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Good Morning,

I've read some of you (Todd?) talking about using vinyl sealer as a base coat under nitro. I've got a couple close to finishing and I'm wondering what the benefits of vinyl are? I'll be using Mohawk Instrument Lacquer on these and have used it in the past with good results.

Being in Canada we don't have access to the range of volatile products that you Southern Bros have but this http://www.mohawk-finishing.com/catalog ... 73&atomz=1 is readily available. I'm wondering if this is similar to what you use?

Thanks for any info.

Danny

from what I'm reading that is for use with a catalyzed top coat and would not be compatible with instrument lacquer...

you need to use air dry sealers with air dry top coats, and catalyzed sealers with catalyzed top coats...the 2 are not interchangable

Contrary to what a lot of people think, vinyl sealer is not necessary as a base coat for nitro. In my experience, nitrocellulose lacquer adheres just fine to woods like EIR and the mahoganies without a base coat of vinyl sealer. Some vinyl sealers, Sherwin Wms brand for example, have a high solids content a base coat of it can help level the finish with less subsequent coats of lacquer. One thing you want to avoid, however, is using a high solids vinyl sealer for drop filling later in the finish process. I just did that for the first (and last) time in a recent project, and ended up with what looks like water spots after the final polish.

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michael propsom
www.propsomguitars.com

If you want to use a sanding sealer, which you do not need to do, and which is IMO of no benefit at all when using nitro lacquer unless you are making furniture on a production line, then vinyl has some advantages over traditional stearated sanding sealer--it's clearer and more flexible, and has better adhesion to the wood and topcoat.

I suggest reading what Flexner has to say about "sanding sealer" and what a misunderstood term it is. You don't need to seal wood with anything prior to using nitro lacquer.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

I used vinyl sealer on my 1st 4 guitars but now use shellac as a base coat and have had great results with it. Dewaxed Shellac flakes are easy to get even on our side of the border.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I don't use sanding sealers but when using nitro (McFaddens) I always use their vinyl sealer. I didn't on a couple builds and both had issues with lifting around tuner holes, etc. Nothing catastrophic, but I've never had any issues when I used the sealer.

I use it mainly as a color block. The vinyl sealer goes on and with the mount of laminations (leaky wood pigment) and possibilities I have for color bleed I just use it to be safe. I also use it to stop the CA in my rosettes from pulling the dye out of my purfling border lines, again as a color block. It works great when you need to scrape back binding too.

I'm just going by the StewMac book, the Finishing video from the 96 Healdsburg guitar festival, and by what my mentors have told me. If it takes filler, and vinyl sealer before the nitro then that's what I'm going to do. Their 2000 guitars bests my 73 so I listen "just cuz they said so." I've been using Mcfadden until now and I just used their combo. Changing finishes now so it's up in the air.

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Todd Lunneborg
http://www.tlguitars.com/
http://www.fretboardjournal.com/

Thanks Guys,

Thought I might be missing out on something. I don't think I'll be using any McFaddens since I don't think it's available in Canada. It will have to be shellac for a blocker. Seems to work well. Howard, I tried to find out what Flexnor had to say but he wanted to sell me a book on it. He does seem like a bit of an authority. I haven't heard of him but I'm going to check him out when when I get time. Fred, Just curious, are you brushing or spraying shellac? It is a nice way to tint a top.

For sealer coats I spray, but for protection of the top while doing rosettes and binding I wipe it on with a lint free rag. I am sure you could brush or wipe on the sealer coat but spraying is much quicker.

Fred

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Fred Tellier
http://www.fetellierguitars.com
Facebook page http://www.facebook.com/pages/FE-Tellier-Guitars/163451547003866

I am 100% in agreement with Todd here. Vinyl sealer helps with finish adhesion . I used shellac both flakes and the Zinser clear and had problems down the road. It wasn't until the finish people at Martin helped me understand the chemistry involved. I agree that finishing as as much about technique as it is about product. If you have something that works go for it , but I found Mowhawk and Behlen's geve me a better result when I used the designed sealers with the product.

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

Thanks! Todd or John. The link at the top in my original post, does that look something like what I'm after? It is compatible and I like the fact that it has a little higher solid content.

Hi Danny,

I was using the Mohawk EZ Vinyl Sealer PN M610-800. It was a 1 gal container. I'm not sure that the sealer in your link is exactly the same. The last time I picked some up from Mohawk in Vancouver They were out of the Mohawk, so they sold me a quart of Behlen Vinyl Sealer PN B611-1706 to get me by. It seems to be the same stuff as the Mohawk, just a smaller quantity. Get hold of Mohawk in Vanc. and I'm sure they'll have what you need. If you are buying from a local supplier just use the PN's I've listed. If you don't want a gal. then the Behlens quart is fine. A gal. will go a long way and could go bad before it's used up. Don't use a pre-cat sealer under nitro.

Cal

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Remember, there are no stupid questions, only stupid answers!

after taking the time to more deeply read about the product, it appears as if the link you give in the original post is what the manufacturer recommends for use with their instrument lacquer.

http://www.mohawk-finishing.com/mhk_cds ... -10%29.pdf

when I see mention of "for use with pre or post catalyzed" systems I normally think that means only for that use...

in this case a different type of warning bell goes off in my head...I've used similar products before that were air dry and supposedly for use under a catalyzed top coat...said top coat started failing within a year...

in your case though you want to use this air dry vinyl sealer with an air dry (instrument lacquer) top coat, and that should be just fine...

as others have noted, a vinyl sealer is an excellent choice for adhesion reasons...I was taught to always use a vinyl sealer with lacquers and always have, and except for the one time I used an air dry sealer under a catalyzed top coat all of my finishes are still holding up fine...

"Vinyl sealer" is nitro lacquer with vinyl added to improve sanding instead of the stearates in ordinary sanding sealer.

Do whatever works for you.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

Todd, I use a catalyzed finish and the manufacturer recommends their vinyl sealer particularly for adhesion issues on exotics, including ebony.

Right. The vinyl sealer for use with nitro lacquer is mainly nitro lacquer. There are some finishes that need a barrier coat, especially over oily woods. Nitro isn't one of them, and vinyl sealer for nitro isn't a barrier.

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Howard Klepper
http://www.klepperguitars.com

When all else fails, clean the shop.

This is very interesting, as I, like Fred above have used shellac on the last halve dozen builds and love it as everything sticks to it and it sticks to anything. I switched to shellac because I had finish lifting/seperating around the tuners and blamed it on poor adhesion to the wood surface due to Vinyl Sealer. Nary a finish lift one since switching to shellac, which is just the opposite result as some of you report. Suggesting that rather than either one product or the other at fault it may be a surface prep. issue. Also, John Hall, if you come back on and read this, from your experience what issues do I need to expect down the road that you mentioned by it's (shellac) use?
Rico

I just put down a coat of epoxy filler on an OM and just thought I would ask to be sure. Have you guys had the same good results over epoxy? West in my case.

Thanks,
Danny

Can vinyl sealer be used under waterborne lacquers such as KTM-9 (LMI) or ColorTone(Stew-Mac) ? Is there a waterborne version of vinyl sealer ?

Whatever method Tacoma guitars used on my Dreadnaught version from them did not work very well. It is thick and peeling off the guitar now and there seems to be no adhesion to the wood (which makes for an easy removal at least). I have never heard of spraying shellac. A guitar is so small I don't have any problem starting an initial french polish-like, rubbed-in coat of it, which won't take longer than setting up a spray rig I would think.

good topic by the way.

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"Preoccupation with an effect gives it power and enhances the error"
from "Your Owner's Manual" by Burt Hotchkiss.

What are the chances a vinyl sealer for a barrier coat between catalyzed urethane and an exotic wood would also work under KTM-SV? (which is a waterbased urethane if I understand correctly) Looking for something to go between spruce and KTM-SV and between zpoxy and KTM-SV. The zpoxy is over a EI rosewood and apparently KTM-SV won't cure properly if it comes in contact with oils from exotic woods.

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Formerly known as Adaboy.......

What are you switching to Todd?

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I have a Tacoma Dreadnaught that was just starting to do this and I brought it to a Tacoma dealer who told me it was under warranty. Apparently they had a batch of them about 8 or 9 years ago that they screwed up a step. I paid $35 to ship it to them and they picked up shipping when they sent it back and it looked as good as new. It took about 6 months to get it back, though.

Matt