media blasting, DIY or farm it out Options

[Mueller]

QUOTE (alpha434 @ Feb 6 2006, 10:28 PM)

So the acid dipping thing is henceforth top secret. Go forth and have an edge over your opposition. (IMG:http://www.914world.com/bbs2/html/emoticons/smilie_pokal.gif)

Top Secrect??? (IMG:http://www.914world.com/bbs2/html/emoticons/wacko.gif)

Let's see, it was done to the Ford Boss 302 Trans-Am cars in '69 or '70, it's not something just invented in the last few years......besides, there is hardley "anything" that you or your shop does that is a secret or has not be tried before....these 914's have been around for 30 years and just about everything has been done or attempted at least once...even your idea of replacing the heating ducting with metal tubes for additional strength.

one of the reasons the SCCA bans the acid dipping is make a more level playing field, not everyone has access or can afford to go to that extreame measure.....



the acid starts to attack the heater ducting as soon as it comes in contact with it.....it's too late to do anything once that happens....and yes, most places that do acid dipping can spray a primer on it after the acid is neutralized

back to the main subject...farm it out, even sand blasting small items like the suspension can be a PITA at home.....

[Katmanken]

Guys,

Not all of those dip processes are acid.

American Metals refinishing in Cinci uses a dip tank and electric current.

Not sure what is in the tank, but it isn't removing material-unless it's rust. Seen engine blocks come out with the bores looking great. Did a great job on my hood and fender.

If it's acid dip, buy some baking soda, a cheap sprayer and go over the car. Baking soda is unique as it turns acid and base solutions to a neutral ph.

Ya guys know that ospho is an acid. Does it leach? I use a 2 bottle Dupont metal prep. The first one eats and nutlraizes the rust, the second neutralizes the first..

Ken

Ken

[Eric_Shea]

QUOTE

can any one show me a picture of where the foam is? I am geting ready to send my car to be soda blasted in 2 weeks, and i am trying to get all the prep work DONE!

Dear Cheesehead... (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Seeing as how Alphster hasn't jumped in with the 'absolute top-secret, foam delete option M412' facts as to where the foam is, let me take a shot at it. (IMG:http://www.914world.com/bbs2/html/emoticons/w00t.gif)

1. Under your sail panel along that section as it comes down to meet your quarter panel.

2. Above the tail lights where the quarter rounds in toward the trunk lid.

[gopack]

Thanks Eric, I wil have to look for it and eradicate it if possible!

[Eric_Shea]

It will be tough... maybe put on a mask and spray carb cleaner up there? Might melt it? Anyone try that? Alphy? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

[byndbad914]

you guys are probably right that the panels were warped by pressure not heat - it was about 8 yrs ago that I looked into it (tells you how long I take to do a project!!!) and my memory could be hazy. I specifically do recall his statement that he basically had to buy the guy another porsche because every panel was warped and since the fenders don't just unbolt...

In terms of the acid deal... I considered the heater tubes originally, but now that I am doing a tube chassis car and just using the body and longs as a shell (the longs are being left in for nothing more than door/body supports basically) I am not concerned.

However, excellent point Eric for other cars - that I had forgotten to mention since I wasn't concerned for my own. Also, the shop I talked to uses the electrical current thing - again hazy, but they assured me that it cost a bit more to do that process but it would work out much better in the end than a "regular" dip (I asked them why most guys weld all the seams after acid dipping a Pcar tub to burn out the acid).

I am NO expert in either of these, so for all I know they were filling me full of (IMG:http://www.914world.com/bbs2/html/emoticons/stromberg.gif) (that icon is called Stromberg - how funny) and charging me an extra $100 for it (IMG:http://www.914world.com/bbs2/html/emoticons/biggrin.gif)

Anyone else out there actually acid dip their cars and have a good experience?? I may start a new thread... sorry to sorta (IMG:http://www.914world.com/bbs2/html/emoticons/hijacked.gif)

[bondo]

QUOTE (Eric_Shea @ Feb 7 2006, 02:24 PM)

It will be tough... maybe put on a mask and spray carb cleaner up there? Might melt it? Anyone try that? Alphy? (IMG:http://www.914world.com/bbs2/html/emoticons/confused24.gif)

I've been burning it out. Chemically, nothing seems to touch it. I've got a fender off, burning it out with a propane torch, digging with various pointy things, and it's STILL a pain. I can't imagine doing it with the fender on.

It's not just foam.. In the front of the rear fender it's expanding foam, with seam sealer liberally applied on top, and then in most cases undercoated on top of that.

In the rear it's a precast foam block shoved in there, with expanding foam to seal it in, and then the seam sealer and undercoating.

All of this is put on over bare unpainted steel, and it doesn't stick that well. All is fine until the seam sealer that's protecting it all cracks... then it rusts from the inside out.

[rhodyguy]

you will prob have to rent a huge screw type comperssor. it will be petroleum powered so you will have fuel costs. a homeowners type comp will be in a constant duty cycle. it will never keep up on a job of this scale and you might even burn it up. what ever media you use, you will have a pretty damn big mound of crap left over and no matter what you do it will be everywhere. you are going to need a first rate breathing system. preferably one with an independant air supply, or take a chance on silicosous(sp) and damaging you eyes. it will take a long time and you will not enjoy this task.

k

[johnmhudson111]

Seems to me that the way to go is to use those 3M paint stipper disks and then spot blast the areas you couldn't get to.

This way you don't have to worry about the acid.

No harmful chemicals.

What do you guys think?

[jd74914]

QUOTE (blitZ @ Feb 7 2006, 11:47 AM)

QUOTE (alpha434 @ Feb 7 2006, 08:33 AM) acid+alkaline nutralizes to water. Usually the most pure water that you would ever see. No impurities, because its artifically manufactured. So the problem is getting it dry quickly after the process, or your car will be right back where it started. I wonder if anyone in the acid dipping business has ever though ahead to offer a dip in primer as long as everything's being dipped. I guess you'd have to be out there to run high pressure aire through the heater ducting as soon as it came out. As I recall from chemistry, several decades ago, acid and alkaline mixed in the appropriate amounts create a harmless salt with a balanced pH.

Water and salt actually, but I don't know how harmless that salt would be in a poisonous-to-human-sense. (IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)