Need some tips for using a breaker

Hey everyone. First I'd like to say that this is a great site that I was referred to from Lawnsite and I've found plenty of good information here. I feel the need to introduce myself and give a little insight to where my posts are coming from. My aspirations for the future are to graduate from college with a business and landscape design degree. Right now I'm a senior in high school and have been running a lawn maintenance business for 6 years while my dad owns a full fledged landscaping/hardscaping business for about 3 years now. I'm hoping to one day take my dad's place and run the business, but I've always had the desire to get into larger scale excavation work, nothing like playing with big toys. Anyway, enough of my introduction and where I'm at, this is my "dilemma".

We have recieved the bid for a full landscape install on a property that is fairly limited on access and we are required to build a retaining wall using granite that was chipped from a very large rock on the property by a previous contractor. Some of the pieces left over are small enough to be used for the wall, yet others are quite large, up to 3,000 pounds. I realize that we could have used a smaller machine, such as a 307, but they are difficult to come by as they are always on rent and they aren't setup for a breaker. In lude to this, we have rented a Cat 312CL with a breaker that will be here tomorrow to break up some of the larger chunks and then swap for a bucket to dig the base, place the rock, then backfill behind the wall. The machine has a hyd. thumb and like I said they will send the breaker up with the unit. I've never done any work with a breaker, so I need a few tips (pun intended!). I know a few things, like keeping the tip perpendicular to the work, not to dry fire the breaker and not to use the tip if temperatures are below 45 without warming it up, but there has to be more than that. I can't see us using this breaker for more than an hours worth of work, but I don't want to break a tip and have to replace it, I know they're expensive. I will be running the machine myself, I'm a pretty competant operator, I've run equipment this size many times before just without the use of a breaker. Any help would be greatly appreciated. Sorry for my rambling thread, but I thought I'd put everything out there on the table. Thanks in advance!

I've used breakers every now and then, although not really frequently. Actually, in terms of actual hours, I've probably spent more time with a 90# hammer in hand than I have using machine mounted breakers, but the principles are the same. It seems like you've got a handle on the basic do's and don'ts. Beyond that...

We don't see a lot of granite here. This part of the world has limestone, and sandstone, but I don't think I've ever seen any granite that hadn't been hauled in here from elsewhere. I have seen lots of old concrete though.

It shouldn't take long to get a feel for how much material you'll be able to break off at a time. One of the tricks is to break off just that much. Any less and you're not being fully efficient, and any more and you'll just be boring holes. With chunks of stone, this might not be as much of a factor, as they'll be more likely to break into several smaller pieces.

Speaking of which, if you find yourself wanting to just make a piece a little smaller, or perhaps cut one just in half, you'll probably have more success by chipping away a little bit in several spots, before you try to break it all the way.

And if you are going to try to chip away a little bit in any given precise spot, the first couple blows of the tip will establish that spot. If you just start banging away, the tip is liable to bounce to someplace other than exactly where you wanted it before it starts to go deeper. Again, I'm not sure how granite will behave in that respect.

You'll sometimes find that you have essentially bored yourself a hole, and the tip is getting bound up. A little wiggle back and forth as it goes deeper can help to prevent this. You may need to wiggle it a little to get it back out as well. You don't want to stress the tip by using it like a pry bar though.

I wonder how much trouble you're going to have with the chunks trying to move around on you? Obviously it'll be easier to keep the tip perpendicular to the work if it's not trying to squish into the ground on one side. A few seconds spent positioning it before you start to hammer on it might save a lot of aggravation.

Those are just a few thoughts off the top of my head. I'm sure there's a whole lot more that can be said...

Dont I Repeat Dont Use The Bit As A Crow Bar.. Or It Will Be A Very Costly Experince!

Thanks for the tip guys. The machine showed up tonight, brand spanking new 312CL :drinkup Came with a hyd. quick coupler. The tip on the breaker is a large, blunt tip, not sure what this is called, but it's probably about 6 inches around and completely blunt at the end. I imagine this is what will help us just split these rocks in half and not create big gaping holes in them. Our rental agent from our dealer came by on his way through town and specified what machine we needed so I'm willing to bet he made the choice on which tip we needed, because I wouldn't have any idea.

large blunt tip is called Needs attention,worn out,but will do for this rental period.

Don't touch the chisel when you've been using it for a while. They get hotter than you'd think.

Keep it greased. Can't over grease a hammer

Have you thought of a compressor and a hand held stone drill ,then using plug and feathers also known as wedges and shims. That way you can have usable pieces. There are excellent videos on youtube.