I have tried numerous things and I keep wasting kits with no apparent change in the condition of the weapon I'm trying to repair, so obviously I'm missing something. Please advise. Thanks!

Equip the weapon you want to repair, use kit. Viola repaired weapon. It DOESN'T go from none to full though.

Can you define "use kit" ?

Say for example I equip my sniper rifle. Do I then go to Misc Items in my pip boy and click on the kit?

Yuppers.

Well, the weapon kit isn't in MISC... It's under AID, I believe. But yes, equip the item you want to repair. Use the weapon kit, and bam, its condition is improved.

It's like a stimpak for the weapon you want repaired. Be sure to check your equipped weapon's condition before using the kit. Use the kit, then check the weapon's condition again. I used it on a laser rifle and it went 25% to nearly 100% repaired. I think the others are correct in that it won't bring a weapon to 100% condition.

As mentioned, you just need to equip the weapon you want to repair and then use it as you would any other aid, and you should notice the condition of your weapon raise. Last I read, regardless of your repair skill each kit raises the condition of a weapon 25%, so 3 or 4 would bring a weapon to 100% (and will, I've created probably 15 or 20 by now and use them all the time).

To improve it's effectiveness, eat a "Fixin' Things" magazine and wear a Vault Utility Suit before you use it. Also improving Intelligence raises your Repair skill.

Hrm I noticed (or at least am pretty sure) a couple of times if I had my weapon actively wielded when I used the repair kits, the condition stayed the say. Although having said that if I have the weapon equipped but holstered then it gets repaired.