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To give you guys some background from back in the day on the OLF around 2005 Mike Doolin was using System III to pore fill and had a toot on LMI's site. OLFers were actively trying other epoxies with Michael Dale Payne coming to mind for ZPoxy "Finishing Resin."

After many of us had success with epoxy folks were experimenting with exploiting the ability of epoxy to really pop figure unlike anything else.

The UK contingent of OLFers back then had their own way of doing things and a look for guitars that was different from the bling encrusted things that are more popular state side. You can probably guess the famous UK Luthier who is well known for superb instruments but not much in the way of bling.

Anyway where this comes into play is the look that some of the UK guys, me too... really liked was a more natural look. One of the UK guys even once said on the forum something like I want wood on my instruments not a bunch of epoxy.

So we learned to sand back to wood for this look and it worked well. I've personally done it both ways and never had any problem with the epoxy coming out of the pores when sanding back like nearly every other filler does and will....

The wash coat was for the folks who loved how epoxy pops figure.

Both methods work as mentioned and that makes this simply a personal preference thing.

Glad it's working out for you Mike and your stuff looks great!

Fred, I was surprised to see that west system has a slight amber tint when cured. It's subtle. But it's there and only shows up on very light wood color. May try that system 3 silver point. Regardless, for hardwood, I may try it. What I like about z-poxy is the forgiving mix ratio and the fact you can over thin with DNA, no issues. Thinned z-poxy cannot be left on in thick layers however (ridges). I only use it for wash coats.

John Grevard mentioned somewhere the silver point cures dead clear. I think that is worth noting.

Hey Fred

Thanks for that post. I have experienced some sink back with Z-poxy as well. I have not mentioned it as no one else seemed to be having that problem and I felt it must be my application technique that was to fault - and certainly still could be. I also changed to West and so far am much happier with the results. Thanks - Mike

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guitarsbygiltzow.com

+1

Never experienced this even when using it very thick, like when leveling fiberglass and wood -- model making application.

For guitar finishing I use the final film coat method --- my thought is that total sanding back will tend to produce tiny voids in the filler which likely show up after the topcoats dry/cure.

And another thought -- if one is using a lot of DNA mixed in for thinning, the drying is not only chemical reaction but some evaporation as well -- so it would seem the product will shrink a bit just like any other solvent borne coating.

I've emailed Pacer for their thoughts.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I've never experienced any shrink back with any epoxy including the one that I used the most, Z-Poxy finishing resin.

It could be technique and I have some thoughts on this that I've posted before some years back here.

My original pore filling with epoxy was Mike Doolin's excellent toot that LMI hosted back in the day. Mike used back then System III and he also used thickeners. Coat one was not thickened and coat two was IIRC.

That got me thinking....

So the next time that I pore filled I got out a 30X microscope and took a look at the pores before and after each of the only two coats that I ever needed to do. Seems coat one has a different function than subsequent coats.

Coat one is to simply get some epoxy into the bottom of the pores so that later coats can grab on to it. Subsequent coats can be thickened for better, faster build and in my case became the final coat.

So coat one is wetting the bottom of the pores and coat two does the heavy lifting with the pore filling.

Now a word about the term squeegee. It's a noun and a verb and Mike, our Mike the OP mentioned IIRC that he credits that squeegee that he used with much of his success.

Another method is to use credit type cards and this is where the noun and verb thing comes into play. My toot talks about using the credit card to "mash" the epoxy downward into the pores again because with coat one getting it into the bottom of the pores seems to be key. Coat two is the build coat.

So back to semantics. I found that describing the use of the credit card as a squeegee was both misleading and would result in the need for more coats with much of the epoxy being "Squeegeed" back off and out of the pores as well. Only the very last passes IME should the card be used as a squeegee.

Back then I bought some squeegees too and found them to be not as useful with the "mashing" the stuff into the pores downward motion that I want to do and have success with. They work great as you guessed it, squeegees to remove excess as the final steps. But for mashing downward I liked cards better.

Besides for 9 years now that terrible organization AARP keeps sending me these cheap, flimsy cards with a bit of a nub on them right where you don't want it for that toward the end squeegee (verb...) action....

I'm sure that either method works, squeegee or credit type card (a quality one not the AARP junk..) but with my method I've never needed more than two coats, have no shrink back and some of these things are 10 years old now and I didn't have to purchase anything instead using old cards laying around.

I also know that some professional finishers who use West Systems apply the epoxy with a foam brush and they use the foam brush to get it down into the very bottoms of the pores. The mashing if you will. I don't know what they use to remove excess.

So if using a card forget the term squeegee because it's misleading when the action with the card really needs to be mashing the stuff downward from all directions and NOT skimming the top and removing excess. Only the very last passes is when I use a card as a squeegee.

One other point that was important to me in finally..... getting something to work for me in filling pores. That first coat again has a very different purpose and that is wetting the bottom of the pores with something that subsequent coats of epoxy will stick to. As such how we use the card and I suspect too having tried it myself that how we use a squeegee (in the noun sense) is key to fewer coats, avoiding shrink back in time by really topping off the pores AND having epoxy all the way down in the pores as well.

Either method with techniques that are specific to the method works. I also suspect that with the foam brush that some pros use that these are not at all the only choices for application methodology.

If you are experiencing shrink back in time I suspect that the stuff may not have completely filled the pores and may have had a void of sorts under it. That's where the mashing comes into play IME.

Remember too if using shellac and lots of woodworkers like to shellac the crap out of stuff for protection while working on it, I did too. If you put shellac down prior to epoxy you will be SOL.... Conversely shellac sticks like.... well shellac to cured epoxy but uncured epoxy will not adhere well to cured shellac. Wonder how Michael Dale Payne is doing - he used to say this exact thing in his excellent efforts to help folks here.

I don't doubt my sink-back experience is (at least partially) due to my application technique and somehow the Zpoxy wasn't properly filling the pores and whatever bridging occurred ultimately failed. I tried 2 kits, just in case there was a QC issue. What I do know for sure is that all sink back disappeared when I switched to West, on the recommendation of a professional finisher. My technique hasn't changed -- yes, I sand to wood and strive for a thin finish.

I do note that the Zpoxy is thicker and sets up much faster than 105/207. With the thinner West you can literally watch the epoxy being drawn into the pores -- I don't recall observing that with Zpoxy.

Obviously, experiences vary with epoxy pore filling. For now, I've got a system that I like and haven't yet managed to screw up, with a product that is readily available.

I would add that I don't use epoxy on neck shafts, at least not any more. Acrylic bead paste filler does that job quick and easy.

And no, this is not a "critic" of anyone. I am learning from everyone's experience and would like to feel that asking questions is part of that process.


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I'm a bit confused. I've always been told never to thin epoxy with alcohol because it will never cure and you end up with a gummy mess. Is there something about z-poxy that allows it to be diluted with alcohol and still cure hard?


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Never had any issues with curing after adding some alcohol but I thought that the alcohol was added to my coffee not the epoxy....

Seriously I've added 10% alcohol to Z-Poxy "Finishing Resin" and it sets up fine. This is only for a final wipe coat to wipe on and even out the pop and color, works great.

I've been thinning all sorts of Epoxies with DNA since I read about it in Don Teeter's repair publication -- gosh I think that was early 80's, anyway never had a problem -- finishing, wood working or model building.

BTW on re-finish jobs, Don used thinned epoxy as a base layer on vintage guitar tops that he thought were badly dried out. His logic was it provided a strong flexible sealer for the top coating -- he normally used nitro lacquer.

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Ken Cierp

http://www.kennethmichaelguitars.com/

I've added more than 10% to z-poxy. Mainly because I'm too lazy to measure it, and its such a small amount of resin, and finally, because it never caused me a problem. I've also found that it evaporates off very quickly. Sooo, guess that's why it doesn't affect it. When I make a z-poxy wash coat, I definitely put the emphasis on wash. I never mix up more than will cover a back at one time (quarter sized circles of resin and hardener). I just get the end of a cotton rag (t-shirt-like) soaked in it and rub away.

I was curious about this. I found that if you thin Z-poxy 50% or more with alcohol, it does indeed set sort soft and gummy. However, thinning 10% (or likely more) cures fine, and that is plenty thin enough for the final wash coat in pore filling.

My 2¢:

RE pores only or slather epoxy over everything: It depends on the wood and your taste....
Sanding down so epoxy is only in the pores isn't that hard. It's nice if you want a quieter look for plain mahogany, walnut etc. Leaving a full epoxy coat as a sort of primer really pops the grain. It can be very flash. The choice is mainly aesthetic for me.

For necks, I agree with Tim. I've only done one in epoxy and while it's nice, it's a bit too bling. Frankly I prefer the quieter look of paste filler (which incidentally is also quite a bit faster to do).

I tried a cheap squeegee after watching Mr. Stock's tutorial, and I found it to work much better for me than either credit cards or plastic resin spreaders I had used before.

No one ever talks about this, but I find that epoxy pore filling has the useful side effect of helping to stabilize crackly woods.

I think it's hard to communicate techniques. I would assume your gummy problem could be due to coat thickness. When I use thinned z-poxy (and it's pretty thin), I'm doing a rub on coat with a cotton t-shirt rag. So thin of a layer, all DNA is gone. In fact, I have to do this quick and decisively. After a point, I'll just mess up my finish if I keep at it. And it cures pretty hard. I do a coat before this, the 4th coat, where I'm careful to not over-thin. That still involves the squeegee. But even that one flashes off quick. I don't think I'd try a coat that involved "trapping" DNA with thicker layers. Pretty sure I've bumped into gummy stuff there.

I haven't used epoxy as a filler but am looking into it. If acrylic bead paste is so quick and easy for the neck, why not use it on the entire guitar?

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It will probably be alright.

Indeed.

I've used that stuff a lot, and it is way faster and easier than epoxy, not doubt about it. It is however, a flatter and more old fashioned look. I prefer epoxy when the wood is figured or ribbon-ey, and you want maximum chatoyance. On something like EIR I'm not sure why anyone would bother with anything other than paste filler -- whether LMI acrylic bead or old fashioned oil based.

I used the LMI acrylic bead filler on five guitars and just finished doing my first one with zpoxy. I'm throwing out the LMI filler and not looking back. I find the zpoxy much easier to work with, particularly the sanding, and I very much like how it highlights the grain. You mentioned chatoyance. The rosewood back and sides on the one I just finished have it and it looks pretty amazing compared to the rosewood guitar I did with the LMI filler.

The one thing I did like about the LMI filler was the option of choosing a color for filling the pores.

I ran into gumminess with the zpoxy only once when the tare function on my scale wasn't working right and the mix ratio was off. For the thinned coat, I diluted the zpoxy 50:50 with DA (based on Hesh's toot on the subject) and wiped it on with a paper towel. That produced a very thin application that hardened very fast.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

I have always found z-poxy mixing very forgiving. I've never measured. Eyeball. 50/50. Would not do that with West System. I agree with the 50/50 DNA wash. Works for me. I used to think epoxy was a PITA. Then I discovered the squeegee. Mix that up with the Caruth scraper and you can scrape a body down in one hour. What's not to love?

This is how the current guitar looks with zpoxy and the finish on but without the final level sanding and polishing done yet (neck on temporarily). I'm very happy with it. The rosewood looks great IMO.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Sanding? The LMI only needs minimal sanding and in fact I usually just go over it with some scotchbrite. The trick is to wipe it off with a damp coarse rag right after it starts to flash dry. The other key is to thin it down a bit, and fill in two coats. Maybe I just stumbled into this cuz they said it works like oil paste filler, so I used the same technique, with a couple modifications.



Indeed it does.

I guess I'm a bit of a hypocrite, as I haven't used LMI filler on the main body for years, though I keep it around for necks. My point is mainly that it can be very fast compared to epoxy, and for a beginner it--as well as oil based paste filler--is a good choice, plus it looks nice when you want a less chatoyant factory sort of finish.

I admit that it's entirely possible that I didn't figure out the optimal method for the LMI filler. That said, I did try it five times with variations and never liked using it or the final results (shrink back). If you figured out a good method for it, that's great. On one neck, I used the rosewood filler instead of the mahogany filler by mistake and actually liked how the contrasting color ended up looking.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Fair question. Honest answer is "that's just the way things evolved." There are many things to like about epoxy, and I started by using it everywhere, but I couldn't figure out a way to sand a neck so that it either has a really thin layer with no sand through, or no excessive sand through into the wood if I try to just come back to wood. I also found that Tru-oil, something I sometimes use on the shaft for "neck feel", doesn't like to be over epoxy (at least not Zpoxy), even if there is a barrier coat of shellac -- the neck surface feels "fuzzy" after a few months. I find the LMI acrylic bead paste easy to use, sands easily on complex surfaces (you wipe most off during application), has a nice colour, and looks good under finish. I'll stick with West Systems on any surface that is easy to block sand, including the headplate and backstrap.

Ever since I read this I've been trying to figure if it is silver point or silver tip. Thoughts?

I tried epoxy twice with dismal results.
Shellac and wood dust filler for this boy.
Shellac makes figure pop and it is pleasant to apply.

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wah
Wah-wah-wah-wah
Wah

Actually not a criticism as It looks like the process worked well for you. Here is one reason to think about sanding back the first coats at least close to the wood.

When applying epoxy to deep pored wood, you may be leaving the some of the pores unfilled with a trapped bubble but bridged over with epoxy. I see them show up when I am sanding back the first coats. I am not sure any harm would come from having a thin layer of epoxy film bridging a pore. My fear was they would open up later.

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http://www.Harvestmoonguitars.com

Sorry if this is covered here already.... is there a tutorial for this process somewhere? The first post has pretty much enough for me to go on, but I would like to try this process on a couple of scrap pieces and see how it come out. Any additional details on this site would be appreciated.

Thanks!
Brad

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