Ballast box design

[joshuabardwell]

I'm contemplating the design of a ballast box for my tractor. My target weight is about 800-900 lbs, or maybe a little more. If memory serves, my owner's manual calls for 800 and change, but I figure the three-point can take more, and a little more ballast is probably better than a little less.

The Internet says that concrete has a density of about 150 lbs / cubic foot, so I'm looking at something like six cubic feet of volume. The steel of the box itself will weigh about 75-100 lbs, but I'm also going to have some tubes in the box for rakes, shovels, chains, etc... and I calculate that they will displace about as much concrete as the steel weighs, so I'm just going to simplify my life and call that a wash.

For dimensions, I started thinking something like 2' wide by 3' tall by 1' deep, but I thought that might be a little bit more tippy than I'd prefer a 900 lb object to be. Wouldn't want to set it down on a hill and have it fall over, or have somebody lean on it and knock it over and crush somebody else's toe or something. The other consideration is that it needs to be cut efficiently out of a 4'x8' sheet. As I played with different dimensions, I realized that a 2' cube is probably the most efficient way to do it. A 2' cube will give 8 cubic feet of volume, which is as much as 300 lbs more ballast than I actually want, but it's as stable as they come, and will cut out of a sheet of stock with no waste. Additionally, a cube provides a near-optimal ratio of surface area to volume, so there's less steel to buy per pound of ballast. (A sphere would be better, but I think we can all acknowledge that a 900-lb sphere would be a bad idea, even assuming I could fabricate one.)

I priced out a sheet of 1/8" (11 gauge) stock at just under $100 from my local steel supplier, not including cuts. I decided to go with them vs. buying salvage because I figured it was worth the extra price to get them to do all the cuts on their shear vs. me trying to get them all straight/square with my circular saw/Diablo blade. Also, getting them to do the cuts means I don't have to hassle with getting a full sheet of 11-gauge (163 lbs) into and out of my truck all by myself. I hope that 11 gauge will be thick enough to avoid bowing out when I fill the thing with concrete. I have eyeballed some photos of ballast boxes online, and it sure doesn't look like they're made of anything thicker than that.

For hookup to the tractor, I plan to weld some pieces of bar stock onto the sides of the box, drill them out, and install Cat-1 pins. I'll do the same with some angle iron for the top link. I think maybe 1/4" stock will be fine for the lift arms and 1/8" angle for the top link.

In addition to the storage tubes, I plan to install a 2" receiver tube for trailer moving. I've already got one on the front of my bucket, but what the heck... the more the merrier.

Any thoughts or feedback is welcome.

 

[Grand_Pooba]

Sounds good, but just a suggestion. If you are going to permenatly fill it with concrete why not just skip the steel and build a wooden form and just cast the cube. If I where to remake this one I would use a drawbar with a 2" receiver and the tubes for tools as you suggested.

 

[joshuabardwell]

I guess I just don't really know how to build a concrete form. What thickness of plywood? How do you keep it from leaking? How do you keep the concrete from seeping up into the bottom of the tubes?

 

[FredH]

Start with a plywood base , 1/2" is fine . Were sides meet bottom , you will get little if any seepage , if good straight cuts , You can also use Duck tape like in picture above . Screw plywood together from outside box , thus after cement cures for a couple of days you can get form off . With your vertical pipe for tools , etc.. , You can either drill holes same size as pipe in bottom form board and run them through , or simply silicon them in place . If you are concerned about plywood " Flex " on back or sides , From inside box , screw through to outside into 2" x 4" 's . The 2" x 4" 's then can be screwed to each other from outside , thus strengthening form . After Pour and cure , Remove screws holding 2" x 4"'s to each other , remove screws from plywood corners and base , then remove screws from inside plywood releasing 2" x 4" 's from plywood .

A pour that size , I would let cure likely at least several days , before trying to remove form . 3' x 14" x 6" steps I poured in back sat for 24 hours before removing form . Your design may allow the ability to use ballast sooner , as basically you would be making a metal bucket and carrying the cement , while a poured ballast would need time to cure before trying to " Lift " the ballast .

I don't need a ballast in back , always have some sort of attachment back there , from 1100 # disk , Backhoe or whatever , But have poured plenty of cement ( Not Commercially , just home use ) , and there is nothing more frustrating than trying to take a form off to soon and pulling the cement apart .

Fred H.

 

[joshuabardwell]

Thanks for the tips, Fred. I'll keep it in mind. I reckon a 1/2" sheet of plywood is going to save a lot of money compared to a sheet of 11 gauge steel. Will the concrete hold together okay without a wire mesh skeleton on the inside or anything? I have this vision of picking up the block and the whole thing falls apart.

Of course, if I go with the wooden form, I lose the opportunity to weld the box together, but I'm not sure that's worth $100+ to me. I could buy a lot of practice scrap with that money.

 

[Ed of all trades]

I just found a tank that fit my needs and welded a piece of square tube in holes cut so I could mount the pins for the lift arms and welded another piece sticking up for the top link. poured it full of crete and its done. Sorry no pics, don't have a camera. I used a saddle tank of off a two ton truck, it only weighs about 400 lb but for a sub it works well.

 

[Ted Summey]

A used 55 gallon barrel will cost 10 to 15 dollars vs. the cost of steel or plywood to build the box/form. Nine 80 pound bags plus the rest of the hardware for the 3 pt hitch will put you in the 900 pound range. It will be stable and you can put your tool holders inside or out.

I built mine for the cost of the barrel, concrete and cat II drawbar. I'm guessing in the range of $90 total. The I beam was left over from another project = free.

 

[joshuabardwell]

A used 55 gallon barrel will cost 10 to 15 dollars vs. the cost of steel or plywood to build the box/form. Nine 80 pound bags plus the rest of the hardware for the 3 pt hitch will put you in the 900 pound range. It will be stable and you can put your tool holders inside or out.

It's totally vanity, but I want something that looks a little more professional than a 55-gallon drum hanging off the back of the tractor. But the price sure is right!

 

[Ted Summey]

Once it is painted it will look like any other implement - a tool on the back of a tractor. A ballast box doesn't earn "style points" for looks. It earns its points for being a big hunk of heavy concrete hanging on the back of the tractor. I'd rather spend a couple hundred dollars on something fun than for a big hunk of heavy concrete that will be used occasionally. Suit yourself.

 

[k0ua]

Thanks for the tips, Fred. I'll keep it in mind. I reckon a 1/2" sheet of plywood is going to save a lot of money compared to a sheet of 11 gauge steel. Will the concrete hold together okay without a wire mesh skeleton on the inside or anything? I have this vision of picking up the block and the whole thing falls apart.

Of course, if I go with the wooden form, I lose the opportunity to weld the box together, but I'm not sure that's worth $100+ to me. I could buy a lot of practice scrap with that money.

Joshua, as you know I went the 55 gal barrel route so I could have room in the top to store things.. Chains, Chainsaws, water bottles. etc. it is pretty cheap too. at $9 for the barrel. One more thing if you use the plywood forms, if you will coat the plywood with a brush on coating of old motor oil, they will release so much easier. Also on the 2 inch pipes for the handle tools, if you will put a bolt thru the bottom of the pipe this will retain your tool handle but still allow dirt and debris and water to fall thru the pipe. (I didn't do this but I should have) Good luck with your project!

James K0UA