Work-ticket
Today's work ticket was to spray broadleaf weeds in the Upper and Hill Orchards with 2,4-D before the heat peaked. I used the amine formulation because I dislike the smell of the ester formulations of 2,4-D.
This year, the weeds beneath the trees were mostly grasses early in the season but then flipped over to broadleaf. Species included wood-sorrel, ground-ivy, mares-tail, burdock, goldenrod and Pilea pumila. The only unifying feature of those species is that they all thrive in moist soil.
The downside of the amine formulations are that they are not as "hot" as the ester formulations and require more time to penetrate the waxy skin of the leaves and enter the plant's circulatory system. The amine formulations are also more sensitive to water quality. The upside of the amine formulations are that there is less risk of collateral damages from wind-drift and volatile deposition of 2,4-D.
I pushed eight gallons of herbicide solution through the two-gallon, hand-pump sprayer. For the record, I used Gordon's LV 400 at 1.5 oz per gallon. The water was "soft" water treated with ammonium sulfate to scavenge tramp Ca++, Mg++ and Fe++ ions that eluded the resin bed and with one oz of 80/20 surfactant per gallon. "Wet-out" was considered more than 50% of the leaf area wetted.
Like many things, I would have been better served if I had done this two weeks ago. 2,4-D mimics plant growth hormones and is devastatingly effective when the majority of the weeds are vigorously extending their flower/seed stalks. It is not as impressive when the plants are shutting down growth due to limited soil moisture. It is the difference between tripping somebody who is sprinting versus tripping somebody who is walking at a very slow pace.
Never-the-less, killing those weeds beneath the trees in the orchard will conserve the water stored in the soil. It will also make the nutrients that the weeds would have absorbed available for the trees. I suspect that we will have more hot and dry spells this summer.
I will go back Thursday morning to check things out. I will re-apply in the areas where it is clear that I missed the target.
The spraying went fast since I had treated the water in-bulk. I rounded out the three hours by mowing between the rows of asparagus plants and berries (blackberries and gooseberries). Then I went and staked out a line that was 100' from the road's edge in the eastern meadow.
I got that all done by noon (which is when the windchill hit 90F). Then I drove to the Harbor Freight on Lansing's west side and purchased a 212cc Predator gasoline engine to replace the flat-head B&S 5hp motor (Model Number 135292) on Troy-Bilt Pony, rear-tine tiller that was in the pole-barn at the bottom of the Hill Orchard. The original engine might have been made to run but the cap for the gas tank was MIA and cannot be found for purchase.
The 212cc Harbor Freight engine has cast iron sleeves, 8.5:1 compression and is rated at 6.5hp. It cost me a freckle under $160 out-the-door. Honestly, it is a much better unit than the motor it will be replacing.
One minor complication in restoring an old Troy-Bilt tiller is that they used bronze for some of the gears. Bronze (or "yellow" gears) are not compatible with some of the modern Extreme Pressure additives used in gear oils. The experts on the internet all insist that you need to use GL-4 level, single viscosity lubricants in gear-boxes with "yellow" gears.
Random garden picture
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| Somebody needs to weed his watermelons |
What do the multi weight oils do to the gears? Are they machined? Or pressed powder metal? What's the failure mode?
ReplyDeleteReading between the lines, the zinc in the brass/bronze is much more chemically reactive than steel/iron. The EP additives in GL-5 formulations are rich in sulfur and/or phosphorous. They react with the iron and form a hard, slippery coating on raw metal that is exposed by wear.
DeleteUnfortunately, they are too aggressive, chemically for zinc-rich alloys and cause intergranular corrosion and suck the zinc out of the "yellow" metals.
Maybe 10X25mm will weigh in. Among other things, he is a top-notch metals and chemistry guy.
I put one of those Predator motors on my 1980's era Troy Built. It's the third engine on it, and the best, easiest to start . If I recall correctly, I needed a bushing to fit the belt pulley to the shaft, found at a local hardware store. Original was a Tecumseh, then a Briggs flat head 8hp. Seems to dig just as well with the 6.5 as it did with the 8hp Briggs.
DeleteBronze gears are usually cut from rolled or continuously cast stock and have pretty good resistance to EP additives. You probably get the best life by using low EP oils/greases with a fine molybdenum sulphide additive. Molybdenum disulphide does not corrode red or white metals, but if the particles are too big they can cause abrasive wear.
DeleteOilite bearings (SAE 841 / MPIF CT-1000-K26 bronze) are seriously damaged by EP additives. They are produced by powder metallurgy with open (interconnected) pores which allow lubricant to travel (wicking) to the wear interface. EP additive corrosion blocks those lubricant passages, starving the wear interface of oil replenishment. You can use very fine molybdenum disulphide (colloidal, something under 20 μm mean size) additives, but it is probably better to just use a neat mineral oil without antiwear additives.
I have been playing with molybdenum dithiocarbamate (MoDTC), an organomolybdenum compound which transforms to a very thin molybdenum disulphide by catalysis on iron surfaces, under pressure. It ought to be able to provide antiwear on steel & iron components without affecting red metal components (they don't catalyze the transformation. MoDTC is the magic additive in SAE 0W16 weight oils and is also used in the offshoot formulation 0W8. A couple of specialty lubricant houses are selling MoDTC oil additives. The one I have been using is Molyvan 3000 from Vandebilt.
Thank-you for the short dissertation. Please add it to my bill. 8-)
DeleteI acquired a B&S motor with my sawmill. Last B&S I'll ever buy!
ReplyDeleteUsing soft water for the weed killer...is that because hard water will "bounce" off of the leaves? Partly asked tongue in cheek and partly because I don't know what the difference would be in that situation.
ReplyDeleteThe metal ions that make water "hard" have two bonding sites. That is why they are listed as Ca++ or Mg++ or Fe++. They have the ability to bond with two molecules that are -, and typically they drop out or become insoluble. That is why soaps don't work well in hard water. The Ca++(typically) will grab two of the fatty-acids (like stearic or linoleic acid) and form "scum" that has no ability to lift oil and grease from hands or clothing.
DeleteVery hard water, i.e. 60 points of hardness, has 1000PPM or 1/10th% of dissolved solids. Very roughly speaking, that means it can inactivate 0.2% of the active ingredient of ***some*** herbicides.
A typical mixing ratio for 2,4-D, amine formulation is 0.8% liquid, of which only 40% is active ingredient. That is, about 0.3% active ingredient, as mixed. So, there is the potential to lose 2/3 of the active ingredient.
Of course, the people blending the herbicide know that and add chelating agents to the concentrate and that inactivates SOME of the Ca++ before it can grab it out of solution...but it doesn't get all of it.
Soft water is cheap. Herbicide is expensive. And, from the environmental standpoint, spraying the minimum amount of active agent via good "targeting", optimal timing, minimal wind-drift (low pressure, narrow angle spray, no wind) and maximum effectiveness due to "good" water is not only good business, it is better for the environment than multiple, sloppy applications of the same agent.