Winterizing irrigation

I have a few rookie questions about winterizing irrigation systems.

When do you start blowing out lines? Do you wait until you are expecting a prolonged period with below freezing temps? Or do some of you start with the first frost?

Do any of you have a "magic number", say line 20 degrees before you begin winterizing?

This is all new to me. But common sense tells me that I shouldn't have to worry about winterizing for another month or so. We've had frost already. Temps in mid 20's at night.

I feel that since the lines are buried and the ground temp is still fairly high that there is no danger yet. Plus daytime highs have been in the 50's with 70's forecast.

My thinking is that until we start having sustained frost every night, and daytime temps start dropping and staying in 40's, that will be the time to start blowing out lines.

I think this may be a good money maker. Very easy work, all you need is a compressor. What are you charging? Do you base price on number of irrigation stations? Do you adjust price if the job is a regular customer, or a one-time job?
I'm thinking of doing some direct mailings targeting this.

I appreciate all replies, thanks.

 

Rookie, my (*&!

You all set, guy. All your thought are on the right track. Depends on how many you have to do and what schedule you have to work with.

We do it when I say so which in early to mid-october for me in Michigan.

Charge? We get $70-80. Go downstairs, turn-off the water, hook up the compressor, cycle the clock thru the each zone until water in no longer coming out. Unplug the clock (or switch it off) and collect.

 

What size compressor would be needed? My buddy just bought a house with an irrigation system, and we talked about blowing it out. I have one that puts out 5.7 CFM @ 90PSI.

My biggest concern is that a line has a low spot in it, and the air just makes a tunnel through it, comes out of the head dry, and there is still water low in the line???

 

i do not do anything w/ irrigation but i was under tghe impression you blew them out and filled them with that coolant usually pink and ok for plants(rv coolant?)

 

The compressor we use is like 100hp Tow-behind you truck.

If you're talking about a 5hp shop compressor, that's not going to get it done.

As far as the dips in the line, the big compressors blow it all out. Even if you had some liquid, as long as it has room to expand when it freezes......

I've never heard of filling with a liquid afterwards.....