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| Lacquer as sealer http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=41442 |
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| Author: | Mike Baker [ Thu Sep 19, 2013 2:55 pm ] |
| Post subject: | Lacquer as sealer |
I've been finishing with aerosol lacquers for the last 5 years. The working properties are good, they buff out nice, but IME the finish is too soft, so I have switched to professional spraying lacquer(Behlens). Right now I don't have a compressor, so I have decided in the interim, until I can acquire one, I'll be using the preval rigs. I am used to using the lacquer as a sealer, just shooting enough until it seals the wood and begins to build. I want to continue this practice with the Behlens. Now, I know a ton of you would not recommend skipping the vinyl sealer. But I have done an extensive search here and elsewhere, and I'm aware of the pros and cons. I'm also aware that there are a few well respected luthiers who use the lacquer as a sealer as well. I'm not trying to debate this, and I'm not looking to be talked out of it; I've chosen the course of action I'd like to take, and would simply like to ask a few questions that I haven't found the answers to. Firstly, I've read about a washcoat, or a heavily thinned lacquer application that most use when sealing with lacquer. Can anyone give me a ratio, thinner to lacquer, for this? Also, I'll be using zpoxy as a pore filler. Does anyone do this successfully using lacquer as the sealer? Thanks. |
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| Author: | Tim L [ Thu Sep 19, 2013 4:08 pm ] |
| Post subject: | Re: Lacquer as sealer |
10% lacquer for wash coat |
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| Author: | Chris Pile [ Thu Sep 19, 2013 4:14 pm ] |
| Post subject: | Re: Lacquer as sealer |
DuPont 1980 S sealer works well as a sealer under lacquer. It's water thin, and requires no reducing before shooting. It's like shrink wrap in a can. |
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| Author: | Glen H [ Thu Sep 19, 2013 4:59 pm ] |
| Post subject: | Re: Lacquer as sealer |
I used to use vinyl sealer under nitro, but quit. Got tired of ordering it separately. I can't tell the difference between with it and without it. |
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| Author: | Tom West [ Thu Sep 19, 2013 7:05 pm ] |
| Post subject: | Re: Lacquer as sealer |
Mike: I fill with zpoxy and then spray regular coats of nitro for the body. For necks I use regular pore fill and seal with shellac. Have used various finishes on necks. Padded shellac is my favorite at the moment. Works for me, but I am no finish guru. Tom |
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| Author: | Mike Baker [ Thu Sep 19, 2013 7:14 pm ] |
| Post subject: | Re: Lacquer as sealer |
Thanks for all the replies. Got what I need. Much appreciated. |
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| Author: | James Ringelspaugh [ Thu Sep 19, 2013 10:48 pm ] |
| Post subject: | Re: Lacquer as sealer |
lacquer won't stick well to some woods without a matching vinyl sealer. You may be able to shoot it and buff it OK, but when bumped lightly or sometimes if you look at it funny it will de-laminate from the wood. And it's not just oily dense woods... this is mahogany after a tiny tap that didn't come anywhere near even cracking the lacquer: |
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| Author: | Mike Baker [ Thu Sep 19, 2013 10:58 pm ] |
| Post subject: | Re: Lacquer as sealer |
Thanks, James. Yeah, I've read that. But I've also read that lacquer doesn't adhere that well to vinyl sealer, which is the reason some folks use shellac in between. Don't know which is correct, but I have used straight lacquer for five years with no problems whatsoever. And I'm incredibly accident prone; all of my guitars get hard knocks and dents. Sometimes deep ones. Never had a delamination of any kind. I'll risk it. To be fair, I've also read that adhesion problems between lacquer and vinyl sealer depend on how long the wait is between when the sealer is laid down and the first coat of lacquer is applied. The sooner the better is the consensus I got. But I don't have any fear of delamination. |
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| Author: | Mike Baker [ Thu Sep 19, 2013 11:42 pm ] |
| Post subject: | Re: Lacquer as sealer |
Todd Stock wrote: Lacquer adheres well to vinyl - just follow the directions, which usually includes sanding if it's been a while since the vinyl was applied. Sand the Z-Poxy to 320 and shoot 50/50 for the sealer coat. No - not as effective as vinyl or shellac, but it will work. Thanks, Todd. 50/50 sounds more like the ratio I read for the sealer coat(s). It was here on this forum, but I've searched and searched and could not find it. |
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| Author: | Stuart Gort [ Fri Sep 20, 2013 12:48 am ] |
| Post subject: | Re: Lacquer as sealer |
Mohawk vinyl sealer is lacquer based so I suppose the same is true for other manufacturers. Their system provides a molecular bond to their lacquer topcoats following the directions. |
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| Author: | B. Howard [ Fri Sep 20, 2013 4:13 am ] |
| Post subject: | Re: Lacquer as sealer |
Depends on the exact lacquer in question, some need a vinyl sealer, some not. The industrial lacquer I use will not work well over a vinyl. Best practice is to use the sealer recommended by the manufacturer. They engineered it as a coating system. Most modern lacquer have lost their self sealing abilities due to environmental compliance. |
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| Author: | DannyV [ Fri Sep 20, 2013 10:56 am ] |
| Post subject: | Re: Lacquer as sealer |
James Ringelspaugh wrote: lacquer won't stick well to some woods without a matching vinyl sealer. You may be able to shoot it and buff it OK, but when bumped lightly or sometimes if you look at it funny it will de-laminate from the wood. And it's not just oily dense woods... this is mahogany after a tiny tap that didn't come anywhere near even cracking the lacquer: I know what you mean James. I've had the same thing happen more than once. How fresh is the finish? I'm beginning to think they are more prone to delambs like that before they have fully cured, like less than a couple months old. I'm not to careful with my guitars and it seems after a period of time they are much less prone to that sort of thing. I use nitro and have had it happen with all different sealers. |
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| Author: | B. Howard [ Fri Sep 20, 2013 11:26 am ] |
| Post subject: | Re: Lacquer as sealer |
DannyV wrote: James Ringelspaugh wrote: lacquer won't stick well to some woods without a matching vinyl sealer. You may be able to shoot it and buff it OK, but when bumped lightly or sometimes if you look at it funny it will de-laminate from the wood. And it's not just oily dense woods... this is mahogany after a tiny tap that didn't come anywhere near even cracking the lacquer: I know what you mean James. I've had the same thing happen more than once. How fresh is the finish? I'm beginning to think they are more prone to delambs like that before they have fully cured, like less than a couple months old. I'm not to careful with my guitars and it seems after a period of time they are much less prone to that sort of thing. I use nitro and have had it happen with all different sealers. Most finish Delamitation has its roots in the prep work. Sanding out too fine is a common cause. The finish needs a surface with enough texture to grip onto. This can happen between wood and sealer or between sealer and lacquer in the case of vinyl sealers. |
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| Author: | James Ringelspaugh [ Fri Sep 20, 2013 12:00 pm ] |
| Post subject: | Re: Lacquer as sealer |
DannyV wrote: James Ringelspaugh wrote: lacquer won't stick well to some woods without a matching vinyl sealer. You may be able to shoot it and buff it OK, but when bumped lightly or sometimes if you look at it funny it will de-laminate from the wood. And it's not just oily dense woods... this is mahogany after a tiny tap that didn't come anywhere near even cracking the lacquer: I know what you mean James. I've had the same thing happen more than once. How fresh is the finish? I'm beginning to think they are more prone to delambs like that before they have fully cured, like less than a couple months old. I'm not to careful with my guitars and it seems after a period of time they are much less prone to that sort of thing. I use nitro and have had it happen with all different sealers. This guitar was several years old and in the shop for a new armrest bevel, so definitely not still curing/drying. |
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| Author: | bluescreek [ Mon Sep 23, 2013 5:56 am ] |
| Post subject: | Re: Lacquer as sealer |
Brian brings out a few points that need to be listened to. Most instrument lacquers are formulated different from furniture finish. Prepping is 90% of the end result and shellac and lacquer may have compatibility issues depending on the brand and formulation. Do not assume shellac will work. Today finishes are as much about chemistry compatibility . I do not sand much past 180 grit. The sad thing about this is that things can look good for years then bingo finish peeling. |
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| Author: | Tai Fu [ Mon Sep 23, 2013 7:38 am ] |
| Post subject: | Re: Lacquer as sealer |
I don't trust shellac... I had finish peel from shellac before. |
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| Author: | SteveSmith [ Thu Sep 26, 2013 9:14 am ] |
| Post subject: | Re: Lacquer as sealer |
B. Howard wrote: DannyV wrote: James Ringelspaugh wrote: lacquer won't stick well to some woods without a matching vinyl sealer. You may be able to shoot it and buff it OK, but when bumped lightly or sometimes if you look at it funny it will de-laminate from the wood. And it's not just oily dense woods... this is mahogany after a tiny tap that didn't come anywhere near even cracking the lacquer: I know what you mean James. I've had the same thing happen more than once. How fresh is the finish? I'm beginning to think they are more prone to delambs like that before they have fully cured, like less than a couple months old. I'm not to careful with my guitars and it seems after a period of time they are much less prone to that sort of thing. I use nitro and have had it happen with all different sealers. Most finish Delamitation has its roots in the prep work. Sanding out too fine is a common cause. The finish needs a surface with enough texture to grip onto. This can happen between wood and sealer or between sealer and lacquer in the case of vinyl sealers. Brian, what do you consider too fine? I've always thought that 320 was the finest I would go to before finishing. |
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