DIY Silicone Heat Blanket

[krp8128]

FYI


If you raise your temps too quickly you will hit the glass transition temp of your epoxy, ruing the structural integrity of the entire composite.

You want to "chase" this temperature point with your ramps...

[Richuk]

can you elaborate further ... does 10 oC/ min fit with your understanding?

This is the sort of thing I'm starting to read ... http://books.google.co.uk/books?id=VkX5 ... le&f=false , which points towards a two stage ramp, pressurisation and then soak.

[endre]

through the cassette plates and base materials the heat needs time to get through.

80C or warmer is what i use for hardening solid blocks of wood for cores, for skis i use lower temperatures and then hardening in a heating cabinet

[brazgotine]

Hello,
I did my own heat blanket. If you want to build one you need:

- silicone rubber plate 3 mm thick x 2000 mm x 450 mm 2 x piece
- silicone in tube (200 degree silicone) - 5 tubes
- cekas wire (I used 1 mm thick wire)

1) You have to spine the wire around another wire (5 mm thick steel wire). I used electric drill, so I could spin the wire in reasonable time.

2) When you are finished you have to grab in one side and pull in another. You want to, almost flet the wire.

3) Clean the blanket (Clean it with hot water) and put it on the table.

4) Template - I nailed the nails in to the table - 10 mm away - on each side - true the blanket - 30 nails in each side.

5) Then I put the wire around all the nails !!! But be care full, you have to measure how much resistant you get. I had to make 3 fields and then wire them parallel - I got 63 oms (that was to much), the I mad 3 pieces and I put them parallel and it was 63 / 3 = 21 oms, mine is 20,8 oms.

6) Put the silicone (in tube) on the wires and silicone plate - you have to put it enough / one to 2 tubes. Then make it even and check each wire that is not in another wire.

7) Wire all up - electricity

Put the silicone (in tube again)

9) Put the silicone rubber plate on everything !!! DON'T PUT NAILS OUT !!!!

10) Put the wood on the blanket - but it has to be between the nails and make pressure on it.

11) Leave it for 2 days

12) Put the nails out and silicone that part as well

13) Repeat the step 10 ! But in this case all the blanket.

NOV YOU HAVE IT !!!!

IT COST ME 130 € !!!!

[MontuckyMadman]

Hello,
I did my own heat blanket. If you want to build one you need:

- silicone rubber plate 3 mm thick x 2000 mm x 450 mm 2 x piece
- silicone in tube (200 degree silicone) - 5 tubes
- cekas wire (I used 1 mm thick wire)

1) You have to spine the wire around another wire (5 mm thick steel wire). I used electric drill, so I could spin the wire in reasonable time.

2) When you are finished you have to grab in one side and pull in another. You want to, almost flet the wire.

3) Clean the blanket (Clean it with hot water) and put it on the table.

4) Template - I nailed the nails in to the table - 10 mm away - on each side - true the blanket - 30 nails in each side.

5) Then I put the wire around all the nails !!! But be care full, you have to measure how much resistant you get. I had to make 3 fields and then wire them parallel - I got 63 oms (that was to much), the I mad 3 pieces and I put them parallel and it was 63 / 3 = 21 oms, mine is 20,8 oms.

6) Put the silicone (in tube) on the wires and silicone plate - you have to put it enough / one to 2 tubes. Then make it even and check each wire that is not in another wire.

7) Wire all up - electricity

Put the silicone (in tube again)

9) Put the silicone rubber plate on everything !!! DON'T PUT NAILS OUT !!!!

10) Put the wood on the blanket - but it has to be between the nails and make pressure on it.

11) Leave it for 2 days

12) Put the nails out and silicone that part as well

13) Repeat the step 10 ! But in this case all the blanket.

NOV YOU HAVE IT !!!!

IT COST ME 130 € !!!!

i guess i understand but some pics would be sweet

[MontuckyMadman]

would it be really bad if the resistance wires touched in the blanket? the parallel circuits touching would be really bad huh?
i guess the nails are a good idea.

[MontuckyMadman]

brazgotine, have you put your blanket under pressure yet?

[brazgotine]

Yo,
I have finished the electornic box and it's working fine. I have press some small test models that I have done and it's was fine. I will test mine next week.

I didn't shoot photos while I was working, because it was dammmm cold and I wan't it to finish fast.

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[chrismp]

7) Wire all up - electricity

nice one! you could make it even cheaper by using just silicone resin and fiberglass mats.

could you give some more info on your point seven? we're having some troubles with the wires producing too much heat around the lead wire connection.

[brazgotine]

I have put my wires near end in TERMO rubber. I knew that here can be some problems.

And again - I didn't put cekas all around in one piece - I made 3 separate parts inside heat blanket and the wire them parallel.

Greetings !

P.S. Do you use AUTO TUNE in your PID ? If you - then mine oppinion is that you have smoked the cekas wire at the begining - to much power.

[MontuckyMadman]

cekas = ??

Your blanket looks very lumpy, will this be a problem? I think so.

Are you using pneumatic pressure press?

[chrismp]

I have put my wires near end in TERMO rubber. I knew that here can be some problems.

And again - I didn't put cekas all around in one piece - I made 3 separate parts inside heat blanket and the wire them parallel.

Greetings !

P.S. Do you use AUTO TUNE in your PID ? If you - then mine oppinion is that you have smoked the cekas wire at the begining - to much power.

well, all our silicone is heat resistant up to 450°C max.

same here, what are cekas? we are using four wires in parallel as well.
i just think the problem is that we just wound these wires around the lead wire in the same place which generates too much heat in that spot.

we don't use a PID. we have a dimmer and control the power manually.

[Richuk]

80C or warmer is what i use for hardening solid blocks of wood for cores, for skis i use lower temperatures and then hardening in a heating cabinet

Endre, can you say a bit more about why you do this? I'm assuming you're concerned about the internal moisture content of the wood you are using, but I still can't make sense of it : (

[MontuckyMadman]

I think he just does his core lamination witha heat cures epoxy. Best way is on the press.

[Richuk]

But the cure temp in less and doing this would affect flex and create uncertainty. Endre is very certain about his results and rightly so. If you want to vertically laminate fibres into the core, then maybe ...