I am debating which Chapin backpack sprayer to buy. The major difference between Chaptin 61900 and 61800 (see bottom of the page for comparison) is that 61900's wand is stainless steel. I am planning to use it with homemade solution (with white vinegar plus salt and detergent) to kill weeds. But will this solution be bad with stainless steel (ie: corrosive)?
Herbicide strength acetic acid is not recommended for use by homeowners. In fact, it's likely very difficult for the average joe to buy. I was curious about it years back and made inquiries. I found rail companies use a 30% spray to kill everything growing along rail lines and it's actually dangerous to use without proper equipment and training.
If you are going to use a vinegar to kill weeds you need to understand why vinegar kills 'weeds'. To make it yourself is silly. Home vinegar isn't as strong as you'll need it to be. Vinegar should be above 5% in acidity. Spraying it is crazy. Forget a back pack sprayer unless you want to ruin your entire yard.
The best use of vinegar is to spray the commercial high percentage 'vinegar' onto and into the soil. What this does is to stop germination of any plant. The pH would be so low no plant could grow.
Make no mistake. Weeds are just plants. All plants that are sprayed with vinegar will be ruined. Even just over spray. No homeowner should ever spray any chemical with a backpack sprayer. Only those that are licensed and know what they are doing should spray anything...and those that are licensed and know what is going on will rarely ever use pesticides or chemicals.
Pesticides or all chemicals for use on soil, insects and plants are only BAND AIDS for problems that happen because of lack of information, thus mistakes. That includes vinegar, soapy water, glyphosate...chemicals that kill; plants, biology/insects, mites, fungus, bacteria or virus.
My worry is why the heck people are so up in arms against weeds? I've never put so much effort into weeds much less chemicals! I simply smother them with soil or better yet mulches with no weed seed nor pesticide residues. Weeds are no big deal!!! Half a century living with plants and soils and animals and sorry, weeds do not deserve the bad ass reputation they've gotten!
Starving weeds by chopping of the top growth, weed wacking the babies, smothering seeds by dumping soil on top is by far more effective and easy peasy.
When one uses herbicide quality vinegar, they spray it on gravel or soil they do not want any growth to be able to happen. The pH will be so low nothing will germinate.
The cool thing is how easy it is to change this pH and have a viable soil once again. Add lime, the pH gets back into a range where plants can grow and no harm done.
Spraying vinegar on live plants is as bad as spraying roundup and very much less effective.