Casein glue help

[3ntin]

Good evening ladies and gentlemen, new member here. I am not a violin maker at all, but I make other historical wood works like shields or sword scabbards (I'm a reenactor). My apologies for coming into this community without being one of you, but many of the researches I did led me here, so I hope someone is able to help.

I'm trying to produce casein glue for my historical woodworking. Final target is making it from milk but, by now, I'm testing with powdered casein. I want to prduce calcium caseinate as in Cennini and Theophilus recipes, to be used for a sword scabbard I'm making. Being my first attempt with this glue, I don't really know what to expect.

I did some tests, but I'm not totally satisfied...I used the recipe from Kremer: 100g casein soaked in 250 ml water, then mix 11g of sodium hydroxide in 50g water and add to casein, and finally add 20g of slaked lime. The glue I made was pretty effective, the bond seemed quite strong, but I could separate the wood pieces with my hands using a bit of brute force. Is it normal? I was expecting a bond stronger than wood (at least, as far as I know, that's when a wood glue is good). Main doubt I have is that on one side of the joint there were some small chips of wood torn from the other piece, which made me ask myself if the glue was prepare well...I tried it also on parchment since the scabbard will be lined with parchment: good bond, but could separate it.

Is the recipe good? has anyone some advices?

[Brad Dorsey]

I’m afraid I can’t tell you anything about casein glue.  But, if you want to use some historically-appropriate type of glue, I have to wonder why you don’t use hot hide glue.  It has been used for thousands of years, and you can get a lot of information and advice about it  here.

[JacksonMaberry]

Try searching the forum using my name + casein. I've posted recipes a few times. 

It's a great glue when made well, but Brad is right, it's really better to use hide. 

Or follow the Japanese model and use a rice paste glue. They want the joints reversible so the scabbard interior can be cleaned, which makes a lot of sense when your full time job is lopping off limbs. 

[3ntin]

10 hours ago, Brad Dorsey said:

I’m afraid I can’t tell you anything about casein glue.  But, if you want to use some historically-appropriate type of glue, I have to wonder why you don’t use hot hide glue.  It has been used for thousands of years, and you can get a lot of information and advice about it  here.

I have already used hot hide glue, works great when covering a shield with wet parchment. I was only curious about trying cheese glue, since it is mentioned as a good glue for woodworking...

 

6 hours ago, JacksonMaberry said:

Try searching the forum using my name + casein. I've posted recipes a few times. 

It's a great glue when made well, but Brad is right, it's really better to use hide. 

Or follow the Japanese model and use a rice paste glue. They want the joints reversible so the scabbard interior can be cleaned, which makes a lot of sense when your full time job is lopping off limbs. 

will do the search, thanks! and yes, you may be right ablut the reversibility aspect, I din't thought about it...! may be useful to be able to dismantle everything in case of problems...

[Claudius]

17 hours ago, 3ntin said:

I want to prduce calcium caseinate as in Cennini and Theophilus recipes,

This is what I did the last month to verify the calcium caseinate inspired to the old recipe from Cennini: put 4p. of distilled water on 1.6p. of powdered casein and leave there for about 7/8 hours, then add a bit of calcium oxide (Cennini called it "calcina viva", but it should work with hydrated lime too), and start to stir the mixture adding other 2/2.5p. of distilled water. Continuing to stir the mixture, you'll see that it will become very dense and viscous, add some water if needed. The calcium caseinate glue is ready to be used.

I tried it as glue, and it is strong enough to be compared to the hide glue, but the casein is not reversible and it's water resistent, even hot water, and you can use it in cold and warm weather. I tried starting with fresh skimmed milk, and I got the same results as the powdered casein. You have to find the right balance of casein and calcium oxide/hydrated lime, if you add too much calcium the casein glue will become weaker, so start to add the calcium oxide/hydrated lime little by little and stop when your casein starts to increase its volume, density and viscosity.

I used it as a ground diluting the calcium caseinate to a watery consistence. The calcium caseinate loves to be used fresh, no shelf life.

PS: the calcium caseinate smells good and fresh.

[3ntin]

I tried to use only the slaked lime, but didn't work: as far as I understand, before proceeding casein must be disolved in alkaline water (that's why the sodium hydroxide)...when it's dissolved lime is addes, and the calcium caseinate forms....or am I missing something?

6 hours ago, Claudio Rampini said:

You have to find the right balance of casein and calcium oxide/hydrated lime, if you add too much calcium the casein glue will become weaker, so start to add the calcium oxide/hydrated lime little by little and stop when your casein starts to increase its volume, density and viscosity.

that is actually interesting, the quantity given by Kremer produced a good glue, it has PVA-like consistency...is that the aim?

[Claudius]

2 hours ago, 3ntin said:

that is actually interesting, the quantity given by Kremer produced a good glue, it has PVA-like consistency...is that the aim?

It's denser and viscous and has air inside, remember to stir the mixture after you have added the hydrated lime for 20min at least. Test the recipe as reported in my previous message on several pieces of wood, let it dry and stabilize for one day or two before testing its strenght. In this way you'll find the best for you. Just in case test the calcium oxide for your calcium caseinate glue.

[Andrew tkinson]

Hello 3ntin. A while ago I started to make a renaissance cornet (still unfinished - naturally!) Anyway I tried to make some casein glue from Cheese and I found my glue seemed ok but was not water proof enough. 

There is an excellent society called FoMRHI, which stands for "the Fellowship of Makers and Researchers of Historical Musical Instruments" I sent them a 'communication' outlining my cheese glue problem which appeared in the society's quarterly 'bulletin' and this was answered by a very knowledgeable person who sent in a ' communication' in the next issue.

FoMRHI very generously uploads the content of its quarterly bulletin free for any interested person to view, a year or so after their publication in the bulletin, so you can find this article on cheese glue by typing the word FoMRHI into google. Once you are into the FoMRHI site you click on  'communications' and will arrive at this page

Here you can see I have entered the term 'cheese glue'. This search will give you something like this page and you can download and read the articles which are known as 'Comms'

I would highly recommend membership of FoMRHI to anyone who is interested in Historical Instruments or even just those interested in cheese based adhesives!

[JacksonMaberry]

Just to point out that one can purchase various caseinates (ammonium, sodium, potassium, calcium, etc). The glue is incorrectly called casein glue, it is in fact caseinate glue. Luthiers are in the habit of preparing caseinates themselves, but industrial food manufacturers have taken care of that for us. All the caseinates are sold as food additives. 

[Andrew tkinson]

One good thing about this making this caseinate glue from real cheese is it can be ate in case of hunger?

[LCF]

1 hour ago, Andrew tkinson said:

Hello 3ntin. A while ago I started to make a renaissance cornet (still unfinished - naturally!) Anyway I tried to make some casein glue from Cheese and I found my glue seemed ok but was not water proof enough. 

There is an excellent society called FoMRHI, which stands for "the Fellowship of Makers and Researchers of Historical Musical Instruments" I sent them a 'communication' outlining my cheese glue problem which appeared in the society's quarterly 'bulletin' and this was answered by a very knowledgeable person who sent in a ' communication' in the next issue.

FoMRHI very generously uploads the content of its quarterly bulletin free for any interested person to view, a year or so after their publication in the bulletin, so you can find this article on cheese glue by typing the word FoMRHI into google. Once you are into the FoMRHI site you click on  'communications' and will arrive at this page

Here you can see I have entered the term 'cheese glue'. This search will give you something like this page and you can download and read the articles which are known as 'Comms'

I would highly recommend membership of FoMRHI to anyone who is interested in Historical Instruments or even just those interested in cheese based adhesives!

I didn't know that Fomrhi still existed. I used to belong ~40 years ago when I would eagerly await the arrival of the typed and duplicated newsletter by airmail.  

[LCF]

48 minutes ago, Andrew tkinson said:

One good thing about this making this caseinate glue from real cheese is it can be ate in case of hunger?

Milk>casein>cowfood>milk>... ad infinitum.

 

They also feed cows calcium linoleate as bulk calories + calcium because the herbivore stomach system can't digest fats so if your cheese tastes like varnish you'll know why (or like glue for that matter). 

Calcium linoleate is a soap btw.

Eat, soap, prosper.

[JacksonMaberry]

3 hours ago, Andrew tkinson said:

One good thing about this making this caseinate glue from real cheese is it can be ate in case of hunger?

I wouldn't eat it once it has an alkali in it, myself. 

But caseinate powders on the market are made specifically as food additives. Caseinates and micellar casein are the main ingredients in a lot of fitness shakes.

[M Alpert]

On 11/16/2024 at 3:55 AM, JacksonMaberry said:

Just to point out that one can purchase various caseinates (ammonium, sodium, potassium, calcium, etc). The glue is incorrectly called casein glue, it is in fact caseinate glue. Luthiers are in the habit of preparing caseinates themselves, but industrial food manufacturers have taken care of that for us. All the caseinates are sold as food additives. 

Interesting, Jackson! Have you tried any of these industrial versions (on violins!), any experience you can share?

If they are food additives, shouldn't they be safe to consume, alkali included?

[JacksonMaberry]

41 minutes ago, M Alpert said:

Interesting, Jackson! Have you tried any of these industrial versions (on violins!), any experience you can share?

If they are food additives, shouldn't they be safe to consume, alkali included?

That's the thing, there is no excess alkali. After reacting the acid casein (the protein from milk) with the base, the product is thoroughly washed. This is a step which is not part of the typical process of making a glue or size because it isn't necessary for the function of the adhesive. 

I have prepared glues and sizes with the commercial caseinates, it's just like hide glue - dissolve in hot water until even in consistency. 

In the case of both hide and caseinate glue, and in fact all protein glues, the protein needs to be at least partially hydrolyzed to become soluble in water (the medium of the glue). This is what the base accomplishes in the caseinate glues. 

All of this said, in my opinion casein and gelatine are excellent glues, but optically speaking they are subpar sizes/sealers/grounds. The RI match with varnish resins and with the wood are not as perfect as they should be for the look I want. They work, but I prefer other options for the desired optical results. 

[LCF]

It's the magic of proteins.

Caseins in milk are not acidic but they are pH sensitive. (As are hide glue proteins.)  Adding mild acid to milk or fermentation of lactose to acid breaks them out of micelles and  coagulates them and causes them to separate out at which point you have curd --- coagulation is the process whereby more or less straight chain proteins are scrunched up into tangled balls.

Unless you start with absolute skim milk, to make glue you need to wash out any fats with excess alcohol at this point also to rinse away the water soluble proteins, globulins etc, the whey (*). Raising the pH again un-coagulates the casein proteins. To get the purest casein proteins the process of acidulating, washing, basifying can be repeated several times. 

You don't want to end up with excess base which is why many recipes suggest you titrate the final basification by adding barely enough base to liquify the curd and give it a little time to react. If you use at least partial amounts of a volatile base like ammonia you can ensure there won't be an excess as it cures. However just as it is with soaps I beleieve the final product still has an innately high pH, to some extent .

 

(*)1  there are always oil soluble substances, even in skim milk. Vitamins etc. 

(*)2 watch out for milkmaids and spiders.

 

[LCF]

PS the gluing action of casein relies on  re-coagulation as it dries. The glue pulls in, gets stronger. In the traditional recipes using quicklime or slaked lime an important part of the process is the reaction of the lime with atmospheric CO2 to complete the "lime cycle" and turn back into neutral calcium carbonate (limestone). That can take a little while. The principle is similar with ammonia in that the alkali makes the casein soluble but as the alkali neutralises out the protein precipitates. 

[Alchemia succini]

Hi 3ntin,

Sorry, I wanted to respond earlier. Looking at your comments, I think the fault is with the lime you're using.

As for your recipe, although my specialty is the old cheese glue, I have experience with casein powder. (Note: "cheese" refers to dry curds produced by the natural souring of defatted milk and not by the addition of organic acids or especially enzymes [rennet] to the milk. The historical recipes made with modern rennet casein from supermarket cheese or processed cheese products when mixed with lime will only make a gelatinous slop with very feeble adhesive strength.)

Now, as for your ingredients, I couldn't recommend anything better than Kremer's casein powder which, you will note, specifically states on the label that it has been derived using lactic acid (Milchsäure), the same as is developed in the natural souring process: LAB→lactose→lactic acid→curdling.

The sodium hydroxide promotes solubility, which is why sodium-caseinate is used in foodstuffs. Instead, to prepare casein powder beforehand, I use the old German method of soaking it overnight in lime water rather than plain water; less lime is then later required when making the glue.

But most importantly, with regard to the lime, you appear to be using hydrated lime (calcium hydroxide powder) and adding the same to water, correct?

If so, you should be aware that adding hydrated lime to water will not work to make proper lime putty, because as its name tells us this form has already been slaked; adding it to water again only makes it "plastic," not adhesive. Leaving it one day or 1,000 will not make it so.

Unfortunately, using it can be deceptive because its high pH will certainly hydrolyze casein, but the mixture will lack the aggressive grip and tenacious hold compared to a properly prepared lime putty or quicklime. 

Only calcium oxide can be slaked to make lime putty. Here in the U.S. there are a number of strict specifications regarding lime putty and the materials used to make it (for example, ASTM-C5-18 and ASTM-C1489).

I don't work with quicklime, though, due to its aggressiveness and danger. While the 12.4 pH of lime putty still requires proper caution, it's much easier to use, and much superior if it has been aged for many years. I think Kremer still sells excellent aged lime putty (Sumpfkalk, "pit lime"). Ageing increases adhesiveness; the longer the better. 

Lastly, for use in finishing, if you want to use a calcium-caseinate glue as a sealer under varnish, since this glue is a mixture and not a true solution, a very thin glue still contains extremely fine particulate matter that will interfere with transparency. Moreover, even a thin glue develops powerful contraction upon drying, which is why minute cracks can be observed in the dried film.

In order to use it properly, make a thin glue and allow the mixture to settle overnight, then only use the supernatant liquid without disturbing the sludge on the bottom. If aged lime putty is used with particles < 1 micron, a unique lambent quality is developed when varnished, to say nothing of having superior durability compared to varnish substances like resins and oils.

Dave

 

 

[LCF]

When you put quicklime in water it is slaked, see the spec:

 

 

 

ASTM-C5-18 ...

Key Requirements:

...

"The quicklime shall be slaked and aged in accordance with the manufacturer’s printed directions."