Use of lye/caustic soda

[Eadie McCreadie]

I made up a solution of lye (aka 'caustic soda' here in the UK) in these proportions:

5 gallons (25l) water to 10lbs (5kg) of lye chrystals

. and i was wondering how long this solution will take to remove the Indian paint from items like the cylinder/rockers etc. etc?

Secondly, for how long is the solution capable of working, and does it weaken over time meaning that it takes longer to strip paint?

Many thanks

EM

[Quinnf]

That's a _really_ concentrated solution.  I used about 3 lbs. of drain cleaner which is mostly lye, in about 30 gallons of hot water.  The paint came off within 24 hours, but I think 4 lbs. would have been better.  Solution was still bubbling 24 hours later when I did the flywheels, so it is still active for at least that long.

The procedure I used is explained here:  http://www.utterpower.com/kit_engine2.htm

Quinn

[Eadie McCreadie]

Could I being doing damage with that solution, Quinn?

Please get back to me, asap, as there is about 20 minutes delay in getting any mails from the server...

[Eadie McCreadie]

btw, I haven't seen any bubbling at all.  Just stagnant.  I had to stir it.  It was very warm, as expected.

[joe wvo]

Eadie,

First:  I hate net nannies or folks who think others don't have a lick of common sense and they admonish others to be careful with electricity as it can kill or with water as you could drown BUT, as I hope that you know, caustic soda is extremely dangerous.

I had a speck of it much tinier than a grain of sand blow into my eye and it ate a hole in it and I had to go to an opthamologist to get treated and it was extremely painful.  He said that it if had hit the cornea, I would have been blinded in that eye.  Took a long time to heal and pain was constant even with Rx analgesics.

Joe wvo

btw, I haven't seen any bubbling at all.  Just stagnant.  I had to stir it.  It was very warm, as expected.

[Eadie McCreadie]

Joe, you're my friend, not a nanny.   

[Quinnf]

Eadie,

Sorry for the delay.  I don't check this board every day.  To answer your question, no I don't think the solution can be too strong (within reason).  However there's no need to make it as strong as you did.  You can see from my experience in the article that I probably erred a little on the dilute side, but had I left it to soak longer, it would have done fine. 

And, yes, there's no harm repeating the cautions of working with chemicals.  One splash of lye solution in an unprotected eye could have profound effects on your ability to ever see again.  But anyone working around engines, electricity and power tools should already be aware of and be practicing "safe soaks."   

Before we use any power tools, let's take a moment to talk about shop safety. Be sure to read, understand, and follow all the safety rules that come with your power tools. Knowing how to use your power tools properly will greatly reduce the risk of personal injury. And remember this: there is no more important safety rule than to wear these — safety glasses.

Quinn

[dmp]

EM

I have removed paint from C.I. soaking in common vinegar.  Powered Tide in water boiling on the stove also worked.
May be worth a try.  A lot safer.

David