Lye container help

[samirish]

I make up 3 lb batches of lye water at a time. I currently mix my solution in a heavy duty restaurant quality plastic bin. In the past, I have mixed it up in heavy duty plastic pitchers. Eventually, the lye eats through it all. I would like to not have to replace my lye container every couple of months.

What are you guys using to mix up your lye solution?

Thank you

 

[DeeAnna]

There have been detailed discussions about this in the recent past.

http://www.soapmakingforum.com/showthread.php?t=61201
http://www.soapmakingforum.com/showthread.php?t=60822

 

[cmzaha]

My 2 gallon batches of lye have never eaten through my hdpe buckets and some are over 5 years old, they are also my soaping buckets.

 

[IrishLass]

What kind of plastic are you using? I ask because not all plastics are compatible with lye solutions.

If you look at the bottom of your container you should be able to see the recycle code in a triangle. The best plastics for use with lye are those with a recycle code of PP #5 and HDPE #2. Containers made of Nalgene are very good, too.

For what's it's worth, I'm still mixing my lye solution in the very same PP #5 pitcher that I bought over 10 years ago, and it's still going strong without any issues. I make up enough 50% concentrated lye solution in it at a time to last me through 7 or 8 batches of soap, and when it is cool, I store it in a reclaimed laundry detergent bottle made of HDPE #2 plastic. I've experimented with how long it is able to last in the HDPE #2, and it seemingly lasts forever in it without any issues (well over a year and counting).

A personal example of how not all plastics are good with lye solution- I once used a container made of PETE #1 plastic to store my 50% lye solution, and it ate right through it within a week, and the solution leaked out onto my floor. Luckily, it happened in my storage room which has a concrete floor, so no biggie as far as damage goes. Moral of the story- know which plastics are compatible with lye solution. Needless to say PETE #1 is definitely not one of them! :shock:


IrishLass

 

[DeeAnna]

Nalgene is a brand name for containers made from a variety of plastics. If you visit the Nalgene website, you'll see a list of plastics used in their current-day consumer product line -- HDPE, LDPE, a plastic called Tritan, and even a few items made from PET. Some older Nalgene items were made from polycarbonate.

I cannot find any chemical resistance information for Tritan, but a few tidbits I stumbled upon suggest it has properties similar to polycarbonate. Polycarbonate is not recommended for use with alkali solutions (NaOH or KOH), so I would shy away from anything made from Tritan in the absence of clear information.

So even with Nalgene, it boils down to checking the mark stamped on the container to know what you've got and whether it's safe.

 

[IrishLass]

Thanks for clarifying that, DeeAnna! I should have specified Nalgene break-resistant lab-ware . I know of trusted soapers who use the Nalgene break-resistant lab jars in which to mix and store their lye solution with good results.


IrishLass

 

[newbie]

I use the bottles that the lye come in. As I use my lye, additional bottles become free to use so I can change them up. However, I have to assume any one bottle would be resistant for a long period of time since it can also hold the dry lye for a long period of time.

 

[penelopejane]

I use the bottles that the lye come in. As I use my lye, additional bottles become free to use so I can change them up. However, I have to assume any one bottle would be resistant for a long period of time since it can also hold the dry lye for a long period of time.

This is what I do too!

 

[Susie]

This is what I do too!

And now, thanks to y'all, so do I! It works brilliantly!

BTW: 32 oz (weight) NaOH + 32 oz (weight) H2O = 40 oz by volume of NaOH:H2O 1:1. Don't ask me how, but it works. That gives me enough of the mixture to have an almost full bottle + what I need for one batch of soap.

 

[DeeAnna]

I do not use the containers I get from The Lye Guy to make/store lye solution. They are PETE (recycle code 1). PETE plastic is acceptable for DRY alkali, based on my experience with storing the stuff for months in these containers. But I speak from experience, like Irish Lass, that PETE (aka PET, PETG) is absolutely not safe for lye solution. Not even for a day or two.

I can see why someone might take the line of reasoning that "if it works for dry alkali, then it should be fine for lye solution." Like so many things in chemistry, unfortunately that line of reasoning isn't valid. The difference is that DRY alkali is in its "tame" molecular form (NaOH). The NaOH in a solution splits into its ionic form (Na+ and OH-) and the ions are much more aggressive.

So always check the code -- if it's not PP or HDPE or (third choice) LDPE, it's probably not good for lye solution.

 

[Susie]

I still get my lyes from ED (I needed to order other stuff, so it made sense), and the bottles have a #2 on the bottom. I am saving all those bottles, though, so when I order from The Lye Guy, I can still masterbatch in the safe bottles.

 

[DeeAnna]

Sounds like a plan, Susie!

 

[newbie]

Yes. ED's bottles are HDPE#2, but I see your point, DeeAnna. My mistake.

 

[DeeAnna]

No mistake made, Newbie ... it's all just part of the learning process! I'm always learning too.

 

[earlene]

I make up 3 lb batches of lye water at a time. I currently mix my solution in a heavy duty restaurant quality plastic bin. In the past, I have mixed it up in heavy duty plastic pitchers. Eventually, the lye eats through it all. I would like to not have to replace my lye container every couple of months.

What are you guys using to mix up your lye solution?

Thank you

Samish, you were asked what kind of plastic you were using, but so far haven't responded. From what you mentioned above, and my own restaurant experience, I conclude it would have been something like this, which if it is the polycarbonate version it definitely will NOT hold up to lye in solution:

Or this:

I don't have any of the second one pictured, so can't look at the bottom of the container to say if it would hold up to lye in solution.

Then you mentioned 'heavy duty plastic pitchers'. That description leaves out the most important part of determining if a container will hold up to lye in solution, as mentioned in the links provided by DeeAnna above.

Are you in the US or elsewhere? Where you live are the codes for plastics used on the bottom of plastics like we do in the US?

One other caveat, is that if you are using old plastic made before the recycle coding system was put into place, there is no way of knowing if those items are lye safe. I still own and see old plasticware sold in thrift stores produced before the recycle coding system was implemented, so I never use them for soap making.

I use a large plastic pitcher with a #5 symbol on the bottom for mixing my lye solution, and store the cooled solution in #2 symbol plastic bottles (from Essential Depot, that the dry NaOH came in). These are lye solution safe containers as mentioned in the links DeeAnna included.