To Dip or not to Dip??

Hi,

Regarding bare metal restoration options. I would appreciate any recommendations and thoughts on chemical dipping, media/sandblasting or stripping with paint stripper/a heat gun.

The paint team is suggesting a chemical dip as there is a lot of ‘tar’ painted on the underside of the car.

I have heard stories about chemicals getting stuck inside panels and causing issues down the track. I am replacing inner and outer sills so that might reduce the potential trap areas.....

Thanks!

This old thread might help... and has other options as well...

http://www.early911sregistry.org/for...ng-vs-Blasting

Thanks Chuck!

Some good info there.

Bit of a crapshoot it seems :)

Too many horror stories about residual acid coming out of pinch weld seams YEARS after dip with resulting ruin of expensive hard work.

As a survivor of several bare metal restorations..... the blasters and/or dippers are lazy and either will not or cannot remove all the tar. The only way I have found is nasty hand work with a butane or MAP torch and various scrapers. Then find a reputable commercial blaster/stripper who uses a proprietary fine media or soda and offers epoxy sealing immediately after blasting. Don't go cheap and find some guy using sand on his back lot beach! I guarantee he will warp the hell out of your precious panels.

Residual media is a nuisance that is generally all vacuumed out by final trimming, but even the potential of residual acid is a disaster...their guarantees be damned.

This would be my personal contribution: http://www.early911sregistry.org/for...t=swiss+cheese

I last did this my 993 engine 914. Complete strip using aircraft paint remover and a power washer. Makes a mess and you get stripper and water everywhere, but it worked well. Goggles highly recommended!

I dipped my 67 911S over 5 years ago. The results are amazing and IMHO, it's the only way to properly strip and clean a car. I have had zero problems with "acids leaking from the seams".

Remove all your panels to be replaced first....inner/outer rockers, gas tank supports etc. this will help them thoroughly rinse the caustic cleaners.

Also remove the heater tubes from both SWB and LWB cars.

Over the past 40 years I have done all 4 methods (hand strip, sandblast, soda, and dip) and I think to really do the job right, the shell and panels should be dipped and e-coated. We have "Redi-Coat" here in Michigan ( http://redi-coat.com/pricing.html) and they chemically strip and e-coat using techniques we use in the auto industry. The beauty of dipping is that every surface, channel, inside cavity, backside of the metal you can't see or get to is treated. The downside is the paper heater tube dissolves so you have to replace/cut windows to get inside, etc. Little acid leaches out. Small penalty for big results. It gets out all the tar/undercoating/sealant. I am taking fenders, hoods, engine lids, doors to them all the time and they come back so nice.

I was going to chemical dip an old Chevy truck but then my painter cautioned me- he said that his paint distributor (PPG) would not guarantee any paint issues if the truck had been dipped. The claim is to really remove all the chemicals is sometimes very hard to do.

I'm not advocating one way or another, just wanted to pass this along.

^^^^^^^^^ Very well-written post. I learned a lot!