Body Filler basics
- Thread starter K13
- Start date
I am good with whatever works for you Frank.
Feel free to move it Frank.
ssmustang I talked to our tech today and we came up with a theory that might explain the problem. We wonder if the tech doing the repair used paint stipper to remove the enamel paint before doing the repair and did not do a good enough job of removing/neutralizing it before reapplying products. If he didn't take things down to bare metal the filler would have absorbed the acid in the stripper and very easily could have spit it back out a month or two later. That is the only solvent we could think of that would have been commonly applied to the surface that would have the strength to dissolve the filler. We test fillers all the time for their hold out to solvents and he said without something being heavily applied and left for a long period of time there is basically nothing in any products used correctly that will soften filler to the point you described other than stripper, especially the aircraft strippers that were available back then.
ssmustang I talked to our tech today and we came up with a theory that might explain the problem. We wonder if the tech doing the repair used paint stipper to remove the enamel paint before doing the repair and did not do a good enough job of removing/neutralizing it before reapplying products. If he didn't take things down to bare metal the filler would have absorbed the acid in the stripper and very easily could have spit it back out a month or two later. That is the only solvent we could think of that would have been commonly applied to the surface that would have the strength to dissolve the filler. We test fillers all the time for their hold out to solvents and he said without something being heavily applied and left for a long period of time there is basically nothing in any products used correctly that will soften filler to the point you described other than stripper, especially the aircraft strippers that were available back then.
Thanks again K13, really appreciate your advice/input and opinion. I do not know what the Saskatoon shop did to prep the whole car for the change from the original single stage enamel to base/clear. I would assume he did the least amount of work and that being said what would be the proper prep for this conversion? It was a PPG certified shop (why the rep got involved here), so all work was supposed to be PPG products, but another memory came to me the other day, when the PPG rep was here and took samples for analysis he found a non PPG primer had been used and that is where they exited. Would the base/clear or other products used for a repaint reacted with the enamel if not stripped? If so then I would say you may have a very good point with paint stripper. The shop originally said they were going to look after this, don't worry, but in the end said it was 'substrate breakdown' and denied any liability. I never did get a complete explanation of what steps they did or products used. To this day I have never heard or seen anything about the old fillers breaking down after a number of years, when I saw your information on fillers and posted here I thought if it existed/ever happened out there someone here would have a story about it? Bash was close with the rust proofing attacking filler which I had never heard of either. Thanks again all!!
I am not an expert on paint but generally catalyzed products over top of non catalyzed products is frowned upon so removal of the non catalyzed product before proceeding is usually the prefered method. Our tech said the enamels of that time period were very hard to deal with for removal so paint stipper was often used as they tended to gum up sand paper. This all predates my involvement in the industry by quite a bit so I am not super familiar with how these products would react but given what you described and in talking with our tech it sounds like some sort of acid (also in rust proofings) is the most likely culprit and the most likely source to have been applied to the top of the filler in multiple areas would be paint stripper. As you said pretty unlikely for the rust proofing to have contaminated the upper portions of the car to the degree needed to cause the issues and I would think it would have been applied before or after all the body work was undertaken not in the middle of it for it to have gotten on the surface of the filler. We will never know for sure but it's the most plausible theory we could come up with.
K13: While you are correct that it will never be definitive, but with your help and new information and I think you have it right. I was guessing the S'toon shop would have used the easiest methods for doing the enamel to base/clear change and in my mind that was sand to roughen the base and carry on but if the correct procedure was remove the enamel that changes my thoughts. It was a good reputable shop and I believe they would have tried to 'do it right'. With the stripper theory I believe it would have been easier for the shop to use it and as you point out not many other things would have had the 'power' to affect the filler this way. This fits and makes sense with all the known facts. Thank you and your tech very much, great information and experience/help on this forum!! And thank you Frank for running it!!
Bob you are stating enamel was used, however there is a difference between enamel and Acrylic enamel which is more than likely what it was painted in for that era, unless you purposely chose to use enamel? Albeit enamels usually an air dryed system, Acrylics do use a hardener and are a chemically dryed system. Are you sure it was plain enamel? I have even seen enamels (sherwin williams had an enamel back in the day that you could convert to an acrylic with a different hardener they called Sherwillgloss or polysol plus) I have never seen an acrylic go slimey (other than with paint stripper as K13 mentioned) but rather wrinkle instead, if anything? It is not likely that anyone would have used paint stripper to do a partially repaired pannel as you stated let alone over bondo. The common usage for stripper is a hard to sand area or product (ie' lacquer) that a person would be removing everything down to the metal, starting over from scratch so to speak, and as you stated this was not the case with the car? Sure would be nice to figure this one out!
OK Neil: You are correct again! I called Bruce today to pick his brain as he was involved with the Fairlane from the start. Definitely was Centari, acrylic enamel, the bumpers were done with Imron (Bruce was working across the street from 5 Star Truck Center at the time which used lots of Imron). So back to the drawing board! As K13 stated the base/clear should have been able to go directly over the Centari which I have to go back to my original thoughts that it would have been easiest for the shop to just scuff the enamel and carry on with the base/clear. The only other thing Bruce mentioned was velvet bond which because he does lots of candy's over acrylic enamel was used here as well but just under the graphics (which are still fine). I can't help but think chemical stripper was involved some how as K13 and his tech think not many other products would have for lack of a better description the 'power' to effect the filler(s)in that way? I sure would like to figure it out as well.
I have to add here that in my 40+ years I have never seen filler old or new when applied over filler go mushy? New one on me?
I have a feeling that there was some operator error involved in the process....
Yes Bash it was and I guess is still a mystery. I had never heard of the old 'white lightning' breaking down ever (and it was widely used back in our day). I think if anything like this would have happened, someone on this forum would have a similar story or heard of a story. I know body and paint is not always done by going back to bare metal. For sure that is the best technique but is not always followed. Another thing came to me, I remember the shop calling me to tell me they were going to claim it was 'compressor oil failure' just in case the insurance people called me but they never followed through on it.
Well likely what they meant by compressor failure was a breakdown of some sort involving oil going through the lines and contaminating the prepared surface prior to paint. I have seen that but never seen one turn bondo to mush, What it does do is blister, because the oil between layers doesn't allow the materials to stick to the substrate therefore causing the paint to bubble up. Could be a result of a catastrophic comp. failure or even worn out rings allowing oil into the system. Even too much moisture in the lines can cause this, but never seen the mush thing from oil or water? They were more than likely trying to get it covered for you by insurance? Perhaps it didn't pan out?
That is exactly what they were doing, although with the spots randomly spaced all over maybe this is the answer. The filler was always suspect by those that looked at it because of the smell (of an open can of white lightning) of the ejected oil, would compressor oil smell like that? When they analysed the bondo or samples that were taken as far as breaking down no one ever told me what was found. In the end I heard the father (who owned the shop) stopped the insurance thing as their rates would have gone up.
Yeah..thats what I said..operator error..,,ahhahah
Compressor oil would smell like oil and there is no way it would cause filler to break down. They obviously didn't actually have a failure or they would have brought it up immediately. They were trying to end around the insurance company for something they screwed up.
Possibly, however as stated the whole car was not stripped and redone, so likely some of the areas blistering were paint over paint? IE; hood and trunk? Which even makes this more perplexing. Usually oil in the lines will cause small (dime size or usually
smaller) blisters and only between layers that were contaminated. Bob when investigated, what was in the blisters? Did they all have the mush under them? And at what level were they, where did they seperate? ie: between metal and bondo, primer, or between layer of old paint and new? It would perhaps be advantageous to know, then perhaps could at least eliminate some things? If they all had that strong bondo smelling mushy stuff in them then again odd, as I would think that unless they had done body work all over the car, (which if I understand you correctly wasn't the case,) I could see it all over. I am given to understand the damaged area was fixed and then a full paint job was done? I wonder.... When was it sent out for rust check? After paint, before paint or in between?
Yup...exactly... dont think you will ever know...Thanks for starting this thread K13. I had no idea what was in fillers....and I see that I did tend to put too much hardener in when I was using them.....but I think we kind of high jacked your thread... I would also like to read anything on difference between primers and sealers or are they the same thing...all good stuff I’m sure we could all benefit from..
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OK Neil, will try to fill in more of the story. The 'bubbles' started quite small and kept increasing in size around 2 to 4 months after bringing the car here. They grew until the paint layer cracked open (like the last photo of the 'new' bubble). The 'goo' (it was much thicker than straight oil, more like resin and smelt like an open can of white lightning) was between the new paint and the bodywork layer below. Once it cracked the paint layer the spots never increased in size beyond what they were but the 'bubble' didn't decrease in size either, the paint was intact (hard just separated) when we opened things up to investigate. The bondo whether it was old or new seemed 'soft' to me when we initially dug into it for the repairs. Another thing I remember was as we were stripping the damage here the bondo seemed to harden up again after it was opened up to the air. It was never mush, just softer than I remembered bondo to be when we initially dug into it. The PPG rep here cut out and took chunks for analysis but I never was told what was found. As soon as they found a non PPG primer that was used under the base/clear they exited. The son who was running the S'toon shop was on holidays on Oahu and came over to look and also took samples, again heard nothing on what was found. The worst area of bubbling was where the repair of old damage had been done by the S'toon shop (below quarter window area behind passenger door) but bubbles came up on other areas that were not part of that repair. The rust proofing was done after all the paint was done just before I brought it over here. Thanks for all your help, hope this added info helps, just would be nice to know.