Incubator Question

Reading posts it seems the general consensus and easier way to go is to build my own incbuator. I ended up with an ice chest cooler type setup. I'm ordering my heat tape. The dimensions are 10 deep by 20 wide. It will only house one clutch. I have a herpstat for it. The only problem I am running into is the heat tape. I was going to order flexwatt in 11 inch. The only problem is 11 is a bit too wide. My question is will 4 inch and 20 across generate enough heat? Also does the thermo probe go on the heat tape of in the egg box?
Thanks

The 4" will be fine! Just tape it to the bottom and put some water bottles on top. You can hang the probe in the middle or tape it to the Flexwatt. Do not put it in the eggs box. When the eggs are close to hatching, the temp. in the egg box will rise, and this will throw off your temp. Just keep a thermometer probe (AcuRite) in the box and monitor that! With this setup, you should be good!