let's make some mastic varnish

[Seth_Leigh]

From the morning of the 19th, six days after mixing in the linseed oil and letting it start to settle and clarify.

[Tim McTigue]

Looking good, Seth! I just got my mastic under turps. This past week I finally got back into the workshop a bit, having had almost a month layoff due to health issues. The last thing I had done before it all started (around April 23) was to get the top joined, and the outline rough-cut with the scroll saw. The past couple of days I've been working to refine the outline and begin to approach the final outline. I hope to be ready to start carving the top sometime in the coming week. I also have the neck blank, and perhaps I'll begin preparing that as well...

[Seth_Leigh]

From the afternoon of the 21st. I'm posting pics of this every 2 days until it's deemed by me to be done, or people yell at me to stop it. :-)

Actually, I'm probably more interested in this at this point than anyone else. I like to scroll up and down and compare the progress every two days, and so far the progress has been very noticeable. Today's shot, though, and the one from the 19th differ by less than any of the previous pairs differ from each other.

I'm starting to give some thought to carefully decanting this liquid into another jar, adding maybe a half ounce or an ounce of turpentine to thin it a little, and letting it settle some more. On the other hand, part of me would rather keep this varnish in its "original" viscosity and save any thinning out for when I'm actually going to use it.

[matthew tucker]

You moved the jar, or changed your lighting setup!! But it looks like a lot of the muck is stuck to the sides, not even in suspension. Why not decant or siphon it off and just leave it the way it is to settle?

[COB3]

Is this stuff just too tiny to filter out? is that why you have to just wait and let it settle?

I never have made my own varnish, yet (though I have purchased the mastic) and I am watching this with a good deal of interest. It just seems that if the particles are large enough to see, they are large enough to filter...would that hurt the process?

[Berl Mendenhall]

Tee shirt material first and then coffee filters work well for filtering varnish but they get clogged (what you want) and require changing. It can be a bit of a hassel, not to mention messy. If you're not in a hurry I'd say just let it settle. I've never make cold varnish, mine is always hot so it filters pretty well. It's still thin and runny.

Berl Mendenhall

[Seth_Leigh]

Matt: well this has been set up and taking pictures every 15 minutes for the last seven days or so. I have to remove the flash from its stand to change the batteries every day or two (I'm cycling between two sets of rechargables), and I have to change the camera battery every day and a half or so (I have two camera batteries I'm swapping between), so tiny movements in the camera or flash will happen. Also, since this is on one side of my office/workshop, I've bumped the camera tripod a couple of times and had to re-aim it. All that said, it's been pointing pretty much the same way for almost all of these pictures since I settled on the particular flash configuration with the snoot. Also note that these pics that I'm posting are free-hand crops from the original images, and that the position within the crop of the jar doesn't necessarily show a significant change in position of the jar within the full frame.

As for filter, I'm pretty sure I wouldn't use a coffee filter for this stuff. It's pretty darn thick, probably like a 50/50 mix of molasses and maple syrup would be. I would use a "screen" type filter if I had one. At some point I will in fact pour off the varnish into a clean jar, and when I do, I may well stretch some panty hose material over the mouth of the jar to try to catch some of the particulate that may be left.

But the bottom line is that gravity eventually takes care of this stuff, at least it has for me in the past, and I have no doubt it will again. I have no pressing need to use this varnish right now, and once I'm bored, and everyone else here too, of letting my camera snap a shot every 15 minutes of this stuff as it settles, I'll probably just put it up on a shelf and not think about it again for a month or two.

It's been interesting, at least to me personally, to look at photos pulled out every two days and compare them in a sequence, and notice a visible improvement in clarity. I think when I stop doing this will be when comparison of a given day's photo from one two days before shows no obvious change.

[mignal]

Mastic varnish eventually ends up very clear, about as clear as you'll ever need it. I wouldn't filter it, just give it time. I don't possess Seths photographic skills but this is mastic made approx. 2 years ago:

[Seth_Leigh]

Mignal, that's a much darker and more orange color than the mastic varnish I've seen. Which linseed oil did you use?

Also, I got in my email a photo from a Maestronet reader, Andrew Pickering, who was unable to post it himself. It's his own mastic varnish that's been clarifying for several days now. This is interesting, because it shows the haze settling in the same way I described earlier as having happened in my batches of mastic varnish that I made in 2004. This haze is just settling, leaving a very clear portion above a hazy portion that gradually grows smaller and smaller until pretty soon it's just down at the bottom of the jar.

[mignal]

quote:

---

Mignal, that's a much darker and more orange color than the mastic varnish I've seen. Which linseed oil did you use?

---

Yes. It does seem a little dark. Mastic was from Kremer and I'm fairly certain I obtained a very similar colour to that shown in your photo sequence. Oil is food grade Linseed. I still have some of the linseed and the colour of that is lighter than my Mastic varnish, half way between your mastic/turps mix and the bottle shown in my picture. Curious, but it can only be the oil or age of the varnish. Of course a few coats of this brushed on still appears neutral.

[EarlyRetiree]

Seth, you mentioned that in the past you had let the mastic / turp mix settle for a few weeks, whereas this time you added the oil earlier. Perhaps this is the reason that the clearing is occurring at a different rate.

BTW, you have now cost me a substantial sum of money. My first pound of mastic arrived last night. Twelve hours under turpentine and it looks exactly like yours did. Thanks again for the inspiration.

[rudall]

No, because I did mine - shown in the pic above - in exactly the same way Seth has just done his. In fact last night after I took that pic I sharply twisted/rotated the jar a few times to dislodge the deposit from the sides and this morning there was just a thin layer on the bottom with 80 percent clear. In other words, most of the cloudiness on the pic is just stuff stuck on the sides. And it has only been settling since I added the linseed on Saturday evening.

Andrew

[Marijan Radaljac]

Seth,

I just came from Lefranc`s artists shop and found out that they

have a variation of mastic varnish on stock. Ingredients indicates

only mastic in rectified turpentine. I`m not sure if you are

familiar with this kind of products, but anyway, do you think it

could be used for testing purposes with addition of some

artists grade linseed oil. 

What is the difference actually, between mastic in turpentine with

and without linseed oil. On manufacturers web site that Pure

mastic varnish is described as an very old recipe varnish, used

few hundred years ago. Thanks.

Marijan

[fiddlecollector]

Marijan, it used as a varnish over oil paintings the same as dammar varnish.

[Marijan Radaljac]

Yes, I know that. I did not follow this tread very carefully but as

far I understand, first faze of DM mastic varnish is to dissolve

mastic in turpentine. That is this (in this case Lefrancs) artists

mastic varnish. I was wandering if one can use it as

the finished first faze and add linseed oil to get final

product, DM mastic varnish, to make some tests etc. without need to

buy pure mastic tears... 

Purely technical interest was, what is the difference between first

faze of production (only ,mastic dissolved in turpentine) and

finished one, with oil added. I mean properties, hardness, drying

rates, durability...

Marijan

 

[fiddlecollector]

Probably isnt any difference.Apart from when you make it yourself you know its freshly made.

[COB3]

And you know the ratio of Resin to turpentine. Could have an effect on the end product.

[fiddlecollector]

quote:

---

Originally posted by:

COB3

And you know the ratio of Resin to turpentine. Could have an effect on the end product.

---

Which is???

Mostly it is a saturated solution of mastic in turps,once that point is reached no more will dissolve and some usable mastic will be wasted(with the gunk in the bottom).I guess like any commercial product ,id expect them to skimp on mastic if they can get away with it,so i suppose it maybe a little more dilute than `make your own variety`.

[Andres Sender]

I doubt we even get to the point of saturation, the stuff at the bottom is just stuff that doesn't want to dissolve.

My worry about the artist stuff is that it was made using heat.

[Tim McTigue]

quote:

---

Originally posted by:

Andres Sender

I doubt we even get to the point of saturation, the stuff at the bottom is just stuff that doesn't want to dissolve.

---

Speaking of that, I just decanted my mastic/turps mixture into a new jar last night and added the linseed oil. I had thought I'd be able to clean out that stuff at the bottom fairly easily, but that doesn't look to be the case. Is it best just to discard the first jar entirely, or is there a way to get rid of that gunk? Maybe it's just not worth the effort? I'm not necessarily attached to the jar, I just don't like to waste things unnecessarily. I put a bit of fresh turps over it, but it seems like it'll be really hard to get rid of...

[Wolfjk]

Hi Andres Sender,

quote:

---

My worry about the artist stuff is that it was made using heat.

quote:

---

My worry would be not using heat, as both the linseed oil and mastic might contain some water. While the turpentine evaporates, the linseed oil might wrinkle and shrink in time and the mastic might go lumpy. I am talking about 15 - 25 years.

Wolfjk

[Michael_Molnar]

Acetone can clean out the jar, but I suggest you toss it out. You cannot use the dregs for good varnish.

Mike

[Tim McTigue]

quote:

---

Originally posted by:

Michael_Molnar

You cannot use the dregs for good varnish.

---

No, I didn't want to use the dregs, I wanted to save the jar if possible...

[COB3]

I have long contemplated making varnish, but it has never seemed a good risk, so I simply purchased it ready-made, and took what I got. Now I have the mastic tears, and the turpentine, so all I have to do is go buy some raw linseed oil....

One of the things that I find attractive about this varnish (apart from the good looks, and acoustic characteristics, etc.) is that you do NOT heat it. So, no fumes, and no fire hazard. And the interesting thing about that is that if you DO heat it, even moderately, you end up with undesireable stuff in the mix, and a varnish that won't dry.

It is also nice to see that it has a good shelf-life...I can't always say how long it will be before I use a batch of stuff-- more than one can of varnish or paint has dried to a lump, sitting on my shelf. :-(

I wonder whether this would work with any other resins beside Mastic? I have a large lump of Kauri resin that my dad picked up in NZ. I'd like to try it someday, but if it just won't work that way, I don't want to waste it.

[Andres Sender]

This varnish works because of specific properties of mastic.