To answer your last question, No. after setting overnight.

Don't confuse dusting of color with wiping off.
With a cured primer or epoxy if you hit it with thinner you may get a smudge of color and that is normal.

If the product is softening it can only be weak activator, improper mixing, cold metal, excessive coats (retarding the cure) or applied over an unneutralized acid or epoxy has not cured long enough.

Some epoxies cure out faster than others and with that in mind perhaps a 2-3 day set time would be in order before wiping with thinner.

This is all I can think of that can cause the epoxy to whip off.

 

No experience with it wiping off.

But it WILL lift along a sanded edge. As a matter of fact I have had problems spraying DP over sanded DP many times. I have learned how to spray it a little better and have not had it happen lately.

So I know thinner will lift DP.

Rich

 

Epoxy will not wipe off after it's reached full cure. Fully cured epoxy will however swell some if subjected to solvent for a long period of time, all 2K primers seem to do this, urethanes, and also polyesters. Example:I've soaked primer guns in lacquer thinner for weeks that had old cured epoxy on them and all the lacquer thinner will do is slightly swell and soften the primer, the primer will never be soluable again after it's reached full cure. If the primer is washing off with solvent it hasn't cured. Epoxy is slow drying IMO, but very very durable after full cure. If it's still soluable after 2-3 days there is definately something wrong with the product, temperature, or application. The thicker it's applied the longer it takes to cure, leave some mixed epoxy out in a mix cup and you'll see the more product in the cup the longer it takes to cure.

 

Well two different brands of epoxy are wiping off after full cure for about six or seven guys who are in different states and dont even know each other. Mine didnt wip all the way off,i rubbed it and it was coming off on the rag.It softened and i'm sure if i continued to rub it would have gone down to the metal. It was sprayed about two weeks ago. If you have some epoxy on something try it out.

 

Well i just tried rubbing thinner on a panel that had U-tech epoxy on it for a good six months.Rag turned black,primer got soft and i scratched it with my fingernail down to bare metal. Next test. I have a decklid that has 'the old' dp40 on it for at least three years,maybe longer.Same result,rag turned green, scratched it down to bare metal. I think the result will be the same no matter what brand.

 

I don't know if it's the same thing but I used SPI epoxy for my engine bay and frame parts and got alot of urethane over spray on it. I then took acetone on a rag and removed all of the cured overspray and it did not soften the SPI, no black came off on the rag. I don't remember if I tried lacquer thinner or not but I'll try it later to see. I'm a believer in the SPI epoxy, haven't used the urethanes yet.

 

In my experience the DPLF epoxy primer will definitly wipe off with lacquer thinner all the way to the metal, even after three or four days. The SPI epoxy primer is not affected by lacquer thinner after three or four days. This is one of the reasons I don't use PPG's DP anymore. In fairness to the DP product I can't say if it will wipe off after 7 or more days because I haven't tested it.
Jim

 

Well i just tried rubbing thinner on a panel that had U-tech epoxy on it for a good six months.Rag turned black,primer got soft and i scratched it with my fingernail down to bare metal.
***************************************************

I can assure you the U-Tech never did this.
Maybe since Sikkens bought them in 2001 its been changed.???

What I'm seeing written just blows my mind, I'm all confused.

 

This whole thread did not seem to make sense so I decided to try it on my own. I am finishing a car that is primed and sealed exclusively in DP90 and DP50LF

I have trunk that was done and sealed at one time but has sat in the corner and got scuff. So it really needs blocked out again. It has DP90 on it and is about 3 years old.

So I got out a clean rag and some thinner and started wiping down an area. The rage became dark so I went to a clean rag, it became black. With continued rubbing it began to soften. I dont know how long it would take to get through the black with a rag, but I can say after doing this with the rag my fingernail took it down to bare metal.

So I have to concur with the above thinner softens DP comments.

Rich

 

Another guy on ABS said it happened to him with RM epoxy also.So i wound'nt say its just a PPG problem.

 

Cured Epoxy will swell and soften but I've never seen it turn soluable. Self etch primer on the other hand will wash off whenever you want and will be forever soluable just like lacquer primer. Urethanes and polyester products will also swell and soften if exposed to lacquer thinner for a long time but won't wash off/become soluable. For the epoxy to wash off after full cure doesn't make any sense. I've got some primered parts in the shop that I'll try washing with thinner tomorrow, the epoxy on these is three months old. Bob

 

"Doesnt make sense" to me either

Like I said, I dont know how long it would take to rub through but after 60 seconds of rubbing, it was soft enough finger nail would take it off.

I told my Jobber to ask PPG on their opinion. Be interesting to see what they have to say.

 

I have experienced the same thing with PPG DPLF74. I had applied it to a four piece Rootlieb steel 34 Ford hood probably a year ago to keep it from rusting in my garage as I worked on finishing the car. The DPLF74 and hardener were fresh from the local jobber and applied the same day as purchased. A year later I discoverd the red PPG epoxy primer will wipe off with a few swipes of a lacquer soaked rag . I removed all of it and applied SPI's self etching epoxy primer and have had no such problems. Considering what I paid for a quart of DPLF74 it really gives me the rosie's.

Vince

 

I've been using Kirker EP611, sprayed some on a table top to empty the gun about 10 days ago. Took laquer thinner and rubbed the crap out of it this morning and the rag turned a little gray and now the top is really clean No softening at all and couldn't scrape through at all with a fingernail.... I would not have been happy if thinner would take it off!

 

I'm not so sure that it's a bad thing that thinner can cut the primer.
Afterall, doesn't that indicate a better adhesion for the top coat?
How well it sticks and stays stuck is the issue.
I think we're confusing the quality of primer with a test
that's not relevant.
You might find a primer like the Mar-Hyde 2k I use that the thinner
has little effect on but the primer won't hold up as good as another one
where thinner really attacks. One test with thinner doesn't indicate its
ability to hold up under paint for the long run.
I have had acrylic enamel with hardener that I've scrubbed with thinner
and no problem, no way is the enamel better than the urethane.
It just doesn't work out that way.

 

I think we're confusing the quality of primer with a test
that's not relevant.
.

Thats highly possible.

 

I admit I don't know a lot about epoxy but after reading this I went out and rubbed thinner on some 5 week old Omni MP170 epoxy I had used on some suspension parts and even though it seemed to pick up some on the rag it did not soften much that I could tell but then I never left it on more than a minute or so. Since MP 170 is an "econo" line I would think the higher priced lines would be even more durable.

 

Ist we are talking about epoxy here.

However with 2k primer it does not effect the product if you can wipe it off with thinner, it can be made to do either or and still not affect the quality.

With that said the epoxy statements just go against everything I know, as
I don't want an epoxy that can be wiped off with thinner or urethane reducer.
Soften is one thing but wiping off is another altogether.
(after cured of course)

Powderbill I believe has experience with epoxies and would like to know his take on this as I'm confused!

 

I too have seen where a lacquer soak rag will pick up DPLF## color residue when wiped. I had heard that this was a result of going from DP to DPLF formulation and thats part of the reason why many have stopped using PPG DPLF. But now I'm hearing the same is true with the DP## product. Whats up?

 

sealer for Variprime - DPLF Primer

I realize there is a million reasons not to do this, but I am going to do it anyway.

I am treating "clean" vintage metal with Dupont Variprime. I have used it before and I obtained good results against rust reforming. I am also planning on covering the Variprime with PPG DPLF epoxy primer because I also like it's properties. I can use my fillers and glazing compounds over the DPLF and reprime with DPLF until I have a perfect panel. BTW, I have never had DPLF "wipe off" after it has catalyzed, but I have had it lift up where rust reformed.

According to the DPLF sheet, there are certain "wash primers" that it is not compatible with. Neither Dupont or PPG wants to make a claim that either of these two products (Variprime and DPLF) are compatible. Dupont says that I should use a 25xxS product (2510S,2540S,2570S,2580S) over the Variprime to seal it for an epoxy primer. PPG says to use K36, K38, or K93 under DPLF when using it over a wash primer.

Has anyone used both products together? I used DP (not LF) over Variprime about 5 years ago and there appears to be no problems to those surfaces now.

Any suggestions on how to make these two products "compatible" appreciated. Also, if anyone knows whay they are not compatible, I would like to know that too.

 

I too have seen where a lacquer soak rag will pick up DPLF## color residue when wiped. I had heard that this was a result of going from DP to DPLF formulation and thats part of the reason why many have stopped using PPG DPLF. But now I'm hearing the same is true with the DP## product. Whats up?

Cheap cheap cheap is what it is all about as much in this industry as any... Just like an auto manufacture or any business, paint companys are always looking to improve cost for themselves and cheapening products is the only way you can do this after some time... Year after year they want more cuts here and there etc... common sense tells us that allot of what we used 7-8 years ago is not at all going to be as good as it once was... This is just a fact... Luckily for us we have spi products to use... Many of us here speak so highly of those products and there is a reason... Did anyone make note that this did not happen with the spi epoxy and I could not believe the Kirker held up....

I too think Jim has a valid point on what is being done, however if some do wipe off and some dont, which one do you want on your vehicle or rolling out your shop door??

BK

 

Cheap cheap cheap is what it is all about as much in this industry as any...

BK

That is certainly a factor, but I think the main reason is EPA compliance that has made the DPLF virtually unusable.

Vince

 

, however if some do wipe off and some dont, which one do you want on your vehicle or rolling out your shop door??

BK

I want the one that my paint will stay adhered to the best and the one
that stays on and protects the steel. That's not necessarilly the one
that won't wipe off with thinner.
Dried cement won't wipe off with thinner, but I'm not picking that.

 

I agree with Jcclark.Just because it will soften doesnt mean its a bad thing.Maybe its supposed to do that so the topcoat solvents will penetrate it a little for adhesion? Self etch prime will wipe RIGHT off wit thinner but i don't see anyone kicking it to the curb.

 

I agree with Jcclark.

That is a dangerous road to walk on.... Jimbo is lke a mad chemist in his garage!! Tooo many years of chems

BK