Critique my Rack System

[justin-branam]

I don't think you actually need a gap for airflow underneath the tubs, but the tubs shouldn't be so tight that they're forced down onto the heat tape. This would likely cause the plastic on the heat tape to rub away, scuff, or scratch and possibly cause the electrically charged metal filaments to be out in the open. Then, not only could the heat build up more, but you could touch it and electrocute yourself. If the tubs you're using have a recessed area on the bottom, I guess the heat could build up a little, but I'm not sure that would be such a bad thing. I would think it could help distribute the heat more evenly. I only have a small gap on the top of the boxes so they slide in and out easily with no chance of heat or humidity affecting their fit.

I wonder what type of tubs the original poster was using because these things typically have a pretty high temperature tolerance from what I've seen. I've run mine up to 110F before without any indication they were affected at all, much less melting. Maybe they weren't the typical Sterilite or Rubbermaid boxes. I'd also be interested in knowing how the temps were measured and monitored on his rack. I keep multiple digital thermometers with min/max memory taped directly onto the heat tape in my racks to ensure they don't overheat. One of the racks is controlled by a Helix and the other with dimmers. Never had a problem and haven't heard too many horror stories about properly installed heat tape, luckily.

i used normal sterlite containers from target. temps were read with an accurate indoor outdoor electronic thermometer (still working fine). probe was placed inside the tub above the heat tape. funny thing is, the middle of the tubs is raised a bit from the outside rim, and the whole ended up in the raised part that did not touch tape (so the plastic could not have been worn through). also after i removed the tape from the rack, i plugged it in to check, the spot on the tape below where the tub melted was about 30 degrees hotter than the rest of the tape! not sure what was going on there. still scares me!