I have, unfortunately, not had the opportunity to go climbing (and thus use my climbing equipment) for a couple years. I know that such equipment, especially the rope and webbing, can degrade over time. So how can I check my equipment to tell which pieces are still OK to use and which need to be replaced?
It's pretty hard to check gear without some high-tech equipment. Metalwork really needs to be x-rayed to see if there are any hidden cracks, and rope can be checked by cutting a length off and sending it for destructive drop testing.
Neither of those your average climber would ever contemplate. So give everything a very careful visual inspection, for the metalwork check that there are no sharp burrs that could damage your rope, no corrosion, and no distortion. For your rope, run it through your hands very slowly, checking for any lumps, bumps, or skinny bits, and check the sheath isn't frayed anywhere.
Also how equipment has been stored is important. Has it been kept warm and dry, away from UV light? Could it have been exposed to any chemicals (such as battery acid or solvents) that might have damaged it?
What ages a rope most is use, so if you have stored it for a couple of years it should not have degraded measurably.
Have a look at the UIAA's document on ageing of climbing ropes for some guidance from the experts (the UIAA is the International Mountaineering and Climbing Association)
I wouldn't worry about a couple of year's lack of use.
Since it has been a year and some of this has not been mentioned I felt compelled to do so. I know you were concerned about your own equipment, and I know this advice can be found all over the internet, but I think the following needs to be said whenever climbing gear safety is discussed:
- Be cautious with gear that was dropped.
- I know Simon Hodgson mentioned UF light in a previous answer, but I wanted to stress the urgency of that concern. I have seen UV-damaged slings rip!
- Friction causes heat and heat is the mortal enemy of rope and slings. If a rope was pulled directly through a sling, the sling has to be retired.
- Webbing and rope have a limited lifespan, even when properly stored. Most manufacturers suggest retiring nylon and spectra after 5 year. That is probably a conservative estimate. I follow that suggestion for lead climbing, but personally would not mind top-roping with a rope that is a bit older. If you are responsible for someone elses life err on the side of caution!
- For the above reasons, only use gear for wich you or someone you trust with you life know the entire history. There is a reason why every climbing store has an all-sales-final policy.
- Anything with cables should be retired if any kind of fraying occurs.
- Cams should have smooth trigger action. If lubricating with the proper cam lube does not help, you should not use them, since they could walk out.
- If in doubt, retire it! It is just not worth it.
For textile materials (like harness, ropes, slings), most manufactures claim a life-time of max. 10 years, even for material which is not used and just stored in good conditions, i.e. in dry and dark environment.
If your equipment is not labeled with manufacture date, then it is certainly older than 10 years and should be replaced, see When did the manufacture date became mandatory written on labels?