Snow White Laps

[jimzim75]

Hi All,
I started a new thread on laps because I didn't want this buried. I took my well used lap and
soaked it in Muriatic acid and then cleaned it in BCR. It came out snow white and as clean as the day it was made. To use this you must use the proper precautions because this can be
dangerous.

BCR (Beaker cleaning reagent) from Oakite
is not dangerous. We buy it a C.R. Hill Co. in Michigan
in one gallon containers for our standard Ultra sonic
cleaner. It doesn't break down but just get murky.
I use it for about three weeks before changing the
tank.

I wear the full kit of safety stuff when doing
the muriatic acid (water down HcL = Hydro clorick
acid). I use full respirator with a face shield, rubber gloves,
rubber apron, with a bucket of water standing by.
This stuff smokes when open. I personally know
how to use this stuff safely. You can get it at
swimming pool supply houses. They use it to clean
the pools. We can get also at Canadian tire
for use on drive ways to clean up oil. So it's not as
bad as true HcL. The thing is your not just throwing
it on the drive way. Your getting up close and
personnel with it. This stuff stings if you get it on you.
You don't do twice. So be careful and don't try to wing it.
Get the safety equipment. Rio Grande is where I got mine.

So, this is how it's done.
Pre clean the lap by putting it into a the ultra sonic with BCR,this gets rid of the top dirt.
Rinse in water and dry. I do the acid stuff outside on the patio.
I use a baking Pyrex dish to put the lap in. IMPORTANT, add the acid after
the lap is in the dish. We do not want any splashing of the acid.
Let it soak for 15 minutes. This oxidizes any metal particles and loosen all the oxides.
Take the lap out of the acid is not what you would think.
I use a small plastic glass and pin the lap to the bottom of the baking dish.
With the lap pinned I pick up the whole dish and pour off the acid in a funnel and back into the bottle.
Make sure the bottle and funnel are supported so they don't tip over.

You might want to practice this with water before trying it out with the acid. Use the funnel and a similar
bottle. Just so you know it works well. Try not to let one drop of water go astray.
After the cap is safely back on the bottle and funnel is rinsed. The take the dish with the lap and put the
whole thing in the water bucket. You can take the lap out while it's in the water by tilting the dish and
lapp sideways. So you have a bucket that will hold the dish comfortable with enough water.
Dry the lap off. It will still be grey at this point. Put back into the sonic with the BCR.
The oxides will fall off and the lap turns snow white.
BCR is a base but you could soak the lap in water and baking soda to be sure all the acid is neutralized.

One last warning, if you haven't ever used strong acid before. Do not do this as your first try.
This stuff will not kill you, but it hurts for a long time if you get it on you. Dilute the acid with water
if it comes in contact with with your skin. Quickly. If your a clutz, then forget it. Don't even start this process.
----------------

ADMIN NOTE: Jim wasn't sure if he should post this since acids can be hazardous to deal with. I consider this important information so we decided to share it. Neither Jim nor I recommend this procedure. If you choose to do it, you must do it in a safe and responsible way. / ~Sam
----------------

 

[monk]

muriatic acid

Hi All,
I started a new thread on laps because I didn't want this buried. I took my well used lap and
soaked it in Muriatic acid and then cleaned it in BCR. It came out snow white and as clean as the day it was made. To use this you must use the proper precautions because this can be
dangerous.

BCR (Beaker cleaning reagent) from Oakite
is not dangerous. We buy it a C.R. Hill Co. in Michigan
in one gallon containers for our standard Ultra sonic
cleaner. It doesn't break down but just get murky.
I use it for about three weeks before changing the
tank.

I wear the full kit of safety stuff when doing
the muriatic acid (water down HcL = Hydro clorick
acid). I use full respirator with a face shield, rubber gloves,
rubber apron, with a bucket of water standing by.
This stuff smokes when open. I personally know
how to use this stuff safely. You can get it at
swimming pool supply houses. They use it to clean
the pools. We can get also at Canadian tire
for use on drive ways to clean up oil. So it's not as
bad as true HcL. The thing is your not just throwing
it on the drive way. Your getting up close and
personnel with it. This stuff stings if you get it on you.
You don't do twice. So be careful and don't try to wing it.
Get the safety equipment. Rio Grande is where I got mine.

So, this is how it's done.
Pre clean the lap by putting it into a the ultra sonic with BCR,this gets rid of the top dirt.
Rinse in water and dry. I do the acid stuff outside on the patio.
I use a baking Pyrex dish to put the lap in. IMPORTANT, add the acid after
the lap is in the dish. We do not want any splashing of the acid.
Let it soak for 15 minutes. This oxidizes any metal particles and loosen all the oxides.
Take the lap out of the acid is not what you would think.
I use a small plastic glass and pin the lap to the bottom of the baking dish.
With the lap pinned I pick up the whole dish and pour off the acid in a funnel and back into the bottle.
Make sure the bottle and funnel are supported so they don't tip over.

You might want to practice this with water before trying it out with the acid. Use the funnel and a similar
bottle. Just so you know it works well. Try not to let one drop of water go astray.
After the cap is safely back on the bottle and funnel is rinsed. The take the dish with the lap and put the
whole thing in the water bucket. You can take the lap out while it's in the water by tilting the dish and
lapp sideways. So you have a bucket that will hold the dish comfortable with enough water.
Dry the lap off. It will still be grey at this point. Put back into the sonic with the BCR.
The oxides will fall off and the lap turns snow white.
BCR is a base but you could soak the lap in water and baking soda to be sure all the acid is neutralized.

One last warning, if you haven't ever used strong acid before. Do not do this as your first try.
This stuff will not kill you, but it hurts for a long time if you get it on you. Dilute the acid with water
if it comes in contact with with your skin. Quickly. If your a clutz, then forget it. Don't even start this process.
----------------

ADMIN NOTE: Jim wasn't sure if he should post this since acids can be hazardous to deal with. I consider this important information so we decided to share it. Neither Jim nor I recommend this procedure. If you choose to do it, you must do it in a safe and responsible way. / ~Sam
----------------

if you get this stuff in the local hardware store, it's still nasty- but not quite as bad as it is full strength. the hardware store version is used to clean masonary and stains on concrete. this weaker version will work, but will take a bit longer- and may be a bit less dangerous. again, use out doors, and with all applicable precautions. this is not for wise ones who have no need to read labels !!!

 

[jimzim75]

You got it Monk. Translation of the above; "this is not for wise ones who have no need to read labels !!!"
= "So be careful and don't try to wing it." You can't sorta know what your doing. You can't kinda do the
safety stuff. Muriatic Acid is a weak a acid, but on who scale. I can tell you it's a nasty chemical burn.
Rather than being dark like a fire burn, it's white like blister. Unlike a blister it does stop hurting for a long
while. Two weeks, no kidding. I sure most you know this.
I haven't been burned in twenty years because I use the proper equipment. For sure, I don't want
to relive the burn, I actually remember it quite well. This acid is a great tool, used in the proper manner.
I've been sharpening blades with my reconditioned lap and am quite happy with the results.
If your not sure about the use of strong acids, go to someone who know how it works. The high school
chemistry teacher, electro plating companies, jewellery supply companies, industrial safety people, etc.

Using acids is sort of like using a torch. You tend to only pick up a hot piece that sticks to your finger
once. Then you have a nice reminder to look at the rest of your life. An acid burn is a sour memory that
stays with you.

So Monk, the short and simple is, " You can't a silly bugger and use acid."

 

[Swede]

JimZim, I'm not disputing your experience, but I can't resist telling this particular acid story, which happened only a few months ago. It was horrifying at the time, but I can chuckle at it now.

The scenario - in my shop, I was working with lye; sodium hydroxide. Lye is a very powerful base, used to make soap. When you get in on bare skin, it is unmistakeable, because it feels soapy, like a thin dishwashing liquid. The reason it feels soapy is because the lye is TURNING YOUR OWN FLESH INTO SOAP! Yuk, no fun. When you feel that soapy wetness, you want to get it off, fast.

So there I was, with a modest but uncomfortable quantity of lye on my hands. Need to wash it off fast, and neutralizing with a mild acid like vinegar works great. I knew that next to my bench was a 1 gallon white jug of vinegar. I crouched down, popped the top off the vinegar, and began to pour it liberally all over my hand, letting it flow to the concrete floor... I'm talking a volume and velocity similar to what you'd get with a normal bathroom faucet. A LOT of vinegar. I want that lye off, NOW.

Then I noticed something quite odd. My concrete floor was melting. A huge area the size of a dinner plate was bubbling and gassing, forming a nasty green foam, popping and hissing.

With horror, I realized that I had grabbed a 1 gallon jug of pure muriatic (hydrochloric) acid, not the vinegar! This stuff was concentrated, the exact jug you buy from a pool store. I had just poured a pint of it all over my bare hand.

I didn't quite scream, but I RAN to the nearest water I had, which was our backyard pool, jammed my hand to the elbow under water, and swooshed it vigorously. I thought I'd pull up a sizzling stump, or the skin would be falling off, something gruesome, but you'll not believe this - there was NOTHING wrong. The skin got very slightly red over a few hours, but there was absolutely no ill effect at all. Not recommended, but I'm living proof that skin itself is fairly resistant to HCl. The eyes - that's another matter. Please listen to what these guys say about acid. I actually have a degree in chemistry, and should have known better, and been better protected. I'm still amazed that it didn't hurt me, really bad.

Of the big three mineral acids, nitric, sulphuric, and hydrochloric - HCL is probably the least damaging. Nitric acid stings, and leaves big golden burn stains behind. Sulphuric is horrific, melting the flesh and scarring terribly. Hydrofluoric acid is in another league - even a small burn can kill you. OK, enough of this! Be careful!!

 

[Sandy]

There is one other thing about Muriatic acid. If you leave it uncovered or the bottle open it will rust any metal in the room with it. If you are outside on a real humid day the acid will react to the humidity. There will be a mist form. This mist will eat your lungs. Jim is correct A resporator is a must. Not one of those little cloth/paper paint mask. It will react to water sometimes violently. Be careful.

 

[jimzim75]

Thanks for the back up Swede and Sandy. This is serious stuff and not to be taken lightly.
I work with it daily and it still gives me the creeps.