Official Luthiers Forum!

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Bill Hodge


One does not simply, own enough guitars!

Well even that 50/50 wet coat didn't flow out and the streaks were hard to level. I ended up putting some 250grit on the ROS and took it back to the wood and went over it with some 400grit. And with a Dust Be Gone on and a dust filter fan sitting there I still managed to get that nasty taste in the back of my throat form some dust. Don't worry I'm working on getting rid of the nasty taste as I'm writting this with a couple of shots of Everclear in my Coke.
Yeah , Popping the grain just isn't enough of a reason for me to use this again.

Great topic! I haven't filled pores yet but I'm learning a lot just reading everyones responses. Right now I'm leaning toward trying CA glue for pore filler. I'v used it quite a bit building RC airplanes. I'm sure the fumes are bad but Ca is used to close wounds nowdays. My 6 yr old daughter recently had a cyst removed from her back and when they brought her back from surgery, they had closed the skin with CA glue.

I'm still trying to decide what finish to use........right now leaning toward either spar varnish or acrylic laquer as I wan't to spray but don't have facilities to spray nitro.

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Formerly known as Adaboy.......

Bob-
Thanks for the info.

re: Your comments about epoxy. Peanut butter, bee stings, pet saliva, penicillin can all cause "a lethal reaction down the line" if you become sensitized to them.

It is important to prevent inhalation of, or skin contact with epoxy sanding dust.

Most of the stories I've heard about epoxy sensitization were from the boatbuilding world, where-
a) the quantities used are much, much, much greater than you'd use to pore fill a guitar
b) people are working with epoxy all day, every day
c) it's easier to get the epoxy on your skin (ever tried to glass an overhead surface with epoxy?)

Still, you should take every precaution to avoid getting epoxy on your skin. If you are using an epoxy (resin or hardener) which is releasing significant vapors at room temperature, switch brands. If you notice any reaction to epoxy, stop using it.

For more on safety precautions with epoxy, see:
http://www.westsystem.com/ss/general-safety-guidelines-2/

It's a dangerous world out there, I guess!!

Cheers
John

Just a word in for egg whites as a pore filler. Cheap and non-toxic (just don't eat them raw!) Kim did a thread on them a while ago, and Colin uses them also. I used them on my build, and was pleased as far as I went (but next time I'll do one more round.)

Joe

I have wondered the same thing about pore filling, but I learned something years ago making window and doors. I was running my own small shop when one of the big boy shop owners came in and offered me a great management job in his shop. Up until that time I had always focused on structure and not the final detail finish, as the finish was done on site by some one else, I just had to prep. My massive spline tennon joinery and all the work that I put into making the door strong was meaningless to the clients, but they loved his product, a crew full of cheap help filling and sanding sold the work, but they doweled their doors, and to make it worse, would double drill to make the holes big so it fit together easily, then glued with poly foam glue thinking the foam was filling the gaps!
The epoxy pore fill looks like a nightmare to me, I have watched Todd's tute and it just seems yucky and
wrong.
I was at a cabinet shop the other day and they were finishing a large batch of mahogany doors, no pore fill. I asked the finisher about that and he said what's the problem, looks like wood, and the customer of this 7 figure home? Loved it.
I have never filled any of the oak on my window picture frame product and have never had a complaint, but that product is on the cheaper rack of products.
I understand both camps, but hey Dave B, welcome to the campfire and pass the smores.
Rob

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http://shastaguitar.com/
http://www.kalimbakit.com/
http://www.youtube.com/user/comfyfootgr ... ature=mhee
http://www.facebook.com/robert.renick.7

I owned a manufacturing business that made composite aircraft propellers for almost 17 years. Epoxy was the primary matrix material though we used urethanes, polyesters, cyanoacrylates, methacrylates, and dozens of other chemicals and polymers. Having hired roughly 150 people over those years I can say that about 25% of the population has epoxy sensitivity. This is basically, an allergy. For those with the allergy there is a threshold of exposure after which symptoms will appear. For most people symptoms will begin to occur within two weeks of exposure. We provided all the protection necessary for an employee to avoid exposure, including air evacuation workstations, but the responsibility to use the equipment effectively ultimately fell on the employee. When it became clear that the employee could not prevent symptoms from occurring, we'd have to fire them. Early on, it became clear to us that a trial period would have to be established to identify whether an employee had the allergy. Ultimately, we lost about 25% of new hires to the allergy. Once implementing a program wherein we conducted allergy tests, we STILL lost about 10%. It was always a problem.

Symptoms almost always manifest as a rash on the skin at the exposed area. The treatment was to eliminate the exposure and treat the skin with calamine lotion. There are very rare occasions when hives and lung issues can occur but they are extremely rare. We never saw any serious symptoms in the 25-30 people we had that showed the rash.

As an aside; my plant was scrutinized by Washington State Labor and Industries for chemical exposure. The state sent people out to attach air collection equipment to our employees for two days. The prescribed protection program, according to the State of Washington, given a fairly generous exposure to epoxy and polyester fumes, was that our employees were allowed to be on a voluntary respirator program. Essentially, each employee was allowed to determine for him or herself whether or not they wanted to wear a respirator during any part of our normal work day.

That surprised me.

It's up to you to decide whether or not Washington State bureaucrats have your best interests at heart but I will say that treating epoxy exposure as a dire risk greatly amplifies the actual danger of epoxy. If you don't actually have an allergy to epoxy then an occasional exposure is not something to fear. Wear your gloves (nitrile gloves are more protective than latex) and keep it off your skin. Use a respirator if you want to prevent minor throat irritation.

If you get a red, rashy itch on your hands or arms you are allergic to epoxy and probably need to find another way to fill pores.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

It's probably worth remembering that there are literally hundreds of different Epoxy products formulated for thousands of different applications. It is a dangerous practices to try and heap them all into one basket when looking at the issues of epoxy sensitivity, to do so is to use your experience with apples to grade oranges and sardines.

I had a sever reaction to Zpoxy that some may remember, those that do will understand why I just can't go there again.... yet with caution, I have been OK with Smith's Allwood Epoxy for gluing etc but even this product still smells very wrong to me. I will be testing West Systems 'low bloom' products as I am told these are not 'amine cured' and therefore may solve two problems at once. Like many lower grade epoxies, Zpoxy is very much amine cured. Higher grade products used in the marine industry (were regular or prolonged exposure is the norm) seek to reduce the use of amines in their formulations thereby decreasing the sensitivity issue for the users of their products.

Aside from being 'the' main trigger for sensitivity in users, the other important reason these high end companies like Bote-Cote and West Systems seek to reduce amines in their products is because amines can cause a real issue if mixed and applied at low temperatures or elevated humidity in the presents of carbon dioxide (don't breath on your work during application). In these conditions "amine blush" (a thin, often invisible oily substance) can form on the surface of the cured epoxy which, if you are to avoid curing problems with the finish itself, must be washed off with soap (cloudy ammonia is better) and water BEFORE sanding. Using abrasive first will only work the clear residue further into the cured epoxy as you sand and spread the problem.

I advice anyone intending to use epoxy products of any kind to fill pores, even those who to this point have not had a problem, to first read and understand what "amine blush and amine blooming is before you proceed, it could save you a good deal or heart ache.

Cheers

Kim

Thank you for this post, Kim. I am probably exaggerating slightly, but
it seems there are two groups: those who've had an adverse reaction to
epoxy, and those who will. For John Guzzwell it took many years, for me
it took a few months. Many will be in the middle. I think it's wise to take
at least the precautions one would with, say, lacquer thinner- once you become sensitized, even a hint of the stuff sends the immune system reeling.

Kim, so I take that you have started using epoxy again (OK, another brand / type) after all you've been through with?

Hide glue, fish glue, shellac and pumice folks....

OK getting off my snobbish horse now, but still, that old school stuff works real well (ok except shellac on a SS perhaps) and hasn't killed anyone.

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Build log

Agreed, though I now like the look of small, clear-edged pores. I've commissioned two instruments, the latter one by a very low-profile English
maker, in BRW and Spruce. The question of intentionality comes up..when I *saw the whole guitar, what he had done and made* (ca 1994)
the unfilled pores were quite beautiful. Not for everyone, no doubt.
I worked in a small production shop a few years later, and our virtual
mantra was "make it look machine-made.. by hand."

Hey Alexandru,

I completed a resto on a cheap 1973 Maton guitar last year. It was a real basket case and some components of that old beater just could not be fixed close enough to allow the use HHG, I needed something that I could rely upon to fill voids, so epoxy it was. I also used some carbon fiber on a special UTB created for that one to over come some design problems with the original, once again I turned to epoxy as the best choice. At the end of the day Epoxy certainly does have it's place at times no question....still using it made me itch man I gotta tell ya but I expect it was more physiological this time just from remembering the horror months of prednisone, phenergan and steroid cream needed to treat the first time I had a reaction.......calamine lotion....I wish, but as I said, not all epoxy is created equal and Zpoxy can be particularly nasty stuff if you let it get under your skin if you you know what I mean.

Carey, I too used epoxy for years prior to becoming sensitised. At one time as a teen in the 70's, I worked full time laminating surfcat hulls for 8 hours a day with never a problem except for a little cracked skin here and there. These cracks were caused by the drying effect of acetone, they were present on the hands of all the other full time laminators working at the same place. They were really quite minor clearing within days of leaving the industry never to return. Since then I have used epoxy on hundreds of projects, chemi-bolts in construction work, laminating spiral staircase handrails together, coating the rod binding of game fishing rods and countless other applications both in wood work and mechanics with products like epoxy muffler tape and devcon liquid metal etc, etc, etc and NEVER a single problem at all, no cracked skin, no rash, nothing, and then...........THAT itch, and my lower legs so swollen I could not pull trousers over them...............Maybe all this exposure without issue was my greatest undoing, had I had at least some kind of previous issue, some redness, some itching maybe, then it is unlikely I would have worn the same dust covered clothing to sand the cured resin again and this may have prevented me from having such an issue...maybe not, but regardless I think you are correct in what you say about there being two groups Carey, people really do need to be careful as things can change for anyone VERY quickly, and speaking from the point of view of one who was never affected it can be a tad unpleasant to be a member of that other group who warns and there is just no going back.

Aside from the obvious, such as wearing a respirator and gloves etc, here are 4 important tips to help you avoid becoming sensitised to epoxy.

1: Mix and apply epoxy with a fan running over you at all times. Epoxy fumes have a tiny molecular structure and will very easily permeate right through your cloths and skin if you do not blow them clear.

2: NEVER sand freshly cured epoxy. The instructions for Zpoxy will tell you that you 'can' sand in just two hours. You 'can' also set fire to your head too if you want, but this does not mean that you should. Always wait at least 24, better still 48 hours before you sand or you are messing with real danger, it's that simple.

3: Never wear the same cloths to repeat the sanding process, they need to be laundered each time. You can probably get away with the same overalls over clean cloths, but why risk it.

4: Do NOT wash epoxy from your skin with acetone. Once again acetone has a very small molecular structure, if you use it to wash your sticky hands, it will simply thin the epoxy and wash it straight INTO your skin. This is probably the quickest way for you to become sensitised.

Another thought, nitrile gloves seem OK to me, but I have read elsewhere that they are too thin and the structure of epoxy so small it can permeate through these breaking them down as they go and carrying toxins from the gloves into your system (I have no proof of this it is just something I read). Standard washing up gloves are recommended if you use epoxy on a regular basis as they are thick enough to prevent this happening.

Geez the eggs are look'in real good

Cheers

Kim

Distilled vinegar as a solvent for epoxies is a great tip- I'd not known of it.

As for fillers, the mahoganies have definitely gotten more washed-out as
the years go by, and what to do about it a good question.. at National, we
were using water-based filler filler, one or two coats at the most, with an
*alcohol wipe to clear*, then a coat of shellac to warm and seal, then Crystalac. A pretty good process under the circumstances, imo.

All these precautions just like Asbestos abatement? Just because it pops the grain? I'm just not getting it.
Anyone ever checked this out?
http://www.ecopoxysystems.com/products.html
I'm a bit confused as to what they're saying in the add section about it being pretty safe. The MSDS sheets is good for the resin but the MSDS for the hardener looks pretty bad. Maybe I'm reading it wrong? Of course it's bad if you have a peanut alllergy.

Chris -
That stuff popped up here (or was it ANZLF?) a couple of weeks ago. I think it was Dennis L. that ordered some samples and said he'd get back to us once he'd had a chance to try it out.

Mike

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Mike Lindstrom

Do you know anything to clarify what they say about it's safty? Or will I have to give them a call?

I called them and it looks pretty good. As you have to watch out for the hardener as with any other epoxy but there isn't a fume issue. Here's a site that the salesman referred me too that talks about it for anyone interested in it. They also have a clear and amber hardener. It's also food safe when curred so the dust shouldn't be an issue.

http://toolmakingart.com/

If it 'is' safe Chris, the big question remains does it sand OK??

Sure you can use just about any epoxy to fill if you have time and patience and lots of sand paper, but you really want one that sands easy if it is going to be worth using for this purpose. Maybe this stuff could be the beez kneez with just the addition of a little silica powder, but that should really be the job of the manufacturer so they can offer an addition to their line up because quite frankly you don't want to be messing with that stuff in your workshop either, the powder is very bad for you ( if you can still find it available). May be it would be worth calling them again to see if they do, or will do an easy sand formulation, something that works like Zpoxy without the exposure risk.

This is the thing folks, if there is a market, some one will certainly make a safer product suited to our specific needs. All the formulations and ingredients are already there to do so, but whilst people are still willing to buy and use a more dangerous product, that is all you will be offered because it's cheaper to make. If you want change, you will need to demand it with your wallet because few companies will do so solely on a conscience vote.

Cheers

Kim

Lots of great info here.

Though there is absolutely nothing wrong with an open-pored finish, most customers want glossy bodies. It appears to be the same with pianos.

I have used a solvent based paste filler, straight nitro, and West Systems 105/207 for pore filling. I use nitro for finish.

Some observations on each method:

For the paste filler, I would spray a sealer coat, pore fill, sand, fill again, sand, and apply another seal coat. Total days - about 4. Some people like the pores filled with a contrasting color etc., though personally I prefer the depth of a clear filler. I found that there can be some continued "pore shrinkage" with a solvent based paste filler as well.

The straight nitro was extremely labor intensive to apply. I did this on a few instruments as a proof of concept. Great depth, fantastic clarity, way too much time to be economical. Again, the possibility of continued "pore shrinkage".

I am currently using the 105/207 epoxy. No seal coat, fill one day, sand and refill the next, and sand/seal coat on the third. I sand back to the bare wood, just as I did with a paste filler. Using a squeegee for application helps tremendously. Visual pore depth and clarity are excellent, and because there is no shrinkage, I apply a thinner finish on the back and sides (as compared to a solvent based paste filler). I fill the rosette, but not the top.

As with any sort of chemical/dust, proper safety equipment is a must.

Great thread!

Anthony

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Anthony J. Lembo
Lembo Custom Guitars - www.Lemboguitars.com

I have been using West Systems pore filler (I think it is 207?) and I struggled at first. As Todd said, I find it does penetrate into the wood and I always feel I am sanding more off then I put on (i.e sanding some layer of wood away also). Sanding back to wood in this fashion always exposed new open pores for me. Lately I have been putting a coat of waterlox down first as a sealer. The West will cure over the waterlox and rubbing the waterlox on ensures it to be ultra thin. If I sand through when sanding the epoxy level I can just touch up with a dab of waterlox, which will also cure over the epoxy. I find this much easier than using a diluted epoxy wash. Later if I find any small pores that were missed I will drop fill with CA.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

Burton

Is that the Waterlox sealer you use and what are you using for finishing over it after the epoxy? I was actually thinking on my next Z-poxy job to start with the 50-50 epoxy to soak in a little and seal the wood, then use the normal coats and sanding. On my 1st 2 with Z-poxy sanded to bare wood I have a little shrinking into the pores after 1 year so I used the wash coat on the next 2 as I think I may have exposed some pores that I didn't notice sanding back to the wood.

Fred

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

Fred,

I am using the normal finish (it may also be the sealer?, I am not as familiar with the product line as maybe I should be), the one with red label. The high gloss one (green label) is harder to get a consistent surface. After the epoxy is on and sanded back I put another thin coat of waterlox over it and then scuff sand lightly. Lately over that I spray a shellac coat and then the Emtech 6000 which is easy to use but I have been having trouble getting the surface as smooth as I would like after buffing. I posted on the forum on the target website but have gotten very little useable feedback. I would also not hesitate to french polish over that base ground, the shellac sticks very well to the waterlox and the epoxy.

In theory, using an oil as a first coat should be a bad idea if we assume that anything penetrating the wood (especially an oil) promotes damping but in practice I cannot notice any negative sound affects at all. I do not do it to the top however. The first thing to touch the top is shellac. If I have anything to fill on the top (purfling mini gaps, pores etc..) I use either a lacquer stick or CA over the shellac if it is close to the spruce. Depending on the rosette sometimes I will mask off and Epoxy fill. I have found that the West Systems epoxy penetrates even deeper into the spruce than other woods, which is not a surprise.

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Burton
http://www.legeytinstruments.com
Brookline, MA.

I'm not saying it's moot as a pore filler (maybe moot to me at this time because of personal health concerns then application bumps. That hasn't stopped me yet. ) but I'm trying to understand all the benifits to it over other fills. But so far it seems like the one benifit to it over other pore fillers is it pops the grain and it's somewhat clear or amber. I understand the use for it with the waterborn that David mentioned. And I understand the process will get easier just like the second time I used a paste filler. I'm just saying with all the health issues and wearing a Respirator not a dust mask and the washing of clothes etc. that's been mentioned it just doesn't seem worth it to "me" for just poping the grain.
That's why I ordered a sample kit of the Ecopoxy to give it a try. If I can use an epoxy that I don't have to worry about the health issues( especially the dust and fumes and if it's self leveling which would be a plus) and does a fine job then I'd have another option and perhaps a healthy one and have something that pops.
He's another question that came to mind on my way to Woodcraft to get some super blonde shellac flakes. It has to do with what Hesh said about not wanting to have epoxy as a finish. If people are putting on a layer of a epoxy "Finishing Resin" then why can't that be the finish? Does it not get hard enough or buff? The Ecopoxy is used as a coating as that's what it's designed for.
And is there any reason that one couldn't pore fill the back just after the back plates are thickness sanded?

I'm also not bashing epoxy and thought this was a pretty good discussion. Pretty much showing different points of view and bringing facts and questions and answers to the table. If I've given that impression then I apologize as that's not my intent.

Right behind you, Todd!

The school where I learn some 20 years ago just started to use epoxy soon before I left the school. So that's why I decided to try it when I started building back again. Tried other stuff but as others pointed out, nothing pops the grain like epoxy. They where also scraping it off rather than sanding it. So without questioning myself too much, that's what i did. When I heard about people sanding epoxy during the pore filling process, I gave it a try. It turned out to be waaaayyyyy harder, messier, gunkier, slower, wateverer than scraping it off. One trick I believe I read here, once the epoxy is fully spread, but still soft, I pass a rag (or heavy duty paper towel) over it to even everything out and get rid of whatever runouts that might still be there. Makes your life a lot easier when scraping it off.

Hope this helps!

P.S.: Still where protective mask when scraping though...

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Alain Moisan
Former full time builder of Acoustics, Classicals and Flamencos.
(Now building just for fun!)

Never get CA on your teeth. It will kill them.

I thin 5 minute epoxy with a bit of alcohol and squeege it on. After about 2 hours MAX.,I sand it off. At that time period,it is "leather hard",and rolls up in little footballs and falls off. I have no problem with fumes or dust. I repeat this operation. It fills the wood fine. Then I can get a very nice finish with just a few coats of nitro.

If you wait too long to sand epoxy,it is like sanding concrete,and I'm too old for that,or breathing the dust. Maybe you guys are waiting too long to sand your epoxy.