Technical Painter's advise on prepping new Brookville body

Hello, I am looking for advise from painters who have prepped new bare metal Brookville bodies or parts. I have cleaned the bare metal with wax and grease remover. Next I was going to sand and scotch brite before PPG epoxy primer. Do I need to acid wash or etch?

 

clean it again, and again. i just did one and i spent a lot of time getting the oil off and out of it. i went through a box of rags, some thinner, denatured alcohol [seamed to work best] and then the wax and grease remover. i then sanded the whole body down with a D.A.

 

I would use a really high end DTM primer. Direct to metal primer. Make sure you clean clean clean. I would sand it with 180 by hand get a good scratch in it and clean. Be careful not to blow air on it if you don't have major filters on your air compressor since they produce moisture/oil. Never touch it with bare hands after you clean clean clean. Make sure it's hot when you shoot it. If the metal is cold it can trap moisture so even if you have to use a blow dryer before you shoot it to warm up the panels. Not hot so don't let the sun beat on it for an hour before you shoot it I'm just saying warm weather. Don't shoot it in direct sun light too. If you do blow it down with compressed air, make sure you clean it right away. Use high end products don't be cheap and take your time. Everybody is gonna have different thoughts on this but ask them how long they have owned a automotive painting bussiness. Hopefully long enough to see their work and the products they use last. Good luck

 

Also use lint free wipes like these. I would sand by hand and not use a da. Orbitals will sand but also act like a polisher on bare metal. Da will produce a smoother surface then hand sanding with the same grit. You want a good scratch so by hand only is how I would do it. Test it out you will see. Just my own thoughts from a guy who paints all day everyday.

 

As said above, many ways to skin that cat. I like to keep it basic and not do too many things, but 1st and foremost it's correct, remove any oils/coatings on the bare steel. I like the alcohol idea but after a good clean and dry with wax n grease remover. Try to use lint free rags. Wont have a major effect on adhesion but will drive you crazy seeing little fibers grow out of your steel as you spray the 1st coats. Clean compressed air is indeed your friend, however, if it's clean enough to spray with it should be clean enough to air dry. As to prep before your 1st prime, good ol Metal Prep from PPG is as reliable as a Model A (see what I did there?). Seriously, apply the metal prep diluted per directions or maybe just a bit stronger. Work it a little with a good synthetic closed cell sponge. Do 1 panel at a time. 1st the cowl, then a door, then a qtr, then the tail panel, etc. If you can, rinse with hot water. The heat will help dry the panel and reduce flash rust (something that can't be helped). Once done the panel should get a gold and blue glow to it, the look of fresh pickled steel. Just dry it as fast as you can and a helper here is just short of a demand. I don't recommend you scar it all up with sandpaper. Too hard to acid prep, might "lie" to you with regard to a good bond, you need to see the metal prep solution flow even on the panel to know it's been thorough. If you get a look like water on an oily surface it's not there yet. Trust me, you'll know it right away. Before your 1st prime there's a conversion coating next. Basically it's a phosphate that promotes adhesion and all the pro suppliers have one. Again label directions, dry quickly, do it all on the day you commit to the priming.

Now for the primer, I too would recommend a nice easy coat of epoxy over everything. Be sure to give it some induction time, don't go heavy, just go even and pretty, 1 coat if you're good, 2 if you find you missed some stuff. Most quality and production epoxy coatings have a specified "Thermoplastic Time", as in can be coated without sanding. Usually 36 hours, some more (up to 72), some less. Go directly to your surfacing primer after that and enjoy the project. There are indeed some nice direct to metal primer surfacers as well and you can avoid the epoxy labor and expense. Shop-Line 202 from PPG, Velocity 3055 from PPG as well, the 2nd one being 3 times the $$$, but it builds fast and shrinks very little, or not at all.

Nobody mentioned the inside yet, and that's where things could make you crazy. I would wash all of the inside down well with brushes and wax n grease remover, follow up with denatured alky (a spray apparatus would help), be sure it's all nice and dry and apply SEM Self-Etching Primer. Within 1-2 hours you can coat it with some single stage color like semi-gloss black and call it done. Maybe semi-gloss upholstery color too like if you're going tan, white, blue, etc. Make it match a little and it makes a really visible difference in a finished trim job. Good luck and keep asking questions, but if you go through all of this and don't share it with us, like with pictures, well then I'll be the 1st to say you're a ****. Don't mean it in a bad way, just sayin...

 

OK, what about all the inside bare metal that you Can't get to? Using a creeping compound like Kroil or Rust Encapsulator wont help as they need rust to bond to. Cold Zinc Galvanizing seems like the way to go, but I thought I'd see what others do

 

we sanded the inside and tried to flood the area with cleaner. i made a wand for my shoots gun to blow it into cavities but on "pinch weld" areas i try to flood the panel with primer so it runs through.

 

http://us.ppgrefinish.com/getmedia/...4437599B/02/p-226_dx_metal_treatment_2-13.pdf
we cleaned with wax and grease remover followed by an alcohol based cleaner
sanded with a 180 -220 ish sand paper followed by 579 followed by the 520 inside and out
then applied an epoxy

I have had good luck with Clausen poly primers, don't know if they work with the metal prep though
they are a DTM and sand well for a polyester


here is a simple tool for getting in the places like rockers and doors

 

I prefer a dedicated wax & grease remover for cleaning because it "floats " contaminants which can then be wiped off rather than smearing contaminants over the surface with plain solvents. Clean several times discarding contaminated wipes as you go.
I would etch with PHIX or a similar acid after sanding. The result will be mechanical and chemical bonding of the primer. This job calls for the ultimate prep.

 

Thanks for the great help. tb33anda3rd what grit sandpaper and primer did you use?

 

80 on the da. i used steel wool on the hard to get areas. i used one good coat of epoxy primer, let that sit for a day then urethane filling primer.

 

Another good sanding friend to use in the strangely contoured areas is ScotchBrite (especially on the inside) - I use it all the time and it really makes it easy to sand some of the ugly areas where paper just doesn't work. Also, no matter what metal prep solution I use, I always hit it with some sand paper or ScotchBrite afterwards - just seems to promote adhesion. If you want to go to the effort of a metal-etching base primer - it won't hurt and it does 'grab' to bare metal. Then you'd coat this with an epoxy primer to seal it (almost like a glue layer).

I also use some really great high-build primers - they are expensive (about $225 for a gallon and 1/2) - but boy do they sand nicely. Epoxy primers are great for sealing, but not the best for block sanding and all that fun jazz.

DTM: 1 gallon PPG VP2050, DTM High Build
2 quarts PPG VH7050, DTM High Build catalyst



Again - lots of opinions! Buy the best materials you can - it does make a difference.

 

Cruising the same boat as the OP- Thanks for the tip's Brothers!

 

I also used some two-stage PPG 'Shop Line' paint to do a lot of partial panels on my 32 Cabriolet -- needed to blend in some new paint into 70+ year old paint (one of the hardest things to do). I was very impressed with this lower-end of their line, how well it blended, how well it buffed, etc.. Nice stuff - will definitely use it again (maybe not for 100% new show-car type stuff, but definitely for interiors and probably even some exterior uses):

I was in a BIG hurry to make the Cleveland Autorama - so I shot the color on Tuesday early evening and had it all buffed out by the following evening . . . a little fast for my liking, but boy did it come out nicely!




Had to shoot in 60 degree temperature . . . so it didn't lay down all that nicely, but sometimes yah gotta do, what yah gotta do!



Color sanded with 800 and 1000


After buffing the next day - worked out well . . .

 

I used clause z-chrome rust defender on the last build
high zinc content, DTM polyester
loves bare metal, sands very good
about $150 per gallon and Owronglies carries it

 

X2 on the shop line stuff
I used it on top of the clausen poly
worked great

 

I would wipe down with preps sol or lacquer thinner using the light blue roll paper shop towels (low lint and absorbs well).

Now here is where a bunch of folks will go nuts: get a clean bucket, clean wash mitt (preferably new), and bottle of original Dawn liquid dish soap. Squirt a good amount of Dawn in the bucket, fill with warm water, soap up your wash mitt and start washing the car.

Yes, I know it's bare metal, that's ok. Clean inside and out and rinse well. Flush out all those nooks and crannies and blow and/or wipe dry with clean light blue paper shop towels. DA sand with 180 (refer to your primer's tech data sheets), blow off and tack.

Next you need to prep the bare metal with a product such as Picklex (www.picklex20.com). I have used this stuff and it works great. Easy to use, stops flash rust, converts rust and preps the surface prior to paint. In fact you can prep bare metal, set the parts aside and come back months later and paint with good results. This product pickles the metal, kind of like an acid etch. Follow the products instructions. If you use Picklex DO NOT use an acid etch primer after Picklex!

Use any good 2K primer surfacer, filler or DTM primer directly on Picklex prepared surfaces.

There are similar products available (PPG, etc.).

I am not affiliated with or have any financial or other interest with this company...

 

who cares
its not real anyway

 

like many of the cars here with lots of fabricated frames and body panels?
or engines with non oem parts?

 

just think of it as one big patch panel.

 

All this still applies if there is some filler on the metal also?

 

do all the prep, metal conditioners and epoxy before any filler work
you can use filler on top of sanded epoxy
I like to do as much metal work as possible before the priming
one reason I like the polyesters is that it is a sprayable filler and can level out many minor imperfections

 

who cares
its not real anyway

Thanks, I have no doubt what the F in F-head stands for! And to all others thank you for the help.

 

Now that was pretty funny

 

Fillers: There is always debate as to whether or not to put filler over bare metal (like the old days), or seal the metal first with epoxy primer, then do the filler work. Both ways will work - as long as you know what you're doing and consider time-windows, flash rusting, how soon you'll do the finish work, etc..

I tend to buy certain fillers for certain purposes -- some are designed to go over bare metal and even have 'etch' chemicals in them. Body fillers have come a LONG way in recent times - they are much better than the stuff (which I thought was good) 30 years ago. My recommendation is to buy your materials from professional auto-paint supply companies, read the data sheets and talk to the reps - you'll learn a LOT by their experiences. Don't just think you know how best to use a new/modern material - ask about it, talk to people (with specific brands and products) and learn everything you can.

Here is a TDS on the EverCoat Z-Grip filler I use - over bare metal:

 

http://www.jalopyjournal.com/forum/threads/still-no-snow-so-lets-get-a-roadster-started.1001571/

 

I've never seen that epoxy primer should or had to be sanded before filler application. I have wet sanded epoxy primer though at times with no finer than 320 grit to a benefit. I never dry sand it because of the remaining dust issues.

 

Along these same lines possibly. I did a 56 chevy body recently for a guy. He said he already had it off the frame and blasted. I didn't know he had it soda blasted. When he brought it over it had a oily residue on it and soda was falling out of the seams. I was petrified , I had never had a car soda blasted and never will, but I got to checking around how to get all the soda out of the cracks and clean the residue off. then I was online and stumbled across something called Hold***e 102. I will try and find a link in a minute. I called and talked to the company rep. He said get out your pressure washer put the body on your rotisserie, put a gallon of this to 55 gallons of water and preferably hot water, wash the body getting everywhere soaked and seams washed out good. Then blow it off with air good. Prep the normal way you do things and go. I said won't it flash rust? He said, no, the contaminants are what causes the metal to rust. He said it will be clean and free of any salts , oil, ect... I bought some, did like he said, bingo a clean residue free body just like he said. Sure saved my **** as I had heard real horror stories about soda blasting.This stuff he said is not a cleaner. It's also food safe to use . Lippy
Heres the link. http://www.holdtight.com/

 

I bet you don't like fake ****'s either!

 

tb33anda3rd, great link to your build. That is just what I needed. Thanks.