Nice color from Ammonium Rosinate

[Marcus Bretto]

Has anyone here ever had experience using an Ammonium Rosinate in oil varnish? I just made up a very small amount, and it seems to have some nice properties! I just want to consult the masses before I make a big mistake in using it for something.

Here are some (bad) photos of a thin layer rubbed into fresh, bare rib wood, unsealed. It's a much more lively, rich color in person. Transparency and depth is also not well shown here.

I prepared a 70/30 solution of grain alcohol and laboratory grade ammonia (30% Concentration), and to that, I added enough crushed rosin to make a thin spirit “varnish”. As the rosin dissolved, and the solution sat, the color changed from the very pale color of the rosin to a darker amber color. On its own, this color is still too light for anything substantial. The magic happened when I heated this solution to drive off the remaining ammonia, water, and alcohol. Just the heat required to drive off these volatiles and soften the rosinate caused it to transform in color to something nearly identical to my 100+ hour “low and slow” rosin cooks. Perhaps even a tad bit more gold. The resulting resin softened only very slightly with direct water contact, and was soluble in alcohol, spike lavender, and slightly in turpentine. I imagine its water softening can be mitigated, and the turpentine solubility increased with further cooking. 

Any advice? May I be on to something?

 

[violins88]

Looks interesting.

 

[Salve Håkedal]

Reading this: ".. The resulting resin softened only very slightly with direct water contact .." makes my varnish trauma return. The Michelman resin had this defect, which was the only cause for me finally giving up on it.

[fiddlecollector]

In my view your not even making a rosinate/resinate, alcohol would act as a solvent only so your possibly producing some type of ammonium abietate. Abietic acid is one of the chief  components of rosin and your making the ammonium salt of abietic acid. Rosinates require a metal salt to form a rosinate.

[Michael Szyper]

4 hours ago, fiddlecollector said:

In my view your not even making a rosinate/resinate, alcohol would act as a solvent only so your possibly producing some type of ammonium abietate. Abietic acid is one of the chief  components of rosin and your making the ammonium salt of abietic acid. Rosinates require a metal salt to form a rosinate.

As far as I know the ending of -ate only describes the anion of a substance, no matter if there is a complexing metal ion or not. Ammonia can act both as an acid and a base as well, so potentially it might form a resin soap.

[Marcus Bretto]

4 hours ago, fiddlecollector said:

In my view your not even making a rosinate/resinate, alcohol would act as a solvent only so your possibly producing some type of ammonium abietate. Abietic acid is one of the chief  components of rosin and your making the ammonium salt of abietic acid. Rosinates require a metal salt to form a rosinate.

I was under the impression that a rosinate and an abietate are two words for the same type of compound, for the same reasons@Michael Szyper describes. Abietic acid is the main and most reactive component in rosin, no?

also, aren’t most (If not all) rosinate/rosin soaps somewhat water reactive? @Salve Håkedal I understand this concern, and I’m hoping further pyrolysis reactions would solve the problem. But it seems many makers have success with rosinate in varnish, so I don’t think I’ll write it off just yet haha. 

[fiddlecollector]

2 hours ago, Michael Szyper said:

As far as I know the ending of -ate only describes the anion of a substance, no matter if there is a complexing metal ion or not. Ammonia can act both as an acid and a base as well, so potentially it might form a resin soap.

I was more talking in the sense of michelmans resinates. yes it could be called a soap as well

[avandesande]

I would worry about PH and long term stability due to acidity

[fiddlecollector]

1 hour ago, Marcus Bretto said:

I was under the impression that a rosinate and an abietate are two words for the same type of compound, for the same reasons@Michael Szyper describes. Abietic acid is the main and most reactive component in rosin, no?

also, aren’t most (If not all) rosinate/rosin soaps somewhat water reactive? @Salve Håkedal I understand this concern, and I’m hoping further pyrolysis reactions would solve the problem. But it seems many makers have success with rosinate in varnish, so I don’t think I’ll write it off just yet haha. 

Yes they are , im not trying to put you off ,im all for experimenting.  I believe the ammonium abietate your making, can turn red on heating but there will also be alsorts of other reactions going on as well.