primer for the 356

[badsix]

anyone here do their own paint work? i'm not sure what to use for primer, the car will be bare metal. what i'm concerned about is the lead, now I've been in the restoration business for over 30 years and painted many older cars lots of them with lead. Most of the time I remove the lead and use filler to get it back. My problem with the lead is that I've seen many older cars that have been restored get bubbles at all the leaded areas. I'm thinking this is caused buy using the wrong primer. I use a lot of etch prime, but I think the acids in the etch prime don't get along with the lead and start a corrosion process that ends up with the bubbles. The new rage is epoxy and I've use plenty of it. But i'm not sure how it will work over the lead and some epoxy's have rust inhibitors so this may be a problem. Has anyone got a good idea ?
thanks Jay D

[George]

Jay, I'm no expert on paint I just do my own painting on my old cars. I used the now out lawed lacquer and since then I've used the Epoxy primers with no problem. I just make sure every thing is supper clean and de waxed. I would suggest getting a hold of PPG or who ever paint/primer you are using and talk with one of there tech folks. I never mix my primer with another paint producer paint. Maybe that can cause the problem I'm not sure on that as I always use PPG paint products and the epoxy paint. Hope this helps and good luck. George

[JTR70]

Jay,
I'm sure Bruce Baker could chime in here with some great recommendations.
As for my own personal experiences over the last 25 years as a hobbyist learning from my father who owned his own shop there are only two primers that I completely trust and use. For a bodywork base and lead seal epoxy I only use PPG DP40. For small parts and the like I use Dupont's enamel based "Veri-Prime" primer. Both are not cheap and the last time I bought a gallon of DP40 with catalyst it was just under 500.00 bucks. However I have been down the road of experimenting with cheaper off name epoxy's and it was hit or miss if my paint was going to be compatible with it and actually bond to it. Nothing is more frustrating as waste of time and money than using an unknown primer; Sanding it and prepping it correctly only to find later after my top color cured that I was able to Zip it right off with a razorblade. Just the same way you could zip-off a top coat of enamel or urethane from an old laquer primer. They are just not compatible.

Here is why I trust PPG DP40. Here is my car in 1987 getting its base coat of DP. It sealed over all the old original lead and metal. BTW: While I never put bondo on bare metal anyway, a selling point about this primer was that the plastic filler actually bonded better to this primer than it did metal.

Here is the same car some 26 years later. Most of that old primer and old body work is still there under these new tracer coats; no bubbling or lifting problems. So my main concern with any primer is: will my paint stick to it?? With these two primers I've mentioned it doesn't matter what I shoot on them, enamel, Urathane, they all bond with no issues. So I trust only them... Hope this helps! Justin

[badsix]

Yes I've used both dp-40 , dp-90 and the variprime an etch prime DuPont product, both very good products. I have been with my DuPont jobber for a long time and I suppose I should contact the DuPont rep. But I would rather here from some one that's been over this several times and knows from experience. personally I think the epoxy is the way to go on this
Jay D

[gkw]

Jay, I used PPG DP Epoxy on my T-1 and
then like Justin, skimmed filler over the Epoxy. Good luck Gordon

[JTR70]

Thanks Gordon!

PPG DP-40 is my choice as well for lead and body seal. While I certainly do not claim to know everything about bodywork I do know about lead and how to create a quality paint job. The lead itself does not cause the lifting or bubbling problem; its the tinning acids used in its application that create it. Lead that was applied 50 years ago really will not pose a problem though some remnants of old acid may very well leach out but unlikely. Its the recently applied lead that must be thoroughly cleaned and prepped of acid before primer.


This go around after being taught leading by my buddy Jason I gapped all my panels in lead.


The leaded areas were carefully washed several times with soapy water and sandpaper until I was comfortable then the entire areas were sealed in DP40. Photo above is two years later with Zero issues and no signs of lead contamination.... Justin

[bbspdstr]

While I am a professional restorer, I can still learn from serious hobbyists and hope to do so regularly, daily if possible!. The whole point is to get as much info as is out there shared and quantified/qualified. Why more pros do not participate on the forums and sites is beyond me but I'm sure they have their reasons.

Justin, thanks for the mention and invitation to take a shot at this moving target of paints and primers.

In my early years (1960s) we used lacquer or synthetic enamels, then acrylic enamels in the '70s.

Then came the epoxies and urethanes and all the changes and laws and health issues, etc.

In the late '70s, my much larger business (Auto Research Inc) was a demo shop for Sikkens when they first entered the US market. They have a nice line, but we moved on after a few years. Then we tried Herbie's Sandbox... I mean Herbert-Standox, then fell in love with Spies-Hecker. All the while, there were always on-again-off-again dalliances with PPG, DuPont, R-M and the other US brands, plus Glasurit, Lesonal, but it was whatever got us the colors old Porsches used in a single stage coating and chemistry was continually changing. Silvers were changed to a two-stage early-on, base and clear, but we learned the 'tricks' to make them look as much like the original baked enamel single stage. Whatever was tried didn't matter as long as the results looked "original."

The same trials were experienced with sub-strata products, always asking techs, other shops, reps and vendors what worked best with what. What we found was that any major brand name was OK and most could be trusted to be compatible with other brands if actual ingredients were not mixed, like hardeners and reducers, etc. DP-40 was OK under all topcoats we tried, for instance.

For urethane top coats now, we are using an acrylic urethane from England, "Pro-Spray," as they have a way to cross their old formulas for Porsche that are still mixed with ingredients made with lead for Europe, to US-legal formulas that are very close and need only a 'little of this or that' to work.

Recently, through my local rep, I had a great educational conversation with a great guy named Barry. He owns a company called "Southern Polyurethanes":

http://www.southernpolyurethanes.com/

He explained what works with all sorts of brands and coatings, which way an acrylic urethane can be used with other coatings of polyurethanes, etc. There are 'thermosets' and 'thermocures' and all the terms makes me aware of how little attention I gave to chemistry in school!

Anyway, for quality epoxy and urethane coatings ('primers') and compatible products to be used over them, he is now my go-to guy. He does not sell actual colors other than basics like black, white and red, but he has great clears that work over base coats like silver. His products are much less expensive than the 'designer labels' and a quality line of products with a tech source like I have not had access to in my past. The Pro-Spray colors now are the only single stage urethanes I can get locally, as all the major brands have stopped supplying that type product due to a lack of demand, as most all bodyshops use now is base/clear.

So, I use S-P epoxy and urethane primers, Spies-Hecker 3508 Raderal as a filler-primer and Pro-Spray as a color coat.

If you are interested, you can call Barry for a local-to-you rep or just to ask a tech question.

(BTW, lead 'issues' are usually from heating of the lead not being high enough to percolate the contaminants to the surface while 'packing,' AKA 'paddling too cold.' I was taught to be 'surgically clean' in all aspects of the leading process, welds, pinholes in the steel, dirty scratches or grinder marks being clean. After tinning, the flux needs to be, as Justin says, thoroughly neutralized prior to being reheated for the filling solder.)

-Bruce

[badsix]

yes , i'm also familiar with SPI products, I have used their epoxy and turbo prime and have some universal clear on the shelf. good products and excellent teck support
Jay D

[JTR70]

Thanks a lot Bruce!! Unlike you who are willing to share their vast knowledge and experience I can only guess that most shops are not interested in showing a person how to do something but rather just getting them in the front door as a job...
Interesting and very true point about most of the finishes going the way of two-stage paints. Especially the metallics. However I can still get single stage acrylic enamel in silver and in Poly-Urathane but acrylic Urathanes are only offered as two stage systems now. What are you doing to recreate the single stage look? Are you mixing the base in with the clear? Thanks again for sharing! Justin

[bbspdstr]

Justin, Pro-Spray acrylic urethane is available in silver one-stage, so I've tried that on wheels. On one wheel, there was a bleeder leak on the brake and that got the inside of the wheel's silver paint soft and bubbly where it landed, so I will likely go back to a silver base and matted clear polyurethane...that's much more tolerant.

For a critical silver paint job done back in the '70s on either a car like a 904 or a warranty respray for a Porsche 25th anniversary edition 911 on a UV laminating clear coat, I got a tip from John Paterek. The silver base is treated as if an old fashioned 'lacquer job' was being sprayed, where it's wet-sanded and resprayed, repeating until no sand-through is seen or expected, then one more coat is made and the slightly over-reduced clear is sprayed with less coats than usual. Nibbed and wheeled, it looks as much like a single-stage paint as possible in a 2-stage.
I've tried putting clear into the base and base into the clear with mixed results, usually not worth the gamble. Just lots of base and sanding of same to be sure the obvious areas won't get sanded or buffed through, thin layer of clear, careful polishing and only as much as absolutely needed.
Obviously, an early single stage painted Porsche is what I mean for a focus here, as the later 911s were originally base/clear.
This all changes with a good painting environment. The best results were easier to achieve when I had a down-draft booth when they were first offered. Better airflow, better filtration and baking capabilities can't be overstated for quality results.

[JTR70]

Thanks Bruce!

I tried mixing base with clear as well with very inconsistent results and yes having a proper spray-booth makes all the difference especially when you have to shoot a light two stage paint. Too much crap gets in it otherwise. Justin

[bbspdstr]

"Too much crap gets in it otherwise"

Like flying bugs that then do the backstroke?

You'll like this story....when I started out, I was working out of my Grandmother's big garage near train tracks. When I was going to paint a 356 I created a 'booth' using 2x4's with spring loaded tops called "pole cats" and stapled clear plastic sheeting all around except for a furnace-filter'd inlet at one end and a row of box fans (on 'low') under the raised door at the other. I readied a T-6B Coupe that was masked and tacked-off, wetted the floor and I had sprayed my first coat of Irish green enamel when a heavy freight train came rumbling by. When I returned for the second coat, I saw that I forgot to clean the very top of the garage door which was now horizontal, and I had a nice obvious sprinkling of dirt across the front fenders and hood! After a LOT of cursing, I decided the best thing to do was to wash off the paint from the doors forward and feather the front pillars with reducer. I did it as fast as I could and was able to catch up with the paint on the rest of the car, as that old enamel was slo-o-ow drying stuff! It eventually came out as well as anything back then needed to be, but those results would not pass today.
I got really adept at using tweezers to pluck out small hairs and pieces of dirt in those early (un-sandable and un-buffable) paintjobs.

[badsix]

ah, the old DuPont Dulux. It was like hanging out fly paper for about 8 hours.
Jay D

[gkw]

I like the fly paper analogy, very true.
I have to spray in an old wood shed with mixed results. But you have
use what you have. Gordon

[bbspdstr]

I had a big shop years ago, before downdrafts, with a new Binks cross-draft in one section of the shop and it was fine. However, after my full-time painter would go home, I'd use the 2,000 sq ft body shop that was separated by doors from all else and had a big slow fan up high. I'd move the cars that could be moved in the bigger rooms and cover any others, wet the floor and just spray in the middle with a few lights in the 4 corners of that room for reflections. Those few I did in that environment to 'stay in practice' came out as good as in the booth.

I was trained by a moonlighter from the local Caddy dealership, Harry Lang. Harry would come after work with his favorite Binks #7 to a friend's used car dealership, as he did paintwork for him, as well. I'd have the 356s there, masked and ready to go in the wash bay. Harry and I would wet the floor, ground the chassis and tack it off, then I stood back and watched. Harry would stir the cup of enamel mix while on a hotplate, pulling the stick up to watch the drips, until it was 'just right' and then tack again and start to spray. He smoked cigarettes while he sprayed! He used cigarettes as timers between coats. He wore no mask....but man, could he lay out the paint! The gallon of DuLuxe was about $15 and Harry got $15 for his time. With a tip, those jobs cost me less than $50 in total. Now, $50 doesn't buy a liter of an ingredient like reducer. Just about buys a good disposable 3M mask. I can't know about cigarette cost for a carton....all the guys I know/knew who smoked have quit...or died.