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rebeldart
04-23-2011, 07:29 PM
Sprayed trunk last week - had a scratch and "picked" at it, did a tape test and came off with no adhesion down to primer. Omni epoxy, then Omni 2K, sand 4-600, days later : Nason Ful Base with no activator then cleared. I really can't figure where it may have went south other than the base was a few years old and no activator (which I've done before without issue). I still have some base left and may buy activator next round. Since it's my car and in the trunk, I ain't restripping anytime soon, maybe down the road if I have trouble sleeping at night ! Any thoughts on what may have caused the failure ?

Bob K
04-23-2011, 09:15 PM
I can think of some questions for you. Did you take it outside after the surfacer was sanded? Did you wash it well after sanding the surfacer, and how much time between cleaning and putting the base coat on? Did you use a tack cloth? Did you put the base on thick enough to avoid dry spray? Did you use a cold weather reducer that flashed off to fast and caused dry spray? Anything there sound like it may have been the cause? Remember I am just throwing out a few ideas, not accusing you of anything.

Bob K

rebeldart
04-24-2011, 10:10 PM
Did not take anything outside (no chance of contamination as I kept covered).

Washed/prepped well and allowed to dry at least 30 or more minutes.

Used tack cloth - lightly.

First coat of base was light - followed with a heavier coat 1o minutes later.

I'm in Florida - don't know if I could even find cold weather reducer !

Really has me stumped - as I said, the only thing that might be "outside the norm" is the Nason base is about three years old - and was reduced at that time and leftover stored (reduced) so I shot straight from the can. Also no activator used as it is not required but I think I'll be using going forward ....

MARTINSR
04-25-2011, 01:12 AM
Sprayed trunk last week - had a scratch and "picked" at it, did a tape test and came off with no adhesion down to primer.

Your answer is right there. You have a paint that has poor adhesion. When you feathered out the area you STILL have the poor adhesion between the base and the primer. You may have sanded out some of it, but the poor adhesion wasn't just in one area, there is a poor adhesion problem with the entire trunk lid.

So when you feathered out that area and put some more primer over it you covered up that edge where the base meets the primer right? That edge is just dying to allow solvents under it. The primer flashes pretty quick, its' solvents didn't get under the edge of that base, it "covered it up". Now you lay the base which again is very forgiving, flashes pretty quick. You likely even applied it a little lighter knowing there could be a problem. You cleared it and the clear, now that doesn't flash very fast. It sat there with the solvents soaking down thru the base and went UNDER the edge of the base that was under it and NOT adhering to the primer! If it was adhering to the primer the solvent couldn't get under it, but with it just "laying" on top of the primer the solvent from the clear can EASILY get under it lifting the base off the primer.

If you can bury it under some fast flashing primer and seal it off you and then apply the base and clear drier and with faster reducer you can usually save something like this. But you are asking for trouble in that you don't get good adhesion with dry sprayed products. But that is what you have to work with. The best way is to strip and do the whole thing over. The "bestest" way is to spray much dryer so solvents don't get under your poor sticking base.

Brian

rebeldart
04-25-2011, 03:38 PM
I'll tackle it the "best" way down the road ........ my "poor sticking base" is an issue, obviously. Do I risk using what I have left ? Or using it but add activator ? Or pitch it and buy new ? So the clear can actually penetrate the base and cause the base to lift from the primer (especially an un-catalyzed base applied too dry) .... never heard that but learning every day. Sounds like a quality, catalyzed base with good flash off is safest bet from here ?

MARTINSR
04-25-2011, 10:35 PM
Think about it, if the base is lifting, how could this happen? You have sprayed clear over it, how could the clear cause this? It is caused by the solvents going thru the base. How else could he happen?

You can stay using that base, I don't think anything in particular is "bad" it is more like too long of window before the base was sprayed too fine of sand paper to prep the primer for the base, too fast a reducer, or something like that. In other words it is very likely an application issue.

Brian

rebeldart
04-26-2011, 09:01 AM
Please clarify "too long of a window before base was sprayed" . Thanks for your help. The primer (2K) was prepped with 4-600 grit and red scotch brite in difficult (tight) areas. I "tested" a couple other areas - same deal. I don't think it's prep, I think it's as you stated. I don't need this to happen elsewhere so I'm just trying to pinpoint the issue before moving on. I'll try a test this week with same base - let it sit w/o clear - then check bond after a few hours. If all is well, I'll know the problem arose after clear application and need to determine where it went South from there. Thankfully as I said, I've only sprayed inside of trunk as I'm a garage "weekend warrior" and have to do restorations in stages due to time ! Thanks again, don't know what I'd do without these forums, this is my third restoration and I've gotten help from all of you for many years ..........

MARTINSR
04-26-2011, 10:16 AM
Nothing helps something cure more than "opening it up" by sanding. If you have applied too much clear for instance and your film is soft with it not curing properly because it's too thick and the solvents all trapped, sand the surface and let some solvent out! Sanding lets it flash off solvents even when it seems perfectly "dry" (urethanes don't "dry" they "cure") sand it, "opening" up the top surface and it will flash off even more.

"Value line products" often have a very cut to the chase product data sheet. If you looked at a top of the line primers data sheet you would often see things like recoat windows listed.

Some primers, sealers, colors, have a strict recoat window where you are supposed to apply the next product be it sealer or color or what ever within a certain time frame after sanding. This could be 24 hours or more, or a lot less. SW had a tintable urethane primer with a recoat window of 2 hours. If you shot the color after that 2 hours you risked poor adhesion because the sanded primer had fully flashed off and cured too hard for the paint to adhere properly! It is sort of a "self healing" effect on the surface of the primer.

I don't know the products you are using at all, but this could have been a factor.

Brian

rebeldart
04-26-2011, 01:19 PM
Pretty much followed directions to a "T" with the exception of activator - just sprayed some base on another area (no clear) and will check it tomorrow for adhesion - if base without clear bonds with no issue, I'll know my clear application caused the issue. Notice on the tech sheet it states topcoat "anytime" - as if I could wait 24 hours to clear (or more) ? Seems odd as I thought we were looking for a chemical bond ? Maybe solvents in clear do the job regardless of how long base has dried ? Hmmmmm

rebeldart
04-26-2011, 01:21 PM
Meant to add link to Dupont tech sheet:

http://docs.google.com/viewer?a=v&q=cache:XRWm3N3KW6AJ:pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/nsn/Nason/fulbaseb-cbasecoat.pdf+nason+ful+base+sheet&hl=en&gl=us&pid=bl&srcid=ADGEESgnmRFmFzJNGZlzaR6d_v8bt-9GZYjDVIqYIHy22FtLCy_09qw0A3J4LYULewsPaV3hmZBYGAua JCqKekg4KZ_EUaw8IDTLh8qpjLnqehzU1kU5-7HXE6M2RF8GjXf05DsgYpXt&sig=AHIEtbTznW4uWgyDsbf3eojjulYCgUF-0Q

rebeldart
04-28-2011, 12:05 PM
Thoughts ?

Len
04-28-2011, 12:45 PM
Remove the paint down to the metal, apply a good direct-to-metal primer then prep and paint using the proper technique with ALL compatible materials. This is the only way you will KNOW that it's done properly. Trying to figure out what went wrong can cause you to outsmart yourself and end up with the same or other problems. I learned this lesson the hard way myself so now I rarely try to cut corners especially on a job's second time around.

rebeldart
04-28-2011, 01:55 PM
I guess that's why I'm asking for thoughts. I have used the same procedures/products on two previous cars. Something went awry this time and I mentioned the only variables above. Bare metal / Omni epoxy / Omni 2K / 400-600 / Nason base/clear , nothing funky about application/weather ................
Here's the results of my "experiment" : I sprayed more of the base alone in another area 3 days ago - I razor bladed multiple areas today and tried to lift base with tape from primer in multiple areas - bonded fine so my issue happened after applying clear as MARTINSR stated. I just need thoughts on what caused this (clear applied too soon allowing it to penetrate through base and cause the issue ?) and 2) would catylizing the base help prevent this issue going forward ? Should I wait longer to shoot clear ? I don't know - that's why I'm here - supply stores are worthless for help. It was an off-brand clear (Zolatone) ...... dunno.

Len
04-28-2011, 02:51 PM
I guess that's why I'm asking for thoughts. I have used the same procedures/products on two previous cars. Something went awry this time and I mentioned the only variables above. Bare metal / Omni epoxy / Omni 2K / 400-600 / Nason base/clear , nothing funky about application/weather ................
Here's the results of my "experiment" : I sprayed more of the base alone in another area 3 days ago - I razor bladed multiple areas today and tried to lift base with tape from primer in multiple areas - bonded fine so my issue happened after applying clear as MARTINSR stated. I just need thoughts on what caused this (clear applied too soon allowing it to penetrate through base and cause the issue ?) and 2) would catylizing the base help prevent this issue going forward ? Should I wait longer to shoot clear ? I don't know - that's why I'm here - supply stores are worthless for help. It was an off-brand clear (Zolatone) ...... dunno.

It could have been any of those reasons so use products that are meant to be used together and use them properly. If the base and reducer call for 20 minutes to flash at 70 degrees then allow at least 20 minutes before applying clear and use a clear that is recommended by the base coat manufacturer. Follow the directions and you won't have problems with the materials.

rebeldart
04-28-2011, 04:02 PM
Lesson learned ...... thanks

averagejoe
04-29-2011, 09:12 PM
Rebel - You're fine with the combo - I've shot Omni primers for years and multiple brands of base/clears over them without issues. I would venture to say you may have cleared a little too soon (?). Since you're saying your base has adhered fine after a couple days drying - I'd say initially the base was still too wet and clear penetrated through to primer causing the issue. The clear is still "setting up" but your bond will not get any better. Going forward I'd say give the Nason more dry time (up to 24, but I'd go with no more than 12 myself) ..... and yes, I'd use an activator for a better chemical bond. Do a test on this as well as I'm no chemist, but as MARTINSR stated - there can't be too many areas things went bad and it sounds like all prep was fine.

Len
04-29-2011, 11:04 PM
Rebel - You're fine with the combo - I've shot Omni primers for years and multiple brands of base/clears over them without issues. I would venture to say you may have cleared a little too soon (?). Since you're saying your base has adhered fine after a couple days drying - I'd say initially the base was still too wet and clear penetrated through to primer causing the issue. The clear is still "setting up" but your bond will not get any better. Going forward I'd say give the Nason more dry time (up to 24, but I'd go with no more than 12 myself) ..... and yes, I'd use an activator for a better chemical bond. Do a test on this as well as I'm no chemist, but as MARTINSR stated - there can't be too many areas things went bad and it sounds like all prep was fine.

Follow the technical information put out by the paint manufacturer. There is no need to guess when the proper materials and procedures are followed.

Note: If base coat needed to dry for 12 hours you wouldn't find many body shops using it.

easymoney
04-30-2011, 01:10 AM
you stated that you used nason paint but no activator. i thought that activator was required. i thought that it would not cure without activator.

rebeldart
04-30-2011, 07:41 PM
I have been told by a number of individuals (both in person and on-line) that activator is not required for the Nason Ful-Base................... going forward I am not taking chances. Same goes for Chromabase, no activator but tried and true, but I kike the thought of a hardener. ...............

Len
04-30-2011, 09:38 PM
you stated that you used nason paint but no activator. i thought that activator was required. i thought that it would not cure without activator.

Some base coats need to be activated and some do not and with some it's optional. If you're guessing what to do there's a chance it can cost you a lot of time and money before you get it right.

Steve g
05-01-2011, 10:43 AM
I have been told by a number of individuals (both in person and on-line) that activator is not required for the Nason Ful-Base................... going forward I am not taking chances. Same goes for Chromabase, no activator but tried and true, but I kike the thought of a hardener. ...............


I know for a fact that with Chromabase the activator is optional, but recommended. However I distinctly remember reading, either on the can label or the older tech sheet, that the Nason Full-base must be activated, with the must highlighted.

I've been using the Omni epoxy and 282 surfacer for a long time. In as much as the surfacer is inert and provides only the mechanical tooth for the next layer I would say with certainty that your problem lies with the base. And with the tech sheet not indicating the activator as optional (and my recollection of the "must" use) I'd be willing to bet large money on that as the problem.

Steve g

MARTINSR
05-01-2011, 01:12 PM
He posted the product data sheet and it says it is optional.

Ful-Base® B/C Basecoat Color should be activated
with 483-30™ Activator for optimal performance.

Click here for PDS (http://docs.google.com/viewer?a=v&q=cache:XRWm3N3KW6AJ:pc.dupont.com/dpc/en/US/html/visitor/common/pdfs/b/product/nsn/Nason/fulbaseb-cbasecoat.pdf+nason+ful+base+sheet&hl=en&gl=us&pid=bl&srcid=ADGEESgnmRFmFzJNGZlzaR6d_v8bt-9GZYjDVIqYIHy22FtLCy_09qw0A3J4LYULewsPaV3hmZBYGAua JCqKekg4KZ_EUaw8IDTLh8qpjLnqehzU1kU5-7HXE6M2RF8GjXf05DsgYpXt&sig=AHIEtbTznW4uWgyDsbf3eojjulYCgUF-0Q&pli=1)

Brian

rebeldart
05-01-2011, 06:57 PM
MARTINSR - thank you. All I'm getting is beat down for not "following procedure" ....... bad monkey, no banana for me. No one but MARTINSR has theorized what may have gone wrong. I followed directions to a T but it appears that since I did not use Dupont or PPG products all the way from start to finish - I was destined for failure. I don't believe this to be the case and it's not like I was using mail order trash product, just not top of the line. So I can't shoot Chromabase on SPI primers ? Please don't respond if you cannot provide some feedback regarding what may have happened.......I'm going to throw away the old base and buy new, and I'll buy Omni, since I "have to" and no other base will work with Omni primers I use............ sheez.

MARTINSR
05-01-2011, 08:18 PM
One of the big problems with the "value line" products is the tech sheets are very basic. This is cool in that they cut to the chase and aren't all muddled up with minutia but if you really want those fine details, they aren't there!

What exactly went wrong with your project is still up for opinion but it is likely that "The planets were aligned" and you were within the recommendations on everything like flash time and such but that you were right on the edge of all of them or something like that.

Brian

Steve g
05-01-2011, 10:04 PM
MARTINSR - thank you. All I'm getting is beat down for not "following procedure" ....... bad monkey, no banana for me. No one but MARTINSR has theorized what may have gone wrong. I followed directions to a T but it appears that since I did not use Dupont or PPG products all the way from start to finish - I was destined for failure. I don't believe this to be the case and it's not like I was using mail order trash product, just not top of the line. So I can't shoot Chromabase on SPI primers ? Please don't respond if you cannot provide some feedback regarding what may have happened.......I'm going to throw away the old base and buy new, and I'll buy Omni, since I "have to" and no other base will work with Omni primers I use............ sheez.

That's bull. I've used those Omni primers under all kinds of base materials with no problems. That primer surfacer is a stable substrate and it's only job as it relates to the next coats is to hold the tooth you sand into it. In my opinion there is/was a problem with the base material. I'm going to go through my old tech sheets and see if I can find anything further about the use of activators with that base. I'm about 90% sure that the tech sheets used to say that it "must" be activated.

Steve g

Len
05-02-2011, 12:21 AM
That's bull. I've used those Omni primers under all kinds of base materials with no problems. That primer surfacer is a stable substrate and it's only job as it relates to the next coats is to hold the tooth you sand into it. In my opinion there is/was a problem with the base material. I'm going to go through my old tech sheets and see if I can find anything further about the use of activators with that base. I'm about 90% sure that the tech sheets used to say that it "must" be activated.

Steve g

Isn't this info available online?

Steve g
05-02-2011, 12:53 AM
Isn't this info available online?

He's posted a link to a current tech sheet which does indicate it as optional. However, I'm reasonably certain that the old sheets (his paint is a couple years old) said that it must be activated.

I know the tech sheets change from time to time, probably coinciding with formulation changes. Like the Omni epoxy that previously didn't call for an induction time where it now does.

Steve g

averagejoe
05-02-2011, 11:57 AM
Rebel - I think pitching that old base would be a good thing - I don't believe you "have to" buy new, fresh Omni brand base - you have a good substrate with the Omni 2K for any base , as long as you're certain it has not been contaminated in any way ....... if any doubt then clean well, allow to dry at least 30 min and seal before shooting a quality base/clear of your choice.