Whenever I add Sodium Hydroxide to water the sodium hydroxide just sinks to the bottom. If I shake it, stir it, swish it, a pile of white sandy stuff still forms at the bottom. Is this bad and what can I do to remedy it?

sounds like there is an impurity, or you have reached saturation.

I added 4 tablespoons (50 grams) of sodium hydroxide to just under 1 pint of near boiling water, I was using marsofolds tek which says to do that. So how could I tell from the packaging if there is an impurity? any words to look for? and is an impurity necessarily a BAD thing?

Garbage-In, Garbage-Out.

An impurity can be from benign to disastrous. check the label, try to find an MSDS for this product and/or call the company for details. Also, does it feel that just a little does not dissolve or that the whole lot of sodium hydroxide does not dissolve?

It is possible that the impurity comes from the water. If your water supply has normally loads of calcium, stuff will react with NaOH and stuff will precipitate out.

And PS, do not add sodium hydroxide in very hot/near boiling/boiling water, this is dangerous practise!

I would say that around half of the material doesn't dissolve.

You might be right about the calcium, I should get some distilled and test.

from Marsofold's tek right under "Basification." That is where I got that from...

P.S. how dangerous is sodium hydroxide? If I put my hand in and picked up a scoop would I feel burning immediately? would I feel it several hours later? or would I only feel it if it was combined with water?

are you using distilled water?

when large lumps are added to water naoh will cake up and harden a shell over the exposed area. take cool water and stir constantly while slowly pouring the grains in. dont let it gather or stop moving.

for 100g bark i take 300ml of distilled water and slowly tilt in 50g of lye stiring until its gone and the water cloudy. i add 200ml water and 50g more lye(this slows the overall temp spike) and stir until gone. let it sit until the cloud goes away.

one time i had 100g lye solidify at the base of a 500ml grad cyl. it soaked for a weak in water and did nothing. had to pop it out with a hanger.

Every time my sink gets clogged, I NaOH it and what appears to be metallic rocks precipitate out. I put water in a glass to test and the same thing happens. Does this happen to others?

Drano brand contains Aluminum metal pellets in their lye based drain cleaners. (Drano) They call the aluminum pellets a stabilizer but those pellets also bubble and create mechanical adjatation so the drain cleans better. They also add sodium nitrate, sodium chloride and colorant. I don't think you want to be using that type for anything other than drains. Some lye based drain cleaner says "100% lye" on the label. I think that's a better choice.

Oh jeez!! I looked up the msds for typical drain cleaners that just say "contains sodium hydroxide", but do not say 100% sodium hydroxide. And also looked up the msds for powder drano. The msds said the same for both, which leads me to believe that all NaOH containing products that are sold specifically for drains, probably contain about the same percentage of ingredients, unless stated otherwise. The msds said the drain products contain only 30-60% sodium hydroxide. 15-40% sodium nitrate, and 5-10% aluminum. That means that there is potentially more sodium nitrate than sodium hydroxide!!! According to this page, http://en.wikipedia.org/...ian_lethal_dose#Examples sodium nitrate has an oral ld50 of 180mg/kg in rats, which is pretty low. In a 75kg person, a lethal dose would be 13.5g. If you use 100g of a drain cleaner product that has 40% sodium nitrate, there is potentially 40g of sodium nitrate in it!!!! Three times the lethal dose for a person!

Jeez, I was thinking that it would be like 95% NaOH and only a small amount of other stuff, but damn, those numbers are waaaaay too high.

Granted, sodium nitrate is a salt that isn't really soluble in anything non polar, but still that's too damn much of a cancer causing salt. But that means that using this type of drain product is absolutely out of the question for harmala teks, in which harmalas precipitate directly out of the salt soluble water.

This stuff is working fine for me:

pure lye at same store.