I changed my upper radiator hose, thermostat, housing and clamp. I still seem to have a leak from the hose. Should I add a second clamp?

One hose clamp should be more than enough. Maybe check for leaks in or around the housing, a pinhole leak under pressure might be spraying onto the hose.

If you have the clamp that you need to use a pair of pliers to remove like a spring remove clamp and replace with clamp that uses a screwdriver to install.

It is a screw clamp. It is definitely leaking around the hose. If I loosen the clamp the spot leaks more. I have taken the hose off. It is a new hose, I cannot find any holes or cracks. I had someone else try to tighten it also, just in case it was me. I have tried clamping in different locations but it's still leaking.

Remove hose and check the surface of the thermostat housing and inside of hose making sure there is nothing on it to keep it from sealing correctly.

If all else fails replace clamp with a new clamp.

Make sure the housing itself isn't deformed, if it's out-of-round you'll never get a good seal. Take a wire brush to it if needed to make sure it's a good clean surface. Also double check you got the right size hose.

I got the right hose. It is a brand new clamp and hose. The housing is also new but I'll check it tomorrow to see if it needs sanding somewhere. Everything is new, this is why it's frustrating me.