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Question 1: Is the appearance of wood finished with Z-poxy resin as a first coat different from the look of the same wood finished with shellac as a first coat?
Question 2: From reading the archives, it seems like at least 2 coats of Z-poxy are required for total filling. What steps need to be taken to insure the second coat adheres well to the first coat?
I am starting to see how Z-poxy might be a really good first coater.....

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--Reynolds Large

1) yes

2)...Apply thinly with a credit card across the grain
...Wait a day and sand lightly
...Add a 2nd coat; wait a day; sand
...Apply finish

It's really quite simple to use...good luck

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JJ
Napa, CA
http://www.DonohueGuitars.com

[QUOTE=JJ Donohue] 1) yes

[/QUOTE]
In what ways? Shellac imparts a depth and richness that would be hard to give up. Does Z-poxy look more like lacquer?

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Stay with the happy people.
--Reynolds Large

It enhances the grain far better than shellac alone...much like Nitro.

Try it...you'll see right away.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Z poxy darkens down Rosewood alot more than Shellac.

I had major problems getting a smooth layer of Z poxy on my current steel string so ended up putting on a 50/50 Zpoxy/alcohol wash coat and then sanding it back to bare wood. Not as dark as the wood would be with a layer of Z poxy left on same but the pores were nicely filled and as far I was concerned that was the aim of the exercise.

Cheers

Here's an epoxy trick that helps smooth and deep penetrate. After spreading use a hair dryer to heat it up a bit. It will flow amazingly well, smooths like butter, and cures a bit faster.

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Thank You and Best To All

[QUOTE=LarryH] Here's an epoxy trick that helps smooth and deep penetrate. After spreading use a hair dryer to heat it up a bit. It will flow amazingly well, smooths like butter, and cures a bit faster.[/QUOTE]

Great tip, Larry...I'll definitely try that one next time around...thanks.

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JJ
Napa, CA
http://www.DonohueGuitars.com

That is a very nice looking guitar Todd!!

I just used Zpoxy for the 1st time on rosewood and it does darken the wood nicely.After 2 fill coats I wiped on a 50/50 coat of zpoxy and D.Alcohol and it evened out the look very good. There is a lot in the archives about Zpoxy.
Good tip Larry!

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Anderson Guitars
Clearwater,Fl. 33755

So for those of you filling with epoxy (z-poxy, etc) - I am getting the impression that you're leaving a coat on the surface rather than just in the pores?

I've pore filled with epoxy before, but I scaped it back so it remained only in the pores, the French polished.

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

Todd, mind if I ask how you apply your zpoxy coats? The pic you show looks as if the guitars were sprayed with it because the zpoxy is so smooth.

Every time I have used epoxy as a filler it looks horrible till I get around to sanding it back. Specially when I use the credit card spreader method.

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Dave Rector
Rector Guitars

[QUOTE=jfrench] So for those of you filling with epoxy (z-poxy, etc) - I am getting the impression that you're leaving a coat on the surface rather than just in the pores?
I've pore filled with epoxy before, but I scaped it back so it remained only in the pores, the French polished.[/QUOTE]

I think the important thing to remember is that the Z-poxy people are using is not exactly like epoxy glue. It is sold as a finishing resin and wetting agent for fabric, etc. What is drawing me to trying this product is indeed leaving a film on the wood and not cutting back to bare wood. No worries about paste wood filler matching the wood or getting in to light colored wood. Plus, you are essentially left with a conversion varnish on the wood which is about as tough a finish as you can get. Anything you apply on top is mainly for gloss and depth of finish. I don't plan on using it on soundboards, however.
As for other fillers, I had some good results with Behlen's waterbased filler. But even with a fair amount of dry color (Van Dyke brown) it was not dark enough in the pores of EIR. John Gilbert used a homemade filler with Durham's Water Putty and powdered aniline dye. I may be paranoid, but I am not really crazy about aniline dust floating around my shop. It is one thing to disslove aniline dye in solution for a wood stain, and another to sand a filler made with it.

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Stay with the happy people.
--Reynolds Large

Just a note. I've used System 3 twice and vowed after the first time that I would never use it again for pore filling, unfortunately I'm a slow learner. IF you don't the mix just right, as was mentioned, it takes forever to set to a barely sandable goo.

It is great for laminating stuff and structural repairs as it is VERY strong but watch it for the pore filling. It can take the fun right out of finishing.

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Thank You and Best To All

I use a thin coat prior to finishing as well as FP lately. I really like the hard and smooth surface it provides as a base. If it provides for a better tone that's an unexpected bonus...although I can't personally vouch for that claim.

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JJ
Napa, CA
http://www.DonohueGuitars.com

Great input on this thread. I think that I'm going to go with Z-Poxey on the one coming up -- EIR with FP on top. I'm swayed.

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Jim Howell
Charlotte, NC

[QUOTE=Hesh1956] Dave White made a post yesterday in which he stated that he has done some work to see what the tonal differences might be and that he likes leaving a thin coat on certain kinds of wood.[/QUOTE]

Hesh,

As Al Carruth so wisely and so often points out, the easiest person to fool is sometimes oneself .. BUT I'm beginning to think there is something good going on as:

- For backs and sides, when the thin Z-poxy coat is on (and I am tending to use 50/50 Z-poxy alcohol from the go) and I rub it back with 0000 wire wool leaving a thin film, apart from it looking good, the change in pop and projection that comes out of the instrument when you tap both top and back is - to my ears - remarkable.

- My cedar/maple Samhain that I love so much was originally finished in FP but my arm was re-acting with the finish in a bad way over the lower bout. So I stripped of the FP and re-finished in Z-poxy on the back and sides and a new pre-catalysed lacquer I have found on top and b/s. Not only did I love the way the Z-poxy brought out the maple, but the sound improvement of the guitar was immense - and it was already a great sounding guitar. Now it could be that the top went a little thinner in the process, or that it was opening up anyway, or that it was the pre-cat lacquer. But I think the Z-poxy film is helping. It forms a great thin level base which means you need less of the top coat you finish with.

- when I did the Weissenborn-copy withe the Sapele top I didn't want it to look that different from the b/s which would have Z-poxy on. So I posted here and Paul Woolson and John Mayes said they had used it on koa and mahogany tops. So I did. An as I say, if the Z-poxy is killing tone I'll happily live with what this guitar is giving me, Again I think it is helping with the projection and sustain

As I say, early days and I may be fooling myself but I think it is adding it's own Mojo. I have heard of others putting a thin wash on spruce tops to "pop the grain". I'd be more interested to see what is going on structurally and tonally. I used to think that no-finish was best tonally. I don't think so now. I think that a certain finish thickness works with the top wood to improve tone, and then you hit a point where damping kicks in and more is bad. My great friend Peter Cree tells me about how he builds his amazing nitro finishes up bit by bit and how for a day or so after applying, the guitar sulks and sounds crap. Then all of a sudden it roars. After he told me I tested it out and he was right.

Sorry for the long ramble

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

But what constitutes a "thin" coat of the z-poxy (I have not used it yet)? I'm getting a very thin finish french polishing, and my fear is that I'd be doubling the thickness or worse if I were to leave anything but the pores filled.

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

I noticed that several of you are using Z-poxy for the sides and something else on the top. Does that mean you would only coat the side of your top binding or do you put the Z-poxy on the top side and purflings.

Thanks

Philip

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aka konacat

If you think my playing is bad you should hear me sing!
Practice breeds confidence and confidence breeds competence. Unfortunately, I'm stuck in practice.

Like Joshua my main concern about Zpoxy (which I'm about to use for the first time) is film thickness; my goal is a finish that is as thin as possible. I have previously used other epoxies and sanded back to bare wood, leaving the epoxy filler only in the pores. It seems to me that a layer of epoxy under the finish is bound to give a thicker total finish film that just nitro.

The other concern is that when I use nitro, sanding through to bare wood as I level the finish seems inevitable; like I said I try to keep the finish as thin as possible, and that usually means sanding through here and there until the very last few coats. If you sand through Zpoxy there will be blotches, as it has some color or hue to it. I don't understand how you can avoid this if you leave it on as a layer.

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Rian Gitar og Mandolin

Joshua and Arnt,

The issue is not about thickness per-se but rather about damping impacts of a finish on wood. The amount of Z-poxy I have to mix to get the layer is also a guide to me. One day I will weigh it. It is not very much all. This resin has good flow-out/self levelling properties and cures very hard.

I thought that as well as the low weight of FP, part of it's tonal plus quality was the hardness that it cures to.

As I said in my post I beleive you have to get to a certain thickness to get best tonal results and after that you start to lose.

I haven't used it on softwood tops and don't really see the need at the moment (would love to do some experiments though if I ever get the time) but I have no resevations at all about using it on hardwood tops.

Joshua - Best thing is try it out on some scraps first. Do the z-poxy plus FP on one part and next to it do your normal fill FP and compare the film thicknesses.

Arnt,

The way I do it is almost 3 stages. First I spend a lot of time preparing the back and sides to get as smooth and level a surface as possible before hand. Then put on the Z-Poxy thinly and spend time levelling this out when it has cured. If you cut through here you just wipe on a diluted with alcohol mix with a paper towel. You now have pore sealed and have the equivalent of your first nitro (or FP) coats. Then I apply my lacquer thinly (usually 4-6 coats) and then level this back. If you cut through the lacquer the Z-poxy layer shows up before you go throgh it - as I say it is a tough coat and you would have to be very unobservant (or unlucky) to keep going through to the wood. If you cut through you just spray on another lacquer coat and continue.

It works for me and I judge with my ears but as Al C always says . . .

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Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Thanks for the explanation Todd!

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Dave Rector
Rector Guitars

[QUOTE=Arnt] Like Joshua my main concern about Zpoxy (which I'm about to use for the first time) is film thickness; my goal is a finish that is as thin as possible. I have previously used other epoxies and sanded back to bare wood, leaving the epoxy filler only in the pores. It seems to me that a layer of epoxy under the finish is bound to give a thicker total finish film that just nitro.[/QUOTE]

The first coat will probably not be measurable in thickness. It will collect in the pores and "wet" the surface of the wood, especially when using a squeegee. The second coat might build up 1 mil, since it is not penetrating and sitting on the surface of the last coat. Most nitro sprayers try to get somewhere around 4-5 mils on the body and less on the top. When I was spraying nitro, it would take 5 or more wet coats just to start making the pores disappear. That is one of the big drawbacks of nitro and the "piano" finish we are after. Nitro naturally wants to pull away from the pores rather than flow into them. It would seem z-poxy is just the opposite.

[QUOTE=Arnt]The other concern is that when I use nitro, sanding through to bare wood as I level the finish seems inevitable; like I said I try to keep the finish as thin as possible, and that usually means sanding through here and there until the very last few coats. If you sand through Zpoxy there will be blotches, as it has some color or hue to it. I don't understand how you can avoid this if you leave it on as a layer.[/QUOTE]
A valid concern. If you sand through the z-poxy, you will have to spot-seal those areas before applying nitro. It is a better plan to insure you don't sand through. All you have to accomplish with sanding the final coat of z-poxy is to remove ridges, lint, big dust particles, and establish a scratch pattern for the topcoat to adhere to, since we are relying on a mechanical bond. I have found that the green scotch-brite pads do a good job of dulling the surface without the fear of sanding through.
I have not used the z-poxy yet, but intend to use it on the next one. I have done lots of finishing with other compounds that share similar application techniques.

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Stay with the happy people.
--Reynolds Large