How to give oil varnish color

[jefcostello]

 

Hi, I’m here to ask questions again, thank you all in advance

My varnish takes five days to dry and harden in the sun.
If I add oil paint, it will dry slowly or crack after drying.
I had to warm them again....

1. Can anyone give me advice if I don’t need toner grinding?
2. Can I add the oil paint directly after it dries, wait for it to dry, and then apply a layer of varnish?

Jef

thanks a lot

[FiddleDoug]

You could try adding transparent iron oxide pigments. I've used them a bit, and in moderation they add color without making it opaque (like paint). The iron oxide also acts as a siccative, and speeds the drying.

You could also use oil soluble dyes.

https://maestronet.com/forum/index.php?/topic/318442-transparent-intense-colors-for-oil-varnish/

https://woodworker.com/oil-soluble-gold-yel-oak-aniline-dye-mssu-846-444.asp

[Michael Richwine]

3 hours ago, FiddleDoug said:

You could try adding transparent iron oxide pigments. I've used them a bit, and in moderation they add color without making it opaque (like paint). The iron oxide also acts as a siccative, and speeds the drying.

 

Won't iron oxide pigments continue to darken with time? As an antique dealer, I learned to estimate the age of things like swords by the color of their tangs; they went from red to brown to black over the years as the oxides picked up more oxygen atoms, or so I was given to understand.

[Nick Allen]

16 minutes ago, Michael Richwine said:

Won't iron oxide pigments continue to darken with time? As an antique dealer, I learned to estimate the age of things like swords by the color of their tangs; they went from red to brown to black over the years as the oxides picked up more oxygen atoms, or so I was given to understand.

I don't think that they do. They are rather stable, actually from what I've heard. 

[Deo Lawson]

Mixing in oil paint will work but your varnish will be a little gummy ( I have tried it). Perhaps it would give good results in a varnish that is very heavy on the resin and dries hard. I think glazing with oil paint would not be the way to go—mixing with varnish is better.

You can also buy transparent artist pigments, which are just the stuff mixed into oil paint to get the colour, only without the oil. This is what I do now.

 

I tried dyes once and they faded very fast.

[Don Noon]

18 minutes ago, Deo Lawson said:

I tried dyes once and they faded very fast.

I tried dyes twice.  The first time only faded slightly, the second time almost completely disappeared.

"Transparent" artist's pigments aren't really transparent.  More like translucent.

Nano iron oxide can be found that works pretty well... but not all of them are the same.  One worked pretty well, but I can't get it any more, and the one I can get doesn't work very well.  Even a "good" one will likely need color adjustment, unless you're varnishing a fire engine.

Michelman/alizarin resins can be transparent, but they're quite a bit of effort to make.... or you can just buy decent transparetnt violin varnish from some folks on MN.

 

[Deo Lawson]

Yeah they aren't *fully* transparent, however being faced with the task of making a purple violin left me with few options

In any case, there is such thing as transparent enough.

[JacksonMaberry]

11 hours ago, jefcostello said:

 

Hi, I’m here to ask questions again, thank you all in advance

My varnish takes five days to dry and harden in the sun.
If I add oil paint, it will dry slowly or crack after drying.
I had to warm them again....

1. Can anyone give me advice if I don’t need toner grinding?
2. Can I add the oil paint directly after it dries, wait for it to dry, and then apply a layer of varnish?

Jef

thanks a lot

I would consider 5 days an unacceptably long curing window. If a varnish, thinly and evenly applied, doesn't cure enough to proceed overnight in the UV box or in a full day of strong son, it would seem that something is amiss. 

If you made this varnish yourself, let us know about your ingredients and technique, especially with regards to the source and preparation of the oil. 

It also sounds like your varnish doesn't have significant inherent color, which I would consider not a deal breaker but suboptimal.

[violins88]

Michael talked about asphalting, bitumen or road tar. It looks black in bulk, but when thinned, it is dark brown. 

[Don Noon]

12 minutes ago, violins88 said:

Michael talked about asphalting, bitumen or road tar. It looks black in bulk, but when thinned, it is dark brown. 

Also similar to Gilsonite, which I use for browning out something that's too RED.  Thinned even more, it's light brown/gray.

[JacksonMaberry]

Gilsonite/asphaltum is a very useful saddening agent that has some fun extra effects on color in difference in different light sources. Be careful how much you use, it can jack with curing and affect final film integrity 

[Nick Allen]

5 hours ago, JacksonMaberry said:

Gilsonite/asphaltum is a very useful saddening agent that has some fun extra effects on color in difference in different light sources. Be careful how much you use, it can jack with curing and affect final film integrity 

Lol "saddening".

[JacksonMaberry]

43 minutes ago, Nick Allen said:

Lol "saddening".

It's goofy, right? It's how I've always thought of color though, not sure what the right words would be. What would you say to describe it?

[jefcostello]

Thank you everyone, because I saw a lot of videos similar to oil paints on the Internet, so I thought everyone was using oil paints

Deo Lawson

Yes, after adding oil paint, even if I heat it again, it will be sticky during the same drying time, and it is difficult to tell whether it is dry or not...

FiddleDoug

Thank you, I will buy some to use. Question: Do you dissolve it in turpentine?

Jackson Maberry

Cold pressed linseed oil from Taiwan chemical factory.

I burned washed linseed oil and rosin in an electric oven for 13 hours until they were less than 1/2 in volume. Then heat and mix the burnt linseed oil and rosin in a ratio of 1:1 by weight.

As for the color change of linseed oil, as in the picture I uploaded, the one on the left is burning amber. Not rosin
I suspect my rosin was not heated long enough?

My paint has a special feature

1 Very sticky, cannot use brush, if use brush. It will probably pull the bristles out. I applied the paint by hand and then brushed it back and forth with a stiff bristle brush.
2 The brush marks on it will be automatically smoothed out
3 Put it in a UV box, one day and ten days, its results are the same. It will cure, but there will be fingerprints, which will disappear automatically after 30 minutes. If you want it to be harder, it will be faster if you put it in a windy place (the UV box does not have a fan)
4 After I cooked it, the color was beautiful, but when I painted it onto the violin, it felt like there was no color at all. In terms of thickness, I can only apply 3-4 coats of paint at most.

at last. Thank you all !

 

Jef

[MikeC]

I don't know what's causing to take so long to dry but once you have a good varnish that dries well, you can add lake pigments for color.   Madder lake or cochineal lake for reds.  

[Dave Slight]

On 9/17/2023 at 5:26 AM, jefcostello said:

I burned washed linseed oil and rosin in an electric oven for 13 hours until they were less than 1/2 in volume. Then heat and mix the burnt linseed oil and rosin in a ratio of 1:1 by weight.

Have you cooked the linseed oil for the same length of time as the rosin (13 hours)?

If you have, this is where your problems are coming from.

[David Burgess]

On 9/17/2023 at 12:26 AM, jefcostello said:

I burned washed linseed oil and rosin in an electric oven for 13 hours until they were less than 1/2 in volume. Then heat and mix the burnt linseed oil and rosin in a ratio of 1:1 by weight.

If you cooked the oil at the same temperature and for the same time as that used to color the rosin, you may have degraded the oil to the point that it no longer acts as a drying oil.

[jefcostello]

Mkie C，Dave slight  and David Burgess

 

Oh, the first time I made varnish, I burned linseed oil into a paste.

So based on experience, I burned linseed oil with "fire" for more than two hours, and it could no longer burn.

I know roughly what you mean. The longer you heat linseed oil, the better, right?

I think I'll have to cook a new coat of varnish and fix the problem

I hope people with the same problem as me can get help!

 

regards

[JacksonMaberry]

On 9/19/2023 at 9:37 AM, David Burgess said:

If you cooked the oil at the same temperature and for the same time as that used to color the rosin, you may have degraded the oil to the point that it no longer acts as a drying oil.

That was my take also. 

In the future, OP should cook his resin and only then incorporate it into the oil, cooking it only as long as is needed to incorporate it and see how they like the results. 

[JacksonMaberry]

10 hours ago, jefcostello said:

The longer you heat linseed oil, the better, right?

No, this is not correct. You should cook your resin for color, then incorporate it into well-washed linseed oil at around 160-200C for only a short time, just until the resin has fully dissolved in the oil. 

By heating your oil at such a high temp for so long, you have destroyed it. It is useless now.

[David Burgess]

12 hours ago, jefcostello said:

I know roughly what you mean. The longer you heat linseed oil, the better, right?

No, that is not what I mean. It's closer to the opposite of what I am attempting to put across.

[jefcostello]

Flaxseed oil is not better the longer it is heated

In fact, the time it takes to burn it is short.

I understand

[Steve Voigt]

3 hours ago, jefcostello said:

Flaxseed oil is not better the longer it is heated

 

Heat treating linseed oil is actually a pretty nuanced topic. In general, it is better the longer it's heated, up to a point and depending on temperature. Four hours at 150 C will improve a raw or refined oil quite a bit; so will two hours at 200C. My own preference is 30 minutes to an hour at 250-260 C. More radical treatments have their adherents also: William Fulton's recipe no. 1 is 300C for two hours. You can buy this oil from WFE.

Before the twentieth century, stand oil was made by cooking at 300 C for many hours, days even. And there was even something called "burnt plate oil," which involved setting the surface on fire, briefly. Neither of these are suitable for varnish, however.

There's also much more to this than just temperature. Under the right conditions, oil cooked at 250 for 40 minutes, in an open kettle, can turn a couple shades lighter. Under other conditions, it'll turn a dark brown/red. Using an open kettle will accelerate drying rate, while keeping the lid on will not, and may even cause the oil to dry slower (stand oil today is cooked in an oxygen free environment, and dries markedly slower than raw oil).

9 hours ago, JacksonMaberry said:

No, this is not correct. You should cook your resin for color, then incorporate it into well-washed linseed oil at around 160-200C for only a short time, just until the resin has fully dissolved in the oil. 

 

I must respectfully disagree with my friend Jackson here. I recommend always always cooking linseed oil varnishes until one can pull a string. At a bare minimum, the varnish should be cooked until it feels sticky, not greasy, between the fingers.

How much string is a variable that can be manipulated. A very short string will give more open time, which might be desirable when finishing a complex object like a violin. If hardness and fast drying is desired, a longer string will be useful.

However--circling back to the beginning of this post--one is highly unlikely to produce a good string unless the oil has been sufficiently heat treated (though blowing with air or sun thickening can also help).

[joerobson]

Was your flax oil intended for food consumption or the paint industry?

on we go,

Joe

[jefcostello]

1 hour ago, joerobson said:

Was your flax oil intended for food consumption or the paint industry?

on we go,

Joe

Actually I am a violin player and in an accident I lost my varnish.
Not many people know how to paint in Taiwan, so I can only send it back to Europe

So I started looking into spirit varnish, and my spirit varnish is not bad. Unconsciously I became interested...

I bought some unpainted pianos from China. Some are of the same quality.
I want to know the difference in the sound of oil varnish and spirit varnish

In Taiwan, there are only chemical and food grades.

The chemical ones are relatively pure and can be eaten. However, applying for certification requires money, and it is considered non-food grade according to regulations.

There are many impurities in food... Almost no one in Taiwan consumes linseed oil

Today I have started on a new varnish and made 2 liters of washed linseed oil.

1. Currently my rosin has been burned at 260 degrees for 13 hours. Do you heat rosin to make it less acidic?

2. This time I will lower the temperature and time of cooking the linseed oil, maybe down to 200 degrees Celsius and see, I used 340 degrees Celsius previously....

I consulted everyone and online information, and the temperature I used was very high, because we Asians are used to using fire (and are not afraid of fire...)

Thank you Joe!