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I just ordered a new batch of fish glue and the consistency is thicker than the last batch that I ordered. Has anyone had experience thinning fish glue? The directions state that it can be thinned with water, but I wonder how that will affect the reliability of the joint.

I heat up my Fish Glue most of the time that I use it to get it to thin out. I've also added a tiny bit of water if I really need it thinner. Nothing's exploded on me yet.

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Tony Thatcher
Bozeman, Montana

What is your goal ? weaker glue joint ? Recently took out back bracing with fish glue , what a pita, and time consuming

Are you asking me or Tony?

Yes, james, what is the reason you wish to dilute fish glue ?

No, I don't need weaker joints. That's what I was wanting to avoid. If thinning weakens the joint, then I don't want to try it. This batch is thicker than before and is a little tackier when spreading, and it seems to have less open time before it starts setting up. I did a small test batch, adding 10% distilled water and it brings it to the consistency of my previous batch. I got use to the old batch and it was easy to get just the right amount on the wood, and the squeeze out was just what I liked.

I did some test joints with the 10% thinned glue and after 24 hours, I got wood fiber failure, (spruce on spruce), with no glue failure when breaking the joints apart. So short term, it seems fine. I just thought someone might have more long term experience on this.

Just curious which two fish glues are you comparing? I've only ever tried Norland and what ever it is LMI sells and they appeared to be the same consistency. I'd be weary of thinning it myself unless it was for non structural purposes like binding.

I have never thinned fish glue. Once hardened it is IMHO a PITA to remove. I use a fish glue purchased from ye olde mill cabinet shoppe in Pa . I use a pint at a time . The rest is frozen. Previously got mine from LV and it was OK , The company above specializes in selling supplies for conservators and repairers

Both batches are Norland. Same container size. I still have a small amount of the 1st batch, that I have had for 3 or 4 years, and it is still thinner than the new batch I ordered. I'm not complaining, it works fine. I was just accustomed to the consistency of the 1st batch. I am learning to work with the new batch. Who knows, it may be better than the 1st one.

I assume you are referring to wood binding, since my tests on plastic, PVC, etc have all failed with the fish glue. Wood to wood joints are all that I have used the fish glue for.

FWIW, I’ve thinned Norland and not had any problems.

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George :-)

Hmmm Interesting. I guess they changed their formula. They don't actually sell it in certain thicknesses do they?

Yeah I was talking about wood to wood binding. I've never tried it on plastic or PVC but I would have guessed that it would have worked for that, good to know.

I have thinned fish glue to as much as about 3 parts fish to two parts water, and used it to flood rosettes. It worked just fine. You do have to seal the grain edges with shellac, or it will stain the top wood. I don't think I'd do that for anything structural though.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

I've been considering using fish glue but after reading this, I'll stick to HHG.

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Hutch

Get the heck off the couch and go build a guitar!!!!

I'm curious, what was said in this thread that would discourage you from using fish glue? I'm not advocating for fish glue, but I don't see any negative comments above. HHG is great, and I use it a great deal. But, I also find some applications where the extra open time, with fish glue, is good.

been using fish glue for years. I never thinned it. I do use HHG for bridges but love the open time and repairability of both HHG and Fish. Norland is the #1 maker so most of it is most likely from them. As stated above heat helps thin this out very well.

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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

The label on the fish glue from LMI says, "thin with water." I use fish glue for most assembly joints because of the tack and long open time -- I'm not nearly adept enough to deal with HHG. I thin the fish glue 10% with water to attach wood bindings -- and I pre-wet the channel and the binding/purfling. That way, having pre-cut 30 or so strips of binding tape, I can brush the thinned glue on an entire binding channel (e.g., half of the soundboard) and install the binding and purfling in one step. When I try to glue-a-little, tape-a-little, I always make a mess. I realize that the thinned glue and the pre-wet surfaces may lessen the adhesive solids in the glue joint, but it does distribute them and the joint isn't structural. So far it's worked for me.