Technical PPG 2050 high build epoxy review

I used poly one time. I found it to be as difficult to sand as anything I have used. I use urethane most of the time but let it sit in the sun for a couple of days before sanding. I wouldn't tell you that I don't have some shrinkage, though. I will look into the product Mark mentioned because of the price being in a range that I can handle.

 

For comparison, I’m also priming parts for an OT build
The epoxy, urethane primer and sealer all cost a little less than the 2050
All no name store brand products.
The 2050 is advertised as replacing all 3 of those products.
I’ll get to see how both hold up

 

$325, for two spray-able gallons?

I don't consider that bad for a quality product.

 

Me neither
I think it’s closer to 1.75 gallons.
Still good for quality.
We’ll see how it works out

 

Thanks much for sharing!

Can you quantify "grainy"?
Like #400 grit sandpaper?
I sprayed 3 coats of Tamco 5310 hi build epoxy with a 2.3 tip & no reducer. It's kinda rough- like #320 or #400.

 

Probably bout the same.
I’ll reduce it properly next time around

 

When I purchased the Polyester primer they warned about the polyester being extremely sensitive to moisture in the air system. Is this epoxy as picky? And is it DTM like other epoxy primers? I have to paint my daughters truck this next year, old toyota 4x4 and the body is a bit dinged. Not a show car but I want it presentable. I just may give this stuff a go Anthony. BTW, I paid more than that for the pink poly I bought. Mind you I have zero complaints about it .

 

Picky?
First time to use it. As far as not liking moisture, I’ll check the tech sheet. Usually wet sanding is not recommended if a product is prone to absorb moisture.

 

Tech sheet doesn’t mention sanding.
Might be a question for the rep
But my money is on it being ok

 

You were told a wives tale. It is no more sensitive to moisture in the air system than anything else. And who were you buying from that was charging you that much for it. I can but the kit online right now for under $200 US and the cost has gone up about 45% since you bought it. Sounds like you may need a new supplier.

 

this was the last DTM polly I used. Worked great.
Dang price sure changed.
This one says moisture ain’t a problem.

 

High build primer saves me hours on final straightening up of the panels. You can't beat doing all your final sanding on the same product with consistent hardness and sanding properties.

 

You can go into edit and delete the extra pictures

 

Thanks for the review Anthony! I do so little painting anymore that I don’t keep up with what is good.

 

Being an old fuck with a lifetime in this phase of our world I've learned 1 thing. MIL THICKNESS. A lot of this discussion is asking about shrinkage, swelling, build, etc. The less mil thickness the better. The less mil thickness the better. Fuckin eh I said it twice. Sometimes you have no choice but to build a little higher but IT IS NOT THE WAY TO QUALITY on a complete refinish. More means more expansion/contraction over the life of the finish. Cost and new products? Like I started out, I'm an old fuck. Not lacquer only old but the principles apply all the way to now, today. "Ok smart ass what do you use?" Well, hammer and dolly 1st. Then all this "...and you need a 1/2 inch of epoxy before you frost 3/4 of an inch of mud then you can go 10 coats of poly primer...". Ok, ok I'm exaggerating but you get the point. I use Shopline. Shopline 377 ( 371 or whatever color I pick) for a light epoxy base on fresh repairs and sheet metal. Then I go with a minimalist application of poly if it needs it or right to JP 202 for primer. Cures fast, hard, shrinks very little and best of all it's fuckin cheap. Sands like baby powder. I seal with 25% reduced epoxy, 4 hrs or no longer than overnight cure, no sanding, right to color/clear. Sounds pretty lazy, huh? I do spend bigger money on clears, my go-to is almost always DCC 4000 "Velocity" clear. Hard as a rock once cures. Cuts and buffs like the old Delglo DAU 82. Who remembers that shit? It was heaven! I'm not an automatic hater on anything new but I sure prefer to save money, save labor, and would rather shovel fresh cowshit on a 90 deg day that have to redo something. I'm old, rememeber? Last time I bought a package of JP 202 it cost me less than $200 for about 2 gal ready-to-spray.

Now here's another trick from your ol "Uncle Jocko" when priming. Reduce that shit a little. yeah, thin it out some. Why do we always want to use a damn flake shooter for primer? "It's just primer, so why do I have to make it nice?" Because you have to cut through all that fuckin texture to get to making it ready, AND THIN ENOUGH IN MIL THICKNESS (you knew that was coming), to get sealed and colored. Put it on nice. I sand poly in 150. I sand primers in 320 or 400. Why go through so many different papers? That shit costs money too. Clears also. " I start with 600 and go all the way to 3000." Aww, ain't you special, yer uncle owns a sandpaper factory I take it. I start with 1200, and yes I finish in 3000 because it's safer than compound, then I finish cut with a wool bonnet and Meguire's #3. See, I'm fuckin lazy. Do I get results? My clients enjoy something in excess of 150 provenance level awards over all my days. Today I could care less if I ever do another but I don't mind being the necessary contrarian to my HAMB brethren now and then. Maybe this product is ok and it helps some of y'all, then again this seems like the annual reminder to look at production products now and then and save time and money. Holy shit, glad I'm leaving my 39 original. I'ma try to keep and eye on this to see how shakes out, and good on you for the product review, but...

 

I generally use shopline products.
No issues ever with their undercoats. But the JP primer will kick fast in the summer with the faster hardener.
I’m not a big fan of stacking a lot of primers to get stuff straight. That part starts with the sheet metal work.
This product is close in price as using the shop line epoxy followed by the JP primer. So that’s probably the main reason I’m trying it out.
This ain’t rocket surgery.
If ya use a product correctly, ya get good results.
I don’t care if it’s lacquer, epoxy, enamel…….or what brand it is.
This crap is 90% prep work

 

Indeed, prep. I'd rather pick n file for a day than spend 3 or 4 days making dust. I'd rather go home feeling good vs going home feeling like I got caught bangin the fat chick under the bleachers. Nothing against fat chicks mind you...
This feels good. The whole car has 1 swipe of metal glaze on 1 small metal finished patch.

 

Unfortunately we don't all have the ability to work the metal to that level of not requiring the use of mud and of high build primer, so we want a product that will get us the best results with our quality of work!

 

I’m not advertising the product.
Just wanted to try it after reading a lot about it.
Figured some of you guys might be curious about the product as well.
I’m pleased with how it sands
some here probably wouldn’t
If it fits your budget, it’s worth a try.
If what you are currently using works, continue using it.
I’m about to start on a blasted cab. Using one undercoat throughout the project is an interesting concept.

 

There's something to be said of using 1 product. At the heart of the matter, well pickled sheet metal likes a coat of epoxy for corrosion resistance. Not a gallon, a coat. NO, it is not needed before fill and can indeed cause fill issues. Polyester likes a "tooth" in metal or other surfaces so etched or clean ground metal gives a preferred mechanical bond that exceeds trying to get a chemical bond to epoxy. Epoxy helps prevent excess solvent penetration into polyester substrates when surfacers and finishes are applied. Finishing primers and fillers, one should endeavor to sand it as smooth as possible. I haven't used rough papers in decades. I may do a quicky with 80 if the mud is a little heavy but I'm a 150 kinda guy on mud. Deep scratches are the fiend that causes the hated "Where the fuck did that come from?" a month later when you're home from a hot day in the sun. Purge time is extremely important. Like it or not even mud serves us best when given time to purge.

For the record I'm not knocking anyone, their ability, or choice of products. When these posts come up now n again I like to add some info that helps lights come on whilst you're dick deep into this, at times, seemingly thankless work. I hope it's taken as such. Carry on, good luck...

 

I’m not the prime over 40 grit guy.
Most of the shrinkage or sand scratch swelling can be attributed to asking a primer to do to much or stacking up materials too quickly.
An 80 grit scratch can’t haunt you if it doesn’t exist.
All these products have a place
Used correctly they work
Refinishing has many correct answers.
Purging or gassing out is a topic not discussed much.
When it counts, I weigh the filler. I prefer a couple thin coats over trying to stack it. However, good metal work should yield a single wipe to shape the panel. But sometimes ya do what ya have to do.
what’s odd is that for collision work, a repair can be body worked, primed, sanded, sealed, painted, buffed and delivered in a 24hr period. (2 work days). 1 day if just refinishing a new part such as a bumper or very small repair. I’ve never had an issue in this time frame. But I’ll let these older cars breath or gas out. I guess it’s the amount of material or size of repairs that’s the difference.
or maybe it’s all just in our heads

 

I’ve read several epoxy tech sheets that have a phrase kinda like this “for best adhesion use xxxx metal conditioner/cleaner”
We used the ppg DX cleaners back in the day.
I’ve used em on brookville bodies.
The 2050 doesn’t mention a metal conditioner/cleaner. The DP does last time a looked.
Interesting subject. Any experts here on the topic?

 

The Insurance Co. have taken all the craftsman out of the business and replaced it with
Cave & Pavers.

 

Product Information Effective 11/18 VB-18
VB-18
DTM High Build Primer
VP2050
VP2050 DTM High Build Primer is a two component, gray,
direct to metal high build primer that is easy to apply and
sand, and offers excellent adhesion and corrosion protection.
VP2050 may be applied over properly prepared steel,
aluminum, fiberglass, and existing coatings in good condition.

Here's PPGs definition of "properly prepared"

What Does "Properly Prepared Bare Metal" Mean?


In many of our product data sheets, you may notice this or a similar statement under the Compatible Surfaces or Substrates section:

“May be applied over properly prepared and treated bare metal”. But what does this mean?

This means that your bare metal substrate must be properly sanded and treated with an appropriate direct-to-metal product such as an SX metal treatment, etch primer, or epoxy primer prior to applying anything else. These coatings insure adhesion for subsequent layers over the bare metal as well as provide additional corrosion protection.

This step is especially important when using urethane primers or sealers. Their chemistry typically does not provide adhesion to bare metal – they must only be used over treated bare metal to insure optimum adhesion. So if you happen to sand through to metal, apply a bit of etch primer to insure it sticks!


Soooooo---
If you sandblast or aggressively sand steel panels you remove the phosphate coating, which is the first step to protect steel from rusting. There are 2 basic ways to replace the phosphate coating: metal prep/acid wash--and--self etching primer. Epoxy primers do not convert or stop rust chemically, and most of the popular epoxy primers have little film build, long cure times and can absorb moisture and solvent--PLUS--most epoxy primer tech sheets recommend treating the metal with metal prep/acid wash for the best corrosion protection. Over the last 50 years, lead, zinc and chromate have been removed by law from paints. These are heavy molecules added to paints to protect from Ultra Violet, chemicals and moisture. The acid in metal prep (phosphoric acid) can affect the hardner part of epoxy primers causing them to air dry but not cure partially or completely. This is why most epoxy primer tech sheets recommend completely neutralizing the acid/metal prep before applying epoxy primer. Epoxy primers have been "sales promoted" pretty heavily in the last 50 years. I remember PPG/Ditzler promoting their DP40 primers with "Just DP it and Forget it", but that was back when DP epoxy primer actually had lead in it and they kept on promoting it because they knew regulations were already removing lead from paint products. Now they are selling DPLF (lead free) epoxy primer. Back then, if I needed to use epoxy (on restorations) I used DPU 35 epoxy (from their aircraft and industrial line) which had 3 times the film build and cured at least 3 times faster-and contained lead. We used metal prep on rusty steel first, and then the DPU35-per PPG tech sheets. Today, I see PPG has some really nice high build epoxy primers (again from their industrial products) that are becoming popular for high end restorations--VP2050 and CRE-X21--of course lead and chromate free. These are quite expensive and still are recommended over properly treated steel (metal conditioner).

For the "informed" hobbyist, I recommend the following on sandblasted steel:
1)Sandblast- carefully to avoid warping.
2)DA sand the sandblasted steel with 180 or 80 grit to soften the blast profile/texture. This helps keep the acid in self etching primer from being trapped in the texture (sandblast profile)--watch out not to apply too heavy of a coat.
3)prime the steel with a "mild" self etching primer (chemical adhesion) followed by at least 2 coats of hi-build 2K urethane primer. This (self etch) will neutralize rust in the pores of the sandblasted steel and the (2K) will add a moisture proof layer to protect during storage.
4) When you are ready to do rust repair or filler, you can cut out the replacement areas and repair/weld and do body filler either by grinding off the primer before filler or sanding the(good quality) 2K and applying filler on it (mechanical adhesion). I prefer filler on bare steel, but good fillers will adhere to good cured 2K. If you do either way, remember to sand far enough out on the areas to reprime (over filler) so you have good adhesion. Also if you apply the reprime 2K too heavy, the solvents can lift/wrinkle your filler edge.


Etch primer
There are 2 basic etch primers-

VINYL WASH primer-has more etching capability but no film thickness or build. It needs to be topcoated with a fill primer or sealer and then paint. This type of etch primer should NOT be put over Bondo. It is for bare metal only.

MILD ETCH PRIMER WITH SOLIDS-has a milder etch and some fill. It CAN be applied over Bondo. Vari-prime (DUPONT),Wash primer EM (SIKKENS AKSO/NOBEL) are a couple of names that come to mind. This can also be topcoated with a filler primer or primer sealer or directly with paint (industrial application.)
You have to check and see what system/brand you are going to use and then get the technical info on the application requirements and read and follow the manufacturers instructions.
DO NOT use metal prep before applying etch primer-it needs just a microscopic amount of oxidation to bond with. The phosphoric acid in the etch primer is usually less than 2.5% (by volume) but that bonds with Iron oxide (rust) to form Iron phosphate which is the etching/phosphatiing process. Removing all the rust with metal prep/conditioner (phosphoric acid) will leave nothing for the primer to bond to and can lead to peeling.

These systems usually go as follows:

Vinyl wash primer-1 medium wet coat (.5 mil) over clean, dry, sanded/sandblasted bare metal. You can see through this coat-its very transparent (vinyl resin). This followed-probably within 30 minutes (wet on wet-no sanding) by a good catalyzed 2 part filler primer for filling and sanding (5-20 mils). Or in straight refinish (trailers/industrial) applications-vinyl wash primer followed wet on wet by a non-sanding primer sealer(1.5-3 mils)-followed by paint.

With the milder etch primer you prepare the metal the same-do your bondo work then clean and apply the milder etchprimer (1-2 mils) followed wet on wet/no sanding (probably within 30 minutes- read the tech sheet for the product) by a good catalyzed 2 part filler primer for sanding and blocking.

For project cars I usually rough out the metal-do my filler work on the large areas then use the mild etch primer followed by 2 part filler primer. Then for smaller areas I can use the spot filler/ catalyzed glazing putty over the sanded filler primer to smooth out small imperfections. I will probably reprime areas that need more fill and block sanding-then on to paint.
If it is going to sit for as while, I prep the steel-then etch prime (either one) followed by good 2 part filler primer. Then when I'm ready for bondo work, I just hit the repair area with a grinder to bare metal and do my bondo work followed by the filler primer.

Epoxy primers DO NOT etch the metal. They bond by mechanical adhesion. There are many different epoxies for specific applications. You need to research what will do the job for your intended purpose for which ever primer/paint system you are going to use.

The acid in etching primers can cause the epoxy primer catalyst/hardner to change chemically and not cure or possibly fail/peel.

The acid in etch primers slows down the catalytic reaction of the hardner in Bondo/body filler (polyester resin-catalyst MEK peroxide). If you put bondo over etch primer and there is still a minute amount of residual acid-you could have a failure/loss of adhesion etc.

The amount of acid is very minimal in these primers. It is mixed with a solvent to reduce/thin the primer. If the etch primer is not fully dry and cured there COULD BE be residual acid/solvent in the primer film which could cause the reactions described above. Self etching primers/wash primers, typically have about 5% phosphoric acid (the etch part) in the hardner/reducer that is mixed 1 to 1 with the primer. This makes the acid content of the mixed primer around 2.5%. Acid is always converting with other substances/compounds like the iron oxide in the steel and the solids part of the etch primer or even the compounds in the 2K primer applied over the etch primer. Eventually all the acid will convert and become non-acid compounds. If your etch primer is applied too heavy it can trap solvents in the film which contain a small amount of acid. There is no real accurate way to know the acid content remaining in a heavy application, so it is best to manage your application to avoid this--don't pound it on!--and be VERY CAREFUL in cold shop conditions, as cold panels and air temperature will slow solvent evaporation and the cure of products with a catalyst/hardner.

Self etch primer followed by a good 2K primer is an excellent system/foundation for restoration and custom work and you can shop for products that have good quality and price. It also makes an excellent storage coating for projects that won't be completed soon and is still compatible with almost all of the paint systems available for automotive refinish.

 

I’ve done both. Etch/urethane or epoxy/whatever
We used etch followed by urethane for collision work. OE and paint manufacturer recommendations and warranty requirements along with time was the reason we used this method.
I’ve also done epoxy and DTM polly. No issues.
Then ya get the filler over/under epoxy debate. We’ve worn that one out all ready.
I’m curious if anyone has attended the PPG restoration classes.
They have a restoration guide for their products.
Simple, basic common sense stuff here
https://ppgrefinish-na.uberflip.com/i/1481439-custom-restoration-guide-2022/29?
mentions using epoxy immediately after blasting
And using metal treatments on bare DAd steel before using epoxy

 

That looks good. The only thing missing is which epoxy they are referencing (Step 2) to use for the 2 coats of epoxy primer.

Anthony, I don't think you have a problem with understanding what products to use and how to use them. It is a good thing that we all post information, observations, and technical data on threads like these, so others with less experience can find good information and ask questions without spending hours and days searching.

( I prefer bondo on bare metal--Read my tech article "Bondo 101" in the Tech Archive).

https://www.jalopyjournal.com/forum/threads/body-tech-bondo-101-magic-dent-erasing-compound.8318/

 

Nope. I teach this stuff to high school students. I read tech sheets, guides, best practices, go to training seminars, ask dumb questions on top of doing this stuff for 30 years. I like to answer questions when asked.
Clean, etch, urethane I’ve done a zillion times
But I’m curious on the subject of metal conditioners. At one shop when I first started, DP was applied over metal prep. Then that changed to etch/urethane.
Then when I got back into resto work, epoxy was the main product used but not the metal preps.
I’ll ask a paint rep and get a grin and shrugged shoulders.
In the guide if you continue, it goes over the various PPG epoxies. Then you check the tech sheet. The 2050 doesn’t mention metal preps but DP did the last time I looked.
This is the reason for the curiosity.

now, the 2050 info doesn’t mention it’s an epoxy but the catalyst, dry times …… are very similar to their epoxy products.

 

It's there, but not directly on all the tech sheets. Here's the link: https://us.ppgrefinish.com/PPG-Refi...7/What-Does-Properly-Prepared-Bare-Metal-Mean

Almost all their TDS sheets have the "Properly Prepared" steel, aluminum, galvanized and substrate listed, but I did have to look to see how PPG defined "Properly Prepared".
If you were wanting to get reimbursed for a product failure, you would probably be asked was it "Properly Prepared" per technical information. As far as surface rust, other Tech Sheets used to and probably still do state: the surface must be clean and free of rust, oils and dirt. How would you get rid of deep rust completely, other than metal conditioner?

 

That particular line is omitted from the 2050


differed from the DP
I guess this is where the curiosity on my part started