To Acid dip or not to Acid Dip

domtoni · 08-27-2006, 01:56 AM

Guys,

I have read the pros and cons of acid dipping to strip a car.

My cousin is in the metal finishing business, and he said that acid dipping is used on $1M cars. He further said that the process is fine as long as the jobber uses proper inhibitors to stop the acid from deterioriating the seams.

What is the latest thinking on this?

Also, if I go with just a standard chemical strip, replace the rust panels, like the front suspension pan, what is the best way to seal the underside? My car was originally zebarted.

Thanks
Dom

1972_911T · 06:48 AM

Hi Dom

Where are you in the UK? Surface processing in the midlands does acid dipping using the apropriate inhibitors. They also carry out the E-Coating that is discussed on the DDK. My car's going there in a couple of weeks. If your close to me id be happy for you to come take a look at mine once its done.

As for the under seal the factory original was wurth underseal I think this is about as good a product as you can get to recoat the underside. Its readily available but needs a special wurth gun to apply it. Its different to a standard schultz gun I belive.

I also have some PDF files that were sent to me about the e-coating and stripping process if you send me your e-mail add ill send you a copy.

Steve

herman maire · 08-27-2006, 07:58 AM

What happenes to the paper part of the heater tube in the rocker?

Also whats the point for acid dipping? I think a good detailed blast job and por15 would be pretty darn good.

gestalt1 · 08-27-2006, 08:09 AM

i had my 73 911t media blasted. it worked great but it does not remove the original undecoating. i used peel-away stripper to remove the undercoating - worked great. there is still media coming out of the shell after 6 months however. i did not do the acid dip because i was afraid that no matter how much they try to get the acid neutralized there might still be some in the seams that will cause rust under the paint. many have had good success however.

gestalt1 · 08-27-2006, 08:09 AM

i had my 73 911t media blasted. it worked great but it does not remove the original undecoating. i used peel-away stripper to remove the undercoating - worked great. there is still media coming out of the shell after 6 months however. i did not do the acid dip because i was afraid that no matter how much they try to get the acid neutralized there might still be some in the seams that will cause rust under the paint. many have had good success however.

1972_911T · 08-27-2006, 08:26 AM

The heaters tubes have to be removed and replaced with steel tubes or left off untill after the dipping process. Acid dipping has the advantage that it gets into all the sill sections and box sections that media blasting carnt. It can then be followed up by e-coating wich is an electrostatic dipp painting process that is the industry standard for most of not all new body shells and chassy components. This coating again gets inside all the box sections that ordinary paint carnt. The combination of the two cures any rust you carnt see and could never get to with a blaster and then encapsulates it preventing future corrosion.

Heres a pic of a 911 thats been through this process.

Steve