MIMF

There are some other threads on some of the other sites like Mando Cafe that have additional info, and some folks propose skipping scruff sanding between coats if recoated within an hour or so, but General Finishes says:

"Surface must be clean, dry, and free of all contaminants. Sand with 220 grit or finer between coats."

The only schedule I see on the Stewmac site is the general one for waterbased finishes, with link to GF High Performance Topcoat...and GF also suggests sanding between coats on that product. Is the schedule a legacy doc from EM-5000, etc. days? If GF gave a recoat time without sanding, I'd love to know it would not generate witness lines on thin finishes.

One of the Portland area builders that has been using Enduro-Var for a couple years on his 60-70 guitars per year has a schedule based on epoxy filling (def not suggested in GF's use notes) - I have four more necks that will get the Enduro-Var finish in the next month, so will try that schedule on the two specs and the GF schedule on the commissions.

FWIW, I gave up sanding between sets of coats with nitro lacquer - no difference in end product, and it saves some time. Still getting .0035-.004 thickness after sanding, so the slightly rougher finish at standout and buff does not make a real difference.

Good info Todd.
So - even over epoxy fill, you did not have any de-lam on heel cheeks or FB edge??
Nor did I, but I was on raw wood, so I'm curious about adhesion to epoxy.

And, you like the feel for a neck? You didn't use flat - from you buffing comment - so did you leave the back of the neck sanded to 1000 or so??
That's what I did - to me the feel was better.

We have not done epoxy fill/Enduro-Var yet...we will be using the Greven schedule for two of the four necks in finishing right now to see how well things stick (the guitars are spec build, so we might get to keep them for more than away or so once ready to ship). Greven uses System 3 Silvertip Fast with thickener for his filling, while we use West 105/207 - a little risk there, but both are low viscosity systems that do not blush. John has a couple hundred out in the wild and has not seen any issues which he's reported, and - given his lengthy experience with a range of WB systems - I am confident there will be no real surprises.

I just did a tabletop in GF enduro-var and tried recoating via brush without scuff sanding after just 1 hour. The surface tension of the wet finish combined with the gloss of the previous layer cause the fresh finish to pull back in fisheyes. Several more passes with the brush caused it to coat completely but I figure that was over-brushing. Scuff sanding with 400 grit Abranet took care of it with a mere 30 seconds of sanding and 30 seconds more to wipe off the dust with a damp sponge.

Buffed to gloss, but waiting for the owner to decide on what he wants. I shoot gloss and sand to 2000 for some clients that prefer the slicker feel, and I expect Endure-Var might be similar in nature. The most lacquer-like of the WBs...had to be to get me to try it.

David King wrote:I just did a tabletop in GF enduro-var and tried recoating via brush without scuff sanding after just 1 hour. The surface tension of the wet finish combined with the gloss of the previous layer cause the fresh finish to pull back in fisheyes. Several more passes with the brush caused it to coat completely but I figure that was over-brushing. Scuff sanding with 400 grit Abranet took care of it with a mere 30 seconds of sanding and 30 seconds more to wipe off the dust with a damp sponge.

So, literally just a swipe of the 400 to give it a wee bit o tooth?

I've used both EV Stain and Gloss recently over epoxy grain fill. In both cases i used shellac over the epoxy as a tinted layer and as a tie coat to the EV. Satin went over the the shellac perfectly, three coats sprayed, sanding lightly with 600 between coats.

For the Gloss, shot three coats on day one, 1-2 hours between coats, block sanded well with 600 between coats. Sanding was more for leveling than tooth/adhesion. Sanded to dead level the next morning, then two coats without much sanding between coats, 45 minutes apart. Let it sit five days in warm weather, sanded out with 1200 then 2000, polished out the Menzerna on a 14" wheel Polished as well as any finish I've ever polished. Polished very quickly and to a very high gloss, very pleasurable. Finish is still a bit soft, but very tough, I expect it will harden up some over the next week or two.

I'm thinking the shellac is important as in a few places where the shellac was thin, the EV Gloss did not flow well until a coat or two built up.

Drop filling with EV Gloss works very well, solid enough to block sand with overnight dry/cure. The finish is tough enough that sanding out the drop fill does not break through the base easily.

Both EV Satin and Gloss spray well enough. Both resist running and sags well. I used a small gravity gun with a 1mm tip for the satin and a larger HVLP gun with a 1.8mm tip for the Gloss. Water base is a pleasure to use of course.

Once cured, this is one tough finish. The one with Satin went out for testing with a friend who played it daily and gigged it a couple times a week for a month. It then went to a festival where several dozen people played it before it sold, at which point it did not have a mark on it anywhere.

Hand feel with both Satin and Gloss is excellent, very satisfying. The neck feels silky smooth, no need to break the gloss. No drag at all like some water based finishes I have used.

Okay, I'll admit it, I like it

so happy i started this thread ... Oct. 2015
wow, time flies

I'm happy you started the thread too!

Yes, thanks for this thread - very interesting and informative.

How easy is it to clean the spray gun after using this? My only experience with water based spray finish is with latex, which for me is really a bitch to clean up afterwards. One of the great things about lacquer (for lazy me) is that I can leave it in the gun for hours, then come back and spray again. I could probably clean it by just putting thinner thru it a few times, but I do take out the needle and nozzle and clean them when I'm done for the day.

I assume that the General Finishes waterbase products dry hard and insoluble, and if they harden in the gun you are SOL. What is the time course for shooting and cleaning?

Peter, I have not had much trouble. I empty the gun and run water through it and leave the gravity cup full of water after I'm done shooting even if I will be applying another coat in an hour, though that not be really necessary. When ready for another coat, I dump the water, spray out whatever remains in the fluid path, reload and shoot. When I hang it up for the day, I run water, then alcohol or acetone through, break down the gun and wash all the parts, dry and reassemble. I wipe out the gravity cup. Having sprayed lacquer, varnish, shellac, etc. EV seems easier to clean up because of the water base. EV does not set up quick in or on the gun like latex.

I got lazy once and did not break the gun down and three weeks later when I used it, no flow. Broke it down, used a wire to clean ports, fingernail scraped residue off the needle, back in business in less than five minutes.

My behavior was pretty much the same as Craig - except I never left water in the cup.
The thing to keep in mind is that this is a cross-linking PU.
So ... if you let a film cure in the gun, you can not "wash" it out like nitro. Nothing dissolves the cured film.
You have to flake it out like Craig described. It is not really a problem on polished metal parts, it comes right off. However, it sticks like crazy to rough bare metal.
And you have to be sure to clean out the flakes very well, or they will foul the gun.

Do you spray the finish right out of the can, or do you thin it in some way? What orifice size do you use? All of my spray background is automotive finishes, which are like water, very thin.

Brian

Thanks Craig and Chuck, that's helpful. And I have the same question as Brian - do you thin it?

I've not been thinning either the EV Satin or Gloss when spraying it. I used a 1.0mm tip on the Satin and a 1.8mm on the gloss, but not because of any major technical consideration. The Satin went down well with the 1.0mm tip, but the Gloss seemed to want a larger tip.

My guns have plastic gravity cups. I got a cured film of EV once and it came off readily with a little alcohol soak.

I only leave water in the gun for an hour or so. More than that might cause corrosion on metal parts.

Cleanup with acetone or alcohol is also fine. If you let the EV cure completely (days or a week) then a long soak in acetone will break it down.

good to know acetone kills the cured coating - didn't try that.

On spraying, I used a 1mm tip for gloss, which worked well for me.
I did not thin it - can't imagine putting any more water on a guitar than need be

Craig Bumgarner wrote:I've used both EV Stain and Gloss recently over epoxy grain fill. In both cases i used shellac over the epoxy as a tinted layer and as a tie coat to the EV.

So, Craig - you did this about 6 months ago. Everything still good? I was really interested to see whether reports of compatibility with your schedule was successful long-term.

Has anyone tried mixing EV Satin and Gloss? I know they make a Semi-gloss but don't have any on hand and was hoping to apply finish today. I have both Satin & Gloss and thought a mix might give something in between. I read of someone mixing Satin and Semi-gloss with good results. If no one has tried it, I'll try on scrap anyway, just see what happens.

Steve, I think its holding up okay. I haven't seen any of my EV jobs after they went out, but I'm not getting any complaints.

Found this in the product description for Enduro-var Gloss on Amazon: .... "Can be mixed with Enduro-Var Satin Urethane (25451, sold separately) to produce a semi-gloss finish." Encouraging!