Monday, April 30, 2007

Test burn in the barrel pit

Just like General Dynamics or any other fighter jet builder tests their latest incarnations of jets, I performed a test burn on part of the pit this weekend. And just like those experimental figther jets, there are a few tweaks needed.

So what happened? What did I learn? What needs to change?

The test burn was in part a necessity because I needed extra grill space for all the food I was cooking for a friend's party. 2 briskets, 12 racks of baby back ribs, 8lbs sausage and 3 pans of beans is a little more than my N.B. Smoker can handle. So once I wrapped stuff in foil it got transfered to the barrel pit for further cooking.

The pit was quick and easy to light with the log lighter assembly. No charcoal needed, just stack up some logs and light the propane.

Temp variations


Once things were going I noticed some real variations in pit temperature. The top right shelf (on the firebox side) got to 300 degrees while at the same time the bottom left shelf (farthest from the firebox) was just a little over 150. The variation was even noticeable on the same shelf. The top shelf for example was 300 on the right side and 250 on the left. I also found it interesting that the exhaust temperature was lower than the hottest part of the pit. In general the exhaust temp matched the top right shelf temp which makes sense as that's where the exhaust is.

I think tuning plates are going to be needed after all. I had hoped that I could avoid them since they make it a little difficult to clean up the grease but they are going to be needed. No problem, my plasma cutter should be back (from repair) on Wednesday so I can cut out some plates from the remaining steel plate I have.

Where's the shelf?

When moving things over to the barrel I quickly discovered what was missing, a place to set things like hot pans of beans. So I need to build a little 12 inch deep shelf for both pits. Just something wide enough to set my baking sheet pans on.

Who cut the foil?

It seems my fresh new metal grates have a sharp edge on them. I don't know if it's part of the forming process in making expanded metal or what but there's definitely a sharp edge on the grate that seems to rip aluminum foil if you drag anything across it. I'm going to try sand blasting the grates to see if that helps. If I still need to dull the edge I'll pull out the sanding wheel for the grinder.

Bottom shelf needs a handle.

It's no good to have slide out shelves if you can't slide them out. That was the problem with the bottom shelf. Since there's not a gap under the bottom shelf there's nothing to grab hold of. So the only way to pull out the bottom shelf is to stick your fingers into the metal grating and pull. Ouch!!! So the bottom shelf will get a small pull handle.

Leaky door

The curve on the door doesn't match the barrel. This seems to be a result of how the barrel was formed in a press brake instead of a roll. I thought I could bend the door into shape but 3/16 inch steel doesn't bend easily. So I think I'm going to source some stove gasket material and use it to seal up the sides and bottom. If I use 2 different size I should be able to seal up the gaps.

Grease drain

After the fact I also discovered another adjustment needed. I failed to put a drain in the bottom of the barrel pit. I thought the grease would simply drain back into the firebox. Nope! I pooled about 12 inches from the firebox. It also seems there's a slight leak on the bottom of the barrel pit where it joins with the firebox. So I need to weld that up. I think it's just a weld I forgot to run anyway.

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