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Thu Sep 18, 2014 5:33 pm

I tried to buy a quart of epoxy primer from one of the only paint supply shops close to me today. They said that they don't carry epoxy primer anymore. They said it is outdated and I should use a DTM primer for bare metal. It is urethane based. Anyone have any knowledge of this. I also wondered if I buy one without isocyanates as opposed to one that does, is isocyanate listed in one of the ingredients. Basically how do I know if it contains isocyanates or not? DTM is direct to metal.

Thu Sep 18, 2014 6:09 pm

what brand? DuPont/sikkins etc make a epoxy that it DTM. odd that they would not carry it...

Thu Sep 18, 2014 6:40 pm

I use PPG DPLF epoxy
http://www.custom-aerosol.com/pdf/ppg-dplf-epoxy-primer-product-sheet.pdf\
It is epoxy and direct to metal. You have to top it with a urethane surfacing primer within a few days time, or plan on sanding the epoxy (sucks!) to get some tooth for the next coat to bite. I have found it to be tough as nails, and I use it as a base for everything.

Thu Sep 18, 2014 9:57 pm

It was their own brand That is why I didn't buy it. Seemed like they were pushing it because their name was on it.

Fri Sep 19, 2014 9:29 am

esde wrote: I use PPG DPLF epoxy
http://www.custom-aerosol.com/pdf/ppg-dplf-epoxy-primer-product-sheet.pdf\
It is epoxy and direct to metal. You have to top it with a urethane surfacing primer within a few days time, or plan on sanding the epoxy (sucks!) to get some tooth for the next coat to bite. I have found it to be tough as nails, and I use it as a base for everything.

Yup, been using that stuff since 1998 when they took the lead out (prior to that, I used DP). Great stuff, and I use it on everything I want to keep around. 8) I wouldn't even think about doing a resto without it. :shock:

Sat Sep 20, 2014 2:43 pm

I went to another paint store further away. I talked to them and they said not to use epoxy on bare metal also. They said etch primer then whatever I want after that. They said DTM is for spot repairs. The epoxy they had contained isocyanates. Does the ppg primer have isocyanates? I want to be able to spray it with a respirator, I dont have a fresh air mask.

Sat Sep 20, 2014 10:16 pm

Yeah I've spoken to a few body guys locally and they have all told me to use an etching primer instead. It gives the paint something to bite onto.
Both guys turn out GOOD work and are both very respected. In fact, the one guy I struck up a barter deal with. He's gonna paint my bug for FREE!! I am doing bodywork for him and learning a lot as I go along. He's logging the hours I've been putting in. For me, it's a win win situation. The knowledge is invaluable to me.

The problem I am having is this:
I have an estimate to bead blast my entire bug inside and out for $1100. Once it is done I MUST do something within a week or rust will set in. I'm not sure whether to epoxy prime it or etching prime it. I've read the etching primer is acidic?

Sun Sep 21, 2014 8:27 am

If I were you I would read and compare the spec sheets on the products and decide from there. Not all epoxy primers have the same characteristics. I would pay attention to how it needs to be prepared to top coat, surface prep and coating thickness.

Sun Sep 21, 2014 9:53 am

jason wrote: Does the ppg primer have isocyanates?

Yes.

Wed Sep 24, 2014 7:04 pm

Is the PPG DPLF compatible with House of Kolors paint and is it "friendly" with most body fillers? How much would I need to spray the whole body (inside and out), doors, hood, decklid, and all fenders inside and out? A gallon?
I have no clue :shock:

Thu Sep 25, 2014 9:26 am

jason wrote: I went to another paint store further away. I talked to them and they said not to use epoxy on bare metal also. They said etch primer then whatever I want after that. They said DTM is for spot repairs. The epoxy they had contained isocyanates. Does the ppg primer have isocyanates? I want to be able to spray it with a respirator, I dont have a fresh air mask.

I think you will find hundreds of ways to skin a cat. Etch followed by 2k primer is the way it's always been done - most painters and suppliers know this route well and it is typically cheaper material costs. There are also the new school of thought which is epoxy followed by 2k. In either case, you want to apply the 2k primer in the reshoot window so that you don't have to worry about corrosion or adhesion.

I would try to do something with an epoxy if your bare blasted body is going to be exposed to elements while it waits for further body work. Etch primer is not water proof, and a lot of 2k primers are also not water proof, but I believe there are also epoxy 2k primers that are designed to be water proof and easier to sand than standard epoxy primer.

Sanding standard epoxy primer (also called sealer) is a PITA - avoid at all costs...

DTM primers are mostly meant to be applied directly to metal in small spots that are typically "sand thru" spots that show up when you do your block sanding and come across high spots. No need to etch or epoxy prime those small metal areas if you are using a DTM primer - just reshoot the dtm primer as needed. I believe you will see most DTM primers tech sheets state that they are not meant for large bare metal areas.

I don't know what suppliers are offering your area and I have never used SPI brand stuff, but they do have a nice write up about how to use their products which might give you some insight on how other products work as well: http://www.southernpolyurethanes.com/TechManual.pdf

Thu Sep 25, 2014 11:02 am

Mark,
Thanks for your answer and I understand there are more than one way to skin a cat! Haha
I will have everything back from soda blasting in 2 weeks and the painter is going to wipe it down with acetone and spray everything with etching primer.
It will be undercover in a garage but I just want to buy some time before surface rust sets in and start working on the little dings around the car.
I told him to let me know what we need material wise and I would buy it....he said don't worry about it...!?
I've got about 20 hours "barter" time with the guy and he said he is ready to do it in the next 2-3 weeks. Just getting nervous about the sequence of events. There is a rusted area I know I have to take care of but don't know if we work on it AFTER the sprays the primer or what....
He mentioned the etching primer had the zinc phosphate (green?) that is great for keeping rust from forming.....just saying what he said as I have no idea about paint/bodywork stuff.. His work is freaking awesome, so I'll just trust his judgement. He paints race cars and runs a 7sec dragster also paints a lot of junior dragsters and they are awesome.
I'm really excited!!

Thu Sep 25, 2014 2:56 pm

I'm fairly certain you will want to put a 2k primer on top of the etch primer right away for protection from the elements AND for proper adhesion. Check out your tech sheets for whatever etch primer you are using - it will say what to do next and what time frame you need to do it before you are require to reprime or sand the etch primer.

Also just to make sure - there are 2 different cars being discussed here - '67 sunroof's beetle and Jason's beetle?

I didn't mention it, but also just to make sure, etch primers are only sprayed on bare metal - don't use etch primer on top of painted or primered substrates - it is an acid based product meant to go on bare metal only.

I have an old chevy truck that was sanded down to bare metal, then etch primed and then primed with high build black primer for that ratrod look - when I sanded it down, the metal was very surface rusted (It was a lot of work but I am glad I sanded it down to see whet was under the primer)

Thu Sep 25, 2014 9:55 pm

Correct, 2 different cars. I apologize if i took the thread and ran with it but they were similar issues and didn't wanna create another new thread :)

Sat Oct 04, 2014 6:51 pm

marklaken wrote:

I have an old chevy truck that was sanded down to bare metal, then etch primed and then primed with high build black primer for that ratrod look - when I sanded it down, the metal was very surface rusted (It was a lot of work but I am glad I sanded it down to see whet was under the primer)

So you are saying you don't think the etch primer did a good job of keeping the rust away? What kind/brand?
Was it shot or rattle can?
Weighing my options here!
Thanks!

Mon Oct 06, 2014 10:37 am

Etch primer is only used to promote adhesion. It is necessary to use an etch primer (or the right kind of epoxy primer) on bare metal so that the next layer of primer can stick to the sheet metal.

In my truck's case, both the etch primer and the black primer that was sprayed onto the etch primer didn't prevent corrosion - it was stored outside in hot/dry Denver. I don't know what the etch and black primer were (I got the car with them already applied). I would guess that the etch primer was standard etching primer (it was yellow) and that the black primer was either rattle can primer or more likely a lacquer primer.

Wed Oct 08, 2014 11:08 am

New here on forum, but I've been super impressed with SPI 2k epoxy primer -- http://www.southernpolyurethanes.com/index.htm. I've shot a couple quarts of the white and black. Great product, excellent support and a helpful user community. You can contact Barry, the President of SPI by phone or text 7 days a week even after normal business hours for your technical questions.

p.s. - Barry recommends laying down their epoxy primer directly to metal before filler to promote a chemical bond; not mechanical. Lays down super flat -- and it's easy to sand.