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| Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulose. http://mowrystrings.luthiersforum.com/forum/viewtopic.php?f=10123&t=39661 |
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| Author: | Irving [ Sun Mar 10, 2013 3:17 pm ] |
| Post subject: | Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulose. |
I have been learning more about these types of lacquers lately. Nitrocellulose clearly seems to be considered the holy grail of guitar finishes to some (simply tradition?). It's long cure time is a let down for me. Other than that I love it (despite it's toxicity). I have recently been investigating Pre and Post catalyzed lacquers. This is how I am best understanding it: "Catalyzed lacquers consist of both pre- and post-catalyzed versions. Instead of curing by the evaporation of a solvent only, they also cure chemically. The catalyst can be added ahead of time (pre-catalyzed), or in your shop (post-catalyzed)." Makes a lot of sense. I am very interested to try pre catalyzed lacquer after learning this. It would cure much quicker. It's shelf life is diminished as a result of this faster cure time, but that's ok with me. Anyone have experience or opinions on Pre and/or Post catalyzed lacquers and how they compare to nitro? I am immediately wondering if you can thin them with lacquer thinner in the same manner as nitro? Will successive layers burn together as well as nitro? |
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| Author: | Chris Pile [ Sun Mar 10, 2013 3:37 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Since when is nitro drying time long? It's usually dry to the touch in 10 minutes. |
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| Author: | Irving [ Sun Mar 10, 2013 4:46 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Chris Pile wrote: Since when is nitro drying time long? It's usually dry to the touch in 10 minutes. Drying time and curing time are very different. I'm talking about curing time, which is 6 weeks or so for a typical thickness guitar finish. Nitro is definitely dry to the touch in 10 minutes or less I agree. |
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| Author: | Chris Pile [ Sun Mar 10, 2013 6:41 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Quote: Drying time and curing time are very different. I'm talking about curing time, which is 6 weeks or so for a typical thickness guitar finish. Nitro is definitely dry to the touch in 10 minutes or less I agree. My bad. Should have read the OP a little closer. |
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| Author: | Irving [ Sun Mar 10, 2013 7:25 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Filippo Morelli wrote: 6 weeks? I get finished 21 days from spray. Todd is like 15 or so in drying box... Filippo Ok ok maybe 6 weeks is a little on the long side. Anyway, totally not the point of the thread.. haha |
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| Author: | Irving [ Sun Mar 10, 2013 7:35 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Filippo Morelli wrote: Well it does seem relevant if you're considering other kinds of lacquers due to the amount of drying time,,, Filippo If pre cat lacquer cures and dries much quicker than nitro - you may be able to not wait nearly as long between coats. Maybe you could get all of your spraying done in a single day rather than spread out over 3 or more days. You also might be able to wait only a few days before being able to do your final buffing rather than a few weeks. I'm not really sure. Need to do more research on the subject and part of that was to have a discussion here and see if anyone has experimented with pre or post catalyzed lacquer and how it compares to nitro. |
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| Author: | Doug Balzer [ Sun Mar 10, 2013 7:41 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
I am working on my first guitar so I can't speak from that perspective but I can from 12 years using lacquer on custom furniture. I am a huge fan of post-cat. It cures much harder than pre-cat. Mixes up very easily. Nearly the same cost. Greater control with cure time depending on amount of hardener. Yes, it burns coats together. I would never use pre-cat again on high use furniture when post-cat is just as easy. Dry to the touch in about 10 seconds. And yes, the fumes are powerful. I use a high quality respirator and can't even detect the fumes while spraying but once someone dropped by while I was spraying and the 70 year old person passed out... Unconscious. Seriously. |
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| Author: | Irving [ Sun Mar 10, 2013 7:54 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Doug Balzer wrote: I am working on my first guitar so I can't speak from that perspective but I can from 12 years using lacquer on custom furniture. I am a huge fan of post-cat. It cures much harder than pre-cat. Mixes up very easily. Nearly the same cost. Greater control with cure time depending on amount of hardener. Yes, it burns coats together. I would never use pre-cat again on high use furniture when post-cat is just as easy. Dry to the touch in about 10 seconds. And yes, the fumes are powerful. I use a high quality respirator and can't even detect the fumes while spraying but once someone dropped by while I was spraying and the 70 year old person passed out... Unconscious. Seriously. Wow. Poor guy. That's some great info though. I have a friend who is in the furniture repair business and his opinion is that post-cat is difficult to buff out after level sanding and for this reason he much preferred pre-cat. Do you think there is any truth to that? Good luck on your guitar. What style is it? Do you plan to spray it with post-cat? |
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| Author: | Doug Balzer [ Sun Mar 10, 2013 8:01 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Irving wrote: Wow. Poor guy. That's some great info though. I have a friend who is in the furniture repair business and his opinion is that post-cat is difficult to buff out after level sanding and for this reason he much preferred pre-cat. Do you think there is any truth to that? Good luck on your guitar. What style is it? Do you plan to spray it with post-cat? Can't comment on buffing post-cat. I typically used a 70 sheen on furniture and no buffing was required. Most, but not all, furniture is finished avoiding high sheen. I'm building an acoustic bass and you can check it out in the 2013 New Builder forum. I haven't yet figured out my finishing strategy...but I'm open to suggestions!! |
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| Author: | Mike_P [ Sun Mar 10, 2013 10:30 pm ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
Irving wrote: If pre cat lacquer cures and dries much quicker than nitro - you may be able to not wait nearly as long between coats. Maybe you could get all of your spraying done in a single day rather than spread out over 3 or more days. You also might be able to wait only a few days before being able to do your final buffing rather than a few weeks. I'm not really sure. Need to do more research on the subject and part of that was to have a discussion here and see if anyone has experimented with pre or post catalyzed lacquer and how it compares to nitro. from my experience there is no difference in the time required to flash off solvents between coats of precat lacquer...it dries hard enough for shipping in about 8 hours (I prefer 24) and reaches its final hardness in about 2 weeks...but that is a totally different subject than time required for recoating...shelf life is drastically reduced with precat and while I've read of many instances where a user claimed to have used the stuff over a year later, I prefer to stick with the manufacturers recommendations for a given product (nothing like having to warranty a finish that fails) unlike many of the 'softer' versions of nitro used for instruments (and autos), pre-cats have a definite final build thickness schedule that should be adhered to (unless you actually like stripping off a failed product to shoot it again)...I've shot over 15 coats of a certain automotive lacquer (air dry) on commercial bar tops (I estimate about 12 coats worth was left after sanding and polishing) and said finish (obscenely thick) is still holding up after nearly 10 years...I wouldn't think of trying that with a catalyzed lacquer |
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| Author: | B. Howard [ Mon Mar 11, 2013 4:24 am ] |
| Post subject: | Re: Pre Catalyzed Lacquer, Post Cataylzed, and Nitrocellulos |
From an application standpoint, they all work about the same. Cat lacquers can be harder to buff and repairs can be harder as well. Most cross linked systems I have used do have a mill barrier that must be respected as Mike said, generally 5 mills. Typically these finishes are used on cabinets and furniture which are not buffed so cure time to buff out its not a concern. They are used for their better resistance to chemicals and wear. |
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