Guitar sized Heat Blanket & Ukes Query

[Clancy]

Does anyone use their guitar sized heat blanket to bend (concert) uke sides?
I'm worried that there wouldn't be enough heat transfer off the blanket & this would cause it to burn out.

What do you reckon?

[Kim]

Don't know for sure Craig but it would have me concerned as well. That said I was up visiting Mr Spittle a while back when he demonstrated his hand bending set up. He simply draped his PID controlled heat blanket over a pre-shapped MDF form that had been placed in a vice, set the temp to around 300f if I recall, turned it on and in a minute or two went to work happily bending samples with seemingly no ill affect to the blanket.

Cheers

Kim

[liam_fnq]

I use a guitar blanket on all my ukes.

I use a solid form with the blanket over it then the side over that. No slat, no craft paper. The blanket and side are fixed in place at the tail end of the mold. I give the underside of the side a light spray with water as I bend it down by hand. I wind the waist section down with a caul once I get that far then carry on with the upper bout by hand.

I do the two sides at once. It takes about 7-8 mins. About half the blanket dangles down the front of the bench

What makes you think that the blanket hanging in the air would over-heat due to a struggle to dissipate heat?

Has anyone had this experience?

I guess it's all to do with the design charateristics of the blanket. A pretty shitty design if they do though.

[matthew]

i use my 10"x18" blanket all the time for small work and it doesn't seem to worry. but I don't leave it on for hours, i just turn on the juice for long enough that the wetness sizzles and the wood bends, then turn it off.

[J.F. Custom]

Yep - use my guitar blanket for my uke's too.

I'd like a uke sized blanket but haven't justified the additional expense thus far. Mostly wanted for convenience though, not for concern.

I've not experienced any issue with respect to your enquiry, either literally or perceived by smell or other. Of course, the blanket is only on for about 1-1.5 min or so too. I could see it being a potential problem if left on for lengthy periods.

An email to the maker in our preferred vendor list may get some further detail into what is ok and what is best avoided.

Jeremy.

[jeffhigh]

I have seen a suggestion before that excess blanket can overheat, can't understand it, surely it will cool in the air.
Perhaps a misunderstanding encouraged by suppliers who want to sell us more different size blankets.

[Clancy]

Thanks everyone.

I'm yet to use the blanket, it's been gathering dust for a while now
(I just metered it out & turned it on to test it when it arrived from LMI.)
I had dragged it out thinking I would finally make use of it & read the warranty warning about turning it on without any load on it & just wondered if 2 uke sides would constitute enough of a load to avoid problems.
Probably just over-thinking matters.

Cheers

[liam_fnq]

I have seen a suggestion before that excess blanket can overheat, can't understand it, surely it will cool in the air.
Perhaps a misunderstanding encouraged by suppliers who want to sell us more different size blankets.

I guess that the 'Blanket Overheating Theory' is a misguided extrapolation of the pot of water on the stove never getting above 100C until the water boils off and there is nothing to regulate the heat.

I suspect this "Theory" is another bit of common wisdom in the luthery world being spread as fact by those that have no first hand knowledge of it occuring.

I shouldn't be so cynical though should I, that never happens....................

[Kim]

I shall leave this one to greater minds but will continue to avoid leaving the blanket switched on for extended periods without a PID/control unit to regulate the heat build up simply because there is no need to risk damaging the blanket or causing another Chernobyl in my shed even if that risk is only perceived.

As others have pointed out it should not be a problem for the short durations required for a set of uke sides and such.

Cheers

Kim

[Craig]

I have a "Protherm " blanket ( from John Hall USA ) It's 1080 watts.

The instructions say :
To avoid damage to the Silicone Rubber Multi-use Heater :
Never operate the heater without an appropriate heat sink . The heater should not be mounted free standing in air.


When I've used it to bend a short piece such as a cutaway section , I have attached a piece of waste wood to the remainder of the blanket ( with big bulldog clips ) .
Simple enough to do rather than risk burning the thing out .

[Allen]

Let see....I've bent close to 100 uke sets and around 20 guitar sets, and 2 Weissenborn sets with my 6" x 38" bending blanket and it's still going strong. I reckon I've got my moneys worth out of it.

I don't have any fancy gear to go with it other than a on/off switch. Full on for 2 minutes and do the bend. Then turn off. Never takes more than 2 1/2 minutes. Let cool, then turn on again for 2 minutes. Let cool and away you go.

[Tod Gilding]

Found this on the LMI web site, may just be to cover their A*$e:

Side Bending Blankets



Our specially made 1/16” hard rubber heating blankets are made to heat thin wood pieces, like guitar sides and bindings, to the 300+°F necessary to bend them to the desired shape. These blankets can reach 500°F in just a minute or two, therefore, they must be used with either a timer or temperature controller to keep the blanket and/or the wood from burning up. These devices are absolutely necessary for safety in your shop. Our LMI Temperature Controller (part #TC or TC220) and timer (part #DT) are highly recommended for use with these blankets and are required for us to honor a warranty.

[liam_fnq]

hmmmm............they lost me at the "specially made to heat thin wood pieces" part.

the blankets are from sources like thishttp://www.michaelsenterprises.com/

clearly made for many and varied purposes.

[Lillian]

Tod, the timer is a safety feature that was easy to add to my blanket. Its an in line wind up timer that is used instead of motion sensors. Mine has a fifteen minute limit on it. Since my shop is in the house, I didn't want to take a chance on a mishap.

Temperature control is nice, but not necessary. A digital thermometer, make sure it goes high enough, works just fine.

[Tod Gilding]

Hi Ya Lillian, I just posted what I found on the LMI site,I am Making a side bender in the not to distant future and very interested in this topic but I know nothing about these blankets, I have seen John Buckhams ( The Woodrat) and his setup seems very good, and john tells me he can bend sides very fast with his blanket, but looking at the cost of this ( with a timer etc), I think you would need to make a lot a guitars to get value for money, that's something I'm not sure about,and maybe I might go the light bulb way, anyway I'm getting off topic, but thanks for the info.

[Bob Connor]

Tod

I don't think that anyone who has tried the light bulb method would recommend it after changing to the blanket method.

Around a hundred bucks is cheap insurance when you can easily ruin side sets that are worth more than that.

I have the temperature controller and associated gizmos but like Allen I don't use them. It takes about 4 minutes to bend a side so as long as you can maintain concentration for a short period of time there is really no need to fork out the extra expense for the extra electronics.

If you build a couple of instruments and decide you don't want to do it any more you will have no trouble at all selling your blanket on this forum.

Regards

[joolstacho]

Tod, I wouldn't bother with light globe heat. When you start cold, the side/slats are sticking straight out so the heat from the globes can't get to the ends. I found I needed to pipe-bend the bout curves by hand first, which then meant I couldn't load into my bender without disassembling the top ((waist) screw.

-Jools

[Allen]

Started with the light bulbs, and bent 3 guitars with them. Would never, ever go back to them. In fact, if you want the ceramic bulb holders and light bulbs you can have them.

[liam_fnq]

Tod, go with the blanket.

You've only got to ruin one nice set and the blanket has paid for itself.

Further more, I had plans to go the light bulb route, until I added up the cost of ceramic bulb holders, bulbs and dimmers. Then there's the fact that they're fazing out high watt bulbs. etc. etc

[Clancy]

Until now, every time I went to bend the sides I'd pull out the heat blanket - then think about having to make the form & a clamping system & set it all up & wrap up the sides & align it all, etc, etc.
Then I'd put the blanket away, get out the bending iron & just do them by hand in about 10 mins.

[Tod Gilding]

Well That settles it, Out with bulbs Idea and I'm ordering a blanket ASAP

Thanks everyone for the advice, I appreciate it

Am I Understanding correctly ,that blankets can be used without the timer,Thermostat etc,just plugged directly to wall socket and adjusted by turning Off after it reaches heat.
The reason I am checking on this is that picture of the blanket on the LMI site seems to have a strange plug on it and I was under the impression that it had to be plugged into the thermostat unit and then the Thermostat plugged into the wall ????

[Bob Connor]

You'll need to replace the supplied plug with an Australian one.

I'd suggest you get an oven (chook) thermometer from Dick Smith too. (about $12.00)

Just plug the blanket in and start bending when the temperature gets to 100-120 degrees C.

Once you've completed the bend unplug the blanket.

This should take no longer than 5 minutes.

[Tod Gilding]

Thanks For Clearing that up Bob, Here's a cold one for your help Cheers

[needsmorecowbel]

What is the verdict on brand? Protherm (available at blues creek guitars) vs LMI (standard brand)??? I was thinking of picking up an Ibex Electric Pipe Bender...would it be better to just get a blanket? From what i have read on the forums having both a pipe bender and heat blanket is best. Thoughts? Suggestions?

[J.F. Custom]

What is the verdict on brand? Protherm (available at blues creek guitars) vs LMI (standard brand)??? I was thinking of picking up an Ibex Electric Pipe Bender...would it be better to just get a blanket? From what i have read on the forums having both a pipe bender and heat blanket is best. Thoughts? Suggestions?

I got mine from MEI - http://www.meiheaters.com who are in our preferred suppliers list. Needs a plug on arrival as expected but otherwise haven't had any issue at all.

However, yes, I've got the Ibex iron as well and would not be without either. I use both of them frequently - the blanket for full side bending and the pipe for touching up spring-back, or other odd jobs such as bending purfling to shape prior to inlay etc.

If you had to pick one for financial reasons, you could always go for the blanket first. The pipe you can do other cheaper versions of rather than the deluxe convenience of the Ibex and you'd still have the best of both worlds then. Not much can replace the blanket itself...

Jeremy.