanket? why not make it outside? Connect each section or the resisting wire to the copper wire then make bus outside of the blanket. Yes it more complicated at first but more I think about it more like it. well basically instead of two wires coming out of the blanket will be 10---15 or so. Does it really matter? I don't think so.

Thoughts

[chrismp]

well, the resistance wire i use is only 0,1mm thick and would easily rip if it stuck out of the blanket.

[MontuckyMadman]

you can have the bus bars extended beyond the contact surface outside of the press but for safety and durability you want them encases in FG and silicon for insulation.

[MadRussian]

well, the resistance wire i use is only 0,1mm thick and would easily rip if it stuck out of the blanket.

I think you misunderstood me.
Resistance wire connect to electrical insulated wire inside the blanket. Then for each section of the resisting wire 2 electrical wires sticking out of the back of the blanket. In other words if you have five parallel groups of resistance wires 10 electrical wires will be exiting the blanket going to junction box of some sort or all 10 going to controller. This way internal bus not needed

you can have the bus bars extended beyond the contact surface outside of the press but for safety and durability you want them encases in FG and silicon for insulation.

I want to get a read of internal bus bars altogether

[MontuckyMadman]

Sounds like wayy more of a pita. You just want a regular plug. Dont think you will never take the blankets out of the press cause your wrong.

[chrismp]

Yep, sounds way complicated. A bus connector inside the blanket isn't that hard to do and like MM said, you should just increase the length of the blanket so the bus is never under pressure.

[MontuckyMadman]

Or run them out the side....

[MadRussian]

Yep, sounds way complicated. A bus connector inside the blanket isn't that hard to do and like MM said, you should just increase the length of the blanket so the bus is never under pressure.

I can make really nice bus. it not about that. Anyway most likely it idea which never going to happen.

On my blanket design.
Looks like single run wire not practical because (I didn't know that at the time) to make it work resistance have to be so high where resistance wire has to be a way to thin. Instead most likely layout will be resistance wire will be running back and forth three times and bus still on opposite side. My only problem here I can't use nails to lay resistance wire hopefully tape will do the trick.

My bus bar. 0.020" stainless steel, can do aluminum instead if it better (probably not)

[MontuckyMadman]

btw if the blanket is anything but completely smooth it will transfer through the cassettes. Trust me.

[MadRussian]

btw if the blanket is anything but completely smooth it will transfer through the cassettes. Trust me.

pictures of the blankets I see in this thread is not smooth and fairly thick compared to commercial one's. Can blanket compressed under pressure?


to run resistance wire three times back and forth I have to use 36gauge wire. Would it be to thin?

[MadRussian]

Sounds like wayy more of a pita. You just want a regular plug.

power strip can be used to plug each circuit into. This way it will be very easy to disconnect. In 120 V no modifications. In 240 V switch and light will not work.