Troubleshooting Lacquer Failure in Putty Areas

      Finishers discuss what may be causing lacquer to fail around putty-filled nail holes — and how best to repair it. May 17, 2010

I finished a millwork job for a customer three years ago, and now the lacquer is turning milky white around the puttied nail holes. This starting happening last year and is spreading throughout the house. The failing areas are about the size of a penny, spreading around the nail hole. The wood used was cedar. Processes included a light pre-sand and I applied Daly's "Benite" wood conditioner. I applied Daly's stain, wiped away all excess and applied sanding sealer and sanded smooth. Applied lacquer finish coat. The general contractor filled the nail holes with a matching putty. Everything was done in place, and products were applied according to the labels. Everything looked fine for about two years, then began failing around the puttied nail holes. Could this be from the customer using cleaning products? Is it something strange with the cedar? This is the only job I have done with this type of problem, also the only one where cedar was used. Now the general contractor and homeowner want me to have a paint rep figure out what happened and who is responsible. Please help!

Forum Responses
(Finishing Forum)
From contributor R:
Sounds like an adhesion problem over the putty to me. Did the contractor use an oil based putty like DAP to fill the nail holes? It's easy to find out. Do an adhesion test on the most inconspicuous spot you can find (the razor blade and tape test, or go to Garco and get one of their testers) Check the adhesion over a puttied area and again over an area with no putty. If the problem only occurs where the putty is, you have your answer.

From contributor D:
Did the contractor putty before or after the lacquer was applied?

From contributor S:
Is the lacquer itself turned milky white or has it disadhered from the wood itself thereby the air space is causing the appearance of milky white? If the latter is the case has it been slowly creeping from the point of the nail insertion over the course of heating and cooling cycles? I doubt it has to do with the putty but was lacquer touch up done over the putty?

From contributor R:
There are many things that could be happening here. That is why I suggested an adhesion test. I have seen many commercial jobs where they used oil putty for nail holes and a couple years later the putty will discolor. If this is the case it is a simple touch up. If there are adhesion issues then there is a much bigger problem.

From the original questioner:
Lacquer was not applied over the putty. The putty was the final step and the holes were filled after everything else was completed. The putty areas were not touched up with lacquer at the end of the job. I believe the putty was an oil based putty. I am not positive, but the areas turning milky white look like an air space gradually forming between the lacquer and wood. Thanks for all the help so far.

From contributor P:
The finish may have never had good adhesion and is lifting in the immediate area around the nail holes. Where the nail holes go through the finish the wood is more susceptible to gaining and losing moisture which can cause failure - just like cracks or thin spots fail quickly on kitchen and bath cabinetry. If the lacquer is regular nitrocellulose, you should be able to repair the spots with a shot of touch-up aerosol lacquer.

From contributor C:
That's the question - is it nitrocellulose lacquer? If so - what brand? Is it happening on every nail hole - even high up where normally any cleaning products would not often be used if at all - crown mouldings, etc.? It may be as simple as some of the replies here so far and maybe not. Follow the advice if it is a nitro lacquer and if that does the trick so be it. But what I'm trying to take into consideration is the adhesion problem which might still be there even if retarder does clear it up. Will that give future better adhesion?

From the original questioner:
The lacquer was a non-sterated nitrocellulose made by Rudd. I only saw part of the house, but the customer says it is happening more and more throughout the house, and in areas where little or no wood cleaning has taken place. I'm not sure how truthful she is being about the cleaning. I was under the assumption she was a neat freak, since she has cleaned even the baseboards with a cleaner or polish, and was going over them the last time I was there. This makes the most sense to me since the problem took two years to notice, and seems to be spreading more over the past year. I plan on going up to the site with a paint rep this week or next. We will try spraying touch-up lacquer from a spray can over some areas to see how it responds. I will also look over high up areas, and the few molding accent boards that were only stained and puttied.

From contributor Y:
If there is moisture it may not re-attach the coatings necessarily unless its retarded enough to fully liquefy the overcoat to the sealer or undercoat. Worth a shot though in-case it does work. If it were me, I would look at the cleaners she is using to see if there is water in them or possibly even alcohol or ammonia - this might have migrated past the oil putty barrier and affected it worse than it might have been otherwise. But the real problem is fixing it. Personally I would try syringing some retarder into the area carefully after removing the putty from the hole. I would use butyl acetate - the main solvent for cellulose nitrate. Amyl acetate would work just as well. But BC is more readily available.

If that works at least you will have knit the coating back together into to a unified film. Then after it's totally hardened again, (wait a few days), use Mohawks wax fill sticks to re-fill the holes. At least spot spray over the waxed area for better protection.

I'm still wondering if you have really personally checked jobs older than this that were done with the same finishing materials with the same putty? Just because you haven't recieved any calls does not necessarily mean there may not be problems even though not as severe - it's worth your time i think just to be absolutely sure. And put your mind at ease about any other future concerns. I believe you should also look for better finish materials than you’re using. There are many nitro finishes made to be used specifically for kitchen/ bathroom use, mainly those with non reactive alkyd resins from semi drying oils.

From contributor P:
When you say the "lacquer was a non-sterated nitrocellulose" you are describing the sanding sealer, not the topcoat. Sterates are a type of "soap" that's added to some sanding sealers to make them sand more easily.

The nice thing about NC lacquer is that it can be re-dissolved. When you apply a new coat of lacquer, the solvents in the wet coat re-dissolve the previous coat and the two coats become one. If you used the Hyplex, you should be able to do spot repairs to fix the problem. I looked on the Rudd website for the various clear coats they offer and they do have a nitrocellulose (NC) lacquer called Hyplex Clear. The other lacquers they list are all pre-catalyzed. The nice thing about NC lacquer is that it can be re-dissolved. When you apply a new coat of lacquer, the solvents in the wet coat re-dissolve the previous coat and the two coats become one. If you used the Hyplex, you should be able to do spot repairs to fix the problem.

If you used one of the pre-catalyzed lacquers, it won't be as easy to repair. Pre-cat lacquers contain some resins that crosslink (e.g., amino resins or alkyds) to make the finish more durable and they do not re-dissolve when you add a new coat or wet them with a solvent. Instead, you'll either just add a new layer to the finish, or in the worst case the old finish will lift and wrinkle causing worse damage than you already have. If the original finish doesn't get re-dissolved by the new coat of finish, it won't re-bond with the substrate and get rid of the milky white ring around the nail holes where the finish is lifting.

As to who is responsible for the failure, that's a matter of opinion. When holes were put in the finish, it provided an easy route for moisture and household chemicals (cleansers) to enter the wood and cause the lifting.

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