Official Luthiers Forum!

Hi guys. As plenty of you know I’m a new builder with way more questions than is good for me. At this point I am working on #5 with wood in the “shop” for 6 and 7.

At this point I have tried several different finish applications and materials, and honestly not done any of them enough to get good at them. I don’t think I’ve found that: “this is my path thing”. However, I find myself consistently leaning toward a spray system finish, although the last was a FP with RL.

That said I’ve yet to GET a spray stem OR pick a finish. I have done one with nitro rattle cans, but honestly the stuff scares the crap out of me for health reasons. I don’t want my kids or wife anywhere near it either. Therefore I’m leaning toward picking a route which involves HVLP and a WB finish.

My process for learning so many different things, at least till now has been: “pick one and go until you get it”. (I mean this is even the 5th OM guitar style haha). So I’m predicting this will me my next attempt when it comes time to finish one out.

So my inquiry comes down to WB finishes I suppose.

In moving away from nitro does one loose a great deal of forgiveness?

Do WB finishes melt into the last layer like nitro or is that due to the chemical solvent, which would be missing.(which I assume is the case)

I apologize for trolling so many questions all the time. I know really mastering something comes down to lots of trial and error, but I’d like to avoid obvious pitfalls that others have made, thus the questions.

Peace
B







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Most waterborn finishes have limited melt in. Once you start, you need to keep going. It’s just the nature of the product. Nitro has essentially an unlimited burn in time. You can go days between applications. In my opinion, General Finishes Enduro-Var is one of the best waterborn because of the amber tint. Em 6000 is good because of relative burn in time. But is problematic on dark woods (blue haze). I’ve given up on the waterbornes. Too much risk. Nitro is my favorite. Dangerous? Yes.

I've only used waterborne finish (EM6000) so I can't tell you about nitro, but I can share my experience with EM6000.

I initially chose to try waterborne because I didn't want to deal with the nasty toxic solvents in nitro, the fire hazard, the need for spark-proof switches, the need to exhaust fumes out of the building, and the off gassing period, etc. I also chose to go with the brush on approach because I don't need a spray apparatus or a spray booth, and I don't have to wear a respirator.

My guitars have been looked over by quite a few builders and many of them assumed the finish was nitro based on its appearance. Many were doubly surprised when I told them it was brushed on. It is definitely possible to get good results. If you are willing and able to set up for spraying, I think that would reduce the total length of time needed to build up the finish compared to the brush on approach.

I have not experienced the "blue haze" problem with EM6000 on dark woods like rosewood, Maccassar ebony, or ziricote. IMO, the rap on EM6000 causing a blue haze is due to applications that were too heavy and/or intervals between applications that were too short.

I've had a few "opportunities" to repair chips in the finish along the edge of the fretboard that I caused when filing the fret ends flush. On both guitars where that happened, the finish had already cured for at least four weeks. The new finish blended in perfectly with the existing finish and the repairs were completely invisible.

Mike is right that you shouldn't stop in the middle of a series of finish applications and start right back up days later like you can with nitro, but if you do a light scuff sanding first, you're good to continue.

I have a pretty detailed protocol written up for how I use EM6000 with notes that I can send you if you are interested. It would give you some info that might help in your process of deciding which way to go.

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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 think, between Enduro-Var and EM 6000, the latter is more friendly. You have more time for late coat additions. Guess it crosslinks slower. If I were a new user, I'd go with EM 6000. You can always overspray these at a later date. The issue you will run into is something called "witness lines". That is where you sand through a layer that is not truly melted. If I were going to do something like that, I would sand down a bit, then apply enough coats to avoid that. But, once into that procedure, you never know.

Jay, I am impressed you can brush on with great coats. What exactly is your time between coats (I always used 30 minutes)

I have used EM6000 and EM9000. Of the two I would pick EM6000. I have found with both products that the wet film thickness is very important to avoid a blue haze. Em6000 is more forgiving of the two in avoiding a finish with a blue tint. I have had real good results with EM6000. As mentioned by others it is pretty forgiving. Each coat does melt into the previous coat. Em9000 I believe is a lot like EM6000 with a higher amount of solids. I found it very easy to overspray each coat and wind up with a blue instrument. I believe that Jay Litchy uses EM6000 (at least I have seen a video with him using it). I have been very impressed with his finish work.

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http://www.Harvestmoonguitars.com

+1 for EM6000

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Steve Sollod (pronounced sorta like "Solid")
www.swiftcreekguitars.com

I use EM6000 over Silvertip like Jay Lichty. I shoot 2-3 wet mills per coat, 1hr apart, @ 70° and 43° RH.

I do have a couple of blue guitars out there. Live and learn..

Cheers

Whatever route you go, don't go thinking that WB finishes are non toxic just because the solvents aren't oil based. All the same safety protocols required for nitro also translate to WB, save for explosion proof fans and switches.

I go three hours between coats to err on the side of each coat being dry before the next coat. Since brushing requires adding retarder to keep the EM6000 from setting up as you are brushing it on, I've been conservative about the interval times. To me, this is the one disadvantage of applying with a brush because those intervals add up. I really should do some testing to see how much I can shorten those times and speed up the finishing process overall.

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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

Just so you know, I still use EM 6000 and Enduro Var. Just ordered some EM 6000. I just don't feel like its necessary to devote ones self to just one. I used to only do EM 6000. No more. Depends on the guitar. I will take to heart a longer time between coats. I never heard that before.

I started out originally with four-hour intervals based on what I read several years ago on the Guitar Refinishing and Restoration Forum from EM6000 users using the brush-on method. I don't know if that four hour interval was based on anything like actual testing or not. I reduced that to three hours without problems so it may be possible to go shorter depending on things like temperature, humidity, and thinness of coats.

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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

Of course. Big for me is the fact my family lives where I build (well not in the same room but you get it). If I can avoid super toxicity then ....
But yes ... precautions followed . I agree



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The waterborne finishes we are talking about are not super toxic. Even nitro is not super toxic (but it ain’t super nice). Now, the modern stuff they paint cars and airplanes with, totally different subject. Same with poly’s for guitars. Nonetheless less, if it ain’t pure air, use a mask. A good one.

Most of the MSDS I have read have waterbourne having the same levels of concern as nitro with the exception of flammability. You should wear a mask and protect skin with both.

Are your necks holding up with the waterbased? Breaking down where the arm hangs over the lower bout? Those were some of my issues. Do they dull over time, another issue I saw.

I used KTM9 and EM6000 years back, (Never Enduro-Var) both brush and spray. Was encouraged by the likes of John Greven, Mike Doolin, and Gerald Shepard. Even Charles Fox. I was never able to achieve a finish that looked as good or held up as well as a professional nitro or catalyzed urethane application. I don't know about Greven but I think the others abandoned waterbased.

Has anyone here been selling guitars in the 3K plus range over a long period of time and finding customers satisfied with a waterbased finish?

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

My body chemistry destroys EM6000 on necks I switched to royal-lac for necks. All of the instruments I have sold with Em6000 on the necks held up well. I have had no problem on the body of the instrument and some I have had and played for seven or 8 years.

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http://www.Harvestmoonguitars.com

Here's Jay Lichty's video on EM6000:

https://www.youtube.com/watch?v=FXr9jYoikcA&t=621s

Question for those still using EM6000. What have you found the useable shelf life to be of the finish? I used to use it but back then it was said most waterborne finishes had a one year shelf life, from the manufacture date. With this being the case I found it to be a very expensive finish for someone only finishing a couple guitars a year. Have any of you used it more than a year out? I know with lacquer the stated shelf life might be a year but I have had no problems after a much longer time.

I’ve been using em6000 and its precursers for quite a while. I but it by the gallon and pour it into quart mason jars for storage and use. Sometimes, it takes me a couple of years to get to the bottom of the last quart. I’ve had no problems with it. I stopped having problems with neck finish dissolving from sweat when Target went from USL to em6000. The em6000 will dissolve under alcohol.