Leaving DP Epoxy primer uncoated?

[Shvegel]

I have sprayed a fair bit of Ditzler DP Epoxy primer in my time and am planning on using it on my suspension components.   I am wondering if anyone has experience leaving DP90(black) untopcoated?  I am toying with the idea as not spraying over the primer with semigloss black would save me a step.  I would guess there might be a UV issue but under the car it should be OK.

[114015]

I've used epoxy paints all over my car whereever I could. Just because it is of far better quality than single component paint.
As to the primer ... well I am not an expert - no paintshop.
But I was told (was told - does not mean I know for sure) that (any) primers are not tight or sealed against moisture. Will say you car or parts are much sooner going to rust without topcoat than with.

My 2 cents from 35 years playing around with cars:
Always primer + topcoat. Best is 2 + 2 layers.
There might be exemptions for particular areas or parts (because of µ thickness or so) but as a general rule its certainly the best advice.

Achim

[wwheeler]

You should be able to download data sheets on the internet about the product. That should state whether top coating is required. Don't call the local auto paint supplier as many don't really know.

My guess is like Achim's. Will also be harder to clean for sure. Primer's function is to act as a bonding layer between the sub surface and the top coat. 

[Pinder]

I know that Epoxy Primer with the Hardner is waterproof and can be left unpainted and is an excellent rust encapsulator. It also has a nice semi to matt look to it. But the Data sheet may help. But offten they wont say if it can be left as is.

[wwheeler]

I agree with the fact that epoxy primer is waterproof. The most current thought with adding body filler is to have it sandwiched between coats of epoxy sealer. It is waterproof and seals the body filler which typically absorbs water. I am just not sure how UV resistant epoxy primer is. 

[Shvegel]

I am sure the epoxy primer is indeed waterproof.  On the ship I work on we use some pretty industrial stuff on the hull under the water.  I once asked the ship maker what he topcoated it with and he said "Who cares"  I just realized I used DP40 on my air conditioning condenser outside my house 3 years ago and although it still looks pristine I think I will still topcoat what I prime.

[Garry]

I don’t quite follow the logic of this whole post.

 Its called “primer” for a reason.  Why don’t you just do the job properly?

[Shvegel]

Boy Garry you just struck a nerve.  At no point did I ask for anyone's opinion on the correctness of what I am doing.  I happen to be a very talented mechanic as well as a pretty fair body man and am quite able to form my own opinions as to what is appropriate to do and not do to my car.  Being a marine engineer I also happen to be quite well versed on what what works and doesn't work in terms of epoxy primers in both theoretical and real world applications.  One of the things I have been stewing on for a long time is a few select people here who want to hop on a horse and flame people for not doing things how they think they should be done.  This site used to get quite a bit more traffic than it does today but thanks to people like you who seem to enjoy whatever trip they are on we now get precious few posts in a given day.

[Garry]

Ok so the chevy bit was over the top and I will withdraw that comment, however I did not give an opinion, I asked a question and I still just don’t get it. If a paints a primer and you are doing up a car worth thens of thousands of dollars, why would you not want to paint it after priming it.  I have clearly missed something in the question which is why I asked the question as to why you would consider not putting a finish on a primer. 


Oh, and as one of many people who have volunteer their time to help run this Forum for some years so that you in particular can remain a free Associate Member, I will tell you as Membership Administrator, your assumptions on decline are just plain wrong.

[Shvegel]

Garry,
Sorry I lost my cool but I just get tired of watching posts where someone will be trying to get by on a shoestring and someone will chime in with something like "You are just making a mess for the next owner.  Why don't you sell the car to someone else?" or 'Why would you build a dog's breakfast of an engine."  I get tired of it.  It hurts peoples feelings and it's uncalled for.  I am lucky enough to not be operating on a shoestring and in fact have spent a fortune having the best metal man I know fix my car's chassis before having it trucked 800 miles to be dipped in epoxy primer in the very same vat where they dip frame assemblies for Ford trucks. The steel frames are left untopcoated for the rest of their lives and after seeing countless numbers of them in junkyards over the years I can assure you that even here in Ohio where they use only salt on the roads in winter the corrosion I see is minimal.  Why would I leave DP 90 uncoated?  Because it's almost the perfect gloss,  there is no inter layer adhesion issues, I don't have to sand it and it is a tough as nails.

Finally as to your not so subtle comment about my remaining a free member all these years i have 2 things to say. If you look through my posts I think you will find that the vast majority of my posts are me answering other peoples questions not the other way around.  In that respect the club has gotten way more from me than I have ever taken from it. As for me not paying dues that is a question of where you are standing.   Maybe I have never made the cash register ring in some account in cyberspace (quite frankly I don't need a magazine and I know how to set up my own linkage) but what I have done is send thousands of dollars worth of parts all over the world to members who need them for free(shipping included).  Dues paid.

[Shvegel]

DP90

[Peter van Es]

Gentlemen,

this must be one of those rare public outbursts between two members that I have seen in a long time. I'm sure it will be the last for a long time too.

First of all, all those that volunteer for the Pagoda SL Group, without your efforts this group would not exist. And without dues paying members, this group would not exist either.

Secondly, for all those members (Associate or Full) that volunteer their time and knowledge, without your efforts this group would not exist either.

The founding members made a wise decision to make this group Inclusive, not Exclusive. Everyone adds to the group what they can. Shvegel and Garry, thanks for contributing, and sharing your experience. Wouldn't it be nice if you could meet up and have this discussion over a few beers?

Let's all forget the difficulties of communicating clearly through cyberspace, and concentrate on why we are here!

Peter

[wwheeler]

That's what the epoxy primer looks like. I have used it before under the '70 Roadrunner chassis to duplicate the factory "dip". That color was a medium grey color though. What I did though was to top coat it with a clear that was flattened down to about 60% gloss which is about what you have here. The clear gives it a top coat (don't know if it is needed) and will clean much easier in the future. No way you can tell it has clear on it when it is 60%. Just a thought.


And yes, did someone mention beer?

[Pinder]

I happen to like the look of Eastwood Epoxy Primer  in Black and would consider leaving certain painted items with just the primer. I read a post in a motorcycle forum where one member was looking for a specific level of sheen and colour for a motorcycle gas tank and he found Black Epoxy Primer to be the ideal choice.

[wwheeler]

If it is Eastwood, that is easy enough. Just call or email the question help and ask if it is UV resistant.

[silver surfer]

 2k epoxy primer can be mixed in most colours at your local motor factors and will be fine on most things. It is availible in satin black very much like the original under body parts. It has great etching properties and is impervious to moisture. It sets very hard so its durable but is affected by UV so will fade if in direct light. Should be ok under the car though.

Its great stuff!