The success that [Julian Baumgartner] has found on YouTube is a perfect example of all that’s weird and wonderful about the platform. His videos, which show in utterly engrossing detail the painstaking work that goes into restoring and conserving pieces of fine art, have been boosted in popularity by YouTube’s Autonomous Sensory Meridian Response (ASMR) subculture thanks to his soft spoken narration. But his latest video came as something of a surprise to lovers of oil paintings and “tingles” alike, as it revealed that he’s also more than capable of scratch building his own equipment.
Anyone who’s been following his incredible restorations will be familiar with his heated suction table, which is used to treat various maladies a canvas may be suffering from. For example, by holding it at a sufficiently high temperature for days on end, moisture can be driven out as the piece is simultaneously smoothed and flattened by the force of the vacuum. But as [Julian] explains in the video after the break, the heated suction table he’s been using up to this point had been built years ago by his late father and was starting to show its age. After a recent failure had left him temporarily without this important tool, he decided to design and build his own fault-tolerant replacement.
The table itself is built with a material well known to the readers of Hackaday: aluminum extrusion. As [Julian] constructs the twelve legged behemoth, he extols the many virtues of working with 4040 extrusion compared to something like wood. He then moves on to plotting out and creating the control panel for the table with the sort of zeal and attention to detail that you’d expect from a literal artist. With the skeleton of the panel complete, he then begins wiring everything up.
Underneath the table’s 10 foot long surface of 6061 aluminum are 6 silicone heat pads, each rated for 1,500 watts. These are arranged into three separate “zones” for redundancy, each powered by a Crydom CKRD2420 solid state relay connected to a Autonics TC4M-14R temperature controller. Each zone also gets its own thermocouple, which [Julian] carefully bonds to the aluminum bed with thermally conductive epoxy. Finally, a Gast 0523-V4-G588NDX vacuum pump is modified so it can be activated with the flick of a switch on the control panel.
What we like most about this project is that it’s more than just a piece of equipment that [Julian] will use in his videos. He’s also released the wiring diagram and Bill of Materials for the table on his website, which combined with the comprehensive build video, means this table can be replicated by other conservators. Whether it’s restoring the fine details on Matchbox cars or recreating woodworking tools from the 18th century, we’re always excited to see people put their heart into something they’re truly passionate about.
does it make pancakes?
I do admire the video production quality and the obvious pride and enthusiasm in the work, but I can’t help cringing at the engineering and electrical build quality.
A 20-amp NEMA-6 plug for a 40 amp load?
No breakers or fuses?
No grounding?
Wood box for something handling almost 10 kW?
A little toy screwdriver to torque down 20-amp wiring?
No thermal fuses or other backup overtemperature protection?
Stranded wire with no ferrules? (but OK, that’s considered acceptable in the USA)
Not to mention those sharp edges and corners right at thigh height. Ouch.
And the interior wire dressing is an aesthetic call, but I call it fugly.
So much cringe.
I hope he’s not putting anything valuable on that thing.
If only he grounded his components :) He’s going to burn something out if he loads the circuit more than 22 amps (max rated for a 20 amp components). He’s downgraded the whole circuit with a 20 amp rated connector. At max load he’s running 42 amps (he states in video/website, the heaters are 240v at 37.5 amps and the pump is 120v at 4.5 amps). He should be running at least a 50 amp circuit with at least a 8/3 soow and similarly rated connectors.
You’re not wrong, but my understanding is that the three zones are mainly for redundancy and not really intended to be used at the same time.
He clearly states at around 9 minutes that he intends to use all three zones at the same time. I do hope he produces a video of it when he does. It could be spectacular.
This build would fail electrical certification by even the most lax inspector. In both its engineering and construction it’s a safety and fire hazard. If the worst happened and his insurance company knew about it, I’m certain they would deny a claim.
Oooh. It gets better.
He’s using that nice SOOW (‘cabtire’) cable, but it’s 14 AWG… so max 18 amps.
And that ‘crimp’ attempt at 8:04 is not going to keep the smoke from escaping for very long.
For which? The main cable or the cabling to each pad?
The 14 AWG SOOW cable he’s attaching to the NEMA 6-20 plug would be the main 240V power cable, and the one he’d be trying to suck up to 40A through when all three thermostats are calling.
The last time I saw someone pull that stunt we had to evacuate a 5-storey building because of the smoke.
What may actually help (a little) is it looks like he’s served by 3-phase power in his industrial building, so his “240” volt service is really 208 volts, and his actual draw will be about 32A, less than double the rated current of that cable or connector: it might survive having two of the three heater pairs on, for a little while.
His best strategy at this point may be just to plug the whole thing into a 120V 20A outlet. Still enough power to ramp at more than a degree (F) per minute.