i have a new site only 30 days old and would like to add some some authority to it if i where to purchase an aged domain name and do a 301 redirect to the newsite i would this pass age to the new domain name ?
You won't pass the age of the domain to another when you redirect it. It will only pass the link juice / the authority that the domain is receiving, going to the new domain where you have redirected it
What Alexander P. said is correct. No age pass (that is tied directly to a domain) but traffic and link juice get passed with a 301. One thing that can help young domains, with their age issue, is to register the domain for more than just 1 year. You are showing a commitment to having the site be around a long time by registering it for at least a few years.
hi if i where to register the domain name lets say for an additional 2 years would this help prevent my site from getting sand boxed ?
Most likely not. Your best bet for a young domain is to simply use the 301 and to get a longer registration period. That's about the only thing I can think of.
If you are already planning on running the site for a long time, then paying for the first few years up front is a decent choice. The impact will be minimal, when looking at other things that impact where a site ranks, but it is worthwhile to do it for a new site that you are committed to long-term.