Thanks for the replies, all  

@ mr. grim
Darksteel Colossus is certainly a Tinker possibility, but he doesn't work very well with Welder, as he is kind of challenging to get into a graveyard. As for Strip/Crucible, that's certainly a viable strategy, and one that Strategic Slaver uses already. I've been thinking about trying it in my build, but I want to get more familiar with what I've got first.
@ Thegreatgonzo
Triskelavus is another one worth a try, I just haven't yet. I am leery about it, however, for the reason that it seems to lose the best parts of each - the manaless activation of Trisk and the 5 counters of Pent. I am really (really) addicted to the five extra chances that Pentavus gives you at a backbreaking Mindslaver. As I say, however, I plan to try it at some point. 
As a general rule, I love Impulse. So far, I like it in the deck. For the record, I have not tried Strategic, because I don't want to pay for them 

 I found that the deck, sans Impulse, was awfully prone to a hand that was keepable, but just never got there. Impulse has helped with that a lot. As to the disadvantage tutors, I don't mind them as much as some do, but I found that I was having trouble making room for enough of a "silver bullet" package to really make them good. This also deserves further attention.
@hitman
Thanks for this very helpful post. I've found the same problem with the Wasteland/Strip route and the Gorilla route. Sphere of Resistance is a good idea, and I just found Thorn of Amythest in my binder, which of course acts similarly, and has the benefit of being owned by me ;P Another possibility was CotV, but I've found that I'm not really crazy about it at either setting (0 or 1), as it either locks me out of almost all of my artifact mana (0), or all the rest of my artifact mana, plus the main point of the deck (Welders). Certainly, all of Sphere/Thorn/CotV get the benefit of being Artifacts in an artifact-centric deck. Sideboarding a couple of Thorns is okay when extras can pitch to Thirst.
I may also post a summary of some of my early CS trial and error, if other beginner types like me think it would be valuable.