Official Luthiers Forum!

I've recently had several requests to again share my process for finishing with Ultima Spray Lacquer. It's been a couple years since my previous post on the subject and I have since changed my process somewhat. I certainly don't believe that my system is the only way but it works for me.

First, a few comments. A couple years ago I mentioned I had previously had problems with inconsistent viscosity from order to order of Ultima. That seems to be corrected now. Regarding waterbase wood finishes in general, between around 1995 and 2005 I saw significant improvements in them. I have not kept up with it as much lately but it appears the innovations have slowed, and in my opinion, for waterbase guitar finishes, there is still a need for improvement in the area of hardness. That said, modern waterbase finishes are much harder than they once were. I am aware that many people poo-poo waterbase finishes for one reason or another. For me it's just a matter of trade-offs. There is no "perfect finish", each type has its own pros and cons. If you want to do a search on previous posts you can read a host of conflicting opinions, including mine. I will say that in my opinion, as I consider all criteria for a perfect guitar finish, I believe if waterbase finishes were a little harder yet retained their great other properties, they would be pretty darn near the "perfect finish". Then again, opinions are just opinions and opposing ones are as welcome as mine.

Many people have problems with their waterbase finishes "shrink-wrapping" into the pores of the guitar after a few months of curing. This happens with waterbase for the same reason it happens with nitro; because the pores were not completely filled with a non shrinking filler before they were sprayed with the top coat. It is imperative that the pores be filled to the level of the surface of the guitar body before spraying top coats. Another reason for the shrinkage is that people do not wait long enough for waterbase to cure as they move through the steps of the finishing process. Some waterbase ads still claim that waterbase can be sprayed, leveled, and buffed in a matter of a couple days with satisfactory outcome. That is simply not true. Conversely, the longer you can let the finish cure before final leveling and buffing, the better the finish will look in the long run.

I should also mention that some inexpensive spray guns will sometimes turn a waterbase finish blue as the finish reacts with the metal tubing in the gun. I use a stainless steel Apollo turbine system with great results.

I use epoxy pore filler. The epoxy does three things. I provides a good surface for waterbase finish to adhere to, it fills the pores, and it brings out the natural beauty of the wood in a way that rivals any of the solvent based finishes. I still use "System Three" epoxy but there are others out there thatwork well. There are many comments on this site about how to use these fillers so I’ll not repeat them – just do a search and they will pop up. If the epoxy is mixed correctly it will work great. It will be very clear, and sand perfectly level.

So, here we go, my finish spraying process (updated):

I spray at 35 to 40% humidity.

I use a total of 12 to 18 thin coats depending upon the pore structure of the wood and how well the epoxy filled the pores. The top will require less coats. I shoot for a final finish of .006" on the top and back, and up to around .010" on the sides. Because necks get more wear, I finish the them a little thicker.

Spray Session 1:
Spray 3 to 5 coats 1 to 2 hours apart,
Wait three days,
Partially level by dry sanding w/400 grit, blow off then gently wipe off the dust. You don't need to perfectly level at this time, just take the high points down. Sanded areas will be dull, unsanded will be shiny. You can leave about 50 to 75% shiny.

More comments:
1. Ultima burns in great. I have often leveled with 330 grit and had no problems, but after leveling it's always good to take a close look at your finish after the spraying first coat of a session. I have accidentally made deeper scratches with sandpaper that did not burn in well. That's much easier to correct this problem if you catch it after only one coat.
2. Dry sanding as opposed to wet? yes, it will take more sandpaper to dry sand but paper is cheaper than labor. Also after the early coats dry, there is almost always a few deep pores and ,low spots. If you wet sand over these areas the wet dust powder from will collect in those low areas and dry white. Then you have to dig it out or the next spray session will seal the white powder in and it can be seen. The powder blows off easily if you dry sand.

Spray Session 2:
Apply another 3 to 5 coats 1 to 2 hours apart
Wait three days for the finish to cure,
Again, partially level by dry sanding w/400 grit, blow off, then gently wipe off the dust. I still do not perfectly level at this time, I leave a few shiny spots here and there.
Wait three days for the finish to cure

Repeat process for subsequent spray sessions but before spraying last session, WET SAND the whole guitar level with 800 grit and spray two thin coats - just enough to cover the 800 grit lines.

I then wait SEVEN days to allow curing before I do final leveling and buffing. You can wait as along as you wish to do the final leveling and buffing. The longer, the better.

I final sand with 1000, 2000, and 2500, then buff. I have at time skipped the 1000 grit session without causing a problem.

I hope this is helpful:

Thank you, Gerald! Yes very helpful.

Target does have a new product out (actually, it's about 2 years old now) called EMTech6000. This is an upgrade to the USL. There have been a few of use trying it out, most notably would be Tim Metcalf, who's sprayed it on 5-6 guitar now (used USL on a previous 50 or so) and reporting it appears to be a bit tougher than the USL. Thought I'd mention it

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

Thank you Gerald. I've used your schedule. I certainly agree you can get a beautiful initial finish with USL. Have you used it long enough to have any thoughts on long term durability? Especially necks.
I've also noticed that boutique guitar stores, at least in my area are reluctant to put an instrument on their wall with a water-based finish. Still seems to have major negative vibes in the world of commercial retail. Has that been a problem for you?
Thanks a million for your willingness to share your knowledge with us.
Terry

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

Refer to it as an Acrylic Lacquer. Problem solved.

_________________
http://www.birkonium.com CNC Products for Luthiers
http://banduramaker.blogspot.com

Thank you Gerald! This is very helpful. I will add to what Rod said about the EmTech 6000. They also have a catalyst (CL 100) that is an extra hardener and can be added to the finish. I purchased some but have not had a chance to do any tests with it yet. They told me about it on the phone, I can't see it on the website anywhere.

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

Did you find this price list? see page 6

http://www.targetcoatings.com/images/PDF/pricelist08.pdf

I've been using water base for 11 years and love it .
As Gerald has stated the hardness & burn-in is much better then it used to be.
I follow pretty much the same schedule as Gerald .

Letting it cure long enough as with all finishes will determine the outcome.

I love it for classical bridges where I get an order for a finished one.
I seal with shellac,fill pores,let dry and sand back to the wood and then another coat of shellac then the top coats.

Looks great !

Mike

_________________
Mike Collins

I used USL on a guitar a year ago with great success. However, I sprayed 3 coats a night, waiting about an hour between coats and sprayed every night rather than every three nights like Gerald. I did end up waiting a week prior to spraying the final three coats as other things prevented me from spraying. Overall, I built up a similar number of coats. When done, I waited over two weeks prior to rubbing out. I also leveled with 400 grit. For the first few coats, I leveled after each coat. Once the finish started building up smoothly, I leveled only prior to shooting the next series of three coats.

I used Target's High Solids Pore filler, but didn't care for it much. My last guitar I filled with Behlen's water based pore filler. On my latest, I plan on shooting the mahogany neck with several coats of Emtech 8800 and sanding back. I am hoping this will will fill the pores after several applications. If not, it will be back to the Behlens.

I am going to shoot Target's EM6000 on this one and see how it compares to USL.

Ken

_________________
http://www.casperguitar.com

Terrance - I've never had a question from shops about waterbase finishes and it's never been an issue.
Rod - thanks for the tip. I was thinking that the last time I talked to the Target folks they told me the burn-in on the Emtech was not as good. They also make water based polyurethanes and varnishes. they pretty much steered me away from those for burn-in reasons mostly. Are they actually saying it is a replacement for USL?

I am also wondering...

Has has anyone used Emtech 6000 enough to know if the process for applying it is much different than the USL process, for example, time between coats, or time between sessions.

Has anyone had an issue with peeling or witness lines, or other burn-in issues?

Has anyone tried to repair it, is it easily repaired?

Does it check?

Have these questions already been discussed here? Ha, maybe I should do a search.

Gerald, I only know of one guitar maker, who I posted in my initial post, who has used it on more than 1-2 guitars. He hangs out at "The Luthier's Community" forum under the name MetcalfGuitars.

I've had to do a touch up on my latest guitar and I have to say, that I'm a little bit disappointed in the "burn in" of it to the previous coats. There is some witness lines as well which isn't so good. I only sanded down to 600 to scuff up the finish around the touch up area, but I would think that would be sufficient.
I sure like the sheen of it though as it buffs out nice. I was hoping that it would be "it" in the waterbased finishes.

This is however only my first kick at the can with the stuff, having come from the nito camp and wanting to switch to something less toxic.

So, from my limited use of the stuff, I'd say it doesn't burn in as well as it was "suppose to" for repair purposes. I may have (and most likely) have done something wrong on my repair. I'm going to sand back a bit more aggressively and try again though and see where I get.

_________________
My Facebook Guitar Page

"There's really no wrong way, as long as the results are what's desired." Charles Fox

"We have to constantly remind ourselves what we're doing....No Luthier is putting a man on the moon!" Harry Fleishman

"Generosity is always different in the eye of the person who didn't receive anything, but who wanted some." Waddy Thomson

I just had a conversation with the folks at Target. Bottom line is that EMTech 6000 is the same product as USL, but has a couple new additives that reduce surface friction. They said things slide on the surface better rather than digging in. They also said the new product feels silkier to the hands - for example, on the back of the neck. I found that interesting in that I loved the feel of USL on neck so I'm a little enticed about the modification. They also said there was probably no difference between USL and EMTech 6000 with regard to hardness. I am in need so I'll be ordering a gallon today.

Hope this helps.