Silicon Blanket

Kim Strode · Post by **Kim Strode** » Sat Oct 20, 2007 2:36 pm

I'm new to guitar making and I've heard reference to using a silicon blanket when bending the sides. Can anybody tell me where to buy these silicon blankets and what are the advantages

TimS · Post by **TimS** » Sat Oct 20, 2007 3:24 pm

Try http://www.michaelsenterprises.com/. Other sources are LMII. I am sure there are several forum members who would also have a link.

regards

Tim

matthew · Post by **matthew** » Sat Oct 20, 2007 3:47 pm

Watlo have an office in melbourne. They sell ALL sorts of silicone blankets and custom make if you want.

Bob Connor · Post by **Bob Connor** » Sat Oct 20, 2007 5:06 pm

G'day Showtell and welcome to the forum.

Sounds like you have or are going to build a Fox bender or similar.

Originally the Fox bender was heated by 150 watt light globes but controlling the heat was a problem and they took a long time to warm up.

The blanket will get to around 300 degrees C in around 4 minutes so it is quick and you can bring the temperature down fairly quickly if things start smoking.

Some sort of temperature control is handy and a thermometer is virtually essential.

I got a motor speed controller kit from Dick Smith which I use as a temperature control.

I got the blanket from Luthiers Mercantile International in the States.

Cheers

Bob

matthew · Post by **matthew** » Sat Oct 20, 2007 5:46 pm

Some advantages are

- silent
- heats the whole rib, not just one bit at a time
- more pleasant to work with than a steamin hot pipe

Some disadvantages are

- tricky to make small adjustments (still need the hot pipe)
- more costly
- 240 volts + water is potentially fatal. But the blankets are pretty safe in themselves as long as you look after the leads and use an earth leakage detector/circuitbreaker in the curcuit.

Kim Strode · Post by **Kim Strode** » Sat Oct 20, 2007 6:14 pm

With regard to temperature control Bob, how do you use the the motor speed controller from Dick Smith to achieve that?

Bob Connor · Post by **Bob Connor** » Sat Oct 20, 2007 6:24 pm

It acts like a high powered rheostat - ie light dimmer.

The blanket I've got is rated at 1500 watts so so it sucks far too much juice to use a standard light dimmer.

You've got to be very vigilant using these things. The get so hot, so quick that they'll set fire to your side bender if you get distracted.

A lot of people use a timer with them as well.

They cost a bit to get set up with but are very easy to use and give a much more consistent result than a bending iron.

What sort of wood are you planning on using?

matthew · Post by **matthew** » Sun Oct 21, 2007 7:30 am

You can also use a standard stove elemt controller to keep them regulated. These little black boxes with knob on them have a tiny internal element and a bimetallic strip. They don't have a thermostat as such, but they heat up in parallel with the heater and go on-off-on-off to keep the temp at the setting you choose.

Or you can be really cheap (but effective) and use a manual switch in the power cable. After experimenting with controllers, I now do this for simplicity. Set up the sandwich with damp wood, turn on the heat. As soon as I hear the thing sizzling (steam!) I start turning the screws and when its nearly there I flick off the switch. If it cools and stiffens too much, I just flick the switch back on again for a few seconds.

Lillian · Post by **Lillian** » Sun Oct 21, 2007 10:09 am

Welcome to the forum Showtell.

I bought mine at Omega in the US. About half the price of LMI or John Hall.

I have a 15 minute timer in the line as a safety precaution. It all but eliminates the possiblity of burning down the shop.

Hesh1956 · Post by **Hesh1956** » Mon Oct 22, 2007 12:22 am

Welcome Showtell!!

Another huge advantage of using a blanket is that you will be far less likely to crack a side...... This is huge because when you crack a side it can cost as much as the blanket depending on the wood.

I learned to bend on a pipe and then after several guitars that I made with a pipe I switched to a Fox style bender and a blanket. What a difference the bender and blanket make and time savings too.

Serge · Post by **Serge** » Mon Oct 22, 2007 1:18 pm

Hi Showtell, welcome here mate!

i use a combo of both the bulbs and heat blanket and love it to keep it all warmed up and for being able to reduce the direct heat from the blanket.

I use 3 x 150 watts bulbs which is more than enough once the blanket has done it's job, once the wood is bent and clamped.

Please keep us informed on how it goes and just remember that we love pics, fox bender pics too!

Allen · Post by **Allen** » Tue Nov 06, 2007 7:05 pm

TimS wrote:Try http://www.michaelsenterprises.com/. Other sources are LMII. I am sure there are several forum members who would also have a link.

regards

Tim

Did you get a blanket from these guys Tim? I haven't emailed them yet, but others I have just give me a bit of the "blank stare" when I ask for a 240 volt blanket.

I guess the other option is to go with a 110 volt one and get a large enough transformer to run it. Then I've got the option to pick up a Festool from overseas at a huge discount.

TimS · Post by **TimS** » Tue Nov 06, 2007 8:22 pm

Whoops! I clicked the wrong button and did the PM thing.

......anyway. I sourced my blanket from LMII that was 220-240 volt. I am sure that there are other suppliers. it is probably more a case of them having a myopic view: all things are 110V!

I have a luthier friend over here who is trying to put together a switching unit to enable me to give the sides a timed burst over an extended period of time. If anyone has any thoughts on the matter let me know.

regards

Tim

Craig · Post by **Craig** » Tue Nov 06, 2007 9:39 pm

I recently bought a 240 volt blanket from John Hall ,(Blues Creek Guitars). in the States. The reason I got his one was because they are industrial grade and rated at 5 watts per inch . That , and the price $100 plus $40 U.S. for shipping. Didn't think that too hefty a price tag for the good gear.

Arnt · Post by **Arnt** » Tue Nov 06, 2007 10:14 pm

I also bought my 5W/square in. 240V blanket from John Hall, it works well.

gratay · Post by **gratay** » Tue Nov 06, 2007 10:28 pm

I bought the LMI 240v international one....
came with a weird looking plug on it which I just replaced with an australian 3 prong standard...and I plug it straight into the wall..
I don't have any temp control or timer.....just a meat thermometer which my eyes never wander from...
It works as long as you have your hands on the job of bending , someone elses hands on the power switch at the wall toggling on and off and a fireman at the ready with a hose.
I don't suggest that you do it this way at all and under no circumstances be responsible for the overcooking of ones house

Kim · Post by **Kim** » Tue Nov 06, 2007 10:38 pm

I have not actually built a guitar with my heat blanket yet, I found it does a joint of pork so well I have given up on that idea and have dedicated myself to dripping pig fat on my keyboard instead....(Homer style)uuuuummmmggggggggrrrrrhhhh piiiiiggg faaaaaattt

Cheers

Kim

Arnt · Post by **Arnt** » Tue Nov 06, 2007 11:26 pm

My "temperature monitor" is a spray bottle of water! I simply spray the top steel slat and observe how the water behaves; if it bubbles its not hot enough, if it goes up in a cloud its too hot, if it sizzles a while before it disappears it is fine. Some woods like it hotter than others to bend and not spring back, so you have to keep this in mind as well. My Fox bender has a couple of halogen light bulbs inside (from old gutted work lamps, they were all I used the heat the bender when I first built it) which I use in combo with the blanket. The bulbs and the blanket can be controlled separately which gives some additional control over the heat. Not fancy, but hey, it works!

Allen · Post by **Allen** » Wed Nov 07, 2007 6:32 am

Thanks everyone. I'll give John Hall a go.

matthew · Post by **matthew** » Wed Nov 07, 2007 4:46 pm

Simple to add an in-line switch about 90cm along the cord from the heat blanket. That way you don't have to run to the wall!

My heat gauge is also water-based. The wood is spritzed before the sandwich is laid up. When I can hear the sandwich sizzling and see a bit of steam escaping at the sides, that's about right. I flip the OFF switch and down go the screws. When it starts to resist again, I give the blanket another 10-15 seconds blast.

Allen · Post by **Allen** » Wed Nov 07, 2007 5:37 pm

I emailed MEI about a 240 volt blanket and they got back to me right away.

Said they should be able to build me one and have asked

Would you like a thermostat (if so what temperature set point would be needed) or a thermocouple wire attached?

Any suggestions here? They would then give me a quote on price and availability.

matthew · Post by **matthew** » Wed Nov 07, 2007 7:49 pm

nice, but it sounds like sophistication you might not need, at least to start with. What sort of cost for the thermostat are they talking?

Allen · Post by **Allen** » Wed Nov 07, 2007 8:23 pm

Don't know, that's the whole of the email other than saying they could build to suit and would provide a quote.

What sort of temperature would I ask for? I'll get them to quote with and without.

Allen · Post by **Allen** » Wed Nov 07, 2007 8:26 pm

I should say that all I've used before has been 3 150 watt bulbs that I let heat up for 20 minutes and went on to bending from there. Or the bending iron and just have set it on to high or just less.

I wouldn't say that I could have ever scorched the wood, though I did get a good sizzle. I don't have a thermometer that is capable of measuring the side bender temp, so it's just a guess for me.

matthew · Post by **matthew** » Wed Nov 07, 2007 9:21 pm

Well, I just turn it on long enough so the thing is too hot to touch, then it's about right. All happens quite quickly after that. And can just turn it off again. And on again for a quick blast. That way I am heating only the minumum time necessary. Not cooking the wood for ages at a certain temp. But p'raps that's another technique?

Dunno, maybe guitars are different.

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