Solving Lifting in Catalyzed Lacquer
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Finishers address the persistent problem, experienced by one of their own, with wrinkling and lifting in catlac. February 8, 2005
Question
I have been having some really crazy wrinkling/lifting problems with my lacquer. On the second and subsequent coats, I get a spotty wrinkling effect. I contacted the manufacturer today and they told me to not add the catalyst until the last coat, thus eliminating the potential problems of recoat windows. This makes sense, but I have never read about doing it this way. Do any of you take this same approach?
Forum Responses
(Finishing Forum)
From contributor J:
Find a new manufacturer, because you never topcoat without a) all coats non-catalyzed or b) all coats catalyzed, including a vinyl sealer, if not using a self-seal system. You have been having a real hard time with your coatings, haven't you? I can't stand a coating with a critical recoat window. If the system is so fragile that it will wrinkle or shatter if you're 30 seconds over this time frame, the coating is messed up. There is ingredient thriftiness and/or inability to formulate to meet new standards. Either way, you're paying for a poor protective product - 86 this and move to the next manufacturer.
From contributor D:
I agree with the above 100%. Call your supplier back and ask to speak to the owner/president and ask him/her to give you that info in writing. These are crosslinkable coatings and need the acid catalyst to crosslink the resins in the formula. If you topcoat with a "catalyzed" material over this, you are a claim waiting to happen. The best way to get around the wrinkling issue without getting into all the many reasons why is to apply a thin coat after your seal coat, wait approximately ten-fifteen minutes and come back with a normal coat. If you get what the rep told you in writing, go for it!
From contributor J:
One way that I'm confident in is catalyzing a vinyl sealer and applying one coat or two, replacing the basecoats of your product or using a barrier coat such as shellac. But still, the rule remains that catalyzed products should be used with themselves, so the use of shellac is okay and it will not react for now, but in the long run this can be the weak link in your finish. Just change and negate all this hassle!
From the original questioner:
Yes, I've had several problems with coatings. I've been trying a few out, and in general, seeing what I like/can live with. I've asked a lot of questions and have exhausted the database here at WOODWEB reading all of the knowledgeable comments. My normal paint guy/dealer wasn't in today, so I thought I'd run this concept by you guys, as I have never heard of doing this before.
My assumption was that I was hitting a recoat window with my lacquer, thus the wrinkles. Normally, I have only been shooting one coat per day with anywhere between 1-4 days in between coats. I called them today to ask if I should just be shooting all 3 coats in one day, sanding in between to keep things smooth as we have a less than ideal environment as far as dust goes. They told me that yes, this was a good idea, and additionally I should only catalyze the final coat.
I've had no problems with the non-catalyzed vinyl sealer. The first coat of lacquer goes down great, no problems at all. It's the second/third coat when the weirdness starts (wrinkles being the big issue).
I really love this lacquer - it's tough and rubs out great. I so want this to work... I really don't want to start on another coating quest. Yes, it has been problematic, but I am not up to pro standards by any means, so I, by default, just assume I have made an error of some kind when stuff happens.
I am using Trinity LC 209. It is a precat, but I am adding the catalyst immediately before use (like 10 min), so the lacquer is pretty hot and fresh. I was told today that not catalyzing the first coat was common practice by the cabinetmakers that he knows of.
I think I will be doing some serious tests tomorrow on scrap.
From contributor R:
I am curious as to just what your entire finish schedule is and if you are adding any solvents to your lacquer. (Like maybe MAK?)
From the original questioner:
No solvents.
After staining/drying for about a week, I put down the vinyl sealer. After that, I put on 3 coats of the LC 209. Each coat is about 5 wet mils, and everything gets sanded down and cleaned with Naptha in between after the sanding (320 grit). Each coat has 1-4 days in between to dry.
We are not a dedicated finish shop. We are a guitar amplifier company, so there is plenty of other work to do... hence the liberal 1-4 days in between coats.
From Paul Snyder, forum technical advisor:
It's typical that the second coat of catalyzed finish lifts the previous coat when you start with a non-catalyzed sealer. Better to skip the sealer altogether if you don't use one that's catalyzed. To fix the problem, you either have to use a catalyzed sealer or don't use one at all.
Some other things to consider:
Get a better stain. Waiting a week for the stain to dry is nuts. A good stain will be ready for topcoats in an hour, will look much brighter/clearer (less muddy), and isn't as prone to blotching as your typical consumer brand. Some good brands of stain include Chemcraft, Valspar, Triclad, ICA, Mohawk, ML Campbell, Behlen, etc.
Shoot all your topcoats in the minimum time allowed. You can easily do three coats in a day and it's probably best that you do. You won't run into re-coat windows and your product will be ready for buffing that much faster.
Cleaning with naptha is not needed. Sand, remove the dust, and re-spray.
First take care of the sealer problem and then see how your lacquer works. If you can't get it to work, switch brands. All the benefits you want from the lacquer (tough, rubs out great, etc.) are standard qualities in a number of brands.
From contributor R:
I'm with Paul on changing the stain. If there was a problem with the stain, it would wrinkle on the second coat. As long as the vinyl sealer is the same brand and recommended as a sealer for the system you are using, I don't think that would be the problem. However, mixing brands would definitely be a no-no.
From the original questioner:
I'm not waiting for the stain to dry... Yes, I could proceed much sooner. I just have the luxury of a not-rushed schedule, so it's not that big of a deal.
I understand what you are saying about the non-catalyzed sealer, but I am using a sealer that is listed on the LC-209's datasheet as okay. Yes, both Trinity products.
If the sealer was causing some sort of funkiness, wouldn't that present itself on the first coat of catalyzed coating? Seems like that's when the problem would be the worst, as that would be when it is in most direct contact.
From contributor D:
I would call Trinity and get a tech's input on it.
From contributor M:
Is this precat self-sealing? Try it without the sealer when you do your samples. Don't worry about the naptha, either, unless you are handling it after eating fried chicken. Just wipe and blow it off.
If you want an answer to your question, make samples using different schedules: one with sealer, naptha between coats; one with no sealer, naptha between coats; one with no sealer and naptha between coats; etc. You should be able to isolate the culprit.
From contributor J:
Get the Tech Data Sheet from the manufacturer and read it thoroughly for the critical recoat window of this product. You do know that a critical recoat time is a period of 1-14 days (whenever lacquer comes up to cure) and then it's okay to apply more coats on top, right? Also, have you ever thought about going to a higher solids coating which will save on the number of spray days you are doing now? Example: with Chemcraft's Danspeed Elite you can lay down a double coat one right after another and pretty much fill all but the most porous woods, like ash and oak. There's a lot more to choose from, also.
From Paul Snyder, forum technical advisor:
It's the second coat of catalyzed finish over a non-catalyzed sealer that causes the problem. The sealer is probably fine as long as you don't add the extra catalyst to the topcoat.
I'm almost positive I saw some discussion on this subject in one of the Wood Digest's Finishing magazines. Maybe somebody knows the issue and can direct you to it. It's a free magazine and they have a link here on the Finishing Forum if you'd like to check it out.
From the original questioner:
Okay, I did a test today. I followed the directions of the tech. I shot the sealer, and 3 full coats of lacquer today. I catalyzed only the final coat. It actually all went down great. No wrinkling at all. I was shooting a full 5-6 wet mils per coat. I did sand between each layer still. The jury is still out as to how tough the final product will be, as the lacquer is still a bit soft. So far, so good, though.
From contributor T:
I'm sorry to be so easily confused, but you state you are adding catalyst to a pre-cat. Please explain.
From the original questioner:
It is a precat lacquer, but they send it un-catalyzed with the catalyst in a separate container in the box. It is meant to be mixed when you get it. I catalyze it as I need it, thus making it essentially a catalyzed lacquer.
What the tech told me to do was to spray all of my coats on uncatalyzed, then catalyze only the final coat. I did it today and it seemed to work okay.
From contributor J:
It would be considered a post-catalyzed lacquer, for clarity's sake.
The comments below were added after this Forum discussion was archived as a Knowledge Base article (add your comment).
Comment from contributor S:
Catalyzing only the last coat may not be giving you the properties and performance that catalyzed finishes offer. It may be a crutch to get you past the lifting finish but I struggle to believe it is doing the job catalyzed finishes are designed to do. Check out the performance once through cure. Catalyzed systems are best served when each application of coating is crosslinked.
Comment from contributor H:
Catalyzing only the last coat may not be giving you the properties and performance that catalyzed finishes offer. It may be a crutch to get you past the lifting finish but I struggle to believe it is doing the job catalyzed finishes are designed to do. Check out the performance once through cure. Catalyzed systems are best served when each application of coating is crosslinked.
Comment from contributor E:
Why not use a post-catalyzed lacquer in the first place? Also, check with Trinity to see about max dry film thickness. You may be exceeding it. Also, the naptha may be oily enough to cause problems between coats where it is not absorbed into the wood, as with stain. That would be my guess as the root of the problems if not film thickness. Waiting several days between coats means you are depending on a mechanical bond between coats (the scuff-sanding), not a chemical bond, and the naptha may prevent a good bond.
