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When it comes to hardware store-grade epoxy, your friend would be right. Hardware store epoxy that doesn't fully cure happens because the polymer chains never fully cross-link.

Aerospace-grade epoxy is another matter entirely. My personal preference is Hysol EA 0151. I've settled on that formulation for a few reasons.

First, it's optically clear. It also cures to a rock-hard state because the polymer chains do fully cross-link. This makes it a good transmitter of vibration.

One of the characteristics of epoxy is Tg, or glass-transition temperature. It's the temperature at which epoxy goes from a solid state into a softer, rubbery state.

Some epoxies have a Tg over 250° F, which makes them unsuitable for luthery. 0151 has a Tg of 136° F which puts it in the removal temperature range of HG.

Once heated, epoxy can be removed from the surface with a putty knife leaving no residue behind.

So thanks for the details guys and we know as I have offered early on that there are quality epoxies out there that may pass the sonic vibration transmission smell test.

So as you all should know when you say "epoxy" on this forum someone, someone is likely to pick-up the 5 minute variety in two applicators from the check-out line at Lowes and go at it in their shops.

I'm very careful and you can search my posts all the thousands of them when I refer to Titebond Original I always refer to Titebond Original. With this said if you are promoting the use of epoxy please be sure to say what brand, type, etc and be specific so that what people come here to learn does not end up harming them in some way if they misunderstood you.

Now here is where I disagree with all of you who are promoting epoxy for a fret board. Again I concede that a quality epoxy such as West, what I used or SIII and some others are suitable when it comes to transmitting vibration for a fret board. But I am not convinced that it's as good vibrationally as HHG or Titebond and I would bet that it isn't.....

Would you use the same epoxy for your bridges? And if you would or would not why would you or would you not use epoxy for a bridge? In the repair world epoxy is ONLy used for bridges when it's suitable for the instrument meaning the instrument is on its last leg or never was all that such as an Ov*tion.

So the bridge terminates the speaking length of the vibrating string via the saddle. On the fretboard side the other end of the speaking length is terminated by the nut for open strings and the frets for a fretted note. That fret is attached to the fretboard glued onto the neck in your cases with epoxy.

If you are terminating the speaking length on the fretboard end when the board is attached with epoxy I ask again why do we not trust epoxy for bridge attachment?

Some of the reasons are that again to many the word epoxy does not mean an aerospace grade epoxy cleared for NASA life support missions. It means the crap in the checkout line at the grocery store....

Glue lines are a topic that we could get lost in all day but I'll avoid that here. One comment though when I build a guitar I want to hear the wood not the glue, not the finish, etc. So a thicker glue line is not desirable to me.

lastly and the real biggie what about serviceability down the line.

It's rather laughable or at least it was in our shop earlier this week when the contention that epoxy is easier to use was shared with other working in the trade luthiers.

It's not easier to use and from the get go you have two parts to mix that you can and people here on the OLf have gotten wrong in the past. This adds complexity and one of the reason why Titebond Original was invented and other glues like it and why they are favored to produce the millions of guitars that are produced every year is it's ease of use.

So 12 years down the line I have a guitar on my bench with a bridge lifting that was glued on with epoxy or I need to remove the fret board that was also glued on with epoxy. Ov*tion day, oh the horror....

If I reglue the bridge after struggling with patch clearing dulling the hell out of my chisels on epoxy residue if I use epoxy once more how to I clean it up on the red, bursted finish on the top and the black finish on the neck? If I use solvents that will dissolve epoxy I eat and destroy finish and now I have to refinish the instrument because epoxy glue is less serviceable than Titebond Original.

I will go so far as to say that the very bad reputation that Ovation Guitars received for being unserviceable has as much to do with the use of epoxy throughout the assembly as anything else....

The ability to release with heat is only one part of what makes a glue serviceable where the other parts come into play when and if the instrument needs servicing in the future. Easy, non dangerous to anything clean-up is also a big part of being serviceable.

So use what you want. I went with epoxy too but returned to Titebond Original and as others have said here simply using a strong back for 48 hours or some methodology of your own to counter any warpage from water in the glue and this need not be an issue nor has it been for the tens of millions of guitars built with water based glues.

And lastly from me. I still think that even a quality epoxy is not as vibrationally transparent as HHG (the gold standard) or Titebond Original and I'll add Extend too since someone else brought it up, good stuff.

And really, really lastly from me for now... when Ovation entered the musical instrument business they were a helicopter company who had lost contracts because of the end of the Vietnam war. The employees were asked for ideas of other lines of work the company could do to avoid layoffs. The guitarists in the company chimed in and thought that an aluminum neck that would never warp would be a great value proposition for Ovation to build guitars.

The company had a great deal of experience with those aerospace grade epoxies that Dan is discussing and one of the reasons why they were experienced with epoxies is that in the aerospace world, my former world vibration is the enemy and not your friend. Nearly all that you do when designing airframes has to consider at some point the impact of vibration on the surfaces and airframe.

Epoxy is dampening and typically has thicker glue lines too meaning you are riding on more of it and I again want to hear the wood and strings not glue.

All day long I deal with loyal Martin customers who find HHG a real selling point as well. Tradition in the acoustic guitar world is very strong, you might say it's the "force" of the vintage guitar market. I see using epoxy as something that others, customers might object and even more so in the "high-end" guitar market and I would side with them as well and I think it's unsuitable for fretboards, not necessary, harder to use and less serviceable in the future.

Thanks.

Just a couple of minor corrections.

Ovation only made one line of guitars that featured aluminum necks (Matrix) and were only produced between 1971 and 1982.

Until 1982, all of their guitars, except the Matrix, had wood necks with conventional truss rods.

Detecting and attenuating vibration is the flip side of the coin to detecting and enhancing vibration.

In the beginning, Ovation calibrated the tops of their guitars using audio oscillators. These recorded the output and were plotted on graphs. What they considered the best sounding guitar(s) was used as the standard to which other guitars were measured. They compared their guitars to other makers' instruments as well. Later, Ovation has used laser interferometers to measure how, where and how much a top vibrates for every string.

Tim McKnight did hardness testing on a variety of glues, including HHG.

HHG has a Shore D hardness of between 81 and 82. Hardware store epoxies had a hardness of 65 to 75. Hysol 0151 has a Shore D hardness of 85. At room temperatures, 0151 takes 24 hours to cure to 75% hardness and 72 hours to fully cure. This gives plenty of time for squeeze-out, so the glue joint is very thin.

WRT removing epoxy from either the bridge or the top, all it takes is a little heat to soften the epoxy and it will peel off the surface leaving little to no residue.

Here's a bridge I removed. I heated it and used an Xacto chisel to get under the epoxy. It still has the large recess the factory routed into it and the tool marks the router left.

To remove epoxy from a top without hurting the surrounding finish, I boil water, then pour it into a 1-gallon ziplock baggie and let it sit on the epoxy until it softens and can be peeled up with the Xacto chisel.



I do agree with you in that Ovation's use of epoxy throughout construction was a bad idea. They gave no thought to future repairs, such as neck resets. There are many areas where wood glue could have been used such as attaching the neck to the dovetail, attaching the top to the wood lining and attaching the bridge to the top.

And the most popular tool for servicing Ovations is an anvil.

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We just don't take them in nor do we see them very often these days and that's telling too. We will on a case by case basis take a look at them and if it's a set-up and not anything that is not a structural repair we usually won't get past the initial phone call with the owner of an Ovation. I doubt if we are asked about them over half a dozen times a year now they are going away, thankfully....

These days they, the remaining survivors and I speak of the ALO (acoustic like objects) to borrow an insult style from Rick Turner RIP need neck resets and that prevents any meaningful set-up.

Dan I appreciate the details and how complete your answers are. We are also aware of the hot water in a bag method but that begs the question - why? Why would anyone want to bring one back to life and Ovations are few and far between now too. I know a professional luthier who never declined on a job and was fond of saying "I do not want anyone to think I can't do this repair." He's been out of his third failed lutherie business for about five years now. Went back to the auto factory.

So yes I can repair an Ovation but not without my responsibility to my other three clients who I might be able to help in the same time frame being on my mind. Exceptions, the stuff where you have to treat them like they are a different animal are what generally have massive scope creep and most experienced shops I know of will decline on Ovations. That is, of course, unless they have nothing else to do that is billable. And as shitty as that may sound for me to say lutherie businesses commonly fail and it's usually because of someone not understanding that small businesses have a tough slog from the get go and you have to be a bit selective in not getting stuck with the basket cases.

There will always be someone who will jump in and screw up the valuable personal property of others though, sadly.

Some lutherie businesses that are part of a retail music store are of course a P&L center within the greater enterprise and can absorb ups and downs. The stand alone lutherie businesses that don't do a lick of retail have to be both selective and careful what we get involved with. Scope creep is a major problem in this business and you learn quickly what not to step in....

I know Tim and Tim is a friend. Tim's been to our shop as well and he's a good guy. That aside for every Tim that you can bring up who may favor the use of epoxy I can cite ten pro luthiers who won't let epoxy anywhere near one of their builds. Tradition... ya know.

So we had an OLFer who passed away some years ago who thought that all the experienced voices who suggested, kindly.... that aspiring luthiers and practicing luthiers who avoid working on Ovations were all wrong. He saw a niche market and actually started repairing Ovations. He was attempting to get the neck resets down since they all were coming of age. This was about 15 years ago. It never panned out for me him and he passed.

The economics, what the instrument was worth after the reset and the honest cost of time and materials to reset one were not in place nor will they ever be. His business model failed on all fronts, not much business, economics did not make sense, etc.

Two more notes off the top of my head. I have a friend who is an amp repair guy and pro musician who was Ted Nugent's tech on the road for over ten years and he survived it all too.... He collects the Ovation electrics and is particularly fond of the Breadwinner and so am I. Just please don't tell anyone...

And lastly for now one other major engineering error that Ovation made in the design of many of their acoustic like objects was the use of dissimilar materials and not engineering for dimensional expansion and contraction. Wooden tops and glass toilet bowl bodies, the tops are going to wanna move and the bodies can't so what results when stressed - C R A C K.

I'm also well aware that mitigating vibration, Kaman Helicopters core competency and encouraging vibration what musical instruments do are opposite ends of the how to deal with vibration sciences. That's why I brought it up.

Dan you did not answer my question if you think that epoxy is not problematic on the fretboard do you glue or why would you not glue your bridges on with epoxy?

I'm not trying to be argumentative with you either and I hope you take my comments as intended to be constructive and professional and maybe even funny at times. I have not wished any Ovations on you...

I glue and used to glue on my Heshtones my bridges exclusively with HHG. I would like to have glued my fretboard on with HHG too and probably could have but by the time I lost interest in building, sanding mostly.... I had never addressed using HHG for the fretboard. But I wanted to, I wanted to glue my bridge and board on with the same glue. For the most part I would have liked to use HHG everywhere, almost... but what stopped me is seeing what happens when folks don't observe the short open time requirements when their stuff falls apart and is brought to me to repair.

So my question on why you would not promote the use of a quality epoxy for the bridge too is meant to be sincere I would like to know what stops you?

Thanks

Friends don't let friends repair Ovations. Let alone play one. I was at band practice about 30 years ago and the rhythm guitarist was all excited about a new guitar he had gotten. As soon as I saw the case I knew, and sure enough he whips out a freaked Ovation. I almost kicked him out of the band just on principle.

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Hesh,

Thanks for the kind words.

WRT the question about why someone would want to repair/restore an Ovation, sometimes it's for sentimental reasons. For example, Jen Chapin inherited her dad, Harry's Ovation 1613. It can be seen/heard in the YT video of him playing "Taxi" for a recorded show.

Long-story short, she was taking it to a gig and slipped on the icy sidewalk and landed on the guitar, completely busting/crushing the top and snapping the head stock off the neck. Over the years, it had also lost a couple of 'ears' on the headstock. Because I've worked on/re-topped Ovations, I volunteered to completely restore it for her. It got a torrefied Engleman spruce top with torrefied Adi braces and head stock repaired. FWIW, the top is jointed and braces glued with OBG.

What she got back was basically, a brand-new 50-year-old guitar.



Before:




After:




WRT dissimilar materials, mating a thin fiberglass shell to a wooden top isn't all that problematic. In a former life, I was an RC model airplane designer and manufacturer. Modelers have been joining fiberglass and wood for many years without issue.

The bigger problem with Ovations is their use of thick polyester resin for the finish on the top. The problem is that polyester resin continues to shrink over its lifetime and the shrinkage is exacerbated when exposed to heat and/or UV. The cracking you see on Jen's 1613 is due to finish shrinking, not because the wood top was joined to a thin fiberglass shell.

Here's the top from an Ovation 1113 that I re-topped several years ago for a friend. I've removed the bridge and braces to allow the top to curl for the photo to illustrate the shrinkage.



On all Ovation re-tops/restores I've done (~15 and counting) I use epoxy (EA 0151) to glue the bridges. I do this to duplicate Ovation's method of construction. I used to use Hysol EA 9462, but it's grey in color and has a Tg of ~250° F which makes it unsuitable to luthery.

On the whole, with the exception of Ovations, I agree with you and everyone else, that epoxy should not be used on a guitar.

Is this anything like, "Friends don't let friends drive Fords"?

Here's the flip side. A good friend of mine is a professional studio musician and composer.

Years ago, I did a neck reset on an Ovation guitar he owns because he said that the recording engineers would rather record him on the Ovation than a Martin or Gibson. (he owns many of both)

They explained that the Ovation was easier to mix because it's more balanced in tone. (not as bass-heavy as X-braced guitars)

He still plays many gigs a year with it.

Dan, kudos for getting that potato chip back in playing condition.

_________________
"Act your age, not your shoe size" - Prince

I fully agree with all of the negative comments about Ovation guitars in terms of the bad design and construction choices made by the company, and how difficult they are to repair and maintain as a result of those bad choices. No argument at all.

I am only posting to remind everyone that there was a time in the 1970s when, among the choices available to us as players, Ovations were not the worst options. In the late 1970s to early 1980s, my main acoustic was an Ovation Electric Custom Balladeer (a deep bowl model with a pickup), and it was actually a pretty useful guitar. It had great action, the neck stayed straight, the guitar intonated well, it stayed in tune, the top never cracked on me, and the bridge never lifted. It sounded like an Ovation, which (as Dan references above) means nothing stuck out as being too much. Yes, yes, we are all smarter now. I like to think I am, too. I wouldn't own one today, because I can (and do) make a much nicer sounding and looking guitar that will hold up better over time and be easier to repair as needed. But I don't want to judge the teenage/young adult me too harshly for having loved my Ovation, any more than I want to judge my younger self for wearing leisure suits in junior high school. It was a different time.

Having said that, if anybody shows up at a gig with one here in 2025, they are begging to be taunted and ridiculed until they leave.

I actually had one for maybe 6 months and then traded it in for a Martin. I didn't know back then anything about lutherie and of course you can guess that the one I bought had a black top....

Wow Dan I'm impressed. I can't see the pics for some reason but you've definitely got some chops and experience with Ovations.

I completely understand someone wanting to restore one that is a piece of musical history such as Harry Chapin's. We had a guy bring us a Martin that John Sebastian played and its neck was being held together with 1/2" thick rope and the rest of it was a mess. Because of who played it we restored it too.

No thanks required I appreciate you and the civil discourse, thank you Dan.

I used to build and fly RC too both fixed wing and helicopters. My best friend lived in Walnut Creek and was a pretty senior Airline captain. He purchased one of the first miniature jet engines from France for RC use. We were building a jet and then he sadly perished when a flight he was on hit a mountain in Jarcarta. He was not the pilot it was a demonstration flight of a new Russian airliner. Anyway my RC days ended when my friend Pete did...

Anyway I'm wondering if I ever built or flew any of your products. I moved onto rotary wing and the joy of $1,000 crashes when learning to do 3D.... But there was nothing like the smell of 30% nitro in the morning

It's great to see you doing repair work and surviving 15 or so Ovations is impressive too.

Don I completely agree Ovations hit the market with an excellent value proposition that was on the spot when it came to built-in electronics making them gig ready. This was not lost on Taylor after witnessing Ovation's success.

At one time 1/3 of all guitars sold in the US were Ovations. Oh the horror

Owning an Ovation is very forgivable but having a mullet is a different story

Sorry to hear about your friend. I come from an airline family. My dad and step-dad were airline pilots.

My designs were RC jets (EDF) built using balsa, plywood and fiberglass. I stopped selling them because the modelers moved on from those to cheap Chinese foamies which were assembled instead of built. I couldn't justify keeping kits in stock that weren't selling, or only sold one or two per year.

I keep my old website active mainly for reference. (See: SavageLight.com) A lot of modelers buy kits then stash them into the someday pile.

I quit flying because I got bored with it. It didn't matter what I flew, it just got boring. I also got tired of fixing them after a crash, or losing the entire model to a crash. You never know how long a flying model is going to last. You could get one flight or a 1,000. I never got into turbines because as a flying buddy used to say, "I can afford to buy and fly a turbine, but I can't afford to crash one."

Ovations are pretty much the only guitars I work on and the only work I really do is re-tops. If it's got a bolt-on neck I'll do resets, but I don't do resets on glued-necks. On Ovations it's easier to reset the neck angle when gluing the top to the bowl.