Tooth Harrow

chucko · Dec 16, 2005

I want to make one of these(see pic below)...I think they would work good down here in fla.
It looks simple enough but I have not seen one live and have a few questions about it
I would think that heavy rebar would make good spikes (correct me if I am wrong)
how big and long are the teeth?
spacing of teeth (looks from the pic to be 6 in staggered at each row)
are the teeth angled back or forward any?
are the ends sharp?
how much wood could a wood chuck chuck if a wood chuck could......?

Farmwithjunk · Dec 16, 2005

OK... First answer is my opinion only. Take it for what it's worth. Re-bar is relatively "soft". I'd about bet you'd bend all of your spikes over in short order. About the only simple way to mount re-bar would be to weld them in place. That'd make it difficult to chage them when they got bent beyond straightening.

This part isn't opinion... You can get "replacement spikes" for harrows through Agri-Supply, Shoup, Valu-Bilt, ect. They either bolt in place, via a threaded end, or there are versions that clamp to a bar with a vee-shaped U-bolt. (Would that make it a vee-bolt?) They're not too expensive, although I've forgotten how much. (I've got a box of around 100 spikes under my workbench in anticipation of a project I have in mind)

And yes, the spikes do need some angling rearward (in most cases) Old spike-toothed harrows were adjustable, allowing slight forward angle, to almost "flat" rear angling.

MadReferee · Dec 16, 2005

I am planning on building something similar. I have looked at 3/8" and 1/2" rebar but I think I have settled on using used railroad spikes in good condition. Much stronger but a little more expensive. I got mine from an Ebay seller in Helena MT for about 50 cents each. A different seller (bucobob) from Helena has the same spikes for sale right now.

jmc · Dec 16, 2005

Good idea on the spikes, I see a pile of them occasionally at the salvage yard. Which direction are you going to run the sharpened edge?

MadReferee · Dec 16, 2005

( Which direction are you going to run the sharpened edge? )

Haven't decided yet. But the top lip of the spike points toward the flat wide side so that may be the final determining factor.

BTW, make sure you get steel spikes not the old iron ones.

turnkey4099 · Dec 16, 2005

If you are in an agricultural area, you could cruise back roads. Here I bet I could find a few old discarded harrows withing 10 miles of the house. A bit of welding to add the 3-point fixtures and you are in busines. At least you could salvage the spikes from one.

Harry K

jmc · Dec 16, 2005

Didn't know there were two kinds.

After thinking about the edge direction, I seems running it parallel to the travel direction would make it "skate" rather than dig.

Thanks,

John

MadReferee · Dec 16, 2005

( After thinking about the edge direction, I seems running it parallel to the travel direction would make it "skate" rather than dig. )

Depends on the angle of attack, how much weight is on top of the harrow, and the soil type. The spikes can be mounted in either direction.

Almost all spikes are steel but there are still oldtime spikes out there that have been sitting around that are iron. These are usually collector pieces and fetch a few bucks or more each.

All the spikes I bought are 6" long and in excellent condition and need very little, if any, wire brushing. They are orders of magnitude stronger than rebar.

OldMcDonald · Dec 16, 2005

I made one in early October and have used it twice over about 15 acres. I do not have the luxury of being able to shop around for teeth so settled for 20mm (near 3/4ths inch)round bar. The teeth are fastened to the front of angle irons using U bolts - four rows as in your pic, and sorry none from me, but my son arrives on sunday, so...... The angle iron is 70mm and the tp hitch is much simpler, just straight up same angle iron. The spacing on the rows (3 metres wide, say 10feet) is at 40cms to give an overall 10cms (4") spacing in use. On the first pass I drag a heavy pipe land leveller behind and on the second just chains (covering oats). I also used it for preparing a grass mix seed bed and covered that using only the chains. The spacings in each row are, in cms, and 5 = 2 inches:-

5 45 85 125 165 205 245 285
25 65 105 145 185 225 265
15 55 95 135 175 215 255 295
35 75 115 155 195 235 275

The only reason for the front row being the one it is, is that it suits that row best to mount the tp hitch. I cut a groove to better fit the round bar to the U bolts so as to give a depth of 3" with the flat of the angle iron on the surface for covering the oats, which I broadcast from a fertiliser spreader, but made longer teeth and also have them grooved for 4.5 and 6" depths. As the points wear I can move them down to the next groove and lose the 6" depth. The bar is very cheap so I am not bothered about wear. I did not sharpen them and would not bother to do so in the future. The seed bed preparation was good, the take excellent, although the seeds are at different depths, and the overall cost in money and time was quite small. Old McDonald.

RonR · Dec 16, 2005

Here's pic of what son and I built to do final prep before seeding lawn. We built it so we could push or pull. Worked well. We used 5/16 x 2 strap for the "teeth". We haven't used it enough to show any wear, but we have snagged roots and snapped them off. If we find them, we re-weld on, or we made some extras just in case.

Nevermind the 2x4 in the pic; I've redone this part to make it stronger (steel).

Ron