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If you've seen any of my posts on finish in the past few years, I tend to vacillate between nitro or Enduro-Var. I think I'm going to use EV on my current project for practical purposes, though. I'll probably be finishing in December, so I'll need to have a heater going in the garage. That just seems like a recipe for disaster with nitro (and a homeowner's claim).

I have John Greven's Enduro-Var schedule from GAL #118, and I've been going through the archived threads on brushing it and taking notes. I'd love to hear more from those of you who spray it. What do your finish schedules look like? How many coats are you shooting? Do you know how thick each coat tends to be in terms of mils?

Coat thickness seems the be the biggest hole I have in understanding how people are shooting it. It seems like people are brushing it around 3 mil, but I saw some comments that it needs to be sprayed on thinner.

Thanks in advance.

Here's a schedule I followed (sort of) spraying an upright bass. https://generalfinishes.com/blog/2016/0 ... lyurethane. Mandola to Bass, quite a difference in the amount of material needed.

I try to follow this -Contributed by Jeff Jewitt of Homestead Finishing Supplies to General Finishes
Day 1:
Prep sand the wood with 220-grit sandpaper.
Spray a wet coat of General Finishes Enduro-Var Gloss and dry for 2 hours.
Level sand with 320-grit sandpaper.
Spray a second wet coat and dry for 2 hours.
Lightly sand with 320-grit sandpaper.
Spray a third wet coat and allow to dry overnight.
Day 2:
Level sand with 320-grit sandpaper.
Wipe down with water mixed with 5% Denatured Alcohol.
Spray a fourth wet coat 2-3 mils thick and dry 1 hour.
Spray 3 more coats, 1 hour between coats, for a total of 4 coats the second day.
Let your project dry 1 week at least, then:
Level sand up to 1200 grit DRY
Here I depart from his polishing schedule and I buff with Menzerna
Stage 1- Glosswax 16 with a G quality cloth mop
Stage 2- P175 with a WDR quality or cloth mop coolair
(He uses this -
Level sand dry with Mirka P800.
Dry sand with Mirka P1200.
Dry sand with 2000-grit Mirka Abralon.
Note: Do not use any lubricants of any type for sanding.
Final:
Buff 3M Finesse-It Material on with foam buffing pad to high gloss.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Awesome. Thank you.

I’m trying to gauge what Jeff means by a wet coat. At one point it calls for spraying a fourth wet coat 2-3 mil thick. Is that the approximate thickness of all the wet coats?


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I think he means as much as you can get on without getting runs and sagging finish all over the place.
The original email I was directed to by Tom Monahan of General Finishes (from Jeff Jewitt) actually said "full wet coat"
2-3 mil is approximate thickness of each of the last 3 coats, 1 hr between spraying.
In reality I've found I can't get much more than that 3 mil anyway without runs and sagging, even rotating the workpiece.
I tried measuring wet coat thickness with one of this type of wet film thickness gauges, but because EV dries so fast, you've got to be real quick!!-https://www.amazon.com/RIVERWELD-Wet-Film-Comb-25-3000um/dp/B01MSPMYNN/ref=sr_1_2?dchild=1&keywords=wet+film+comb&qid=1602414506&sr=8-2

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

A "wet-coat" is exactly as Colin said, it's a visual way of telling if you have enough finish. The finish should be wet looking enough so that it looks shiny.

A thin or dry finish wont level out because it doesn't have enough "weight" to relax and form a smooth film.

A clear finish needs to be applied at a certain mil thickness, usually 2-3, so that it can flow out under it's own weight to form a smooth film. A smooth film is desirable because it eliminates a lot of wet sanding surface roughness out, such as orange peel.

1. Solvent lacquers can typically be applied thick without drips because the way the solvents flash off quickly. That is why Nitrocellulose lacquer remains one of the best finishes.

2. Water based finishes are trickier. Water in the finish makes them want to run or form drips at a thinner mil thickness.

I usually tell new finishers to apply the last coats to the back and the top (which usually get the most critical attention) horizontal so they can get a little better thickness to the finish which helps them flow out better.

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Jeff Jewitt
www.JewittGuitars.com
www.homesteadfinishingproducts.com

Nothing to beat the horses mouth, thanks Jeff.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Unless General has recently changed the formulation in the last 5 years you can’t spray EV without fisheyes because the finish can not be atomized. It was engineered to be brushed and not sprayed and that quote comes direct from General chemists. I nearly pulled my hair out trying to spray this stuff until I spoke with them and they explained the product does not like to be atomized and if it is then fisheyes are common. Generally fisheyes are the result of some oil or surface contamination but are common with this product with no contaminants present.

I know John had some success spraying it using a low cost touch up gun. At the time that I was experimenting with this finish, I was using a HVLP Iwatta gun and had zero success spraying it.

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tim...
http://www.mcknightguitars.com

Come to think of it, I had fisheye problems on the bass too.

Interesting..I thought it was something I was doing. It wouldn’t happen after sanding it level. It would always happen in the following coat or two. Explains why Greven brushed the first 4-5 coats, then sprayed the last two after leveling. Begs the question...What is the finish that’s easy, non-explosive, won’t kill you (immediately), doesn’t turn blue in bright light on dark wood....??!

Thanks, M

Let me know if you find it......

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Just when you think you have a plan.

https://youtu.be/HP8sofAN4xc


Sent from my iPhone using Tapatalk

Latex paint.... You didn't say it had to look good.....

I'm sensitive to latex paint--can't be in a room with it without my lungs feeling like they're on fire. I'd be better off with nitro...

Dave

Been using EV (matt, silk and gloss) for builds for about 10 guitars over past 6/7 years.
All cans of lacquer I get in UK are about 2/3 years old.
Here is today's output, the last 3 coats on my current spray job - first, second and third coats of Gloss Enduro Var (Fuji Gold Q3 with G-XPC gun, i mm tip. Air is fully open, flow control 1 turn open)
Dust, yes, still a little despite all the precautions I can muster, I'm trying to be Zen about it
A little orange peel. (I'm trying to get better)
But I can't find any of those darn fisheyes. Not any.
Only saw them when I contaminated the lacquer (waxed stir stick )

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

That looks great, Colin. Are you using a rotisserie or rotating by hand?

I appreciate Colin’s “no problem” report regarding spraying Enduro-Var, and would love to hear about more of those positive experiences from other folks.

By hand.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Didn't say no problems, just worked out lots of wrinkles over the years

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Well, I meant no fisheye problem so significant that you simply shouldn’t try to spray this material. That’s what Tim has described. I’m encouraged by the fact that you have not had that experience.

In the image of the guitar top, about 1-1/2 up from the bottom I can see what I’m referring to as the “fisheye” problem. It’s not like true fisheye caused by contamination, it’s just a half dozen little low spots in the finish. If I level the surface and reshoot the “fisheye” doesn’t show up until after a second or third coat, and then in a different place from before. This would indicate to me that the fisheye appearance is not caused by contamination. BTW I’m using a large wall mounted oil/water separator, plus another inline unit at the gun. My gun is an ANI R150 HPS with a 1mm tip. This gun lays the endurovar down quite well.

Best, M

So, Michael, you see it as a manageable imperfection in the sprayed finish; is that fair?

If Colin’s results are what a person would see after spraying Enduro-Var, that certainly would be an improvement over brushing it. Brushing it is fine, but man, a lot of level sanding is necessary.

Yup, odd little dimple, I certainly wouldn't stop spraying EV because of a few imperfections like that, no more of a problem than most orange peel.
I think I may be limited by the 3 turbines in terms of atomisation, but unless Father Xmas is extremely kind to me I don't see anything bigger in my future (cost/benefit analysis done by my better half).
Warming the lacquer, and thorough mechanical stirring seems to help. as does suggested temperature and humidity of course (my spray shop is heated which I was told is impossible)
Be very interested to hear from anyone with a 4 or 5 stage Fuji turbine spraying EV.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I'll leave Micheal to answer your question.

I've never brushed EV, but sometimes delicately use a very sharp scraper with a fine hook as a starting point for leveling a finish (especially ridges, runs and sags), and use one all the time for epoxy coats.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

Yes, that’s fair