[trackdown]

i recently used DPLF Epoxy for the first time to evaluate its properties. Here are my findings for your perusal and comments to those who are more familiar with the use of this product than i am.
The Product took about 30 hours to cure or become reasonably hard.
When recoated 2 coats of Epoxy after 60 mins with a Basecoat , the Epoxy film got soft and the combined film even after 72 hours was removed by scraping. also lacquer thinners rubbed onto the surface removed the film. Most professionals that i know uses an Epoxy Primer as an isolator to prevent recoating problems through its properties that act as a barrier coat. Which apparantely this product would fail to deliver.
Your comments please.

 

[OneMoreTime]

It would be instructive to know the conditions of application. Epoxy needs heat to cure so the metal itself needs to be above 60-65 degrees for the product to cure properly..

Sam

 

[John long]

I have used DPLF for years and even though I have recently changed to SPI epoxy which I much prefer I do not think the PPG is a bad product. I am in the middle of repairing some bubbles in the crease of my 36 Ford roadster door that was painted 4 years ago. The door was stripped to bare metal, primed with DPLF, primed with K36, sealed with DPLF and painted with Concept? In order to determine why it failed I took a razor blade to it yesterday to determine at what level it failed.

I was amazed to find the bubbles go all the way to bare metal. All layers of paint have good adhesion. To my surprise the metal is perfectly clean and shiny.......Too shiny. THIS FAILURE IS MY FAULT. When I stripped this door I treated it with RustMort and wire brushed the crease area. There is no doubt The failure is the result of me failing to neutralize the acid and/or polishing the metal to the point the paint had no tooth to bond to. Add to this it was painted in a very cool shop.

The point I am trying to make is these modern materials work by chemical reactions and depend on the proper procedures being followed. That includes temperature, preparation, Mixing ratios etc, etc. Rarely is a failure due to the product being bad even though I wish I could blame it on the paint. ain:

John H

 

[DanielC]

My comments.
Like it was pointed out, MANY factors can affect the properties of a paint or primer.

In the data sheet for DPLF, it states you can recoat DPLF anytime up to a week, without sanding.

That tells me that DPLF needs at least a week to cure, and before a week is up, it is not fully cured. My belief is PPG formulated this property to aid crosslinking (bonding) with the next layer of paint or primer that goes over DPLF. This can also be useful in a shop where you can prime a car on a Friday afternoon, and not have to get the next layer of paint on the car until Monday.

A lot of areas in the USA, you cannot use lacquer thinner any more due to VOC regulations.
Are you still painting cars with lacquer?

Is DPLF better than SPI, or the other way around? If depends on you knowing the properties of both products, and READING THE DATA SHEETS ON BOTH PRODUCTS to know which is the best to use.

 

[mike the painter]

I have used DPLF for years and even though I have recently changed to SPI epoxy which I much prefer I do not think the PPG is a bad product. I am in the middle of repairing some bubbles in the crease of my 36 Ford roadster door that was painted 4 years ago. The door was stripped to bare metal, primed with DPLF, primed with K36, sealed with DPLF and painted with Concept? In order to determine why it failed I took a razor blade to it yesterday to determine at what level it failed.

I was amazed to find the bubbles go all the way to bare metal. All layers of paint have good adhesion. To my surprise the metal is perfectly clean and shiny.......Too shiny. THIS FAILURE IS MY FAULT. When I stripped this door I treated it with RustMort and wire brushed the crease area. There is no doubt The failure is the result of me failing to neutralize the acid and/or polishing the metal to the point the paint had no tooth to bond to. Add to this it was painted in a very cool shop.

The point I am trying to make is these modern materials work by chemical reactions and depend on the proper procedures being followed. That includes temperature, preparation, Mixing ratios etc, etc. Rarely is a failure due to the product being bad even though I wish I could blame it on the paint. ain:

John H

Hdy John, a couple questions about the rust mort...
I dont use it, I use Ospho, but did you sand the mort before you primed it?
I always dewax first then sand with 180 DA and since the da wont sand dngs and little dimples I scuff with a red pad then dewax again tack (yes I tack the bare steel) then epoxy prime....
How did you apply the rust mort? I use a red scuff pad and scrub it inwipe all the excess off with a paper shop towel leaving almost nothing when I'm done.
phosphric acid is about the best way to remove rust at a micoscopic level I even use it on sand blasted surfaces but I've never had this problem ..its fairly common and I'd like to get to the bottom of it and why people are having problems using it. like I said I only use Ospho but how different can the products be???

 

[John long]

Hdy John, a couple questions about the rust mort...
I dont use it, I use Ospho, but did you sand the mort before you primed it?
I always dewax first then sand with 180 DA and since the da wont sand dngs and little dimples I scuff with a red pad then dewax again tack (yes I tack the bare steel) then epoxy prime....
How did you apply the rust mort? I use a red scuff pad and scrub it inwipe all the excess off with a paper shop towel leaving almost nothing when I'm done.
phosphric acid is about the best way to remove rust at a micoscopic level I even use it on sand blasted surfaces but I've never had this problem ..its fairly common and I'd like to get to the bottom of it and why people are having problems using it. like I said I only use Ospho but how different can the products be???

Mike I honestly do not remember the details. It has been 5 years ago I think. I am sure I would have scoured the crease area with a red scotchbrite pad. I always do. I don't remember what I did to neutralize it nor do I remember for sure what I sanded it with. There is no doubt I would have sanded it but it is so shiney I am wondering if I didn't decide that the scotchbrite pad was good enough. The rest of the car is still looking good but the doors (done the same time) are bubbling badly in the reveal area only. The rest of the doors are both still excellent.

John L

 

[mike the painter]

Will you be stripping them (the doors) ?I'm interested in seeing how well the primer stuck to the metal everywhere else....just for giggles try using a razor blade to scrape off all the material to the metal...Then try sanding and feathering the epoxy to see if it feathers nicely where it meets the metal or if the edge breaks away at all... BTW ,your cowl looks great all painted upand I love that V-8 emblem on the dash...:thumbup:

 

[John long]

Will you be stripping them (the doors) ?I'm interested in seeing how well the primer stuck to the metal everywhere else....just for giggles try using a razor blade to scrape off all the material to the metal...Then try sanding and feathering the epoxy to see if it feathers nicely where it meets the metal or if the edge breaks away at all... BTW ,your cowl looks great all painted upand I love that V-8 emblem on the dash...:thumbup:

I don't know yet how far I am going to strip them. One thing for sure is, the whole area along the body line will have to be taken to bare metal. There is so much material on them they meed to be blocked down as far as possible for sure. Both doors have been partially skinned. I hope I don't have to re-do the body work on them.

Here are a couple of pictures.

John

 

[mike the painter]

That certainly looks like an acid issue,if thats metal showing..
I think I'd toss that rust mort and either use Ospho or nothing at all..
Did you epoxy then use the filler on top of that or filler to the metal?
The thickness of the material is one of the main reasons I hate 2k primer,once you guide coat it and get it straight most people stop right there but theres still a ton of material on there that doesnt need to be there,causing thick,nasty lookin chips and cracking in some cases,door edges especially...
I think I'd try getting a razor blade in there between the metal and whatever that is and trying to scrape it off until it sticks..It should scrape right off,at least down as far as it starts sticking again ...is that happening anywhere on the rest of the car?

 

[John long]

That certainly looks like an acid issue,if thats metal showing..
I think I'd toss that rust mort and either use Ospho or nothing at all..
Did you epoxy then use the filler on top of that or filler to the metal?
The thickness of the material is one of the main reasons I hate 2k primer,once you guide coat it and get it straight most people stop right there but theres still a ton of material on there that doesnt need to be there,causing thick,nasty lookin chips and cracking in some cases,door edges especially...
I think I'd try getting a razor blade in there between the metal and whatever that is and trying to scrape it off until it sticks..It should scrape right off,at least down as far as it starts sticking again ...is that happening anywhere on the rest of the car?

Yes, I did Epoxy and then filler and then 2k. Sealed with epoxy and painted. I have used RustMort for years as you have used Ospho. Scrubbed my 57 Olds with after stripping because surface rust had begun to come through the paint. I had no issues with it ever.

This roadster had either been rolled or broadsided hard. The body work was very badly done. Even the lip had been cut off the rear of the doors. I made new skins and replaced about the the rear 8 inches of both doors. The point is the doors were far from cherry and indeed do have more material on them than would be optimal.

I agree totally this is an adhesion issue. I don't think it is the fault of the RustMort. I do think I have probably failed to clean and sand the surface properly. Once I get the cowl buffed I will take a razor and test further.

This is the door before it was painted.

 

[302 Z28]

PPG DPLF epoxy is crap that is the best thing you can say about it. In a thread on the build of my 34 I showed how DPLF even after sitting on a hood in my garage for six months wiped right off with a lacquer thinner soaked rag. I was told that I didnt mix it right or didnt apply it right., which was pure baloney. I removed all the PPG epoxy primer from my hood and replaced it with SPI which will not rub off with a lacquer thinner soaked rag. PPG paint is first rate but they really need to do some work on their epoxy primer because it is far from durable.

Vince

 

[John long]

PPG DPLF epoxy is crap that is the best thing you can say about it. In a thread on the build of my 34 I showed how DPLF even after sitting on a hood in my garage for six months wiped right off with a lacquer thinner soaked rag. I was told that I didnt mix it right or didnt apply it right., which was pure baloney. I removed all the PPG epoxy primer from my hood and replaced it with SPI which will not rub off with a lacquer thinner soaked rag. PPG paint is first rate but they really need to do some work on their epoxy primer because it is far from durable.

Vince

I just used my first SPI epoxy on the cowl and really liked it. The original DP was really good and I loved it but the DLPF is a completely different product.

John L

 

[mike the painter]

I cut my teeth on the old dp 40 ,Back then it was the best but as good as it was it was nothing compared to the SPI..

 

[Dayo5]

Hi,
I am having some sim. issues. Are you guys recommending: full sand/ repair, then epoxy primer, Then filler on top of the primer, then Base? I am trying to get my order of operations set. Thanks!!

 

[John long]

Hi,
I am having some sim. issues. Are you guys recommending: full sand/ repair, then epoxy primer, Then filler on top of the primer, then Base? I am trying to get my order of operations set. Thanks!!

The Epoxy is designed to go over bare metal before any filler work is done. The beauty of that is it will protect the bare metal from moisture. For heavy filling you will want to use the normal body filler and/or 2k high build primer surfacer and finally sealing with Epoxy before paint.

What some of us have done on minor issues that do not require filler or heavy build is to apply extra coats of SPI epoxy to attain moderate build. Then all that is required is blocking and painting. From what I understand, the build qualities of SPi epoxy are about 1/2 that of a 2k primer surfacer.

John L

 

[Old Fool]

I have used DPLF for years and even though I have recently changed to SPI epoxy which I much prefer I do not think the PPG is a bad product. I am in the middle of repairing some bubbles in the crease of my 36 Ford roadster door that was painted 4 years ago. The door was stripped to bare metal, primed with DPLF, primed with K36, sealed with DPLF and painted with Concept? In order to determine why it failed I took a razor blade to it yesterday to determine at what level it failed.

I was amazed to find the bubbles go all the way to bare metal. All layers of paint have good adhesion. To my surprise the metal is perfectly clean and shiny.......Too shiny. THIS FAILURE IS MY FAULT. When I stripped this door I treated it with RustMort and wire brushed the crease area. There is no doubt The failure is the result of me failing to neutralize the acid and/or polishing the metal to the point the paint had no tooth to bond to. Add to this it was painted in a very cool shop.

The point I am trying to make is these modern materials work by chemical reactions and depend on the proper procedures being followed. That includes temperature, preparation, Mixing ratios etc, etc. Rarely is a failure due to the product being bad even though I wish I could blame it on the paint. ain:

John H

Wire brushing burnishes the metal, it leaves no anchor pattern.

 

[Dayo5]

I really appreciate the replies!
Thank you

 

[mike the painter]

I have used DPLF for years and even though I have recently changed to SPI epoxy which I much prefer I do not think the PPG is a bad product. I am in the middle of repairing some bubbles in the crease of my 36 Ford roadster door that was painted 4 years ago. The door was stripped to bare metal, primed with DPLF, primed with K36, sealed with DPLF and painted with Concept? In order to determine why it failed I took a razor blade to it yesterday to determine at what level it failed.

I was amazed to find the bubbles go all the way to bare metal. All layers of paint have good adhesion. To my surprise the metal is perfectly clean and shiny.......Too shiny. THIS FAILURE IS MY FAULT. When I stripped this door I treated it with RustMort and wire brushed the crease area. There is no doubt The failure is the result of me failing to neutralize the acid and/or polishing the metal to the point the paint had no tooth to bond to. Add to this it was painted in a very cool shop.

The point I am trying to make is these modern materials work by chemical reactions and depend on the proper procedures being followed. That includes temperature, preparation, Mixing ratios etc, etc. Rarely is a failure due to the product being bad even though I wish I could blame it on the paint. ain:

John H

So the rest of the door didnt have any adheasion issues,it was just at the body line???

 

[John long]

So the rest of the door didnt have any adheasion issues,it was just at the body line???

It appears so Mike but I am not ready to answer for sure yet. I have blocked the door down with a long board and 180 grit and am going to feather it in about 3 inches from the body line. At that point I can tell if the DPLF is adhering out to where the 36 grit scratches are. If it is, I am going to prime it with SPI epoxy. If not, obviously I will have to go ahead and strip the whole door. The doors have been painted for at least 5 years and these bubbles along the crease line are the only failure anywhere including the jams. Ironically both doors have bubbles in exactly the same places.

So far, I am finding places in this groove I can peal the epoxy of with my pocket knife and areas that are adhered well. Even though I have no failures outside the groove I need to feather it down and check it.

I will post pictures and description of what I find.

John L

 

[John long]

Well, here we go. I have one door blocked ready for Epoxy. It appears to me the issue is only in the body reveal line. You can see that the DPLF feathered well once I got back from the reveal. It also has adhesion and can not be scraped easily with a razor blade. I found:

Very shiney metal in the groove

Lots of material build up.

Unable to determine if any acid residue.

I have scuffed the bare metal well with 180 grit dry and will clean it well with W & G remover letting it dry well before I prime with 2 wet coats of SPI black epoxy.

I am going to post a couple of pictures that I hope show what I have done.