Technical Difference in Primers

You wouldn't need it, but I would get 2 gallons, that way you have enough to do top sides, bottom sides, inside and there is always a redo for a door or a fender you screw up etc.
I will look and see if I have any blue, I just donated a bunch of paint to the local high school which believe it or not has a mechanical and auto body class.

 

Dupont very prime, is a self etch primer, and does require an activator. it is mixed one part primer to one part activator, thus making it a 2K paint.

 

The most anti-corrosive system is two coats of aluminum pigmented moisture cure followed by an epoxy surfacer. All the cars I painted have two coats the silver followed by epoxy surfacer and haven't had a comeback in years. Just remember quality rust work starts from the inside out.

 

What do you recommend for use on a door skin before putting it on the door, i.e. on the inside folded door edge? Once the door skin is installed, then folded over, it must have the spot welds welded back up again. What is the best product for that application?
Also, I have scraped all the old tar like substance off the interior panels of the 57 Ford I am working on. Probably a dumb question, but should I use a degreaser like brake klean to remove the last of the tar residue, or will the epoxy primer seal over that and stick to the metal? Will a degreaser cause more problems than not using one? Thanks.

 

No its not. It requires a converter which is a acid. Not a hardener. You can bull shit on the label and description, you can't bull shit on a tds sheet. They do this to help people understand that they require the acid to be mixed in and not just some reducer. It's not a 2k product by industry standards it can retard and soften.

 

Also the reason for calling it a 1k is you teach people that they can do their body work on top of 2k primers etc. You can not put body filler over self etch nor can you put polyester primer over self etch.

 

For the door skin edge use a weld through primer. It comes in aerosol cans, spray that first put your skin on, Weld, then epoxy primer.

As far as the tar, you need to remove with vm and p naphtha (charcoal starter) which is what a lot of automotive wax and grease removers are made of. Brake cleaner dries to fast not allowing time for the solvent to soak in and soften up.

Improper degreasing causes a large majority of paint issues. Always use 2 different types - a solvent based to get motor oil, tar off. And a water based to remove hand oil, sap etc. Usually any brand of wax and grease remover, but the water based you can buy glass cleaner with ammonia. I prefer using solvent first, water based second because water based has alcohol in it and that helps eliminate static electricity which will keep the trash down in your paint job.
Soak one rag and wipe back and forth, not in circles then have a clean dry rag to dry off. Don't let the solvent dry on the panel because all you are doing is spreading the contamination around the entire panel. I could do a entire thread on degreasing panels but for now let's keep it simple and stupid.

 

Can you explain DTM vs Epoxy? I see some labeled DTM Epoxy and some just DTM some companies produce a DTM primer but not a Epoxy within certain lines. It gets confusing. Also I plan on painting with Sherwinn Williams ATX because it is a simple system and a mid range line and not some ultra cheap stuff. What is your opinion of this stuff? How the heck does one pick one brand or line vs another?

 

All epoxy will go direct to metal. You can make a urethane a direct to metal by adding certain additives that basically helps adhere to have a layer of corrision protection.
OK so atx which is pro base at the Napa stores, I can't answer your question on this. I will say this brand is the reason I quit S/w 4 years ago for not standing behind a warranty for product compatibility. If you are going to use it, Make sure the clears you use are a approved topcoat for atx. If you want great products at not so high prices try some of these brands they are not second tier lines. Just not as popular but their quality is top notch. Also note I don't sell some of these lines but I'll give credit where credits due.
Matrix, Pro Spray, Genrock, Kapci, Color By Design, automotive art, Besa
Here is my opinion on major companies mid tier and low tier lines. Why would you make your lower gross profit lines as good as your premium line? If it's lower quality what did they cheapen?
Also while the local Paint reps talk crap about those lines I mentioned above, their bosses are taking those same paint companies out to eat to try to sell them their raw materials. Just a FYI

 

I don't know much about paint. I have taken refinishing courses but its still confusing trying to pick one system from another. I thought I would go with ATX because with my student discount its quite cheap its not some cheapo stuff its from a reputable brand and my refinishing instructor said it would be a good choice and simple to use.

I know this is a complex question but what makes a top quality paint better than a bad one? Higher solids? More toners for better color matching? More products within the line.

 

What makes the paint good is Mainly the pigment and resin. Non fading pigment cost up to $25/lb you have to put a certain amount in there so you get coverage. Fading pigments are what's found in industrial and architectural coatings and lower end automotive. High prices have to do with a lot of big paint companies giving a lot of money to big body shops and put them in contracts so they have to have high prices to off set this. But also you pay high dollar for research and development for Paint color formulas, the car manufacturers use so many different formulas that this 1 issue accounts for 90% of every Paint company's research and development budgets in automotive. Here is a prime example as well - to match some colors takes 10 mins, some take 6-8 hours then each color may have different shades or alternates, so you figure about 500 new colors per car manufacturer per year paying someone by the hour to match, that's where the money goes.
Back to quality i hear so many people say use a cheap base and spend your money on clear.... WRONG! You have to use a good base and look at the solids content of your clear and make sure you get enough mils on there for a lasting finish. You are doing a great thing by researching and asking the right questions before you spray! You don't have to spend a ton of money to get great products.
If you want to use atx use the atx brand clear. We had huge delam problems with atx under Finish One clears. The issue im sure is fixed. Where is your school located? We like donating left over supplies to schools if your instructor is interested. We know the budgets suck for this type stuff.

 

I never understood people who would mix different products. Sure pros can get away with it because they might have experimented but I dont want my car experimented on and who is to say it will always work?!

This makes a lot of sense. I stay away from HOK paint because of the fancy marketing they do and just assume there is diminishing returns on quality for money in the high grades.

I planned on using the whole ATX system being my first paint job I want to keep it simple and eliminate possibly failures.

 

Paint pricing is such a gimmick.


1 quart of DBC 500 is $50.00 or $200 a gallon. All in all its not terrible.

Mixing Pigment is all over the place in price but lets say its 200 a pint average. Awe hell, say its $500 a pint.

So with 1000 part formula : 3 parts reducer, 27 parts of pigment, 970 part of DBC 500 and now it costs you $175.00 a pint or $1400.00 a gallon. If it were priced on a straight per ounce cost plus basis nobody would complain. It would be about $300 a gallon not 1400

 

Good lord I need to raise my prices. I charge $30 for a quart and deliver, and free sticks, strainers and mixing cup....wtf maybe that's why I can't afford to finish any of my cars.

 

Read all the info so far and this is valuable info to the Hamb community.
You've answered so many questions I've had. Thanks

One thing I notice is in regards to the Ospho and epoxy primer compatibility question.
It seems some e-primers like it and some don't. Is there a way to know other than trial and error?
Or do you recommend simply staying away from Ospho under epoxy primer.
I have bare clean metal with tiny pits that show up as little black dots (speckles) when acid is applied. Are they so small that I shouldn't Oshpo and just spray epoxy?

 

Just use epoxy. As long as you get the scale rust off in hard to reach places, epoxy is exactly what you need. Every primer or rust converter that's built is tested up against epoxy, because it's the most durable. Nothing can compete, but get epoxy straight to the metal. Don't sandwich anything in between.

 

Sat in on a paint tech lecture, the formulas written on the chalk board were intimidating!
Your advice helps to make sense of this particular art.

 

I just learned more about primer and paint than I had ever imagined.

Thank you Paint Guru!

 

There is nothing wrong with HOK they are backed by Valspar. Now no one is going to give you a warranty for candy Paint etc, but there are a lot of beautiful cars out there with HOK on them. But if you wonder about product compatibility, just ask. Good luck!!

 

OK so Epoxy is good for bare metal only. What then is the best primer for a mix of bare metal and body filler?

 

Paint Guru=good stuff!
Here's some older paint/primer threads for those of you wanting to read more.
Some primer/paint discussions:
http://www.jalopyjournal.com/forum/showthread.php?t=293553&showall=1

http://www.jalopyjournal.com/forum/showthread.php?t=297587&showall=1

http://www.jalopyjournal.com/forum/showthread.php?t=380585&showall=1

http://www.jalopyjournal.com/forum/showthread.php?t=364032

http://www.jalopyjournal.com/forum/showthread.php?t=350749&showall=1

http://www.jalopyjournal.com/forum/showthread.php?t=282299

http://www.jalopyjournal.com/forum/showthread.php?t=244070&showall=1

http://www.jalopyjournal.com/forum/showthread.php?t=182387

 

You can use epoxy as a filler. Urethane would work as long as you don't have any bare metal spots over the size of a basketball. Urethanes sand easier.

 

Epoxy first the yer plastic work, then more epoxy. Ya make a samwich outta it and you'll never have a problem.

 

shoot the epoxy on the bare metal, scuff with say 80? do the plastic work and then over shoot with epoxy again and then paint. I got that correct?

 

After much thought to this thread, I stopped at my paint store today to see it I was wrong in my thinking. Veri prime 616s uses 615s convertor to make the product dry. Without the convertor the veri prime will not dry, which makes it a 2k primer any way you cut it. 2k paints need both parts to dry which veri prime needs the convertor, you could also call it an activator because of what the convertor does.

 

I am not knocking HOK at all. I know it is good and there are many cars painted with HOK. I just wonder what kind of premium is paid for it and if there is any noticeable difference.

 

I build self etch primers and mine dry without a activator. It's lacquer based. I could put in 2 separate cans with acid in the other can but I will just pay the extra 45 cents for a lined can, and make it simple for the end user.
Your thought process, which I understand , would be like my air dry enamel which is 1k because it doesn't require a hardener, but when you manufacturer coatings you put additives in to make it crosslink with oxidation to dry. But I could technically not put it in my coating and make the end user put it in as a converter. It will not dry without a "air dryer" in it, but its not considered a 2k unless my enamel is cross linked with a Hexamethylene diisocyanate.
I bet the veri prime will air dry, with some mek. It won't etch into the metal, but it will air dry. But hey what do I know.

 

There is a large premium paid on most any paint out there unfortunately, but I would say hok probably has about a 30% extra premium for using the brand only because it has a extra step of distribution to get to the end user.
Pricing is a weird game in this business. If it's real cheap people expect it to be junk. If it's the most expensive it's the most popular.

 

I prefer 180 grit scratch. You can rough the filler out with 80 then final sand with 180. You can just spot prime over your bodywork.

 

I wonder if its because its so hard to choose as someone restoring a car just giving up and choosing the most expensive and equating it with quality. Also buying cheap but recommended paint is a gamble if it sucks. It would be much easier just taking a car to a shop that has done good work and just trusting them in whatever their system is.