Stripping Paint

[chevelle518]

I have been a new member for a couple of week's and really enjoy my 64!

I have a tip for everyone!!!!

A friend told me about the way he stripped paint off his wheel's and boy does it work!!

I was wanting to completely remove paint from all panel's under the hood and just didn't use wire brush and sand paper.

I poured 4 gallon's of Muriatic Acid in a tub with 4 gallon's of water and put the part's in and in overnite for small piece's and 2-3 day's for bigger part's.
I put my fender in to remove old bondo and rust and it really worked. I was able to just lift the bondo out with my finger.
You guy's may want to try it.

PS It burn's like HELL if you have a cut on you hand, USE GLOVES!!!!!

[orange66fleet]

That sounds great, where do you get the acid and what does it cost.

[60ratrod]

i think you can get it at your local hardware store like lowes or home depot. not sure of the price though. and i hear it makes for an awesome degreaser

[Captainfab]

Muriatic acid is commonly used to clean concrete and masonry, so places that deal with those items usually carry it. I sometimes use it full strength to romove zinc/cad plating on things I want to weld on. I haven't tried it on paint or grease. I'll have to give that a try.

[chevelle518]

Originally Posted by orange66fleet

That sounds great, where do you get the acid and what does it cost.

any hardware store $4.00nper gallon

[63 & 64 Bowties]

It's used in swimming pools, so any pool supply place will have it also. Some of them sell it in bulk, just bring your own container.

[slorio]

Folks:
You might want to do some more research on this. I believe that muriatic acid is bad for the metal. I think the term for what is does is "embrittlement" if you want to search on that. Here's an example from a boat site:

Be warned, muriatic acid causes hydrogen embrittlement in carbon and alloy steel, cast iron, some stainless steels and aluminum alloys.

During the "pickling" process, the material takes on available hydrogen atoms from the acid. This causes what is called "hydrogen embrittlement." Hydrogen embrittlement causes the material to fracture along sheer planes more easily. Thus, the strength of the part is greatly diminished.

Hydrogen embrittled fasteners or parts under stress can fail suddenly without any warning.
I hope this is helpful.
regards,
Steve
New Orleans

[chevelle518]

Originally Posted by slorio

Folks:
You might want to do some more research on this. I believe that muriatic acid is bad for the metal. I think the term for what is does is "embrittlement" if you want to search on that. Here's an example from a boat site:

Be warned, muriatic acid causes hydrogen embrittlement in carbon and alloy steel, cast iron, some stainless steels and aluminum alloys.

During the "pickling" process, the material takes on available hydrogen atoms from the acid. This causes what is called "hydrogen embrittlement." Hydrogen embrittlement causes the material to fracture along sheer planes more easily. Thus, the strength of the part is greatly diminished.

Hydrogen embrittled fasteners or parts under stress can fail suddenly without any warning.
I hope this is helpful.
regards,
Steve
New Orleans

You must of had a lot of time on your hand to research that in info. I have used on a couple times and there hasn't been any problem!!

[60ratrod]

the biggest things that you need to watch out for hydrogen embrittlement in is your engine block, rotating assembly, heads, and anything else that either supports weight or takes extreame pressure and temperatures. but things like the tins on the engine are ok.

[chevelle518]

Originally Posted by 60ratrod

the biggest things that you need to watch out for hydrogen embrittlement in is your engine block, rotating assembly, heads, and anything else that either supports weight or takes extreame pressure and temperatures. but things like the tins on the engine are ok.

Thank you!!

[suville]

slorio is spot on! I worked in the aeromotive plateing industry for several years and we replated Pratt-Whitney Radial engine parts ,mil spec called for if I recall 400* for around an hour to: release trapped hydrogen from the pickeling process which is necessary in certain plateing operations, I refered to this very subject in a previous post about using acid to derust fasteners it is critical on structual fasteners sheet metal may not be a concern but you're taking a chance here.

[63 & 64 Bowties]

Nobody has mentioned how the paint is going to adhere. You'd end up with a nice "sanded" surface, but what about the acid reacting with paint? Anybody know? I know you'd have to clean the surface before painting, but what's the chances you're gonna get every single molecule of acid?

[slorio]

slorio is spot on! I worked in the aeromotive plateing industry for several years and we replated Pratt-Whitney Radial engine parts ,mil spec called for if I recall 400* for around an hour to: release trapped hydrogen from the pickeling process which is necessary in certain plateing operations, I refered to this very subject in a previous post about using acid to derust fasteners it is critical on structual fasteners sheet metal may not be a concern but you're taking a chance here.

Thank you!
Regards,
Steve
New Orleans

[slorio]

Suville:

Originally Posted by slorio

slorio is spot on! I worked in the aeromotive plateing industry for several years and we replated Pratt-Whitney Radial engine parts ,mil spec called for if I recall 400* for around an hour to: release trapped hydrogen from the pickeling process which is necessary in certain plateing operations, I refered to this very subject in a previous post about using acid to derust fasteners it is critical on structual fasteners sheet metal may not be a concern but you're taking a chance here.

Thank you!
Regards,
Steve
New Orleans

[60ratrod]

well i work in the aviation community of the navy and hydrogen embrittlement is a big concern with aircraft parts, like landing gear braces. and this is from using isoprophyl alcohol atomized from spraying it from spray bottles. and we use a chemical stripper to do inspections on various hardened items like wing cross members and arresting gear tail hooks. and aircraft paint stripper we use is similar to muriatic acid. so if you aren't using it on a load bearing part or something that still needs its tensile strength or carbon content to hold any kind of pressure then go a head and use it, like on your engine tins, which don't maintain any serious amounts of pressure due to the evac system with the pcv valve and breathers.

[Heater63]

My 2 cents is there are better, safer, and gentler methods.

Example: Trans-Am racing '69- factory bodied mustangs were getting whipped by factory bodied camaros....one of the camaros was dipped in acid to thin the metal and lighten it! OK for a brand new body going one race season, but is that what you want to do to a 40 year old panel that you are trying to preserve???

just my 2 cents

[lakeroadster]

Originally Posted by slorio

Folks:
You might want to do some more research on this. I believe that muriatic acid is bad for the metal. ....

Hydrogen embrittled fasteners or parts under stress can fail suddenly without any warning.[/I]

As a Mechanical Engineer I have had actual hands on experience with Hydrogen Embrittlement. It is a problem for highly stressed components such as Grade 8 fasteners or aircraft components as 60ratrod eluded to above. It will not be a problem on sheet metal auto body panels.

And the Muratic Acid you buy at a pool supply place won't hurt the body panels if you use it the way Chevelle518 described in his first post.

I hope this helps.

[63 & 64 Bowties]

Originally Posted by lakeroadster

As a Mechanical Engineer I have had actual hands on experience with Hydrogen Embrittlement. It is a problem for highly stressed components such as Grade 8 fasteners or aircraft components as 60ratrod eluded to above. It will not be a problem on sheet metal auto body panels.

And the Muratic Acid you buy at a pool supply place won't hurt the body panels if you use it the way Chevelle518 described in his first post.

I hope this helps.

Thanks John. That clears that up. Is this forum great or what? Free advice from a Mechanical Engineer. It don't get no better than that.