Topic: To Dip or not to Dip

[nham3407]

My body person has recommended that I hot tank my 72 Mach 1 body prior to beginning the replacement of the bad sheetmetal.  I have the car stripped to that degree so it is not a question of tear down.  I have inquired with other folks who have stated that hot tanking a body is good to get rid off all remnants of any corrosion, but they have heard occurences where all of the stripping material is not neutralized around spot welds and in small cavities and later comes back to start eating away the paint and any material applied onto the body.  My body person stated his recommended location uses 3 neutralizing baths after dipping.  Does anyone have experience with hot tanking the unibody (pro's or con's)?  My body person also has a contact who can EDP dip the car after the sheet metal work is done to avoid any possible future corrosion.  Would the EDP coating affect me in concourse driven judging if I still plan to apply primer over the EDP to match my factory primer and overspray?

[J_Speegle]

Have no experience with EDP sorry

As for dipping I did a car years ago that was dipped and I would not do it again (but of course our cars don't typically have the rust issues others do) Dipping meant that we had to redo all the factory seam sealers (some panels were sealed between the panels and this could never be replaced) and all the original sound deadener. Though the chemicals MAY have changed the stuff that was used on that car continued to leach

Just one opinion as always

[MyRed66GT]

My buddy has had two cars dipped and e-coated before paint. His paint guy swears by this method. I agree about the fact that all seam sealer will also be affected by this method. The 66 coupe he had done looks absolutely gorgeous. The car started out as an Arizona car. The body guy said hes never seen such a rustfree car in his life. Dipping and e-coating ran about $3000.

[Aussiemach]

A quick reply.
I had mine dipped here: http://www.minuspaint.com.au/
Agree with Jeff that I would not dip a car that had minimal rust. The dipping process will remove paint, rust, sealer, everything, except it won't hurt rubber and glass but those items were out anyway.
As the dipping removes paint you loose all the factory markings so identify and record those first.

I am updating photo's on my restoration so hope to add to this topic tonight.
Andrew

[nham3407]

Thank you to each of you for the feedback.  I do wish my car was from a part of the country that did not have the corrosion issues I am dealing with, but that just is not my luck.  My car was sold in Ogden, UT and ended up in Wisconsin when I bought it as a kid.  It will not be 100% numbers matching as I lost the original engine when my folks sold their house.  Everything else is matching #'s and I have a period correct November 71 complete engine to install in my 01/03/72 production date car.

If anyone else can add their two cents worth on the body dipping idea I would greatly appreciate it.

[mustangtown]

• … You asked if anyone else could add theirtwo cents; here is my experience. 
  … [/color]If this Hot Bath method uses Acid;avoid it; these places use the word “Alkaline” which is Madison Avenue hypeinstead of saying Acid. A unibody car has too many captive areas that are almostimpossible to thoroughly drain. Once you introduce that acid to those captiveareas it continues in eat the steel; because that is what acid does. To neutralizeacid in captive areas is not completely effective; that’s why it continues toleach out. Besides the loss of obvious factory seam sealers there is alsosealer in areas you will not be able to get at, that will swell and distort.[/b]
  [/color]… You mention you’re objective is to buildthe Mustang for concourse driven judging. Depending on the rarity it would bemuch more cost effective to start with a better car;  it’s only original once.[/b]
  [/color]… With the money you save buy a Rotisserieand rebuild you present Mustang for just street driven enjoyment. [/b]

[JKWilson]

Not to be critical, but alkaline is not another way of saying acid. They are on opposite sides of the ph scale. To neutralize an alkaline, you apply an acid (and vice versa).

[thefordshow]

I've dipped items like control arms, bumper brackets and rear end housing. All came out very nice.  A good shop is not easy to find. Items can get damaged in the process, dings and dents, too long in the bath eating away at hood and trunk sealers between the frame work and outter skin. Bleeding if not cleaned correctly. The body shell, I much rather take to my media blaster, doing the floors, engine bay, trunk area and jambs. Then I will DA sand the top coats of paint off the outter skin. Clean, then epoxy prime asap.

[cobrajetchris]

Not to be critical, but alkaline is not another way of saying acid. They are on opposite sides of the ph scale. To neutralize an alkaline, you apply an acid (and vice versa).

  That is exactly right and I had my car dipped by REDI STRIP and they used ALKALINE and I have had parts left in bare metal, primer and paint and no evidence of creeping problems at all. There are a lot of high end restorations out there that have been dipped and every car is different. As for the original seam sealer this stuff is 40 + years old and was not that good when it was new. Use a quality two part seam sealer and spray seam sealer and you can duplicate the look pretty nice. The undersides of hoods and decklids can be a bit more of a challenge but again a two part seam sealer daubed in places works well. If you really want to make it rust proof, have it E-coated in a tank like the new cars are and you will be much better than original. If these old cars were dipped back in the old days they would not have a lot of the corrosion issues they have today. Just my experience on the subject.

[Aussiemach]

The dipping process I used is alkaline bath, took 3 weeks and came out bare steel.


The body shell was washed out thoroughly after dipping and then all seams dried with compressed air. Then the body was left in the sun to help dry any moisture remaining. After it was dry a coat of etch primer was applied. They had different length and shape wands to reach in the cavities.
The only area that was not accessible for the above is the sill panel, with my ok, a hole was drilled in the wheel arch to access that cavity. This will be filled later.


there was a lot of surface rust on some of the sheet metal, I can only presume it had spent a lot of time near the coast .
The right hand front floor pan looked ok before dipping, here it is after. Quite a few pinholes in it.


Typical rust from the battery acid



Drivers floor


A lot of the seam sealer was cracking and falling off


Overall I made the decision to suit me and the car. Saved many of hours work, in fact would have been very difficult without dipping.
In my case the advantages out weighed the disadvantages.

Take a good objective look at yours and go with what best for you.