Early 911 Restoration: media blast, acid dip, or electrolytic immersed??

[Boosted3s]

I plan to use these guys to dip my 67 912 chassis, doors, fenders, etc. I have seen good results from their process.

http://www.americanmetalcleaninginc....eservices.html

And they are in Toldeo, just up the road from you.

I can second this recommendation. I used them to do my doors, fenders, bumpers etc. I was actually just there to get some old Mopar engine parts stripped and there is a 72 T there now. I believe she told me that from there that car was going to Indiana to get some sort of dipping process, maybe E coat.

[Ivan Fuller]

I am not a fan of dipping - despite all the assurances I just cannot see how the acid can be removed from all of the seams. When contemplating this years ago I heard the odd story of seams popping out after cars were finished - just once was enough to put me off - notwithstanding reputation or profitability issues if you are silly enough to try and make restoration a business

We set up our own media blasting facility as its very easy to damage panels(write off a car) if the wrong hands get a hold of a media blasting unit and attack a car

But if you must dip then the only way is to E coat. There is a lot of factory paint inside chassis rails box sections that will be unprotected if you don't.

[David Liam]

Dip it. I've heard the chemicals have changed. I have only media blasted, it's great, but still tons of rust inside. I'm moving towards dipping when appropriate, every project is unique. Your car looks crusty, internal cavities will be all surface rust, just the way it is, it can all be fixed though.

[GeorgeK]

About dipping, I had a talk with the people who did the '69 a few weeks ago:
-2 days in alcaline solution, removes paint, bondo, sealer.
-2 days in an acid bath, removes rust, leaves only steel and lead (tin).
-2 days in a neutralising solution (that is, imersed in a bath) to stop any reaction.
These baths get additional agitation by pressure washer and moving the shell around in the bath.
-Optional treatment with a rust preventing primer, including every hollow cavity, applied with gun/nozzle.

I doubt any alcali or acid is left anywhere. But my sample is only of 1.5 cars.

[Dougieboy1]

i had my shell acid dipped and was very pleased with the result. As regards acid leaching out of the seams, i took comfort from 3 points:
1. Many of the areas where this could be problematic were opened up during the body resto, e.g. bottom of the A pillars and the aggregated rock hard gunk that had settled in there was removed manually
2. As George says, the acid is neutralised after dipping
3. I had all the seams sealed to prevent any missed 'acid' leaching . Seam sealing is cheap and easy on a totally stripped car so why wouldnt you

Was i happy with the result. Hell yeah. The shell came back clean enough to eat your dinner off and remained unblemished for 6 months during the body work repairs



Can i vouch for its long term performance, no as the car isnt fully back on the road yet.

When i made the same enquiry several years ago, there similar numbers of people supporting each method so at the end of the day, you go with convenience/cost/personal preference (prejudice)

Regards

Andrew

[endo911rs]

I've done both blasting and dipping...several times. Depends on the case as to which technique is better. If the car is really solid and you don't have to open the rockers, then blasting is probably better because you can preserve the heater tubes and you don't have the strip the car down quite as much.

If blasting, I would be very picky who did it and I would mechanically strip the large flat areas with a DA sander and/or some aircraft stripper. You will have media left in areas you cannot clean out so you need to go through extra efforts to get as much of it out as possible. Immediate coverage with epoxy primer is mandatory since you have removed all protection and increased surface area. It will flash rust.

Dipping is by far the way to go if you are willing to open the rockers and remove the heater tubes (BOTH LWB and SWB cars!). I have had zero issue with 'acid leaking out of body seams! The chemicals are completely rinsed and neutralized. It gets everywhere so there is zero rust on the car, it's really amazing to see a chassis in this state. They will then e-coat or phosphate coat the bare metal and that will leave a very durable finish so priming immediately is not as crucial. I had my 67s in just the phosphate coating for 2 years while we did metal work and it was fine.

Good luck. Now go open your rockers because you will have rust there, remove your heater tubes...and call you local dipping facility.

[uai]

I'd just like to add ultra high water pressure to the list of possibilities. It also removes rust (within limitations - if you have very bad pitting you'd need phosphate for these areas).
If I was to strip a car and I didn't want to dip I'd do that.
https://www.autozeitung.de/ratgeber-...ell-84703.html
https://www.strahltechnik-mobil.de/leistungen/oldtimer/

[moito]

About dipping, I had a talk with the people who did the '69 a few weeks ago:
-2 days in alcaline solution, removes paint, bondo, sealer.
-2 days in an acid bath, removes rust, leaves only steel and lead (tin).
-2 days in a neutralising solution (that is, imersed in a bath) to stop any reaction.
These baths get additional agitation by pressure washer and moving the shell around in the bath.
-Optional treatment with a rust preventing primer, including every hollow cavity, applied with gun/nozzle.

I doubt any alcali or acid is left anywhere. But my sample is only of 1.5 cars.

which company did performe that 6day job? and how much was it?

[GeorgeK]

Company: https://www.meier-rafz.ch/

They kept the car 3 weeks because of a waiting list, but work was 1 week.

1400 CHF per meter of car, plus Mwst. the Doltane primer was extra, I think 2800.

[scottscarz717]

Have you tried Redi-Strip before? They're this great company by me and I know they work on all kinds of parts and do the kind of stuff you're looking for. Here is a link to thier media blasting page: https://www.redistripco.com/blasting/ and here's a link to their acid dip page: https://www.redistripco.com/chemical-immersion/ I hope this helps!