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Posted by: BPic Mar 19 2018, 10:08 AM

I am considering getting my car dipped to strip off everything to bare metal. After stripping they dip it again to neutralize and then again for rust inhibitor.

Has anyone done this? If so what was the charge? I have a place near my house in Miami that will do it for $2800. Does that seem high?

Posted by: sithot Mar 19 2018, 10:11 AM

Preferred to sand blasting. You never get all the sand out.

Posted by: Krieger Mar 19 2018, 10:23 AM

There are a few threads here. Do a search. The heater channels in the longs are not happy with that method.

Posted by: mepstein Mar 19 2018, 10:41 AM

It will dissolve the heater tubes. You will also need to E-cote the chassis. Dipping strips all the seems and inner channels to bare metal. These will rust unless you put some protective coating back on. Epoxy or etch primer wont flow to all these spots. Plan on $5-6K when all done.

Posted by: dr914@autoatlanta.com Mar 19 2018, 11:12 AM

I agree, no dipping! media blast the sheetmetal, sand blast the underneath, some are even doing the blasting with dry ice to avoid all of the media debris

Posted by: Coondog Mar 19 2018, 11:32 AM

Plus one on the dry ice method. I watched a Boeing 737 stripped of its paint using this method. Pretty awesome process.

Posted by: McMark Mar 19 2018, 11:52 AM

It feels like a thorough and necessary process, but the cost-benefit doesn't work in my opinion. Too many compromises and too many concerns. I also prefer the dry ice or baking soda blasting.

Posted by: mepstein Mar 19 2018, 11:57 AM

I wish there was one, great way to remove paint but there isn't. Soda, plastic media and dry ice all work on paint. sand, coal slag or dupont's media for rust. media gets inside of seams and crevices. Dustless blasting/wet media leaves sand or glass inside nooks and crannies that can rust later. Most blasting won't remove seam sealer. Dipping isn't great for a unibody, even if you e-coat.
It also depends where you live and the time of year. We get flash rust within a day or two unless its winter time.

Posted by: BPic Mar 19 2018, 12:02 PM

This is why I use this website! I forgot about the heater tubes in the longs. Dry Ice or Soda blasting it is.

Thanks I appreciate everyone here!

Posted by: GeorgeRud Mar 19 2018, 03:41 PM

What about the Dustless Blasting system that’s being advertised on the Velocity Channel programs? It seems much nicer than sandblasting, but I don’t know any particulars. The easier cleanup seems attractive.

Posted by: McMark Mar 20 2018, 07:18 AM

It's dustless not 'media-free'. So it's essentially normal media blasting carried by a liquid instead of just air. So the dust that's created is just washed away. But you're still media blasting -- just like using air -- and only preventing the dust.

Soda is highly water soluble: so you can wash the car out and get rid of the media. Yes you're hitting it with water, but I don't feel that's an issue over time.

Dry Ice 'melts' into a gas: so once you're done blasting, the media literally disappears.

Neither of these medias are particularly harsh, so any heavy coatings (like undercoating) won't be removed by soda/ice. The true way to 'geek out' on stripping your car, in my opinion, is to put the chassis on a rotisserie, and spend as much time as you can stand cleaning with scrapers and wire brushes. Think of the media blasting as the final step that comes in to clean up only what you missed or couldn't reach effectively.

But that's a time commitment reserved for only the most thorough of restorations. I've only done it a couple times. Mostly it's just not necessary to go to that level for most restorations.

Posted by: rgalla9146 Mar 20 2018, 09:34 AM

What are the issues if the heater tubes are removed before dipping / ecoat ?

Posted by: McMark Mar 20 2018, 10:57 AM

No issues, just compromises. So everybody will weigh the factors differently.

I don't like the idea of cutting and repairing the main structural member of the car for a superficial* process (dipping).

Can you do the work correctly and safely? Absolutely.
But what do you gain from all your effort?

And especially if you're looking to eCoat the body afterwards. You'll still have to go back and weld the longs shut again. That welding will leave a bare metal section that's been heated (which increases surface rust penetration). Welds will always rust before 'virgin' metal. So your eCoat process, which is typically chosen for its 100% coverage, will never live up to 100% coverage on our cars. So then you're eCoating to get it 'mostly covered', and if you're only getting 'mostly covered' how much different is that than just shooting the inside of the long with a wax/oil protectant like Cosmoline™?

For me, the whole question of rust prevention must also take into account two important factors:
1) What life did the car have in the past that made it rusty?
2) What type of life will you give the car when you're done?
If the car is rusty from sitting outside for 10 years, and you're going to park it in a heated garage 100% of the time, then you really aren't at much risk for repeating the past. Your restored car in the garage will never end up like the 10-years-in-a-field car.



*I'm calling dipping superficial, because IMHO there are other more effective processes for stripping a car, and the difference between those processes and dipping is the part that I'm calling superficial. i.e. cleaning the inside of the longs on a solid car is superficial.

Posted by: Mueller Mar 20 2018, 11:03 AM

I have not tried it on the 914, however on my Volvo 242 it had the tar like undercoating in the wheel wells so I used my oxy/acet torch and basically "cooked" the tar and turned it into carbon which which came off easier with my soda blaster.

Posted by: jmitro Mar 20 2018, 12:21 PM

I dipped a BMW 320 for $1500 about 6 years ago.

If the car has heavy undercoating, media blasting will not get that off. I was building a racecar and wanted every ounce of weight off the car.

Posted by: rick 918-S Mar 20 2018, 02:04 PM

Love the process. Totally depends on the car and how far you have gone with the welding and panel replacement. This car has all NOS body panels, inner structure, floors from the trunk to the cowl. Thick rubber under body coating. The car was cooked at 800 deg. dipped, rinsed twice and e-coated. There is no way I could have done with top coatings what was done internally for 3k. Hell, I couldn't crawl under the car with a wire wheel and strip the rubber coating for 3k! The wheel wells were 3/4" and thicker in some places. The way I look at it is this. I would rather only have to protect four horizontal spot weld flanges and four vertical butt welds on the longs than every internal patch and weld point over the whole car.

This process is not for every car. Only extensive rebuilds worth the investment.

Posted by: rick 918-S Mar 20 2018, 02:06 PM

One more photo. Oh, and BTW. This car was assembled with spot welders and metal finished.

Posted by: mb911 Mar 20 2018, 04:13 PM

Ok should know but is that a tr4?

Posted by: rick 918-S Mar 20 2018, 05:06 PM

Mercedes 280 SL Pagoda

Posted by: mb911 Mar 20 2018, 06:04 PM

Oh yes now I can visualize it.

Posted by: JmuRiz Mar 20 2018, 08:06 PM

W113 = worth it, especially knowing how older MB cars were put together with rust pockets due to strengthening
Funny thing is these cars were $15k all day long 15 years ago or so.

If you can afford it and are doing a ‘forever’ or high end build it would be worth it for a car that’s not a garage queen

Posted by: rick 918-S Mar 21 2018, 07:50 AM

Posted by: raynekat Mar 21 2018, 05:08 PM

The biggest problem with dipping a 914 is all the seams that will be exposed by the dipping process. The seam sealer will all be eaten away exposing the seams to infiltration by the dipping agent. A problem if you don't completely remove the dipping chemical. It will weep out with time from all your seams and ruin the paint work. Mechanical cleaning sounds way better to me.

Posted by: rick 918-S Mar 21 2018, 07:33 PM

Here's what you don't see and can't treat with a can of spray paint or wax oil. This is on the outer long. The paint was clean and shiny.

Posted by: Perry Kiehl Mar 21 2018, 08:20 PM

It depends on the chassis. If it's a nice dry country chassis, no way. If it's very rusty and you are going to replace a lot of metal, maybe.

The problem with dipping have been mentioned, but the problem with e-coat is the boxed sections with the Faraday effect. I have not personal experience, I just did some research for a current project (car that had been dipped). A bridge too far for me. I'll just do my own corrosion treatment and hope for the best.