Dock, I'm not Neill, but I may be able offer a bit of assistance. A few random thoughts:
Photographing shiny things without specular highlights is always challenging. It's the nature of small light sources, and shiny, curved surfaces. In the top photo, the most distracting hot spot is coming from the top light. (It looks like you're using a desk lamp to light the upper panel of the light tent.) I'd turn it off, and just use the side lights. Also, keep an eye on how the ambient lighting in the room changes things. When you're using small incandescent lights, room lighting can be a significant factor to the overall result.
You can move the lights around, and position the pipe and camera to minimize the hot spots, or at least place them where they'll not be too distracting, but unless you want to use a VERY large, diffuse light source, you'll have to learn ways to live with them.
Moving the lights farther away from the tent will increase the diffusion of the light to some extent, but it will also sacrifice brightness. You'll need increasingly long exposures as you move them farther back. In any case, you can achieve different results by placing one light closer and one farther away from the tent.
It looks like you used on-camera flash in the second photo, which is never going to provide optimal control, and will always result in hard shadows and hot specular highlights, unless you put a diffusor over the flash.
The first photo is very softly focused. Either the auto-focus didn't lock on the right image plane, or there is blur from camera shake during a long exposure. (I can't tell from the small pictures which it might be.) For close-up work like this, autofocus is more of a nuisance than a help. Focus manually, if possible. And, use the self-time on the camera to minimize vibration from pushing the button. (If you're using an SLR, using the mirror lockup can also help a lot, especially with exposures in the 1/15s range, where mirror slap is most problematic.)
For most of my work, I use a single light source - generally a medium softbox. The set is littered with little reflectors, scrims, bits of silver foil, and light-subtracting black panels to control spill. It can take a long time to get the lighting precisely where I want it, but I have very specific results in mind when I shoot pipes. The basic techniques aren't hard to get down. You can see some of the results
here.