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I'm filling with Epoxy for the first time and so far I think this will more then likely be the last time. I'm not really seeing any great benifits to it. Lot's of sanding to it if you just want it in the pores and then there's the sanding dust problems and the in the back of the mind toxic problems always learking. And I really don't see it being a time saver so far. Although that could just be because I haven't got the technic down yet. But none the less.
So what's the benifits ? I'm just not seeing it so far.

Chris, I think that the main benefit is that zpoxy will pop the grain better than most other pore fillers. Nonetheless, I haven't been using it recently, for the same reasons you wrote. I have since switched to ca pore filling. It fills easier, sands easier, and sets quick enough that you could fill a guitar in a few hours if you wanted. The only downfall with ca that I have found are the fumes, good ventllation is a must.

Chuck

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I stopped using Zpoxy after 1 try. I have since learned to use the paste filler. As for grain "pop" I get a much better pop using Nitro Lacquer. I don't rely on the filler for that. Also using stain helps. I am a martin style builder but have used natural finished per customer request. Nitro is still the finish for the best results. While Poly and UVs are not bad Nitro is still the measure finishes are compared to. The back door repair is terrific.
The health issues with this is not something you want to take lightly. If you need to use other finishes for health reasons , That is a priority you must choose. Without proper spray equipment you need to think what is best for you. Health or finish.

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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

John,
What paste filler are you using?

Jeff

The one thing I'm really wanting to ge away from are the chemicals. I shoot nitro and glue inlays and stuff with CA. I try as use HHG and titebond where I can mostly. I figure I get enough chemicals as it is so CA for pore filling is something I wouldn't even want to try.

Chris buddy is the problem that there is too much epoxy left on the surface which causes you to have to do a lot of sanding? If so are you using a squeegee or a credit type card to squeegee off the excess.

I have little sanding to do how I pore fill with epoxy (West, SIII, or ZP) so I am wondering why you have seemingly more to do.

If chemical exposure is not for you and I most certainly respect this personal choice and hope that I don't have to make it one day... there are lots of other ways to pore fill. Robbie is a good one to consult on this in as much as he describes about 6 methods in his FP class including drywall mud - cheap, easy, not very toxic if you wear a respirator, and can be colored too.

So far it is the easiest method I have found, but I also have become more aware of the chemicals we expose ourselves to after developing the reactions I have to CA. I like the fact that it doesn't add any color to the wood as I don't like the way paste fillers with stain in them change the shade of the wood. I also found my 1st time a mess to work with and the second was better but still not as simple as paste filler. The next 2 went better but I think my quest for the perfect filler is not over yet, the requirements for me are a clear fill or at least minimal changes to the wood color, minimal mess, good fill and not to crazy to sand. So far epoxy is the closest I have found, I have several cans of fillers in the shop that I probably will never use again.

Fred

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Fred Tellier
http://www.fetellierguitars.com
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Exactly-
I've used the 'traditional' paste-type fillers with the rubbing off excess with burlap, etc. in the past. If you are trying to re-create that Gibson/Martin look (stained wood, black/dark pores) it is just the thing to use. After basically 'ruining' the look of a koa guitar, I learned my lesson. I don't like wood stain.
When I heard about epoxy pore filling, the advantages seemed obvious - transparent, known working properties (and hazards) since I'd used epoxy a lot, and compatibility with practically anything I wanted to put on top of it. There is a 'knack' to using epoxy for pore-filling, though - don't be afraid to seemingly 'scrape it all off' -it's easier to do a 2nd application than to have to sand a lot off the surface.

If I wanted something less 'chemical' (epoxy allergies are real) then I would definitely go to shellac and pumice. I've done it a few times and it works well.

Another possibility I've read about (but not tried) is using HHG or fish glue as a filler- I don't see this working very well for me.

CA in the quantities needed for pore filling is a non-starter for me - too expensive, and I'd want to have a spacesuit and workspace isolated from my house- I find the fumes quite irritating.

Cheers
John

Hesh, with me the problem was I tried the squeeze like Todd first and the second time. When I tried to sand it back to the wood it always has areas that some epoxy is left on and I really don't want to sand any more off the back as it's thin enough and it's a responsive back and when sanding the middle of the back with the ROS the back tends to vibrate. I stopped trying to get it all to the wood and just decided to put the 50/50 on it. But even so I'm not seeing much of an up side to it for me. To tell you the truth so far filling it the old FP way with pumice or Robbies end grain way seems like it might be the way to go. Sit down and put some tones on and fill the pores and put a seal coat of shellac on at the same time. Then a couple of sessions of FP. No noise ,no dust and no toxians. But that's just my thoughts so far. I'm trying to see what the benifits of the Epoxy are though.

Sounds like a way to go Chris and tunes while pore filling always is a relaxing time for me too.

Some of the benefits of epoxy pore fill when it works for you.... are a complete fill in 2-3 coats, inexpensive since you can just use some West if you keep that around and I do, and the process gives you the first indication of what your wood/guitar will look like under finish. If you wanna leave it on the surface, and I don't, it pops figure great. Another benefit since nearly every guitar that I have built has an epoxy pore fill is so far no signs of it shrinking back. That's a good thing....

The down side is that it's a sensitizer and we all remember the horror that our friend Kim went through because of epoxy... It can also turn the wood a slightly amber color if left on the surface. The amber color can be a plus too - just depends on your wood and your goals.

Then there is Washburn..... Yesterday in the shop I did a set-up for a customer on their Washburn and that guitar had NO pore filling.... It was EIRW with giant pores too.... Maybe it's an acquired taste but I think that I like my pores filled thank you....

Just finished buffing my oak parlor after 4 weeks drying. No grain showing period. Filled with McFadden's pore filler 4 times (well, it is oak).

I still don't understand why luthiers insist on making wood look like plastic!! I can find no reason why the pores of the wood need to be filled!! A few coats of clear satin lacquer is a beautiful finish. I have worked wood for fourty years and have never seen a piece of FINE furniture enhanced by a plastic finish. Please help me understand!!

It's always a good idea to test on a bit of scrap. I've had epoxy (WEST) on occasion turn some wood color quite dramatically- I think it is the amine hardener in the epoxy reacting chemically with the wood (?). But usually, it's just a bit of amber. BTW, the amine hardeners darken over time (in the can) but remain effective in reacting with the resin, so no shelf life worries.

Cheers
John

Dave-
It's a 'tradition thing', mostly.
Go to a good museum and check out some of the top-quality 17th-18th century furniture and you will see plenty of smooth and shiny finishes- though not the 'inch of plastic' look, I agree.
BTW, 'clear' and 'satin' are somewhat contradictory. 'Satin' lacquer has additives which make it translucent, rather than transparent. You may be referring to a gloss lacquer finish which is rubbed with steel wool etc. to give it a 'satin' look?

Check in a large music store- I think you will find that most of the open-pored satin-finished acoustic guitars are at the cheaper end of the rack.

It's a pity- I like oil finishes on furniture and the natural wood look is very appealing. And I don't like sanding, filling, finishing and polishing guitars! For a 'strictly personal' guitar, non-glossy is fine.
I think most guitar builders have found that buyers aren't very interested in non-glossy guitars. Even if you are making a guitar as a gift, it will be devalued by not having a glossy finish, I think.

A guitar with a glossy, but thin, finish will show some 'evidence' of the wood underneath after the finish shrinks over time- grain lines in the top and some sinking into pores - this can be part of the charm of an older, good-quality guitar. French polish (shellac) and thin nitro lacquer will both show this.

Cheers
John

Of course like everyone else I'm looking for that perfect filler as well Chris and I've used a lot of the silex type fillers (Martin type) over the years when I did Nitro finishing.
When I started with classical guitars and French polish I first used the Lacquer "Transfill" from Behlen Bros. which was basically a thickened nitro cellulose lacquer. Difficult to apply, fumes, hard to sand and of course it shrunk anyway. Next was pumice and shellac, worked but was thoroughly unpleasant to rub this gritty dirt-like stuff over one's nice recently sanded instrument. Finally and presently I'm using the LMI micro-bead which is easy to apply, has minimal toxicity and sands easilly and most importantly CLEANLY off wooden purflings and marquetry. This works fine for FP but I hear it will collapse under lacquer and I have not tried it with anything other than FP.
Recently a luthier whom I like and respect showed me a sample of Z-Poxy filled wood and mentioned that with this method he could FP a guitar in a day or two. No wonder in that the wood was indeed not only filled but had a substantial layer of epoxy (read "expoxy" finish here) over the surface. Since the entire point of a French polish finish in my mind is thinness, this seemed to be counter productive not to mention the toxic factor. Sure, one can sand it back to the wood though that sounds like a major chore given the toughness of epoxy. I also don't like the fact that the Z-Poxy has color.

David-
I'm considering this product, after your recommendation.

I notice that it is opaque (?) like the silex fillers? What colors do you use with different back woods?

And the color in the LMI filler doesn't stain light purfling? This would be a big advance over the silex fillers with oil stains.

Do you tint/stain the filler beyond the three colors (maple, mahogany/red, RW/dark) available from LMI?

Thanks

John

I'm still waiting for an easy-to-use transparent, colorless filler......

John, I'm using the dark brown stuff (walnut?) on rosewood. This stuff is more paste-like (almost the consistancy of tooth paste) than the silex type fillers. It's waterbased and does not carry it's color into the wood as the color seems to be ground pigment only (no soluable stains). I'm using a credit card (my AARP one) to apply as it seems to be most effective at getting it into the pores and leaving minimal on the surface.

I haven't found the need to add any colorant beyond the way it comes right out of the jar.

If one might hope to sell a guitar it is quite necessary to make it look good and visible pores are not what any buyers I know would accept especially when the guitar is priced at what it is really worth. The business is customer not builder driven.

Fred

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Fred Tellier
http://www.fetellierguitars.com
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Dave welcome to the OLF!

There is an old saying in these parts that goes like this - whom ever decided that guitars should be shiny and perfectly smooth should be dug up and shot.....

Minimalism can be quite satisfying I agree. If you do care to sell your guitars or build to order you may find that the market often it not nearly always expects the fit and finish to be on a par with the perceived bar. That bar, at least as far as I know, includes filling the pores.

But of course if your guitars are for you or folks who don't care about pores I certainly can see the justification for not filling them.

Welcome aboard.

I have tried a few fillers with varying results. The rub fillers like pumice are good if you have a consistent color of wood. If you have wood with a lot of color variation or figure I find the pores can fill with a different color than beside the pore. I won’t use CA as a pore filler because it was factor in the death of Les Rietfors a luthier from Hawaii. Please be sure to use ventilation and an appropriate respirator for protection when using this product. When using the target filler I found it had a huge shrinkage issue and wasn’t satisfied.

The two filler I’m currently using are epoxy and True-oil. The epoxy works pretty well with a few coats squeegeed in with light sanding. You can make the grain pop with a 50/50 (alcohol) wash if you leave a thin coating on the surface. The tru-oil really is the absolute easiest for me. That is of course if you finish with tru-oil. You just keep applying very thin coats (wipe on) and allow the pores to fill without any additional sanding. When the pores are all filled you are ready to dry then level and polish. But both of these methods do add a bit of color to the wood.

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.

That's far too prescriptive for me Fred. Visible pores ARE accepted in certain quarters. it would not be frowned upon in the Lute world and is increasingly becoming acceptable in the modern Classical guitar genre. There are some 'big name' makers doing simple Danish oil finishes - no pore fill.

The real reason for epoxy pore filling, at least in fairly recent history, has to do with the waterborne finishes. These modern finishes don't pop the figure the same way, but more importantly their physical structure is different from solvent based finishes in that they tend to float on top of the wood rather than soaking in and case hardening the surface the way solvent based finishes do. This is particularly problematic with soft top woods that would get dinged much more easily with waterborne finishes. Consequently, Greven and Doolin, to whom I point to for much of the R&D on waterborne finish application in the context of guitars, chose to pore fill the entire guitar -- top and all -- with epoxy to both pop the figure as well as case harden the woods.

I stepped out for a bit and it seemed to get pretty active here. That's a good thing.
In regards to the tru-oil filler post. I was wondering why one couldn't put shellac over the tru-oil and then shoot nitro?
As far as the color changing. I personally like the fact that Nitro darkens with time and scratches come and all that. I like the charactor factor. Yeah, I like it looking nice when it's new but don't see a down side to it looking like it's been played. I'm hoping it get's plenty of playing. Like I tell a lot of people, half the cost is the finish.
Good and interesting facts David.

David-
Thanks. Sounds good. I have some IRW guitars on the project list, so I'll try it out.
Guess I'll be spending some $$ at LMII..... the challenge is to keep the 'What else do I 'need' under control!


Cheers
John

You'd actually be surprised what is and isn't bad for you, especially if you're going on the 'how horrible is the initial experience' scale. Ebony is horrible right away, but cocobolo is more likely to eventually cause a severe reaction. Epoxy is much more pleasant to work with than CA is, but CA is nontoxic while epoxy could cause a lethal reaction down the line. Orally, acetone and ethanol have about the same lethal dose but longterm ethanol exposure is worse for you. Lacquer thinner wants to murder you ten different ways.

Most woods can become allergens for some, so it's best to just limit your dust exposure and hope for the best. Woods with smells tend to become allergens easier (cedar, rosewoods), but there are people with acquired spruce and maple allergies. Either way, wood's sort of a requirement in this line of work

A lot of finishes want to kill you, but it's a matter of how good they are at it. Lacquer thinner is nicely volatile and carcinogenic. MEK catalysts are nasty stuff, but at least the finishes using them are a small % MEK and mostly solids instead of nearly all solvent like lacquer. Waterbased finishes are mostly cool if you wear a mask and don't drink them. Photocatalyzed finishes are similar to waterbased in that you'll be cool if you can keep them out of your mouth.

Epoxy hates you, and it will try to get you eventually. The hardener hates you, actually. The fumes will sneak up on you, and getting un-cured dust on you is even worse. You can eat Titebond, fish glue, or hide glue...and if you're a dog you might even like the latter! You...could...eat CA...but it's pretty much impossible to swallow. Rare people can become/are sensitive to CA, but it's not the sort of medically dangerous type of reaction that can happen with epoxy. Polyurethane glue is moderately evil, and definitely bad for you, but much less so than epoxy.

Knowing this: I use acetone as a solvent anytime I can, and I never use lacquer thinner unless there is no other earthly option. Likewise, I use hide, fish, and CA glues for everything I can, Titebond if I have to (because I just don't like it), and epoxy only as a last resort. For finish exposure, I'll be sending my stuff out or using a water-based finish in a booth until such a time as I can get a UV setup.

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Bob Garrish
Former Canonized Purveyor of Fine CNC Luthier Services