Official Luthiers Forum!

If you want to go through hell with hot hide glue -go ahead.

Fish glue works the same without heating-or special heating pots!

PLUS it separates just as easily if need be.

I've made over 300 guitars since 1977 when I studied with C.Fox & George Morris.
Plus restored 1000's
Just try It!
long set time -long shelve life -you can freeze it!
& it still works after thawing!
Mike

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Mike Collins

I am glad that you have a long history of good results with fish glue. I use it a great deal and always hope that the long range performance is good. No failures to so far.
I have nothing against hot hide glue and I also use it for many different things. Fish glue gives me the open time I need on certain gluing operations, when I can't get it done before the hide glue starts to gel.

Go through hell? A bit hyperbolic, no?

I use both fish and hhg. They both have their place and advantages. I have heard from a few luthiers that gluing bridges with fish glue is not recommended.

I think fish glue smells worse than hide glue.

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

been using fish flue for at least 15 I use Norland high tack not stew mac

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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 have been using fish glue for it's longer set time when gluing back the bottom on old guitars. You need time to be able to match the edge of the bottom to the rim. I use HHG on the neck and end blocks for safety though, I can clamp the two ends of the bottom quick enough. This has been working great, but I know that fish glue is not as strong as hot hide glue, with water and heat the glue seam is a bit too easy to separate.

I have recently started to use two batches of HHG, one with added urea for the rim instead of the fish glue. I must say that this is better, and I can recommend that. HHG with urea will surely lose some of its strength, but not much. The open time increases. I put the urea spiced HHG on the rim and kerfing, then regular HHG on the two end blocks. I clamp the ends quickly as before and use a heat gun to keep the urea HHG liquid if needed when taking my time clamping around the rim.

I use around 3 ml urea granulate to 30 ml HHG granulate (about 10%). This gives the HHG at least 5 minutes of open time (I haven't actually timed it), and as long as you need it to be when heated.

I will probably only use Fish glue for gluing paper labels from now on.

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New will change the old,
turn to ashes or gold

http://www.gammelgura.se

I find fish more difficult to separate than hhg. I have used it on bridges successfully but stopped because of the problems that well respected luthiers have had with it.

Others have had bad experience with joints coming apart when the guitar was subjected to high humidity but is that really the glues fault?

I still use it for some things. I use it for bracing on torrified wood and for closing the back and for filling fret slots when fretting.

Around 2008 we used fish for steel string bridges and had around 6 lift the following summer and fall and as such we recalled another 6 and replaced the bridges with HHG. We used Norland, it was purchased fresh and directly from Norland and kept in the fridge while not in use. And yep we purchased a gallon at a time.

Glue requirements were followed to the letter by David Collins who also has presented about all of our glues at the Northwood Seminar which is a gathering of the top pro luthiers who work in the trade. Dave is considered an expert on glues and has done a number of presentations taking things to the breaking point, etc.

We decided we could not trust fish in our climate for steel string bridges, note the continued specifics here from me about steel string bridges. Tension is greater than classical. We did not have any classical bridges reglued with fish to see how they would do.

Happy Mike's experience has been stellar, our's was a disaster and it is and remains the only black mark on our work that has ever happened where anything was returned because something we did or selected failed to function as we would have hoped.

As such we can't have it and fish is not used in our shop at all these days since we can do all we need to with HHG and other alternatives.

I've seen glue joints fail with all glues.
Ya must make a good gluing surface before using any glue.
Not it's close enough.
NO gaps .
I prefer Elmers Carpenter glue for any good glue joint.

But it does not hold my burger to the bun like fish glue!

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Mike Collins

I made a test with hot hide glue with 10% urea. Set time, when the parts can be moved, is about 15 minutes, after 45 minutes the clamps can be released if the part is not in tension, after about 6 hours (or overnight as I like to do it) I suspect that the glue is about 95% as strong as it will ever be. It may take a couple of days for all the moisture to evaporate before it's 100% strong.

_________________
New will change the old,
turn to ashes or gold

http://www.gammelgura.se

Roger, when you say 10% urea, are you talking about the dry weight of glue granules to the dry weight of the urea?

So what did I do? I mixed my regular hot hide glue 2 volume parts granulate to 3 parts water. I filled a small 30 ml plastic bottle to about 80% with mixed hot hide glue. I added 1,5 ml urea granulate to bottle.

In the bottle, I had 30*0.8 * 2/3= 16 ml hot hide glue granulate.

1,5/16= 9,4% urea measured in volume of the hot hide glue and urea granulate.

Well. Weight is the better measure, but I always have hot hide glue cooking and I like to use that to make a small amount of urea laced hot hide glue on the rim/kerfing when gluing back the bottom. Not exactly scientific...

Next time I will fill the whole 30 ml bottle and add 2 ml urea granulate, that will be real easy and close to 10% in granulate volume I might add that I previously did an experiment using volume of granulates, making separate batches with 5%, 10%, 15% and 20% urea. The open time increased with the amount of urea, but the glue joint also became weaker. I think 10% urea (using my granulates) was a reasonable compromise, but the glue was plenty strong even with 20%.

This is the 30 ml bottle: https://thealchemistscupboard.co.uk/pro ... r-bottles/

Edit: I double-checked the volume contra weight ratio for my two granulates, urea and hot hide glue. The density was the same, so in my case I can use either volume or weight and get the same result.

_________________
New will change the old,
turn to ashes or gold

http://www.gammelgura.se

you are not talking about fish glue"?

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Mike Collins

Fish glue is very similar to hot hide glue. They both contracts with a big force when drying, for example. Fish glue is thicker and more sticky than hot hide glue, and it fills out voids a bit better. The glue joint is not as thin as hot hide glue. The best thing about fish glue is the long open time. The least good thing about fish glue, compared with hot hide glue, is that it's not as strong and also sensitive to humidity. The fact that fish glue is liquid at room temperature is something that is convenient, but not that important. Hot hide glue is as easy to work with when you get used to it.

I used fish glue many years, only for the long open time. Now I don't. Instead, I put urea into regular hot hide glue. I get the long open time and also a stronger glue joint that is not sensitive to humidity. This is my experience using fish glue.

_________________
New will change the old,
turn to ashes or gold

http://www.gammelgura.se