Can't get a boil - ok to use aluminum foil to reduce surface area?

[jybingbrew]

Not sure this is the right forum, but it's caused by my electric setup, so here goes...

I recently finished building a 120V 2000W Recirculating eBIAB system (using all the great advice / schematics on here) and cannot get a rolling boil with my pot. I'm using this element that seems to have mixed success on here:

http://bostonheatingsupply.com/sp10868gl.aspx

I'm trying to bring about 4.25 gallons to a boil to end up with about 2.5 when I'm done after boil off and loss but it just can't seem to do it in my 9 gallon pot. I think it's about 14 inches wide.

After watching the steam just pour off it seemed like it was just dissipating heat too quickly with all that surface area so I took piece of aluminum foil and let it float on the surface, covering about half of it -- that let a nice rolling boil develop.

I wanted to get thoughts on if there are any concerns with this? Since about half of the surface area is exposed I would think I could boil off all the nasty stuff that isn't desired -- but have also heard a lot of concerns with using aluminum in brewing and wondering if those apply here?

 

[Brumateur]

Do you have your kettle thermoinsulated?

 

[jybingbrew]

I do, but it didn't seem to help much. I wrapped a layer of reflective insulation around the outside but that still didn't seem to be able to get it the extra couple of degrees needed for the rolling boil.

That seemed to be the most common way I saw on here to insulate.

 

[Brumateur]

I found that one layer of reflectix is not good enough and put a second one on top.
Could you make a picture of your kettle?

I beleive that aluminum is safe enough. It can fail mechanically but OK from a food safty point of view. However it is my personal opinion and I can't provide a hard proof.

 

[jybingbrew]

I tried to wrap a couple extra layers around tonight and re-test -- but still no luck. I can get it to 1 degree below a rolling boil but just can't seem to get it above. I hear a bunch of people on here boiling easily with 2000W so quite stumped. I've measured the resistance of the element and it's in line with what I'd expect (~7.8 ohms) so i'm getting close to the full 2000W.

Here are pics of the kettle.

 

[iaefebs]

The foil or using a aluminum pie plate on top of your wort is an acceptable method to getting to a boil... brew on.

 

[Brumateur]

I can recommend to put some insulation on the lid as well. everything else looks OK

 

[wilserbrewer]

I think the geometry of your kettle, being wide and short is the issue. I would try making a temporary partial lid with foil covering 1/2 the top if the kettle, or just partially covering with your kettle lid. 2000w is borderline enough power, and your wide kettle is stopping the boil.

What gauge and length is your power cord, might you have voltage drop due to a small gauge and/or long cord?

 

[jybingbrew]

Hmm, hadn't thought about the cord. It's 14 gauge and about 6 feet. Should that be an issue?

I did try to out the lid partially on, but still didn't get up to rolling. I think the direct contact of the foil was much more effective at stopping the dissipation.