DI water vs Hard water

[RAG]

I just started using DI water and had a pretty "far fetched" quandry:



Does anybody think hard water (with lots of minerals and deposits) can actually contribute to washing-induced marring...or are the deposits so small this can`t possibly be the case? My gut tells me it won`t make any difference, but wanted to see how other weigh in.



Also, so far, DI is not worth the extra $2 per wash it costs me, as you still have to dry the car and clean up runs or some degree of spots will show.

[Setec Astronomy]

Those minerals are dissolved in the hard water, at a molecular (ionic) level, not particles which can scratch.

[RAG]

Those minerals are dissolved in the hard water, at a molecular (ionic) level, not particles which can scratch.



I`m sure you`re right...it just wasn`t something I had contemplated before.

[Setec Astronomy]

That`s not to say that once they plate out into a water spot that they aren`t abrasive. And a DI rinse isn`t a panacea; you still have soapy/dirty/hard water drips that come out. I think I`ll really have my process nailed when I get around to piping the soft water out to my outdoor faucet, then I`ll be washing/rinsing with soft water, and final rinsing with DI, then blowing the water off.

[fdizzle]

So is it worth spending 150$ to 400$ on these filtration systems I am seeing so much of now for your hose, or if your plumbing savvy - just taping a hose bib right after your home water softener. Will the home softener remove both minerals and hard water from the line?

[Setec Astronomy]

There have been many threads on this, but DI is a world of quality away from soft water, although soft water is a world away from very hard water, if that`s what comes out of your tap. Water softening is an ion exhange process which exchanges the calcium and magnesium ions in your hard water for sodium (usually) ions. So you still have roughly the same TDS (total dissolved solids) but they are different solids. The consensus here has been that the water spots left by soft water when car washing are much easier to remove than hard water spots...I don`t have personal experience as mentioned previously.



I do use a CRSpotless system for final rinse, and I guess I wouldn`t be without it now. If I had soft water on my outside faucet, I don`t know if I would have sprung for the CR :nixweiss