Barrel burner question

[Hunt4sap]

So my first boil on barrel yesterday.
I preheated using my turkey fryer.
I only got 2 gallons per hr.
Which is double my turkey fryer rate.
I did not cut the top of my barrel out to expose direct flame to my ss flat pan( 20" by 4')
My thoughts are, im pretty sure i need to cut a hole in top of barrel, but how big and where?
I didnt want to cut barrel out and burn first time and hurt ss pan, or wish i didnt cut a hole...
My average sap depth was 1" or less and i never actually seen a boil and my digital thermometer never got above 180, even at very end when liquid was only 1/4" deep, very hot fire the whole time with wrist size split pine and maple.
Awesome draft too...
Anyone thoughts?

[johnpma]

Cutting the barrel will help big time the flame needs to hit the pan. But cutting the barrel will depend on how you plan to support the pan. You want the cut out to be as wide as possible. Also after you cut the pan make a gasket to block any spaces heat can escape.

Are you using good dry wood? Is your fire/wood up on a grate?

Insulate and brick the inside of the barrel to keep the heat inside the barrel

Make a rear wall before the stack with bricks to block heat escape and only leave a small space open for draft A slight ramp will also help with internal heat

a 4' pan on a barrel unit may be pushing it.

Here is what I started on years back, and her is what I'm using now.....already thinking of an upgrade :)

[Bernie/MA]

With a 4 foot pan you could make an excellent arch out a furnace oil tank. I've done it. Cut the tank like a baby cradle, leaving a foot closed in at one end. That's where the stack will be. Weld angle along the sides for the pan to sit on, wide enough for the pan to have at least an inch to sit on. Make a door(s) and a hole for draft and make grates above the draft hole. Send email for pics of one I made for my SIL. bearlysaneforty-three(numerals)at yahoodotcom

[Weekend_Warrior]

Johnpma, Your current barrel unit looks about as good as I've seen. I'm thinking about switching from a block arch. How many GPH to you get on your barrel evaporator? Thanks.

[johnpma]

Johnpma, Your current barrel unit looks about as good as I've seen. I'm thinking about switching from a block arch. How many GPH to you get on your barrel evaporator? Thanks. Thank you did quite a bit of research before building. Adding a blower this week to the unit.

We boiled last weekend. I used pallets and stayed feeding the fire. I got about 3.75 gph but I think I can do better though with the blower but will say the blower will turn any bare barrel steel glowing si I have to really insulate well. I have other pictures if you need any additional info

[waterfowlah]

I have the same set up, but with a auf blower set up. The blower turns it into to a completely different animal!! When I was using the two steam pans. I put in a flame diverter pan to direct more heat to the front pan. It worked great. As a matter of fact, I put it back in Now with My divided flat pan because the middle boiled harder than the rest of the pan. With it I get a full boil except where the cold sap is entering the pan.