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Perhaps consider contacting one out to see if you even like the results before making such a deep investment.

Thanks, Ed. I read some of your past comments on the topic and definitely made them part of my consideration.

I’m just a hobbyist. If it doesn’t work out I’ll sell it for a grand less and chalk it up to learning something new.


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The cureuv.com site claims their product to be zero VOC except in on place where they say it is 99.9% VOC free. Go figure. The MSDS does classify it as non-flammable. I've been using it several years now and haven't blown myself up yet despite not have an explosion proof fan. My fan is a used blower from a furnace and I use it to suck the over spray into a filter in the back of my spray box in my basement and I do not ventilate to the outdoors. I don't want to create a vacuum in the house or blow out all the warm air in the winter and getting all the over spray sucked into filters is good enough for me for the amount of finishing that I do. The low VOCs and non-flammability are the main reasons I have stayed with the cureuv.com product.

I have brushed this stuff with the end result being no different to my eye than spraying. Spraying however is easier with less work being required afterwards in terms of level sanding. One of the main points I want to make in this post is that if I could not spray, I would still stay with this product and brush or foam pad it on. In my opinion there are just too many advantages to the uv cured finish to go back. If I had a professional spray booth, I would be trying other uv cured products that have more volatiles etc. since there must be a reason that other people use them. That being said, I'm getting pretty good at the partial cure approach (to overcome the poor hang qualities of the cureuv.com stuff) and I can probably get all my coats completed faster than if I was using something where I had to wait between coats for volatiles to flash off. If you wanted to try the non-spraying route my recommendation would be to practice on a vertical board to the point where you can apply a coat thin enough that it does not sag.

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There are three kinds of people:

Those that make things happen,
those that watch things happen,
and those that wondered what happened.

It's stuck in my 20s, when I jumped out of perfectly good airplanes, rappelled off buildings, climbed railroad bridges (illegally), and did work on the roof of my house without a safety tether. In my 50s, I now feel kind of . . . mortal.

Brad,
Given the options you mentioned. You might find the garage to be the best one.
When I agonized over cutting a big hole in the side of my garage shop, I settled on guilding a duct between joists in the ceiling and venting it out the soffit.
Result is an invisible vent that no will ever know was there. When it is time to move on, I can easily repair the soffit and sheet rock in the ceiling. Or at least easier than plugging a hole in the siding.

Just thought I would throw the idea out there.

Dave

Thanks, Dave!

Indeed, I’m also leaning toward the garage. I talked with the boss earlier tonight. One idea was that if it is in the garage then maybe the hole could be cut in a way where a window could be installed if we moved. I like your idea better though.


Question - the garage is three insulated walls (two interior and one exterior) and the garage door itself. The space is a standard two car garage.

I want to be able to spray during the winter. I’m in Ohio. Maybe this is not possible.

Considering I would be doing just one guitar at a time, would I be able to bring the garage up to temp (there is a heater already installed) and then kill the heater and spray a coat or two before the temp dropped too far?

Again, I don’t really have a good sense for how quickly one of these 2-3k cfm fans would turn the air over causing the temp to plummet. My thinking here is that majority of the air coming in naturally will be around the garage door seams. Would I need an additional air vent coming in from the outside?

The garage is ~3900 cubic feet. So if I had a 2k cfm fan, the entire space is exchanged for outside air after just two minutes?

Thanks everyone for the help.

Brad


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Hey Brad,

After spending the first 12 guitars finishing myself in my shop, I've come to conclude that finishing is not even close to the fun part of this hobby! I had an explosion proof fan in my shop and I sprayed nitro as well as EM6000.

All your gut thoughts will be right. You've gotten a lot of good advice here and if you really want to go down the road of UV cure, it's probably worth the investment. However as you've already concluded, your garage will certainly see all the air exchanged in a matter of minutes and you won't be able to keep up with the heat or humidity loss for the duration needed to exhaust the overspray, let alone the fumes. Also, you'll need explosion proof lighting, or at least lights that are outside of your booth...

I'm so happy to have just sent my latest guitar off to a pro finisher... I'm not going to miss anything at all about the finishing process. Just another thought to throw at you.

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So lets clear the air on VOC's a bit..... They may not be what you think they are.
.
Shellac is one of the highest VOCc finishes you can apply. Up to 730 gm/ltr. Yet shellac is pretty harmless and really doesn't require any breathing protection. It is flammable though. Clear lacquer on the other hand is lower in VOC at a limit of 550 gm/ltr but because the compounds are more dangerous even with 50% less VOC the product is far more dangerous and requires breathing apparatus in addition to being flammable.

So what are VOCs? Well I found this nice definition..."Specifically,VOCs were found to be ozone generators.When exposed to sunlight,VOCs in the air form ozone, which is an ingredient of smog. The problem is that not all VOCs are ozone generators. Some are not, and even among those that are, some are very slow or weak ozone formers while some are very fast or strong ones.Thus, not all VOCs are created equal. Because of that, some volatile organic compounds which do not generate ozone have been declared exempt. That means that even though they are VOCs by definition, they are not legally regarded as VOCs as far as coatings and strippers are concerned. Acetone, methylene chloride, methyl acetate and parachlorobenzotrifluoride (PCBTF), which was originally marketed under the trade name Oxsol 100, are all examples of exempt VOCs.Thus, you can buy zero VOC lacquer that is 75 percent volatile organic compound solvent, yet is legally free of VOCs. In this case, the solvent is usually a mixture of acetone and PCBTF."

Now another term you need to know is HAzardous Air Pollutants or HAPs. these may also be VOCs but are under this heading due to health concerns from exposure. And again a nice explaination from the same source..."The issue with VOCs, as far as the EPA is concerned, has to do with whether or not they generate ozone. It’s that simple and that specific. HAPs, on the other hand, focus on hazard to both humans and the environment. As you can see, it is a much broader term. That said, there are VOCs which may be hazardous to the environment as ozone generators, but not hazardous to humans, and vice versa. For example, methylene chloride, the main ingredient in many paint removers, is not considered a VOC because it is not an ozone generator.Thus, the EPA allows it in formulations without penalty. However, it is harmful to humans, and if you use it, you must take the appropriate safety precautions.Thus, it is a HAP but not a VOC. Acetone, on the other hand, is not an ozone generator either, nor is it considered by the EPA to be particularly harmful. It is neither carcinogenic nor does it appear to cause any other serious illness. For that reason, the EPA sees it as neither a VOC nor a HAP. That does not mean there is no danger connected to it. Acetone, like many other ketones, is very flammable, so it is a fire hazard. In contrast, methylene chloride is nonflammable — so nonflammable, in fact, that you can add it to flammable compounds to make them nonflammable. Isoparaffins, the ingredients in “odorless” mineral spirits, are a good example of a third category. They are ozone generators, but are not particularly hazardous to humans.Thus, they are restricted by the EPA, but generally do not require extreme handling cautions."

So what are you really spraying??? Is "Green" really VOC free? What exactly are you dealing with? Don't leave it up to the advertising and salesmen to tell you that. You need to learn to read the MSDS on any product you work with. Even if the compound is redacted for trade secret a CAS# will be assigned which you can cross reference to a type of chemical.

Now I have looked again at the CureUV MSDS and notice the CAS#'s are redacted..... Having spent 10 years as a compliance officer for my former job I suspect that this isn't legit...... The MSDS needs to identify ingredients for first responders in case of an accident because some of these things get really wicked if you add water! So they haven't been caught at this by the EPA, but the fact remains that some type of solvent is needed to make the clear coats sprayable. It is either that or add more polystyrene which alters the hardness and flexibility of the coating drastically as it changes the viscosity. Polyesters are much different than any other coating you have worked with, trust me.

source for quoted text- Rockler woodworking

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

And this is why wipe-on finishes have become so popular....

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I have only ever French polished guitars. After I complete the finish on a guitar, I get tempted to look into other ways of applying finish, because it is a lot of persnickety work. But then after looking into the alternatives, I am reminded of why I continue to French polish. On balance, hand applied finishes meet my overall goals better, even though they are a pain in the arse. The hard truth is that ALL finishing methods/materials are a pain in the arse, one way or another.

At least hand applied finishes allow a hand builder to differentiate her/himself from the big factories.

Makes sense, I appreciate the feedback. I think for anyone selling instruments beyond just a couple a year, outsourcing the finishing makes total sense. There’s some tipping point where doing yourself is only costing you more time / money and for a lower quality resulting finish than outsourcing.

Where I get hung up is, for me, I’m mostly interested in learning about the process. After the outsourced finish transaction is complete I walk away with a fantastic finish and 500, 800, 1k (I don’t really know the costs ) less money but that’s where it ends. I didn’t learn anything, which for me is the most valuable part. That is until what I learn is I suck at finishing and really should be outsourcing it!









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Brian Howard wrote:
"So what are you really spraying??? Is "Green" really VOC free? What exactly are you dealing with? Don't leave it up to the advertising and salesmen to tell you that. You need to learn to read the MSDS on any product you work with. Even if the compound is redacted for trade secret a CAS# will be assigned which you can cross reference to a type of chemical. "

This is some of the best advice you will receive about finishing. In addition to what it will tell you about what is poisoning you or going to blow you up, it can give you an idea of what you might use to thin it and what you can mix with it.

Another approach to finishing for the amateur builder is to apply the finish when the conditions are right. If you don't finish in the winter you don't have to worry about fans sucking the heat out of the space before the finish cures. Waiting until the conditions are right is what many of the old timers did. You can also pick a finish that can be applied at lower temperatures (usually solvent based). If you apply the finish with a brush you only need to do enough air exchange to vent the fumes that are off gassing rather than clearing overspray.
Most of us "suck" at finishing compared to a professional. Not that we can't make a decent looking job of it, but that it takes more material and effort than a pro would need for the same results. My finishes have improved over the years. They are "good enough"You learn by doing. Outsourcing will never be in the budget.
It doesn't hurt to try different finishes from time to time. I mostly use Nitro and sometimes F.P. shellac. Since people have reported good luck with Enduro-var, I bought a gallon and will see how I like it. I'm not sold on waterbourne finishes, but maybe this one will change that.

You can build some sort of foldable tent for your garage as a spray booth so you are not constantly dealing with the volume of the whole garage. I make instruments as a hobby so for me learning to finish is important and enjoyable. If I were trying to make a living building guitars I think I would move toward a professional finisher. From what I understand, all of the prep work prior to finishing is left to the builder. I find the hardest part of getting a good finish is in the prep work. Without running into the problems caused by poor prep work I think it would be hard to learn how to send off a guitar to a professional

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Yeah, my satisfaction with my finishing is almost completely dependent on how well I did the prep work and the pore filling. After those are in good shape, the rest is relatively easy (for me, anyway).

BTW, Rod. I spend an inordinate amount of time searching the archives on the OLF. I’m glad to see you posting on a few threads here recently. I always get a lot from your comments.

Brad


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If I were to be able to do it all again, I would have French Polished. Early Larsons were F/P. Mandolins would still need to use violin oil varnish as a base with F/P over. All sunburst or dyed instruments would need a shellac sealer spray before violin oil varnish or F/P. I would still use a well ventilated room, and that would double as the offgassing room.
The unfortunate part of all this is that no one can tell you how much you have damaged your lungs until it is too late. Lacquer, UV cure whatever, various so called "varnishes" have who knows what in them, no one will tell you and there is no personal "badge" to tell you when you have had enough. One day you will find yourself huffing and puffing up the stairs and the doctors will tell you that you have COPD. It's the same as 'coal miner's lung', asbestos lung, whatever. No one will be able to tell you. No canary in the birdcage here...

Thank you Brad. It’s good to be back and back in the shop after far too long being distracted by many other things.


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"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

Just to close this out...

I spent the last week researching online and reading so many articles my head was spinning.

I decided to go out and visit the local makerspace. They have a proper spray booth and a day rate that is more than reasonable. I talked over the UV scenario with the owner and he thought there should be no issues with me closing off an area to do the UV curing and to use their proper spray booth.

Now to re-read Brian’s article on UV half a dozen times and go do some test panels next weekend!

Thanks for all the input. After carefully considering the options, there wasn’t really a good way for me to do this at home.

Brad


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I for one am glad to hear that...