Post by francis on Dec 29, 2016 17:03:13 GMT
Cheap - Silicon Heated blanket – Guitar side bending review
Bought this unit off E-bay advertised as:
Advert images showing the blanket, controller and connection, close-up of the controller:
The unit shipped from the Channel Islands as they’re within the UK I expected it to come with a UK mains plug – it didn’t, it came with a USA style plug (twin blades and a round earth pin). No documentation came with this unit just the blanket in a plastic bag, inside the plastic postal packaging.
After numerous emails back to the seller I was informed that I just needed an adapter for UK use. So armed with a USA / UK adapter I plugged it in (after setting to °C which is also the off position). I have a digital probe thermometer which I used to monitor temperatures rather than relying on the temperature settings on the controller’s dial.
My test pieces were walnut sides which I’ve had for over 40 years and measuring: 810 x 100 x 2 (mm) not great pieces of timber but ideal for this test.
I used my Fox style bending jig with an OOO/OM side former, two stainless steel slats and the blanket. I placed one slat onto the former then the walnut side piece (this was lightly sprayed with water on both sides), the heater blanket, then the second stainless slat. Pressure was lightly applied at the waist to keep things in position (compared to doing this with light bulbs as the heating source the blanket made alignment easier as nothing slipped around).
The thermometer probe was slipped between the upper slat and the blanket at the lower bout position. Turned the controller to 50°C – left for some time but nothing happened, then 60°C – ditto, at 80°C it came to life with lots of fumes which was just from the blanket itself. Left at 80°C the thermometer agreed ± 5°C. Temperature was then raised on the controller in 10°C increments to 120°C. More fumes were given off at each stage along with steam from the wetted sides. I left the setting here to see how it stabilised. The temperature increased to 137°C, then cooled back to 120°C where it cut in again raising to 140°C again and cycling between these temps. The thermocouple is obviously cutting in/out controlling the temperature range but it doesn’t seem particularly exact in when it does it. That may be due to other factors as I’m not taking the thermometer temperature adjacent to the thermocouple.
First side came out very well despite the walnut having problem short grain areas (which is why it was never used in all those years!) no spring-back and it laid in the body mould without me needing to spring the ends into the mould.
For side two I packed the bender in the same manner as side one, this time I set the temp controller directly to 120°C. The blanket heated quickly and it was possible to apply clamping pressure to the waist area much earlier than I would have with the light bulbs. Also noticed whilst applying pressure at the waist, the lower bout end was beginning to self-wrap around the former with just the weight of the blanket and steel slat. Once the upper and lower bouts were fastened down I let the heater go through three heat/cool cycles before turning off and unplugging the blanket. Full cool down to ambient (12°C) takes about 20-25 mins.
I went directly to a 120°C setting with side two to see if the stepping up in temperature for the first side and thus a longer (if lower) heating time had made a difference.
Side two successfully bent as well – both very even, no spring back, coped with problem grain areas, little water needed.
Pros: Even heat directly against the timber making bending very easy, comes to temperature quickly, clean in use. Thermocouple limits temperature range
Cons: Holding Temperature ± 12-15°C quite wide, not something I would leave unattended.
I’ve been impressed, this is my first use of this particular heater blanket (can’t comment on others found on the bay or elsewhere) working with what I would consider poor quality side material and it has handled it well. Initial impression is one of being much better than the light bulb heating used prior to this. I can see my bender being modified (or a new base unit – just in case!) as I no longer need a light bulb housing. I used the same temperature indicator with operating temperature attained very quickly (a few water droplets on the upper slat and watching how quickly they sizzle and evaporate). I guess time will tell just how well this blanket works.
I now have a pair of OOO/OM sides that I didn’t anticipate…
Francis / Dec – 2016.
Bought this unit off E-bay advertised as:
Advert images showing the blanket, controller and connection, close-up of the controller:
The unit shipped from the Channel Islands as they’re within the UK I expected it to come with a UK mains plug – it didn’t, it came with a USA style plug (twin blades and a round earth pin). No documentation came with this unit just the blanket in a plastic bag, inside the plastic postal packaging.
After numerous emails back to the seller I was informed that I just needed an adapter for UK use. So armed with a USA / UK adapter I plugged it in (after setting to °C which is also the off position). I have a digital probe thermometer which I used to monitor temperatures rather than relying on the temperature settings on the controller’s dial.
My test pieces were walnut sides which I’ve had for over 40 years and measuring: 810 x 100 x 2 (mm) not great pieces of timber but ideal for this test.
I used my Fox style bending jig with an OOO/OM side former, two stainless steel slats and the blanket. I placed one slat onto the former then the walnut side piece (this was lightly sprayed with water on both sides), the heater blanket, then the second stainless slat. Pressure was lightly applied at the waist to keep things in position (compared to doing this with light bulbs as the heating source the blanket made alignment easier as nothing slipped around).
The thermometer probe was slipped between the upper slat and the blanket at the lower bout position. Turned the controller to 50°C – left for some time but nothing happened, then 60°C – ditto, at 80°C it came to life with lots of fumes which was just from the blanket itself. Left at 80°C the thermometer agreed ± 5°C. Temperature was then raised on the controller in 10°C increments to 120°C. More fumes were given off at each stage along with steam from the wetted sides. I left the setting here to see how it stabilised. The temperature increased to 137°C, then cooled back to 120°C where it cut in again raising to 140°C again and cycling between these temps. The thermocouple is obviously cutting in/out controlling the temperature range but it doesn’t seem particularly exact in when it does it. That may be due to other factors as I’m not taking the thermometer temperature adjacent to the thermocouple.
First side came out very well despite the walnut having problem short grain areas (which is why it was never used in all those years!) no spring-back and it laid in the body mould without me needing to spring the ends into the mould.
For side two I packed the bender in the same manner as side one, this time I set the temp controller directly to 120°C. The blanket heated quickly and it was possible to apply clamping pressure to the waist area much earlier than I would have with the light bulbs. Also noticed whilst applying pressure at the waist, the lower bout end was beginning to self-wrap around the former with just the weight of the blanket and steel slat. Once the upper and lower bouts were fastened down I let the heater go through three heat/cool cycles before turning off and unplugging the blanket. Full cool down to ambient (12°C) takes about 20-25 mins.
I went directly to a 120°C setting with side two to see if the stepping up in temperature for the first side and thus a longer (if lower) heating time had made a difference.
Side two successfully bent as well – both very even, no spring back, coped with problem grain areas, little water needed.
Pros: Even heat directly against the timber making bending very easy, comes to temperature quickly, clean in use. Thermocouple limits temperature range
Cons: Holding Temperature ± 12-15°C quite wide, not something I would leave unattended.
I’ve been impressed, this is my first use of this particular heater blanket (can’t comment on others found on the bay or elsewhere) working with what I would consider poor quality side material and it has handled it well. Initial impression is one of being much better than the light bulb heating used prior to this. I can see my bender being modified (or a new base unit – just in case!) as I no longer need a light bulb housing. I used the same temperature indicator with operating temperature attained very quickly (a few water droplets on the upper slat and watching how quickly they sizzle and evaporate). I guess time will tell just how well this blanket works.
I now have a pair of OOO/OM sides that I didn’t anticipate…
Francis / Dec – 2016.
, the figures on the dial are loosely (because it's a bit awkward to set the temperature lines exactly to the indicator) the lower temperature and the upper temp is about 20 - 25°C above that. So I have a ball-park range to work with now. 
'anything that gets the pig clean' not heard that one before 
Jo whoever he is.
