Building boom sprayer w/foam marker

[PineRidge]

Cool project and pictures.

Regarding the foam generator, what kind of system were you thinking of building?

You've probably already thought of this, but what a system that uses inexpensive (cheap) shaving cream like Barbasol that is mounted at end of each boom. Then, 12V DC from the tractor would operate a gear/cam system that would periodically depress the dispenser.

The advantage (if this works) is that this could built very cheaply. Some wire, a switch, some hobby motors and plastic gears, and something to mount the cans. I'm guessing I could build the system for under $20.

Some potential disadvantages might be getting the cam system to work so that it dispenses the right amount (not to much or too little). Also, I'm not sure how long shaving cream would hang around in the open air nor do I know what it would do to grass.. Finally, if you have a large area to spray, it's unclear if two cans would make it.

It might look a little weird but Barbasol makes a variety of colors that would go well with any color of tractor. http://www.barbasol.com/index.html and at about $1.50 a can you'd have to do a lot of spraying to get to the starting point of the commercial systems.

Thoughts?

These plans are subject to change but these are my initial thoughts.

I have acquired a very small 12 vdc air compressor that is capable of 200 psi. It will most likely be mounted within my tool box along with two miniature 12 vdc solenoid air valves.

One solenoid will control air to the left foam generator and vice versa. Each flexible air line will run to a 4" diameter PVC foam generator, containing an air stone & the same foam concentrate used in AG booms. The stuff is cheap at 29 bucks a gallon and it is mixed with water somewhere around 600:1. It makes foam in the consistency of shaving cream. The output from each generator will run to a small tube at the end of each boom where it will dump on the grass.

The air compressor will be powered through a DPST switch. In one position the compressor will run constantly to initially prime the system. In the other position a solid state timer will activate the air compressor automatically. There will be two pots on the board, one to control the on time, the other to control the time between on cycles so it should be easy to adjust according to ground speed.

There will be a second DPST switch that will control each of the two air solenoids so that foam can be dumped from either the left or right boom.

On my initial tests of the foam generator using household dish detergent it made gobs of foam, unfortunately the foam quickly broke down in the sun. The liquid foam concentrate that the AG booms use boast foam that lasts in the sun for between 30 to 60 minutes which should easily cover my needs.

If you guys have any further suggestions or questions I would like to hear them.

 

[PineRidge]

Here's a shot of the small single cylinder 12 vdc air compressor and a small mount that I welded up to fit it. This will supply the air for the foam generators.

 

[PineRidge]

How long did it set in the Solution for the end result?

Time varies from hours to days depending upon the initial condition of the metal, how much soda is in the water and the amps that you can deliver to the mix. I used 2 full boxes of soda for 50 gallons of water, & the battery charger supplies a steady 5 amps so the electrolysis normally takes 4 hours to strip the paint and convert the rust. Not bad considering the manual work it saves me.

 

[PineRidge]

Here's a picture of the timer that arrived in kit form. It will need some minor modification, a heftier relay to handle the compressor, two 250K pots, and two 220 mfd. caps to increase the cycle rate to 2-60 seconds.

Solid state timer kit

 

[PineRidge]

Here's a shot of the hinges being welded up to the collapsed boom.

Wanted to get some primer on the boom because if you use electrolysis to strip rust it's like freshly sandblasted metal. If you don't prime it quickly rust forms very quickly.

This was the 1st test of one of the foam generators using only 2 psi of air pressure and 1 teaspoon of the foam concentrate.

The 3rd picture was after the generator ran for 2 minutes, you couldn't even see the generator at this point it was covered with suds.

I'm going to add an air stone tomorrow to see if I can get the consistency more like shaving cream. My guess is smaller bubbles will form using an aquarium air stone, we'll see.

 

[woodlot]

This is kind of off topic,but, Is that foam safe and non-toxic? My kids would have a ball playing with that! I could fill up a swimming pool and let them have at it. Maybe add a few drops of food coloring for fun.

Did you make the PVC foam generator, or is that something you bought? I'd like to see a close up pic of that.

 

[PineRidge]

Today I used a small aquarium air stone and got a much drier foam which is what I was after. The 1st picture shows the generator working with the air-stone and at between 1-2 psi air pressure.

The dollop of foam in the second picture was an hour old placed on warm concrete, the ambient temperature is 85 and the humidity is fairy high. The fact that it stayed intact without breaking down is what I'm shooting for since it will have to last for a bit on grass before disappearing.


Woodlot you can purchase the foam concentrate from Agri-Supply here is a link to their page.

Once I get the foam generator dialed in I'll show a breakdown of how it's assembled from PVC pipe. (it's pretty simple in construction and yes, I made it)

I'm also pretty sure the foam is non-toxic but you may want to call Agri-Supply just to be sure. I have seen 110 volt foam generators at eBay that are used for the kids. They look like a sock stretched over a squirrel cage blower and they generate gobs of foam.

 

[PineRidge]

Making a little more progress.

I'm very happy with the way the boom is turning out. Yeah it's probably a bit over engineered but the steel used in the boom was a gift so I figured what the heck, use what I have. The only items that I've had to purchase for the boom so far were the two break-away boom springs (not installed yet in the picture).

And before you ask just because it's close to the 4th of July it isn't going to end up red, white, and blue, nosirreebob. The white that you see on the boom is just bare metal primer. It will eventually end up New Holland blue just the the Carry All in the foreground.

Still experimenting some with the foam generator.

 

[PineRidge]

Took advantage of the nice weather today before our Independence Day Party (tomorrow) to spray the initial coat of New Holland blue on the boom. You can see the boom being supported by an identical gate from which it was made. The two make an interesting comparison of sorts.

After some initial testing done with the foam marker think I need a larger chemical tank for the soap/water solution tank. The one I was testing held about a gallon of mix and it only produced foam for about 30 minutes as a result (way to short of a period). I'm looking around a bit to see what my options are. I would like to find something about 15 gallons.

 

[kennyd]

Looks like a great project as usual Mike.
You really should finish that lathe before you start new projects