[BO185]

Some facts verses speculation. The chemicals used today for dipping are not the same. I have used the old style chemicals in small batches (95gals) to do wheels and its pretty horrible stuff but works great. But hard to get and expensive now.

I talked to the guy that does the videos he works for the company, just to pick his brain. The old style dip was pretty nasty stuff and would eat alot of things, and would remove the paint in one dip in not alot of time. The chemicals they use now are pretty off the shelve and not harsh to humans or the environment. They do take longer and they have to power wash the paint off as it doesn't completely dislodge and melt it. Basically there is a "base" paint stripper then its power washed and dipped in a mild acid which netulizes any base and removed any rust. Then powder washed and spray with rust inhibitor. So the days of the acid leaching out of everything are pretty much over.

I looked into dipping on this large of a scale and for me just not worth it. It takes like 2-3 days of the car in the tank for it to work. And they only do one at a time. Granted he adds small parts in same tank but just not worth it for me. I will say $3k for that service is a deal. But he is booked up a long time in advanced.

I may try the acid he uses as he did an engine block and it came out like new.
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[BO185]

Fifteen years ago when my buddy's Challenger was dipped, they used Sodium Hydroxide (I saw the labels on the drums of the stuff myself). That's the main ingredient used in most drain openers. After the body came out of the tank, they hosed it down with water to neutralize, and finally, to prevent flash rust from occurring, they sprayed the body down with a mild phosphoric acid solution, similar to Ospho or Metal Prep.

Sodium Hydroxide is what is used now. Its used in most off shelf paint removers now too. The good stuff is Methylene Chloride I still have a nice scar on my arm from just a drop of it. Its like from the movie Alien, their blood would eat through 5 decks of a ship. Well this stuff is almost as bad LOL.

Ideally you dip parts in 10-15% solution of Sodium Hydroxide then power wash, then dip completely in phosphoric acid solution which neturlaizes base and removes rust. But that takes days to complete. With Methylene Chloride it will remove paint or powder in 15 min typically. Nasty stuff but WAY faster. But Methylene Chloride will eat soft metals like AL and magnesium. I ruined one AL wheel leaving it in to long 18hrs by mistake. It pitted the face and back to render it unusable. Had to buy a new wheel, as well as didn't charge customer for the other 3 to make it right for my mistake.

Most dips shops are the Base acid dip. Which the base just removes the bond the paint or powder has with the metal, vs the nasty stuff will melt it completely!

 

[BO185]

I know about Methylene Chloride. When I graduated from high school back in 1980, I got a summer job working at a marine paint factory. Among the chemicals I used to clean the paint vats was Methylene Chloride. Imagine standing inside a 6 foot high paint vat that's coated with wet marine paint, and brushing it clean with MC. I probably lost a few brain cells from the fumes.

Methylene Chloride was the active ingredient on all paint stripper at one time now its been removed due to regulations. The concentrate I use you won't be breathing it, I use full face mask when opening the tank. Its nasty stuff. I tried just wearing a mask but it burned my eyes to bad. On thing to note is when the fumes are burned IE introduced to flames they break down into a nerve gas. Good stuff. lol

 

[BO185]

B-17?
NASTY stuff!
My bud's powder coating shop used a 55-gallon drum to strip small parts and wheels.

Yes Benco B17. Building a 500 gal tank now for it getting a 330 gal tote of it. So we can dip parts in it to remove powder and paint quicker.

He got some on his arm and before the pain let him know, it had made a nasty chem burn bigger than a silver dollar. Took weeks to heal.

I really thought it wasn't that bad of stuff till I put a wheel in my small barrel and got about a dime size drop on my arm. In about 5 seconds I was running to the sink. It burn pretty bad and left a scar on my arm like a cigarette butt burn. Nasty stuff.

 

[BO185]

There is a place in WI that did this guys nova, when he picked it up, they helped him push it in his enclosed trailer, when he got home his first time to see the side they were "helping" on found the quarter to be crushed

This is why we take pictures of everthing as they come in and after blasting. Did have one guy try the game of getting something free deal. Showed him pictures and he shut up real quick. But alot of shops will do just that damage stuff and not say anything. If one of our guys messes up something we fix it and make it right. Had a door crushed by a fork lift. It was an early ford sedan door, cost us $2k for the door, yes our mistake and our loss but it was made right and customer was happy.

 

[BO185]

I don't see the benefit of oven baking, and without knowing how high the temperature is set at, I'd worry that it might anneal the sheet metal.

Its not hot enough to damage the steel's strength in reality. There is a difference in oven heating it and a car on fire that is burning WAY hotter.

I've read a good bit of commentary on the process. It dosen't leave any chemical behind in the seams. However, if the ashes aren't completely removed you have a problem with that later on. It seems that no matter what the process, the key to success is the skill level of the operator. Sand Blasting can damage a car if not done correctly, chem dip can cause problems if not removed correctly, oven bake can also cause problems if not done correctly or cleaned properly afterwards. Nothing is 100% problem free and it all hinges upon the knowledge and skill level of the person doing the job.

Some of the strippers use an over to remove paint, undercoating, bondo, and anything elso that will melt. It gets a high pressure wash after that, then its dipped for rust removal. The over is set to rise slowly to 800 degrees, then slowly cool down. The key is heating it slowly, up and down, and doing the whole panel/car. I used an acid stripper that used an oven for years, and the only damage I ever had was an operator set my hood down too hard on the back corner of the hood as he put it in the oven. Thats when I started looking for another place.

Usually 800 is max you always set the bake off, temp to max temp needed to back off whats on it, one this saves money in natural gas, two is time less time in oven means more you can do, and three saves the part from any damage.

Most powder and auto paints cook off below 600*. I have used back off ovens for paint and powder for small things like hooks. Never liked them. Dipping them is way quicker too.

 

[BO185]

I am in 4th camp media blast it, but I am bias.

You hit on key being trade secret which is the mix of the chemical as to what works best. They don’t give that up, can’t get a direct answers om that, but can be figured out. I have researched the body dipping alot and know the chemicals used but unsure of the concentration level. Which can be found via testing.

For my business the numbers just aren’t there for car dipping, time, tank cost, chem cost, and ability to produce just aren’t there. I can say $3-4k dip is a deal IMO. But I blast for well under half that. We blast 1-2 full bodies a week on avg on top of everything else vs it may take a week to dip on car (5 business days) So media blasting make more sense time wise for me. Provided the blaster is skilled.