Lye Question

[Lee Sumner]

With cold weather approaching soon i was wondering if a lye bath can freeze?

[Sandy Glenn]

Yes indeed it can.  That's why I keep mine inside year round, but I'm in a cold clime.

[Lee Sumner]

Thanks Sandy. mine is kept in a outbuilding right now so i guess I'll have to move in the basement when winter hits here in VA but that might be a little tricky moving that Rubber maid tote down the steps :-/

[C. Perry Rapier]

Lee, I have the same problem, not really a problem though. I have Rubber Maid tote just like you're talking about, and I don't want it in the house no more, I want it in the garage. SO, it don't really hold that much, so, I can either bale it out and get rid of it or, bale it out and put it in five gallon buckets and carry it to the garage and refill the container there. BUT, be sure and have your safety glasses on when you are handling the lye water, and rubber gloves if needed.  ;)

[Lee Sumner]

i will certainly use the goggles and rubber gloves no doubt about that. good points on how to move it though thank you.

[Jeff Friend]

Since it is summer time, here is a little data on caustic soda solutions at 80F.  This informatin came from Olin Chemical's Caustic Soda handbook, published in 1983.  Dow Chemical has similar data on their website.

1% NaOH     8.402 lb/gal     0.084 lb NaOH/gal
2%                8.494               0.170
3%                8.584               0.258
4%                8.675               0.347
5%                8.765               0.438
6%                8.855               0.531
7%                8.946               0.626
8%                9.039               0.723
9%                9.129               0.822
10%              9.220               0.922

To determine the specific gravity, divide the solution weight by 8.308.

Adding NaOH decreases the freezing point of the solution by about 1 degree C for each percent, up to a 10 percent solution.The minimum freezing point is -28C for a 19.1 percent soultion.  This solution is much stronger that we'd used for cleaning iron, so I can't advise making a strong solution to avoid having it freeze.  After 19.1C, the freezing point increases.

To dilute 50% caustic soda on a weight basis
2%     1 lb 50% diluted into   24 lb water
4%     1 lb 50% diluted into   11.5 lb water
6%     1 lb 50% diluted into   7.33 lb water
8%     1 lb 50% diluted into   5.25 lb water
10%    1 lb 50% diluted into   4.00 lb water

Knowing that 50% caustic weighs 12.681 lb/gal at 80F, and water weighs 8.308 lb/gal, you can use the data above to convert to a volumetric dilution.

Here in SC, my caustic has not frozen out in an unheated garage, but it sure works a lot slower.

[Jesse and Kim Dunfee]

Thanks Jeff for the time it must have taken you to put that togeather

[Jeff Friend]

I should have mentioned that 50% caustic freezes at about 54F and it is much too concentrated to use for what we're doing.  Oh, it will work just fine, but if you should get any on your skin, well . . .  that wouldn't be good.  I once got some on a leather boot and it was about half way through the leather in just a few seconds.  It would also be tough to rinse off your iron without creating a lot of alkaline rinse water.

If you dilute 50% to a lower strength, always add the caustic to the water very slowly with agitation.

Here is Dow Chemical's caustic soda handbook.  Anyone that uses this chemical needs to be familiar with the way it behaves and the appropriate protective equipment, so I encourage you to read it.  Maybe one of the administrators can move this to the PDF section.

Perry is pretty close about my line of work.

[Lee Sumner]

I wonder how good this would work in an unheated garage for a few pieces at a time.? http://www.valleyvet.com/ct_detail.html?PGGUID=30e07420-7b6a-11d5-a192-00b0d0204ae5

[C. Perry Rapier]

I wonder how good this would work in an unheated garage for a few pieces at a time.? http://www.valleyvet.com/ct_detail.html?PGGUID=30e07420-7b6a-11d5-a192-00b0d0204ae5

Lee, if you have a lye tank in an unheated garage, I'd put my stuff in it and not worry about it. Put something floating in it so it won't freeze, like Jimmy talks about and then I would not worry about it. It is true that it does not work as fast  in cold weather, but where you goin? It ain't like you are running a factory where you are trying to maintain a production schedule. If you want more going on, make two lye tanks. If it was me, I would not spend the 31.00 on this bucket at all.

[Lee Sumner]

Perry good info ;) my main concern was if i put a piece of CI in there and the bath froze perhaps it would crack the piece and ruin it. you're right about me not goin anywhere i have plenty of time ;D for it to do it's work.

[Tom Neitzel]

I should have mentioned that 50% caustic freezes at about 54F and it is much too concentrated to use for what we're doing.

Jeff, does it really freeze at 54F?  That's almost a warm summer day in the NW.

My rough rules of thumb are that if it is 45F outside it is winter and raining.  If it's 55F it's summer and raining.

Tom

[Lee Sumner]

I put four pieces in my bath today. It wasn't frozen a few weeks ago it was a little slushy cause we had a cold spell but now it's warmed up a bit so i went ahead and took your advice Perry and put me some pieces in. Might as well try to get some cleaned it's stating to accumalate at a fast pace i swear that CI has rabbit blood in it ;D i think i need a bigger bath  i can only clean about four pieces at a time 

[Jeff Friend]

Tom,

I checked again . . .freezing begins at 54 F.  Go to page 11 of the Dow Caustic Handbook (reply 11 of this thread) for the phase diagram.  If your solution strength and temperature are above the heavy line, the solution is all liquid.  Below the line, and it becomes a mix of solid caustic and liquid (partly frozen).  If the temperature continues to fall, the entire mass will solidify.

Caustic soda is always shipped in insulated tankers or rail cars.  Under some circumstances, the tanker has to be steamed when it arrives at its destination to get the caustic to flow.

Jeff

[Lee Sumner]

I checked my lye bath today and sho nuff  it's gotten pretty frozen but not solid, with all this single digit temps we've been having >:( the last i checked on it was on 12/10 and put 4 pieces of CI in it, wasn't froze then but anyway I keep it at my fathers house in his detached unheated garage since i live in an apartment and can't keep it here so i was wondering will the ice damage my CI ? should i just go ahead and take it out or what.?

[C. Perry Rapier]

Lee, IMO, of course as long as it don't freeze solid and bust everything, I'd say leave it right in there, that won't hurt it and the lye is taking care of it and "holding" it. Thats what I call it. I have several pieces in lye water right now, and I take them out and work on them as I want. Now if somebody can invent a "last in last out" system for a rotational kind of deal for cast iron, that would be sweet. As it is, unless you clean one completely out, you're just burying something else for a longer period if you put a fresh one on top.  :-/