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By dumb luck, I was able to buy a decent quality, used UV cure lamp, the 1500 watt UV III one, for not much money. So, I have been experimenting with UV cure finishes. I know my friend Brad Combs also applies UV cure finishes. Of course, Brian Howard has provided excellent guidance in this area. Who else on the OLF is currently using UV cured finishes? It would be great if we could exchange information about lights, finish materials, methods, etc. This is not everyone’s cup of tea, and the up front cost can be significant, but as Brad and I have discussed, the ability to skip weeks of cure time is a big deal to those of us who bunch up our guitar building hours on the weekends. It would be great to be able to talk with other folks who have gone down this road.

To clarify, this thread is meant to find out who is using UV cure finishes, not to debate the virtues of such finishes. Thanks.

Bueller? Bueller?

I assumed from the lack of responses to this thread that few OLF-ers are using UV cure finishes. To the extent the cost of the UV curing lamp is a factor, I just looked on eBay and saw a used UV3 Cure Buddy for about half the cost of a new one. Perhaps a deal like that might entice some of you to try out this way of finishing. That’s the way I got started with it.

You probably don't have many responses as many of us small builders seem to use other finishes. If I had a client who wanted a guitar to be both road worthy and pristine looking for as long as possible I would consider UV but I would farm out the finish and have the client pay for it. What I would be curious about from you since you are just getting into it is what is the learning curve, how easy do you find it to apply and polish out, are you happy with the results and so on... Then of course pics

Finishing is probably the, no actually it IS the, thing I hate most about guitar making. I almost exclusively do FP now and of all the ones I have tried this is my favorite but it takes a lot of time and of course it's delicate, which I think is good for tone but I digress... If UV turns out to be a dream finish, easy to apply with great results quickly then it sure would be tempting.

I am also very interested to try UV finishing.

I recently saw a trade show video talking about a new UV finish system which using very inexpensive LED UV cure lamps.

https://www.youtube.com/watch?v=NCVTWZIXI0k&t=839s


From this company https://www.cleanarmor.com/

JF--

My learning curve was/is steeper than what most folks would face, because I also am learning to spray finish (any kind of finish, not just UV cured), and I'm working through my process for spraying and curing safely.

Comparing the things I have to learn about spraying to the extra things I have to learn about UV cured finishes, I don't think the extra knowledge required for UV cured finishes is all that bad. If you had a long history of spraying nitro, and just didn't like learning new things, it might be hard to "unlearn" how you worked before, but I didn't have that problem. I should also say that UV cure finishes and catalyzed finishes have a lot in common, so if you learn and gear up for one, you are mostly ready for the other (excepting the lamp and extra PPE for UV cured finishes, of course).

Let me break it down for you, in terms of products.

The first product is always a sealer, barrier, isolante, whatever your product manufacturer chooses to call it. It keeps the wood's oils out of the finish, and it keeps the UV cure finish from seeping too deep into the wood. The one I am experimenting with is a dual cure product from Cardinal, so that whatever doesn't cure with the lamp will cure on its own. It's a great product, and is very easy to spray and cure with no skill. Because it is dual cure, it is essentially a catalyzed urethane, so you have to be diligent about using PPE while mixing and spraying. But once it is cured, it is harmless.

The second product is a gel pore filler, also from Cardinal. This stuff is awesome, and worth gearing up for UV cure all on its own. You spread it in thin coats by hand (no spraying), cure it with the lamp, sand it back a little, and apply however many coats it takes to completely fill the pores. No down time between coats, other than letting the wood cool down a few minutes after a cure. I love this stuff.

Last is the topcoat. This is the first snag I hit in my experiments, but I am sure it is a spray gun setting issue, rather than a product issue. I first experimented with Cardinal's UV cured urethane topcoat. It cured great and looked great in terms of shine, but I was getting some pinholes that I didn't like, and I am working on how to prevent those. I think I need to increase the air and decrease the fluid, and experiment with better atomization. We'll see. But in the meantime, I also experimented with Cardinal's UV cured polyester topcoat. That stuff is amazing! It sprays on great (again, coming from a person with no spraying skills), zero pinholes, cures easily, sands very easily, and polishes up well. I took a test board from bare wood, through sealing, pore filling, topcoats, sanding, and buffing all in one day last weekend. Pore filling (many thin coats) took the most time. The rest took hardly any time at all.

In terms of money invested, I have put a lot of money into this, but in fairness, I did not have a spray setup at all before this. I designed a spray booth for my home shop (there is a thread on the OLF about it), bought very good PPE (3M Versaflo PAPR, purchased used to save money), bought spray guns, etc. But all of that needs to be purchased if you are going to spray safely in a home shop. The extra UV money went into the lamp (purchased used for a HUGE cost savings) and the extra PPE needed for UV curing.

Am I happy with it? I am still just experimenting, but yes, so far, I am very happy with how this is going. The elimination of down time for curing is wonderful. I don't have any photos for you at this point, because I am still just applying it to test boards. No guitars yet. Those will come soon. These finishes provide great protection (comparable to catalyzed finishes), and minimize (for me, anyway) the amount of work involved in getting there. Like you, I dislike finishing more than anything about this craft. After French polishing most of my guitars thus far, I am ready to get maximum protection for minimum hassle. It is way too early to proclaim "mission accomplished," but I am very happy with how things are working out so far.

That entire video is worth watching. The interview with the guy from Titebond is quite good.

FWIW, yet another builder in my area is moving away from UV cure and has a complete setup including some paint for 2500CAD if anyone is interested.

This is the first time I’ve been envious of the process. What a dream in terms of pore-fill.


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This sounds like multiple builders left UV in your experience. Do you know why?


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This thread is specifically not about that. Just thought that someone interested in getting into it may be interested in a deal…

James--

As I mentioned above, finishing is my least favorite part of building a guitar (isn't it everybody's?), and pore filling is my least favorite part of finishing. It just seems to take me forever to get it truly flat and ready for topcoats. With the UV cure gel, you can keep going back and fixing little problems with no real downtime. It's pretty awesome. Even if I choose to apply some other topcoat at some point, I'm going to pore fill this way for the foreseeable future. And keep in mind, I am a real cheerleader for Silver Tip epoxy as a pore filler; I think it works great. But I like this even better.

Brad Combs' posts here on the OLF are great resources for the specifics on UV cured finishes. I encourage anyone interested to read those for more details, and to see some really beautiful results on guitars and ukes. I'm just getting started, but Brad is years further down the road.

Some "deep thoughts" I have developed over the last few years that contribute to my appreciation of the UV cure path:

1. I am definitely in the camp of believing that the most important consideration regarding the impact of finish on the tone of the guitar is film thickness. In my view, if the precise substance used to coat the surface matters at all (and I'm not convinced it does, but some people think it does), it doesn't matter nearly as much as film thickness. Keep it thin (whatever the substance is) and the tone of the guitar will shine through; lather it on (again, whatever the substance is), and the tone will suffer. So, in my view, you might as well pick a substance that provides excellent protection, and endeavor to keep it thin. I didn't always think this way, but I do now.

2. I am also in the camp of believing that we hand builders could stand to focus a bit more on the utility of the instruments we build, and a bit less on whether we are squeezing every last iota of "tone" out of the box. If the perfect magic tone has to come from the guitar equivalent of a Faberge egg (i.e., extremely delicate and prone to damage), and if that magic guitar costs $5k and up, do we think the buyers are going to use those guitars to their fullest, or do we think they are going to baby those guitars so much that the guitars are under-utilized? I think there is a high risk of the latter. Speaking for myself, I want my guitars to be the ones that get taken out and used in the rain, subjected to bug spray and sunscreen, and bad body sweat, etc. They should be the toys that get played with, rather than the toys that wind up in a museum (a la Toy Story 2). Again, I didn't always think this way, but I do now.

3. The most expensive thing I put into the guitars I build is my time, by far. And the part of building a guitar that feels like the biggest time suck is finishing. So, if I can get a finish that protects the guitar well, doesn't mess with the tone too much (i.e., keep it thin), and minimizes my personal hassle and frustration with the process, then I'm on board. So far, this UV cure stuff feels like it is the smallest pain in the arse of all the things I have tried. So, I'm going to keep on moving down this road, happily.

You’re in good company as to your third point (and others). Kevin Ryan, et al.

I also think about what went well and where I got hung up after every guitar. I’m working on the final fretwork for the latest guitar today, thinking about making my cutaway process more efficient, locating the bridge, workspace efficiency, etc. This one’s taken three years. Not much I can do about learning how two newborns effect the build process during that time, but there are definite areas for improvement!

Alright, enough of my derail.


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Ed—

Even though I asked folks not to veer off into debating whether UV cured finishes are a good idea, I’m fine with you letting us know (if you know) why one or more builders are moving away from this type of finish. I figure you won’t proselytize, which is what I would like to avoid. My real goal with this thread is to flesh out what more experienced folks can tell us about their experiences with UV cured finishes, so that I (and others, maybe) can get better at it. Thanks for sharing, if you know.

Babies override everything, for sure!

It would be good to distinguish if you’re using polyester or polyurethane.

Side note, if anyone gets to .002 top and .003 back and sides and is willing to do an outsource, lemme know. I’d give it one more go just to see…:)

I’m experimenting with both polyester and urethane. The polyester so far is easier for me to apply without problems (pinholes in the urethane), but as I mentioned, that’s probably a spray gun setting issue, which is on me, not the urethane finish material. I will figure it out eventually.

Although it was 2k and not UV, I can say that urethane was way better than UV polyester on my guitars.

Thanks, Ed. And have the builders you know who are moving away from UV cured finishes told you why they were doing that?

Not directly, no. I’d be curious to know myself exactly, rather than just surmising from hearsay and scuttlebutt…

Thanks, Ed. If you ever hear direct reasons, let us know, please.

As for hearsay and scuttlebutt, where would the Internet be without them?

FWIW since it came up in this thread. I’m actually pretty curious about it myself, even though I’ll learn to FP PCRL if it kills me, lol.

From Clear Armour

Hi Ed,

Thank you for your interest in our products. I'll respond to your questions below:

I have a few general questions. Is your buffable top coat suitable for acoustics, where a super thin film coating with low damping is desired?

A: Yes, all of our coatings are designed for very low or very high build specifications. We recommend you experiment with different finishing specs as you will find a very unique ability to for our coatings to perform in ways traditional products cannot.

Is it repairable? For instance if there’s a sand through, can it be spot repaired, or does the entire panel need to be recoated to avoid witness lines?

A: Absolutely, it is repairable and blends exceptionally well due to how thin our coatings can get and cure flawlessly.

Does it require a special UV light blocked room for application, in other words, is ambient light from overhead flouro/LED’s and daylight from windows enough to start the cure before desired?

A: Yes you will need to control the upper UV spectrum of light to prevent curing 350nm-420nm specifically. Again we recommend experimenting in your environment to better understand how it behaves. If there is a lot of outside light coming through windows you may need to either purchase some transparent UV filtering window covering or block with full covering.

Is it possible to get a sample to do test panels, using daylight to cure, and how much daylight is required? Full sun, or will it still cure on an overcast day?

A: We have quart sizes available for purchase. Not much daylight is required and indirect sunlight is best so it will cure a bit slower than direct sunlight. Overcast days should be fine as long as it's not too dark.

What is the actual material, polyester, polyurethane, epoxy?
A: It's a proprietary polymer blend. See our SDS sheets for more detailed information. They are available on the website.

Are there any acoustic makers out there that you know of who have been using it?
A: We have many customers using our products for acoustic instruments which is why we developed the Classical Instrument line to meet their unique needs including producing a rich burnished finish while still providing a strong abrasion resistance.

Please let me know if you'd like to purchase some of our products to experience it for yourself.

I then asked…

Is it necessary to use a separate sealer and porefill, or is this an all in one solution? If not, can you tell me the compatible products you have to go with it?

Hi Ed,

We have a 800 grain filler, an 810 sealer, and an 820 or 830 clear coat. They are all different with specific purposes. It's really up to you and the project to select what you need.

We have 2 types of clear coats. The 830 buffable clear coat is softer which allows for a faster finish build up and mostly used for show pieces. The 820 is our highest strength clear coat for improved durability which is the most commonly used for a production finish.

The 800 is $120 a quart.
The 810 is $130 a quart.
The 820 and 830 are $135 a quart.

The 820 is the recommended one for long term durability.

So…whose gonna take the plunge and test it for me, lol?

I’ll probably get a quart of the 820 at some point just for kicks. If you can just walk outside and cure it waving it in the sun, sand it, and touch up any sand throughs and cure it again minutes later, well…it sounds too good to be true. And if it cure in the sun you don’t even need to invest in the cure light to give it a go!

Ed—

The other sunlight curable brand is Solarez. I have never tried it. Personally, I prefer the products that are not kicked by simple sunlight. I think I would have trouble keeping it from curing too soon. Just my view. Good luck with the experiment!

I couldn’t get solarez to work either. But that was before I knew about sealer.

It does mention you need to avoid UV in a certain range to apply.