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My Varnish


MikeC
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I have an interest in varnish making so I'll start this thread to post the occasional results. This is cooked pine resin with boiled linseed oil. It's not high quality oil, just the stuff in the can with driers from the hardware store.

It's hard to get accurate color pictures. I tried several times. Even trying a short video. It's very transparent and has a gold amber brownish color. One thing that makes it so hard to photograph is the bright reflective wood underneath. It looks great in bright light but not so great in a cheap digital camera.

It's dry to the touch but still soft and takes a fingerprint, maybe it will get harder with a few days sun exposure.

 

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what exactly are you trying to establish with this experiment. Are you thinking of actually using this on an instrument?

Most auto focus cameras have a feature that allows you to 'lock' the focus by pressing the shutter half way down. You could put the sample over a piece of cardboard, lock the focus, remove the cardboard and shoot.

Oded

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If I build another instrument I may use this or something similar, depends on results of future varnish making. But for now just experimenting mainly just doing it for fun to see what I can come up with. I would like to build another violin but it may be a while.

The camera is my iphone which has a close up focus. Sometimes it works well and sometimes not. I got real good closeups of a bridge but it's really hard to capture this varnish. I tried various backgrounds, white, black, close and far. I'll try again with a better camera.

I like the amber color in sunlight, I was trying to capture that outside in daylight in the photo. In normal room light it's not as spectacular but still looks nice.

Dichroic? maybe, at an angle it's a nice redish brown, straight on it has a gold undertone especially in good light.

It's very viscous, like cold honey or molasses.

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I like the color of the varnish sample on the right. Nice shade of amber.

same sample different viewing angle. The one on the right has the light reflecting off the wood underneath. On the left it's reflecting more off the varnish.

These pictures came out better:

In the jar it looks like burn motor oil

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I have an interest in varnish making so I'll start this thread to post the occasional results. This is cooked pine resin with boiled linseed oil. It's not high quality oil, just the stuff in the can with driers from the hardware store.

It's hard to get accurate color pictures. I tried several times. Even trying a short video. It's very transparent and has a gold amber brownish color. One thing that makes it so hard to photograph is the bright reflective wood underneath. It looks great in bright light but not so great in a cheap digital camera.

It's dry to the touch but still soft and takes a fingerprint, maybe it will get harder with a few days sun exposure.

My Youtube Video Link

Mike,

I would be very interested in the details of your cooking process.

Thanks

John

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Mike,

I would be very interested in the details of your cooking process.

Thanks

John

Hi John

It's very simple but needs a lot of refinement. This was just a quick n dirty batch I whipped up while doing some yard work. Despite my scientific nature I didn't have any real controls of the variables such as exact amounts, cooking times and temperature. I think you could start with ww rosin but I melted some Hawthorne brand venice turpentine (which I think is just pine resin in turpentine not real larch turpentine) in a large coffee can on a charcoal grill with enough bricketes to surround the can. Cook it until all the volatiles are gone and it coats a white wood stirring stick with a thick red brown coating. It should be hard when cool, takes about an hour. When it was cooked to that stage I added in an equal amount of boiled linseed oil (not high quality stuff but the stuff in the can at Lowe's). I cooked that mixture on a hotter bed of coals expecting it to reach ignition temperature and sure enough after some time there was a whoosh and flames coming out of the can. I let it burn for about 5 to 10 seconds and extinguished it by placing a cover over the can. Then took it off the heat and set it on the ground to cool. I think the burning carbonizes some of the material and gives it some of the brown color. Without that I think it would be more redish.

Future improvements would be to add lime or something similar to neutralize the acidity of the rosin. And maybe use a better drying oil and maybe less oil, and maybe add some driers to it to make it dry faster and harder. I could add in other types of resins or coloring agents... I can think of lots of things to try out in future experiments. :)

I'll downplay some the dichroic look, I think that golden color has a lot to do with good strong light and a very reflective wood under the varnish. It does look nice though! :D

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Hi John

It's very simple but needs a lot of refinement. This was just a quick n dirty batch I whipped up while doing some yard work. Despite my scientific nature I didn't have any real controls of the variables such as exact amounts, cooking times and temperature. I think you could start with ww rosin but I melted some Hawthorne brand venice turpentine (which I think is just pine resin in turpentine not real larch turpentine) in a large coffee can on a charcoal grill with enough bricketes to surround the can. Cook it until all the volatiles are gone and it coats a white wood stirring stick with a thick red brown coating. It should be hard when cool, takes about an hour. When it was cooked to that stage I added in an equal amount of boiled linseed oil (not high quality stuff but the stuff in the can at Lowe's). I cooked that mixture on a hotter bed of coals expecting it to reach ignition temperature and sure enough after some time there was a whoosh and flames coming out of the can. I let it burn for about 5 to 10 seconds and extinguished it by placing a cover over the can. Then took it off the heat and set it on the ground to cool. I think the burning carbonizes some of the material and gives it some of the brown color. Without that I think it would be more redish.

Future improvements would be to add lime or something similar to neutralize the acidity of the rosin. And maybe use a better drying oil and maybe less oil, and maybe add some driers to it to make it dry faster and harder. I could add in other types of resins or coloring agents... I can think of lots of things to try out in future experiments. :)

I'll downplay some the dichroic look, I think that golden color has a lot to do with good strong light and a very reflective wood under the varnish. It does look nice though! :D

Mike,

Thanks for posting that. I think I will try it with a hot plate. The ignition point tells you it has reached a high enough temp. No need for a thermometer. LOL.

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After several days of sun it is still very thermoplastic. I was thinking that may be because of the high oil content. On the other hand, the cooked resin without oil in it is also somewhat thermoplastc. Also linseed oil even when dry is still kind of rubbery so maybe not good to put a high oil content varnish on an instrumet? This is a learning process so my opinions are subject to change.

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well, if you told me that the resin dried hard but the resin and oil combination didn't dry, then I would be tempted to agree that maybe the problem was the oil. But you're saying that neither the oil nor the resin dried so it's not logical to blame only the oil for that problem. Is it?

I don't think you have to be an 'expert' to make observations and come to logical conclusions based on those observations.

Oded

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I would say the resin dries hard and has only a little sensitivty to finger heat / pressure, also the resin is friable and brittle, maybe only a little softer than the rosin that you would use on a bow. On the sample piece the varnish is dry to the touch but still quite soft. I have one sample piece with the varnish on it that I put in my pocket to take to work to show to a coworker, when I took it out of my pocket the glossy surface was now a matt surface with an impression of the cloth from my pocket. Maybe it just needs more cooking below the flash point? I've read that varnish should be cooked untill you can pull a thin thread but I didn't give it that test.

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I've read that varnish should be cooked untill you can pull a thin thread but I didn't give it that test.

Yes. The procedure I use is to take a drop of hot varnish drop it into a glass of water, let it cool for a few seconds then pick it up on the tip of my finger, shake off any water. Then I pinch the varnish and slowly spread my fingers. A thread of varnish should connect the two fingers. You should be able to spread your finger out at least a couple of inches before the thread breaks.

I don't know why your experiment isn't drying but I would not automatically assume that the oil to resin ratio is the reason. I've worked with varnish containing the same ratio that dried fine.

Of course you didn't exactly start with the 'finest ingredients'. ;-)

Oded

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Yes. The procedure I use is to take a drop of hot varnish drop it into a glass of water, let it cool for a few seconds then pick it up on the tip of my finger, shake off any water. Then I pinch the varnish and slowly spread my fingers. A thread of varnish should connect the two fingers. You should be able to spread your finger out at least a couple of inches before the thread breaks.

I don't know why your experiment isn't drying but I would not automatically assume that the oil to resin ratio is the reason. I've worked with varnish containing the same ratio that dried fine.

Of course you didn't exactly start with the 'finest ingredients'. ;-)

Oded

about the oil. I heard from a friend bow maker that some of the old bow makers used straight linseed oil for varnish on there bows. but I would have to ask Joshua Henry if he had heard anything like that.

However I think his name is Dan from woodfinishing said that linseed oil can be elastic

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speaking of safety issues.. Lyndon warned against using an aluminum container so while waiting for the varnish to cook I decided to try and melt some aluminum. So now I have this big amorphous blob of aluminum that used to be something recognizable. I thought about using it as a paperweight on my desk at work

It's drier now but still takes a finger print but in a half hour the print is gone.

I put a second coat on my sample and now it looks very deep 3D. Second coat also went on more smoothly and more even than the first.

Back to the subject of dichroic. It looks brown under a florescent bulb but then I held it under an incandescent bulb and it looks red. I thought wow! But I think the bulb has some specific wavelengths that do that. It is a GE

Reveal bulb.

http://www.gelighting.com/na/home_lighting/products/reveal_main.htm

so the look depends a lot on the lighting.

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dichroic generally means two different colours under different angles of the same light source, not under two majorly different light sources. i think

Hi Lyndon

It just surprised me to see it turn red like that. I know flourescent lights have a green tint usually and incandescent lights usually have a yellow tint. I think this particular bulb has some red in it's spectrum. With the gem stone alexandrite it's not the angle but the light source. Maybe in violin varnish it's the angle that matters and not the light source. Two different definitions of dichroism. I said earlier that I didn't want to put too much emphasis on that aspect of this little batch of varnish because I'm not sure it's really there. But I would like to achieve that in a varnish.

You said that your nitric treated varnish is dichroic, is that right? I will eventually try that recipe of yours including the nitric. I found an online supplier of it.

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  • 2 weeks later...

Update. A better picture closeup and the color looks right on my monitor. It's hard to get accurate color representation. Is it just me or the camera? But this looks about right. After another thin layer to get a little more color and a few more days of sun and it's dry enough to call it a varnish but that's something that still needs improvement. I cut a small cross section to see how thick the layer is and can't see it without a good magnifying lens. I'll have to mic it sometime for an accurate measurement. Bottom area is where it's smooth, the upper area is where it smeared out thinner and I scratched it some places to test the hardness of it.

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