Official Luthiers Forum!

I'm curious what folks are using for finishing.

I've been using EMTECH EM-6000 for some time now and feel like I've dialed in my technic. It's pretty forgiving and easy to spray on, level sand, and buff. I'm pretty happy with it. Seems like every finish has some things people may not be thrilled with. Do you love the finish you are using? Is it relatively easy to use? Brushed, wiped, or sprayed? Thoughts?

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

For the most part I use Nitrocellulose, but I'm thinking of using epoxy as a base on the back and sides and top coating the back ,sides, and top with fewer coats of nitrocellulose. For the smaller bodied instruments I generally build I am less interested in a responsive back and more interested in loudness.
I did like using the original Enduro-var as a waterborne , brush on finish, but I have heard the new formulation is not as good, so for now it's Nitro.

I'm a beginner builder and have finished 3 guitars with Nitro.
Nitro (Behlen/ Mohawk Stringed Instrument Lacquer / Reducer/ Vinyl Sealer/ Retarder) has been easy to spray, easy to clean, ok to sand and buffs out beautifully.
But I have had a problem with the lacquer cracking.
Jeff Jewitt has stated (twice) that he switched to Urethane for that reason, cracking.
I am moving to your EM 6000 for the same reason. Also, NC Lacquer makes me sick, even a whiff.

MORE:
Sometimes it cracks at week 8 and sometimes at week 52, but it has all cracked. One Sitka top was scraped back to bare wood and re=finished, with a thinner schedule. It cracked a year later. I have been posting about and working on my finish thickness. I basically cut the number of coats in half, yet my third guitar developed a crack at week 16 (it was curing while I repaired the cracked top/ lacquer after it fell on hard concrete).

_________________
Measure Twice,

Karl Borum

I finished my last using Post Cat Royal Lac and really liked it. It sprayed incredibly well, cured fast, sanded easily, wasn’t a health hazard, and looked fantastic. In the future I’ll be choosing between Post Cat RL and nitro. The only advantage nitro has is repairability.


Sent from my iPhone using Tapatalk

I've been using Royal Lac for the last 5 or 6. Got some Royal Lac Post Cat coming for the one on the bench so I'll be trying that out next month.

_________________
Steve Smith
"Music is what feelings sound like"

Most of my guitars are shellac the alternative is Nitro. Those two are my favorite finishes. I've tried just about all of them except for UV stuff.

I'm not a fully seasoned user yet, but I am very happy with the Cardinal UV cure finish I am currently working with. I've also used the following on guitars: Royal Lac original, Royal Lac post cat, regular shellac (French polished), and Enduro Var over Silver Tip pore filler. All things considered, I am partial toward the more durable modern finishes like Enduro Var and the UV cure stuff. I want maximum protection. The beauty of UV cure, compared to the other modern finish options, is the elimination (or near elimination) of waiting around for curing.

I've been using one or another of the oil-resin varnishes almost exclusively for a long time. I keep having to change brands when the manufacturers change formulas or pull the stuff off the market for whatever reason. Currently it's Murdoch's 'Ure-alkyd 500' floor varnish from Sutherland-Welles. I brush it on. It cures nearly as hard as nitro, but it's tougher: more scratch resistant. It also goes on very thin; I end up with a film about .0025"-.003" thick, almost as thin as French polish. It's a fair amount of effort to use, and it does have some drawbacks. In particular, it can be hard to get it to cure on some tropical woods. It sure looks good, though, and should hold up better in the long run than nitro, which is not chemically stable.

Other than that I use shellac as French polish. It's not as durable, but it is more flexible, probably has lower damping for a given thickness, and it's traditional.

How many coats do you use, Alan? And do you sand between coats?

Alan, would a shellac barrier coat help on oily woods?

Nitro is what I primarily use. It’s not perfect but it has two great advantages - it is simple/forgiving to apply and it is desired/accepted by many buyers who, rightly or wrongly, perceive it as the premium finish. It’s also a fact that its main disadvantage - its instability- is actually seen as an advantage by a significant portion of the guitar-buying public, who perceive checking, flaking, yellowing etc as desirable patina.

I also love shellac as a finish.

Recently, it was recommended to me to try a 2k rattlecan product on a maple fb/neck refin and I was pleasantly surprised by how well it laid down and buffed and by its durability. I will use it again in my repair shop on poly-finished instruments.

UV cure is interesting and promising but I’ve yet to try it. From the repair perspective there is a famous manufacturer who uses a UV cure finish that, in service, is well known to repair folk for being prone to dramatic adhesion failure. I have no idea if this is caused by the product they use or their production processes but it is certainly A Thing.

EM-6000 for me as well, for the same reasons you stated Steve.

I have found CA to work better as a barrier for oily woods than shellac with this varnish. Their 'Hard Sealer' also seems to cure better on them than the varnish itself. UV lights do a lot to speed up the cure time in those cases too, although the first coat can take several days. Do not recoat until the first coat has cured enough to 'dust' when sanded: the second coat seems to seal things in sometimes so that the first one doesn't cure, and the whole thing can peel off later. DAMHIKT

My finish schedule begins with a French polish type shellac and pumice fill. When possible this is allowed to settle in for a week or more after the last coat, and it's then sanded back to the wood (using 220 paper), leaving the pores filled. Shellac on the surface has a different refractive index than the varnish, and produces a 'veiled' look that can be spotty in reflected light.

That's followed by three 'fill' coats of varnish, with the first being hard sealer. If that doesn't harden (often enough on ebony fingerboard edges) I'll wipe back the finish there with acetone, and seal with CA. The filler in the pores always absorbs a bit of varnish, and those shrink back some. I'll leave the three coats to cure for a week or more if possible, and then (again) dry sand back to the wood. Now I'm ready to build the finish.

I generally build up with 8-10 coats of varnish. This stuff goes on thin: it was meant as a floor finish and tends to run unless you really pull it out thin, but it does give plenty of brushing time to do that. I use a soft 1" brush. I do at least one coat a day, and two when things are going really well. Try not to let it go more than a day between coats, as this risks poor adhesion and 'witness lines'. I sand between coats with #400 paper, just to knock down dust or 'sand' (the inevitable particles of dried varnish from the brush) and remove sags or small runs. If it's been more than a day a more thorough sanding is in order to produce a uniformly dull surface with higher surface energy. Often when doing two coats a day you can feel the drag on the brush from the high surface energy of the mostly-cured varnish, which indicates good adhesion (and makes it a little harder to pull it thin).

Always keep in mind that good finishing is all about surface prep, and the last coat is the surface for the next one.

All through this 'build' phase I'll check after each coat for 'cats eyes': low spots that need filling. I fill those with CA, which seems to be quite compatible with this varnish, before sanding.

Once I've built up enough coats I like to allow some cure time. Varnish cures by an oxidation reaction, and this goes a lot slower than solvent evaporation. It often takes a few months for varnish to fully cure and stop shrinking, but most of that will happen in the first hours, and almost all in the first week. This stuff gets really hard if you let it cure beyond a couple of weeks, and can be difficult to rub out.

I usually start wet sanding with #1500 paper, to get through the hard surface layer. Then I'll switch to #2500.

If you go through into the wood at any wet sanding or polishing step you'll need to dry sand and put three or so more coats on the whole surface. It seems as though there is stuff in the water that reacts with the varnish and interferes with adhesion, producing a lot of witness lines if you don't dry sand.

As with any abrasive, you're doing most of the material removal with the coarse paper. The other steps are just taking out the scratches from the previous one. I alternate between going in circles and along the grain with successive abrasives. It's easy to tell when you've gone from having one scratch pattern to the other.

The abrasives I use are #1500 and #2500 paper, fine pumice and water, rottenstone ditto, and Novus' #3 and #2 plastic polishes. The rottenstone and polishes are a bit soft for this finish, and you may need to rub hard. Meguiar's polishes are more aggressive in general, and you may find they work better for you. A second run with the fine polish may be needed after a week or so.

With all that effort this generally ends up being a film about .0025"-.003" thick. The wood grain structure will telegraph through
any finish that thin, especially one that's as flexible as this is. Withal, it's quite hard and tough. It resists scratching well, but can be dented. It doesn't seem to crack from most dents, though.

Hope this helps.

I am a nitro guy I did dabble with the cat varnishes but in the end I still prefer the Nitro. I am geared up for it. I have a booth and I do not live in a populated area. I also used emtech 6000.
For me it all comes down to repairability. I use azko nobel nitro , 2nd choice is mowhawk or shirwinn williams. I stopped using the vinyl seal and use flake shellac and ever clear for the sealer.
I so control the booth atmosphere so I still wait 14 to 20 days for good cure time. I also will say the level technique and prep and more important. I no longer use micro mesh I use T Act paper and Assilex exclusively of the finish work. I still use Menzerna cakes for pre buff and dual action hand buffer that really took my finish to next level

_________________
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

I am finishing up a batch of guitars using EM6000. I do like it, but I don't know if I love it. First off you have to be almost perfect with your pore and gap filling. The finish isnt thin enough to fill any of the gaps. You can drop fill, but it's kind of a pain. I suppose you could maybe thin it to help fill gaps, but then I would worry about it running (which it is prone to do if you spray too thick). You cant wet sand it as it's a water-based finish. You cant use naphtha on it to clean it (I understand they have an additive to combat this tho) because it will cause major ghosting.

I do love the cure time! Same as Mr. Hall, I use Tolecut and Assilex exclusively now (just gotta remember to toss old sheets).

Buffing is tough. I had to change how I buff compared to nitro. Heat buildup is a real problem with EM6000. Move around faster and run your buffer slower. It does buff nice, you just have to dial in procedure a bit more. Learning this can be painful.

The best part is the smell doesn't upset the Mrs.

_________________
-Marcus
http://www.bailieguitars.com
Instagram | YouTube

I am a lucky guy , because an uncle of mine was a furniture restorer and I have learned french polishing both with shellac and nitrocellulose as a child! So for me my guitars will be french polished, the top with pure shellac, back and sides with hard shellac wich is less sensitive against scratches.

I used EM6000 as a brush-on finish on 12 guitars and then switched to Endurovar. I liked EM6000 fine and you can get a very nice gloss finish with it. I especially like it's repairability. The problem with it for me was that since you have to use retarder to brush it on, it builds reeeaaaly slow. The individual coats were very thin at less than 1 mil wet. By contrast, Endurovar brushes on without any need for retarder and has higher solids content. Combined with shorter intervals between coats, using Endurovar reduced my finish application time from about 8 days to 2 days and the quality of the finish is just as nice as with EM6000.

I haven't tried the reformulated version Endurovar II yet. I'm about to open up the last can of original Endurovar I have for the first time.

The last thread I remember that discussed Endurovar II from a year and a half ago http://luthiersforum.com/forum/viewtopic.php?f=10101&t=54837 had initial mixed reviews of the reformulated product. Some poor results and some good results. Any updates on using Endurovar II?

Some people who posted in that same thread were giving High Performance Topcoat a try as an alternative to Endurovar II. Does anyone have an update on how that has worked out?

 


I wet sanded EM6000 on several guitars using micromesh pads after the finish was cured and it worked great. Very tedious though.

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

It could be a timing thing. I got a ton of ghosting (I think thats what its called) when i tried to wet sand. Maybe I did it too early.

Most (if not all) of my issues with EM6000 very well could be attributed to user error.

_________________
-Marcus
http://www.bailieguitars.com
Instagram | YouTube

When I sprayed EM6000 I wet sanded but I used low-oder mineral spirits instead of water. Worked fine.

_________________
Steve Smith
"Music is what feelings sound like"

I use yellow Mirka or 3M paper and sand EM6000 dry so I can see what I’m doing. I clean the dust and seeds off of the paper by wiping it on a carpet piece as I go.

Rather than water, like Steve, I use odorless mineral spirits to wet sand EM-6000, and it has worked fine for me. I use a HPLV system which produces warm air, which probably helps. I have had no need for retarder. I am open to other finishes, but it seems every finish has it's challenges…

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

I haven't had that problem in over 20 years using the same nitro. Maybe it's the climate around here but no cracking.....yet.