Advice needed (after soda blasting shall I.........)

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Alexander George
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Location: Malta (Europe)

Advice needed (after soda blasting shall I.........)

#1 Post by Alexander George »

OK
So, my 55 will be a bare metal shell by Tuesday.
I am totally confused if I should prime paint the body shell or leave it in bare metal.
I would like to lead the car instead of using body filler(bondo). To my knowledge Porsche use to finish the body by lead.
Is there something I can put instead of primer paint to reduce surface rust?
Maybe some kind of Oil or ..........???
Any advice will be highly appreciated
Thanks
Alex

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On the way (check out Malta's old capital city today known as the silent city Mdina)
1955 Pre A Reutter Coupe Vin #53232

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Greg Bryan
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Re: Advice needed (after soda blasting shall I.........)

#2 Post by Greg Bryan »

Alex - depending on the regulations in your area, there is a metal conversion system that all the major paint manufacturers sell. It's usually a two step process, and it leaves a microscopically thin layer of a rust inhibitor and conversion coating on the metal. It will prevent rust from forming for a while although I imagine Malta is very tough on metal since it's in the middle of the Mediterranean. . . Here's a PPG product.
http://www.bapspaint.com/docs/psheets/P ... /P-226.pdf
Greg Bryan

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Bob Cannon
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Re: Advice needed (after soda blasting shall I.........)

#3 Post by Bob Cannon »

Soda blasting does not etch the metal like sand or pumice blasting, so any metal conditioner will work well to neutralize the bicarbonate and provide a zinc coating to prevent rust. The PPG products recommended are very good, but may not be available in Malta. There are a number of advantages to not using primer on the body shell until you are ready to, so a metal prep solution makes sense in many situations.

Over the last few years, I have been very pleased with a product from Eastwood for use on sandblasted metal called "After Blast". This is a phosphoric acid/zinc phosphate solution which most likely comes from the powder coating industry. I cleans any residual rust and dirt, prevents rusting and does not cause flash rusting (which most metal conditioners will do if applied to freshly sand blasted metal). You might check locally with various powder coaters to see if a similar product is available to use. The addition of zinc phosphate to the solution gives a long lasting protection against rust until you are ready for paint.
Bob Cannon
Sacramento, CA

Roy Smalley
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Re: Advice needed (after soda blasting shall I.........)

#4 Post by Roy Smalley »

Free opinion. You don't want to use any more different chemicals, including paint than absolutely necessary. I have used soda...once, and never again. In any case, the car has to be neutralized and you can Google to see how to neutralize soda.

Using phosphoric on bare metal can be done. Very carefully and hope you don't get it where you can't remove it later. Yes, in some conditions you can leave phosphoric on bare metal for a period of time and it won't rust...depending. A preferred method after neutralizing, and cleaning...particularly the surface to be painted, would be to put a light coat of epoxy over all bare metal. Yes it would have to be removed for following work....or should although many manufacturers state you can do body work over some epoxy materials. That is the most foolproof method.

A good friend of mine has been a very high quality repairer, restorer for over 40 years. Last year, despite following the advice he gave me when I started working on my own cars (see my first comment above; it came from him) he used a phosphoric chemical, carefully following the manufacturer's instructions. Car (very expensive MBZ metal up repaint) was painted and polished and he noticed a small blemish. He ran a fingernail over it and the paint came off. The further he went the more came of. He had to strip the car. The culprit: phosphoric residue.

One thing to remember when reading and following manufacturers instructions. They are selling a product. The product is primarily for collision repair shops which usually, not always, means quick and inexpensive.

I hope I have been adequately politically sensitive.
 Roy Smalley
Texas

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Alexander George
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Re: Advice needed (after soda blasting shall I.........)

#5 Post by Alexander George »

Hello All,
Thanks for your suggestions.
Was very busy tring to find the correct chemical, but looks like I will have to go for a 1K primer.
I looked at Wurth and asked our local PPG Suppler, with no results.
The PPD DX cannot be stocked in Malta due to EU regulations,.... etc.
So
The guy restoring the body told me that he is more confident spraying some 1K primer on the metal.
He explained that he will be still taking off all the primer before restoring each section, so he is the Boss.
Anyway
will post some pics of the project and see how it goes
Thanks
Alex
1955 Pre A Reutter Coupe Vin #53232

Roy Smalley
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Re: Advice needed (after soda blasting shall I.........)

#6 Post by Roy Smalley »

Sounds good Alex. IK will take care of any potential flash rust.
 Roy Smalley
Texas

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