Official Luthiers Forum!

Hi dg what is hot fish glue ? Have never heard of it. I/ve always used either Lv fish glue . am now getting it from ye olde mill cabinet shoppe. TNX Are you referring to isimglass fish glue ??

Yep this is what happens every time this comes up. Those wishing to defend what they have done do so and others remain open to some views as Al would say from the "trenches" and from the few pros here.

We service over 1,100 guitars annually and our minimum service is a full set-up at about $100. This does not include a couple hundred mandos and likely over a hundred bases too. I work nights now to keep up with the half dozen or so guitars that come to us every day. We still turn away about 50% of what comes our way for various reasons, often bandwidth. And we are not affiliated with a music store and were even offered one for free and declined. It's not what we wanted to be that someday when we grow up.

Our primary concern with Borland fish was for bridges and as you should know... a bridge is under a lot of string tension. For the classical crowd the tension is less so they may not have issues and if you are making high-end classlicals and charging a decent rate for same your clients probably know how to take care of a guitar RH wise if they are buying $5K guitars and up.

But no worries use all the fish glue that you guys want and especially on bridges and Dave and I will just have to make even more money repairing your stuff too.

Makes no difference to me.

DG your post is great and I appreciate that you took the time to post it. Your experience is considerable and different from the usual naysayer with two guitars under their belts that push back on these threads all of the time. I find it interesting that you cooked it and that makes all the sense in the world to me since it is a collagen glue like HHG. I can also see where heating it would be helpful in a decent joint before it cures.

Good stuff and since I never welcomed you prior here is a big welcome to the OLF from me to you.

Lastly and back to fish glue. Gluing two pieces of wood together does not simulate a bridge under tension or come anywhere close. It also does not address the specific application of a cross grain glued guitar bridge either where things are expanding and contracting at different rates. I would suggest a different test. Get a beater, remove the bridge, reglue it well with best practices with fish, string to pitch and then throw that guitar in the attic and revisit every year and retune to pitch. Bet that bridge won't be doing so well with this test.

If this is any way directed at me (even in part), let me clarify that I would not recommend using fish glue to glue bridges, even on classicals. IMO, the questions surrounding it well outweigh any convenience factor.

_________________
Instagram: @jfrenchluthier

Sounds like bottled fish glue may suffer from the same issues bottled hide glue does. Just throwing a theory out that maybe whatever additives, preservatives, or retardants they add to make them useable at room temp with no prep plus minimum storage requirements cause reliability issues. I guess it’s always a trade off or you don’t get something for nothing. Shear strength may not even be the issue like with welding & metal fab strength alone or PSI is not the whole story, a level of ductility while maintaining strength under load with movement axial & radial are the true judge.

This same discussion comes up with Franklin LHG too and I always like to point out that about 25 years ago I build a classical guitar out of FLHG and I still play this guitar today and it's been my beater guitar and has been to hell and back. Would I recommend anyone use FLHG to build a guitar? Heck no. But my experience is still valid in such a discussion.

Same with a Flamenco guitar I built about 10 years ago almost entirely out of CA. Still going strong.

As for the fish glue experiment I forgot to mention that I had a 20 pound weight on it for a few years. I did this thinking that the shear force should be considered but then in thinking about it I think what pulls a bridge apart is the rotational force that peals up the back of the bridge. The strings are essentially a clamp when they go over the saddle to the bridge plate. There is still a bit of shear but mostly it wants to peal it off from behind.

Anyway this is how science works. You do an experiment, 'publish' it and people talk about it. You can say it's a terrible experiment for such and such reasons and that's fine. That's what it's all about and in that sense it adds value.

In the 'real' world I have 3 guitars out there with bridges done in fish glue and many more where the braces are. Those in particular are Torrified tops with Torrified braces as I heard that Fish was a good glue there. My guess is that it's the slow set time. T-wood is very hydroscopic, or so it seams, so a slow set water based glue might have a better cure when clamped up for 24 hours. So far so good on all of those.

Lots of factors no doubt. A ca glue guitar now that’s a heck of an interesting experiment I probably will inquire more about this in the future! I have a fondness for ca it’s saved me many a trip to the hospital for stitches!

Hi Ernie - if you caught my initial post with the photos, that pretty much gives a visual of what I'm referring to when referencing HFG. Isinglass is isinglass and while it is also cooked in essentially the same fashion as HHG and HFG, it should not be mistaken for HFG. Isinglass is prepared solely from sturgeon maw. I have prepared isinglass from the maw of Northern Sturgeon but I did not find it the same as the isinglass I acquire from Europe which is prepared from Russian Sturgeon. It could have very likely been the fact that I prepared the maw myself, that the Northern variety didn't seem as effective as the processed Russian variety I use but in any regard, Russian is the traditional variety.

HFG or Isinglass are both prepared in essentially identical processes as making HHG. The Bloom is lower (Isinglass being a little higher than HFG) and they are more elastic and cure quite glass-like.


Thanks kindly for the greeting Hesh! It's my pleasure to be here, however infrequent it may be.


Doc

Torres style 7 fan braces. Once you have all the fans cut to shape smear glue on one hold it for 30 second and move on to then next. I think I had the whole top braced in ten minutes

It was an experiment. I will admit that for a flamenco guitar, the first one I ever built, it basically sounded like a classical guitar to me and I have built far better classical guitars than this one. I doubt very much that the choice of glue had anything to do with that though. None the less the guitar is still held together by CA today.

DG tnx for the explanation, I met a russian violinmaker many yrs ago in st louis who used sturgeon glue on his violins.. At the time , I did not inquire why. I am familiar with sturgeon, having spent 35 yrs in Canada, Which part of the violin do you use the russian fish glue .. LInings . sizing end grain ? tnx

Wanted to share what I see when any of the many guitars with lifting bridges come into our shop. Just reglued a bridge on a small builder guitar yesterday as well so we do a lot of bridge reglues.

Below is a list of things that I see commonly that contribute to a lifting bridge.

1). Poor fit in the first place. The bridge would not sit down all the way around without being forced with clamps and in time it failed....

2). Neck reset time: Neck reset time is often preceded by way-to-low-a-saddle-time that gets the strings pulling the back edge of the bridge up.

3). Guitar has dried out. A dry guitar has all manner of things happening that hate bridges. From cross grain dimensional instability where the wood under the bridge is trying to shrink at a different rate from the bridge to the neck going into back bow and the action being reduced to any defects in the original glue joint when a guitar dries out bridges want to leave....

4). Slotted pins. Slotted pins were created to be mass produced and cheap and to avoid any semi-skilled labor to slot the bridge, top and plate at the f*ctory. The down side is that the string balls now bear on the pin hole edges because of the sloppy slots. This in turn results in additional pin hole wear quickly with the string balls even in bad cases migrating up into the top.

Birdge plate pin hole wear ofter develops a "crease" that connects the six or so pin holes and then the bridge plate distorts and "tents" upward along the line of the pin holes. This makes an uneven surface topside for the bride which either has to also distort to stay glued down or it lifts in the most likely place, the back edge.

5). Poor prep for bridge gluing where the finish has not been cleared back very much. We frequently see this on less expensive instruments where the bridge foot print could be expanded to take advantage of up to 40% more gluing area that no one took advantage at the f*ctory. I am NOT speaking of clearing finish to the perimeter of the bridge, we stay .010" in from that and prefer the nicer look of the finish going under the bridge. We also mill in a ledge around our bridges so that the bridge sits firmly in a pocket of sorts again with maximum gluing area but no sloppy perimeter exposed.

6). The one I just did yesterday had been starved and they used white glue but there was barely any glue anywhere under there to clean up.

I'm sure there are other reasons why bridges lift and I will add that we reglue bridges on guitars with mediums on them about two to one over guitars with lights.... Am I saying that string tension of heavier strings is a factor, yes it can contribute to a cornucopia of other things that are not perfect for a bridge to be a happy bridge and stay where it's put.

So with all this said this is the "money joint" on a guitar, the bridge glue joint. It cannot fail or the show is over. This is not the place to use anything but what works well, is time tested and will endure the environments that guitars are exposed to.

HHG is NOT hard to use and it never would have become the standard to which all others are held up against had it been considered hard to use. If you already use if for braces you are only a few simple steps from learning to glue bridges with HHG.

The only hot fish glue I've used is sturgeon glue, made from swim bladders. I was given a small store of the raw material some years ago, and have used it a few times. You soak a piece of the bladder in water until it stops swelling, and then heat it. Fish out the solids before use. It is almost water white when freshly made, which is why it's the preferred glue for artists gesso work; it doesn't turn the plaster dark. It also smells like the area under the dock after the party fishing boat came in on an August evening. A couple of whole cloves in the jar help mask that. It is very strong, and I'm told it's also more heat resistant than HHG. Perhaps the flake version of fish glue is a similar product that has been purified.

It's likely that the liquid fish glue is related to hot fish glue in the same way that liquid hide glue is to the hot stuff. All of my experience with room temperature liquid hide has been negative, so I'm inclined to be cautious with anything similar.

Check this out https://shop.kremerpigments.com/us/shop ... lored.html

Fish glue flakes & they also supply rabbit glue?

The russian sturgeon glue is very expensive! 250 gr hideglue costs 7,20€, 100 gr russian sturgeon glue costs 58,80€! Or to make it more clear: 1 kg hideglue = 28,80€, 1 kg russian sturgeon = 588,00€! For restauration and technologie of art rabbit glue cooked out of rabbit skin is a very recommended glue because of its elasticity.

No thread resurrection is evil if it is for a good cause.

Direct wisdom: Fish glue has no place in guitar making

Long version: When I started building in 2007, fish glue was one of the wonder glues lots of people were raving about. All the good aspects of hide, no downside. What's not to like? I have used it extensively in my first guitars for a few years. Alternatively I was schooling myself in the use of hide glue, and replacing fish with hide, but mostly just for the sake of unnecessarily complicating things.

I have heard a few horror stories pretty early. I thought they were extreme cases of neglect, not worthy of concern. I even glued up several pieces of wood and left them in the bathroom which of course is constantly high to extremely high in humidity. After a few months I would still get wood failure when destroyed with a hammer. I did notice the glue squeeze out was turning soft and sticky, but again, the joints were solid and who keeps their guitars in the bathroom anyway?

Turns out guitar owners are inventive and resourceful. One guy moved to a freshly built brick house and put the guitar collection on the wall. Another guy was living in a damp basement, and so on. Over the years, all these yearly guitars came back with problems. One bridge flown. One ebony fb curled up separated over the guitar. Several with back braces loose. Bindings torn apart at the tail. Luckily nothing bad on the soundboard bracing as they were hide glue. Soundboard joints also OK, as they were held by the typical center brace in a classical.
And this is not the end of it. Imagine the glue gets soft, the wood expands. Even if they separate or not, as soon as the humidity starts to go down, the glue will also start to reharden. Effectively, the build is reset and the guitar is being "rebuilt" in something like a 60% environment. Meaning, at the first hint of low humidity, the plates will begin to crack. And this happened on two guitars without being severely dried (I could tell from the frets not sticking out very noticeably)

Learn to use hide glue. it is much much easier and forgiving than the internet makes it look. Where you can't, use Titebond, no shame or quality loss with it. There is also pu and epoxy. No place for fish glue.

_________________
Build log

Still using fish glue on top bracing and closing the box with no issues But as I have learned it takes a different clamping technique
glues are in 2 catagories
Drying
fish and hide
Curing
tite bone
CA
Epoxy

Todd Stock turned me on to fish glue a while ago at an open house in Maryland after trying it as an engineer I had to experiment and learned most posts against it were often the I heard catagory. I do agree it isn't the perfect glue for everything on a guitar
So by doing some testing this is what I did learn
Great on spruce to spruce
not so good on ebony and cocobolo
OK on mahogany walnut sapele
it seems the resin and oil the less stable it was

Did clamp experiments on spruce to spruce and spruce to cedar and spruce to mahogany were the most successful
played with clamp times and found that you need a good 12 hr minimum
on Torrified you need 24 hr

I did find that it is harder to release than Hot Hide glue

Tite bond hide glue was reformulated a few years ago and it isn't worth the time in luthery

so in my list of glues

HHG
Fish
Fresh tite bone

CA is ok but use it only for special occasions

no wood glue works long term on plastic

Duco and weld on still my go to glue for plastic to wood and rosettes

Elmer White is also a good wood glue can be used in place of tite bond

West sytems and system 3 for epoxy

CA star bond
gave up on glue boost had too many issues with it and it has a short shelf life
Love locktite gel super glue

_________________
John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I still use fish to close the box, the back gets glued on with fish glue. I also use it for bracing on torrified tops because I have read recommendations for using it from other accomplished luthiers. My 'theory' on that is that T-tops are very hydrophobic and as such a slow cure water base glue like fish can take it's sweet time and make some good bonds and like John I clamp for 24 hours.

I have also used it on bridges on a few guitars and ukes, one guitar is my personal dred (the one and only one I ever built) for myself. That guitar is of course kept in good environment but it's still perfectly fine ten years on. Having said that I have also, as Alexandru mentioned, heard horror stories of using fish by accomplished luthiers so I no longer use it on bridges preferring hide but in almost all the horror stories I've heard talk about the guitars were kept in terrible conditions. So who's fault is that? I realize that we should build for error handling (i.e. build for idiots) but still...

From my admitting minimal experience using fish and hide I have found that fish takes way more heat to break apart then hide but it seems as though fish absorbs water better so high RH is probably the enemy of fish. I would wager a guitar built of fish would fair better in a hot car than one built with hide but if you add a bit of moisture in there the roles reverse.

I've done my duty. For me it is way past finding excuses for the glue. I have used various batches from Kremer or LV. I always clamped it everything overnight, with excellent surface prep. As soon as the wood soaks up enough water, it will melt right back at ya, every time. I know it is not a nice feeling to have a doomsayer preaching about, but I simply can't go past my own experience. And I have a been a strong believer and proponent for years. Actually in my destruction test it often looked better than hide or PU, especially on very dense wood, ebony for example. Probably because of the slow set it has plenty of time to impregnate the surface.

If I draw the optimistic line, from that period I have more guitars which are still OK. A pair belongs to a duo who have travelled extensively for study and concerts. Those guitars performed even in India :O I was very sure the bridges will fly the second they stepped off the plane but no

BUT, as soon as some doofus leaves the guitar hanging on the wall during the rainy month...it can explode. Attaching a couple pics. It is obvious 90% of the fault lies with the owner and environment, but still... After I dried this up to workshop level it lost something like 60 grams (and it was a lightly built classical)

_________________
Build log

Thank You Alex this was our considerable experience with it too and as I've said like you just said we approached it's use like it was surgery, fresh, date coded Norland fish glue.

We used it for bridges for a little over 6 months and then bridges started coming back lifted. We had 1/2 a dozen come back so we went out of our way to research who else we used it on and recalled a bunch of repairs and did the bridges with HHG. BTW it's a nightmare for a repair shop to have this happen a dang nightmare....

We also reported it here that high RH and fish was a bad idea and some people were defensive and protective of it's use and still are.

So I say again and I thank you very kindly too Alex for the honesty and I feel bad this happened to you too. I say again if what you build is going to leave your 45RH shop (your shop is at 45% or an appropriate RH for your climate isn't it...) and go out in the wild it may disassemble itself and possibly right before a gig if the RH rises..... and you used fish glue. Been suggesting this here for a long time and truth be told the more you guys screw up the more repair people like us make more money.... Please keep us poor and guitar players happy

Also interesting Alex we now have verified reports of failures from multiple glue suppliers.

We discontinued it's use for anything and HHG is a great alternative or even Titebond original. BTW we have used Titebone extend too, sounds like a marital aid doesn't it... with good luck too.

One thing I don't understand though and maybe OLFers can help me with: How does a fish not come apart in the sea if the fish swims into high RH?

60 grams? Yikes!

Liquid fish glue I have used always had a sediment layer on the bottom of the container. I never knew whether to shake until mixed or just to disregard.

I no longer use it due to its short shelf life.

I’ve never used fish glue in my own building. But here’s an anecdote from the repair bench:

I had an OM from a well-known boutique maker in the shop some months ago. Several of the fish-glued soundboard and back braces were loose. Before doing any work we first contacted the maker to see if they would handle it under their warranty and they obliged, but they insisted on replacing the instrument entirely. It was a limited edition model that wasn’t in stock so they needed some lead time to build the replacement.

This same maker has, since the time the original OM was built, discontinued the use of fish glue in their factory and gone back to titebond.

So, they sent my customer a new $6000 guitar, built with titebond, rather than conduct a couple of billable hours worth of repairs on the fish-glue-built instrument. I offer no judgement but leave you to draw your own conclusions on their motivations for behaving in this way.

Thank You Josh and I'm not as diplomatic as you in not offering any judgement.

For years people have reported here on this forum fish glue failures. There are dozens of them and from very credible people such as my business partner David Collins. David also did the glue presentations at the Northwoods Seminar and is considered among experts to be a glue expert.....

I've reported half a dozen bridges lifting and the details on how they were glued. And I've reported that we discontinued fish use and went back to HHG and have not lost a bridge since, this is out of hundreds.

So don't question the sources anymore there is significant information out here that higher RH and fish may not work well and in my business and with my fierce intent to provide real value to our clients if I ignored this information I would be negligent. I also would be placing my glue selection ego before value for my clients and that is..... BS.

Here we have an example of a maker taking a multi-thousand dollar hit but doing the right thing for the information that they had. Was Josh their first experience with a fish failure or one of many for them? We will never know but they did the right thing to discontinue it's use in my view.

Interestingly they went back to Titebond. I maintain that Titebond is an excellent choice if you are not SURE that you have the chops down for HHG use. HHG is our first choice for bridges and we have the chops to have all clamps secured in 10 seconds or less.

But sheesh OLFers how many dang times do we have to go around and around and around.

There are significant fish glue failures reported on this forum from credible people - deal with it and do what you wish but stop questioning the men and women who bring this stuff forward you are fortunate to have what we share with you.

What you do with it is up to you and always has been.

Guess what? I just got a guitar in my shop with loose braces that was built with Titebond

Yes I'm being a wise guy but I do have such a guitar. Also doing a very in depth search on fish glue and luthiery I do not see many reports of disasters. I do see the same stories from the same authors on different forums though. Of course experience is very valuable but at the same time it's kind of like being afraid to fly. Flying is not at all dangerous else planes would be falling out of the sky all the time.

One thing I will promise you though is if one of my T-Top guitars with the bracing done in fish glue comes back for repair I will report back here and humbly bow my head in shame.

---

Hey Josh, so what happened to the guitar that was replaced?

I sure hope “a Titebond-ed brace will never loosen” is not the message people take away from that story. Of course braces glued with Titebond pop free, it’s a common repair.

The story was about risk and liability for companies trying to make a buck in a tough industry.

As to what happened to the original guitar, you’d have to ask the company that, they insisted it be returned rather than be repaired.

The owner thought about canceling his warranty claim and having me fix it, it was such a cheap repair and he felt he’d really “played it in” over a few years. But there was some concern that doing so could jeopardise the future warranty coverage.

My experience with warranty repairs is that a total replacement of an expensive instrument due to a minor, easily fixable problem is something that rarely happens. Yet it happened in this case. Like I said, draw your own conclusions.

I use to use fish glue to attach tops and backs to sides due to the long open time. But this discussion got me wondering, so I went out today and hunted down a bottle of Titebond "Original" Extend.