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rltromble
02-26-2009, 12:39 AM
Alright here is the deal. I am doing a master study, which loosely translate into using a dark back ground. I used Ivory black and ultramarine blue and then added a couple drops of copal medium (just enough to make it fluid) to speed up the drying time since I wanted the background tobe dry before I started the next layer of glazing on the figure.
It took more then three days for it dry. Is this normal? Should I have added more? Or maybe should I try a different medium to aid in the drying next time?

Einion
02-26-2009, 11:41 AM
Just to check are you painting on top of the dark background you've created, or is this just surrounding the area still to be painted?

It took more then three days for it dry. Is this normal?
It might bem for the temperature and humidity, the specific paints you used and on the support you're working on.

Should I have added more? Or maybe should I try a different medium to aid in the drying next time?
Personally I wouldn't suggest you use copal medium at all, even if it were made from real copal which is unlikely these days.

Faster-drying layers can be achieved with little recourse to additives by careful selection of paints which naturally dry faster.

A small addition of Liquin or similar can be added if necessary.

Einion

LarrySeiler
02-26-2009, 12:30 PM
I've painted with copal for about a decade now...

Traditionally it was used with glazing applying a thin layer over dried paint, then painted into...allowed to dry or set up, then another thin layer was applied over it and painted into. Many many layers built up.

Myself, I paint alla prima and first used it painting outdoors. What I liked about it from day one was that the buttery consistency I painted with took to the support in the thick stroke staying right where I put it. The medium added a greater jewel-like brilliance to the color and since pigment is a deficit to begin with in imitating the color of natural light, the extra little boost was appreciated.

Next I appreciate its quality of being a siccative...that is, a natural drier and one that attaches molecularly to pigment meaning it dries throughout. Not just a drying of the surface with months yet for the paint beneath to dry.

Now...problem is, art stores produce a cheaper synthetic resin imitation of copal...clearer in color, and it does not act as the copal past painters used. In the 1850's thru early 1900's...painters referred to their "oil of copal" which was essentially the same thing as copal I'm using. A resin extracted from rock like petrified trees, but a very painstaking means to do the extracting and expensive. My copal is a darker brownish fluid...but the paint is not affected by the color.

About 2-3 drops of copal per one inch ribbon of paint from say a 37ml tube and it begins tacking up before I'm done with my 1-1/2 to 3 hour painting, tacks up on the palette and I cannot afford to not clean my palette til the next day really. Within 3-5 days...the painting is dry to touch, and about a week later I'm confident enough to spray it with Krylon Kamar varnish should the piece be bought.

Sounds to me as if you have a bad batch...or a synthetic imitation.

Sadly...it is now very difficult for small operations to acquire copal as countries like Turkey that supply today want very large quantities of the resin/rock purchased and its become cost prohibitive. I have acquired a good amount that should last me another year or two hopefully...but then I'll probably look at something like Walnut Oil or use amber...

My paintings look fresh, clean...great color with no ill effects over the past decade of any work.

gunzorro
02-26-2009, 01:49 PM
Like Larry, I also recommend genuine copal for use as medium, and often use it in all layers, or even a single layer painting.

But, as Einion says, finding genuine copal is not easy locate, and not found in the average art store. So what you undoubtedly have here is imitation alkyd medium, not copal at all.

Another tip is that you are trying to use "copal" to speed up drying, so that lets me know you are new to it, as well as being unsure of the quantity to use. If it is an alkyd quick drying medium you are using, you can certainly continue adding more until you achieve the drying time you are looking for. Hopefully you have time to do some experiments and observe the results in drying time (over a day or two).

What you are really looking for is a drier, or siccative, to speed the drying so you can paint over a layer right away. If you have an urgent need, you can buy cobalt drier at the art store and add a couple drops to each paint mixture. A better solution is to order Lead Napthanate from a supplier like Robert Doak -- again added a couple drops to a small paint mixture.

You can also use a quick drying alkyd medium, such as WN Liquin, or other brands -- I like Schmincke, Talens and Lucas and avoid Liquin.

In the meantime, as Einion indicated, some paints will assist in speeding drying. If you have a medium to dark area, simply mix in a portion of either Raw or Burnt Umber and that will help dry overnight. The downside is that the finish might appear dull or "sunken" the next day.

Einion
02-26-2009, 02:48 PM
But, as Einion says, finding genuine copal is not easy locate, and not found in the average art store.
Maybe impossible - what I was referring to is that some sources indicate that true copal, as used in the heyday of copal mediums, was long ago exhausted.

> See previous thread or threads if interested.

Einion

Termini.
02-26-2009, 03:17 PM
Like Larry, I also recommend genuine copal for use as medium, and often use it in all layers, or even a single layer painting.

But, as Einion says, finding genuine copal is not easy locate, and not found in the average art store. So what you undoubtedly have here is imitation alkyd medium, not copal at all.

Another tip is that you are trying to use "copal" to speed up drying, so that lets me know you are new to it, as well as being unsure of the quantity to use. If it is an alkyd quick drying medium you are using, you can certainly continue adding more until you achieve the drying time you are looking for. Hopefully you have time to do some experiments and observe the results in drying time (over a day or two).

What you are really looking for is a drier, or siccative, to speed the drying so you can paint over a layer right away. If you have an urgent need, you can buy cobalt drier at the art store and add a couple drops to each paint mixture. A better solution is to order Lead Napthanate from a supplier like Robert Doak -- again added a couple drops to a small paint mixture.




Jim,

You are right on about copal. I also recommend using the actual medium. As you know, Groves is very good.

Copal isn't a drier as such. For example, if one fuses "hard" copal, and then combines with nothing more than turpentine, what will result is a liquid. If a few drops of this liquid is added to a small paint nut, and the paint copal mix is painted onto a canvas, and the brush is held against the canvas for 5 to 10minutes, one would be hard pressed to pull their brush away. 30 minutes later, one could even touch the paint and have nothing come off. It would appear as though it dried. In fact the paint did not dry that fast; we all know that oil paint doesn't dry that fast. What has actually happened is that the copal acted as a very strong glue, amongst the other materials present, in the paint. This is why the proper amount of oil is combined with the solvent and the fused resin, to make a medium (Not a varnish). My example is extreme and used to illustrate that as you pointed out, there are other materials that are better as driers. Based on the above, all of the rules of oil painting must be followed, when copal is used as a medium; which includes fat over lean, and waiting 6 months to a year to varnish with a removable varnish, in order to maintain a sound practice.

Jim

Termini.
02-26-2009, 03:20 PM
Maybe impossible - what I was referring to is that some sources indicate that true copal, as used in the heyday of copal mediums, was long ago exhausted.



Groves makes some good copal varnish. Studio Products is pretty good, and Kremer pigments sells very old "hard" copal for those who like to make their own.

fran dalton
02-26-2009, 03:52 PM
Listing the wn brand liquid copal souunds like what I ,ll try. I am painting an
oil on paper an going to see if the paint layer will dry faster.
If you have a further suggestion I'd appreciate help.
Thanks, a new member ,Fran

rltromble
02-26-2009, 07:40 PM
I was using W&N copal medium and I was painting over a dark wash layer. I know that Ivory black is a slow dryer, it takes up to a week by itself, and ultramarine isn't all that speedy either. However, these where the colors I needed as far as I know all blacks are slow dryers.
The study is being done on a small canvas (9X12), the figure skin tone is about as light as it gets. If the dark background had contaminated the lighter figure it would be a serous head ache. By using copal I was hoping it would dry in 24 hours. I do have liquin fine, but it produces this plastic like surface when used in mass. I have other mediums but they increase the drying times :eek: .

rltromble
02-26-2009, 11:07 PM
Thank you everyone for your time.

monkhaus
02-27-2009, 12:06 AM
Has anyone tried products from these folks?

http://www.woodfinishingenterprises.com/varnish.html#cgocop

Not that I'd even know how to go about heating to make my own...

(Termini, every time I see a comment from you I think I learn something new. Thank you.)

jpacer
02-27-2009, 10:54 PM
Hi there, I'm new here and I was going to ask this question anyway, but I saw this thread and figured I'd just ask the people here since they seem familiar with Copal.

Basically, I'm aware of the debate about whether or not copal should or should not be used and I'm not really interested in that sort of discussion. I'm just curious and really want to try it because despite all the talk that it should be avoided there are people that swear by the stuff. (The same can be said of Maroger Medium, but there's enough bad press about that stuff I'm not interested in trying it, despite its many supporters. But I digress....)

Anyway, I've found various suppliers online who claim to have genuine copal and I would like to know which ones you guys recommend or think has the best working properties which make Copal unique. So far the main suppliers I know of are JC Groves, Studio Products, (who apparently now have Congo Copal) and Garrett Copal (who doesn't mention what kind of Copal it is, which I find odd because from what I understand there are many different varieties of Copal all with VERY different properties).

Thanks for any information you may have.

-John

oilpainter98
02-27-2009, 11:39 PM
ivory black and ultramarine blue are some of the slowest driers on my palette, so i would first use something that dries faster. i think you should try a defferent drier medium. i only have grumbacher fast dry medium, and that works well for me as it dries in a day or two for slower drying pigments.

gunzorro
02-28-2009, 02:50 AM
Garrett is unreachable, and possibly out of business.

I would go with James Groves -- the product is reputable (amber, and others are also excellent). Groves is a pleasure to deal with.

monkhaus
02-28-2009, 03:41 AM
Blue Ridge is supposed to have a congo copal medium available soon too.

Einion
02-28-2009, 08:17 AM
Anyway, I've found various suppliers online who claim to have genuine copal...
That's the crux of the issue. I'm sure most are quite genuine in thinking they do, but they may all be mistaken.

Anyway, this is off-topic to your query - regardless of what the resin is technically users/fans are using what it is and that's what you'll be buying. Groves is probably your best bet.

I would caution though not to be swayed by the idea that paintings done using a hard-resin medium don't need to be varnished.

Einion

Termini.
02-28-2009, 03:55 PM
That's the crux of the issue. I'm sure most are quite genuine in thinking they do, but they may all be mistaken.

It seems that those making these products should know what raw materials they have. It seems that it would be very difficult to be mistaken, regarding things like copal. There are some simple tests, and the process of making the varnishes itself, should be enough to convince one as to the nature of the raw materials/product they have.

When something is called "copal" what does that actually mean? The word is about as useful as saying I'm going to dinner tonight and will eat "food." It is very important for people to know what type of resin was used, in what amount, and where this resin originated. Copal can refer to recent resins fresh off the tree, to very old resins hundreds of thousands of years old, and buried under quite a bit of earth. It can come from many parts of the world, from Columbia, to Africa, to South-East Asia, etc., and originate from a variety of botanical sources.

A manufacturer could purchase some "soft" copal, something such as Pontianak, make a medium, and sell it as copal, and be entirely legitimate. However, it is a much different product than a "hard" copal such as Congo, Sierra Leone, Magdagascar, etc. In fact, hard and soft are not good words to use, and whether the copal is considered "soft," or "hard," they are both generally the same in hardness (moh's scale). The real difference comes when each is fused. The "hard" is much more difficult to fuse, as it is much more polymerized (Not fossilized as it contains its original components). Baltic amber being millions of years old is exceedingly difficult:eek:

One of the reasons that many of these materials are no longer available, is due to politics, rather than entirely due to availability. However, the raw materials have indeed been used up for other purposes, in other times. They were used for a variety of products such as floor covering. Things that in today's world, petroleum products are substituted for. One need only look at Magdagascar, the island has been or is in the process of being stripped of almost all of it's natural resources. Uncounted animals that were unique are now extinct. Certainly, one isn't likely to obtain much copal from there nowadays.


Anyway, this is off-topic to your query - regardless of what the resin is technically users/fans are using what it is and that's what you'll be buying. Groves is probably your best bet.

To be frank, if I were in the market to purchase a commercial copal product, having used quite a few, I would go with the Studio Products Congo copal. I say that even though I am in Coventry on that site. Groves Copal is good as well.


I would caution though not to be swayed by the idea that paintings done using a hard-resin medium don't need to be varnished.



I fully agree with you regarding this. Folks need to remember that although amber and some copals are referred to as hard-resins, in their raw state they generally fall at about 2 on Moh's scale of hardness. That isn't very high; not much harder than talc, in the total scheme of things. Once cured much of their strength comes from the physical properties of the oil they are combined with. Their use in paint should be based on a special effect that they permit, and not on some desire to kill two birds with one stone; and create a painting that doesn't need to be varnished due to it containing a certain amount of varnish. Over time, surfaces can become dirty, dusty, etc. Removable varnishes allow that an old protective layer can be removed and a fresh layer applied.

As a side issue, I have tried many of these so-called copal mediums that have no copal in them, but appear to be combinations of perhaps alkyd and acrylic resins, and found that they do not behave at all like actual copal. They could be used in place of things like Liquin (which has it's uses), imo. My concern is when something is called copal medium, and has no copal in it. In fact, I called one manufacturer about this, and asked why they would sell something called copal medium, when it has no copal in it. The representative I spoke with was going to speak to the chemist, and call me back. That was back in 2003, and I fully expect to never be contacted by these folks.

I for one do not believe that the masters of the Renaissance were using copals from sub-Saharan Africa, Amercian, nor South-East Asian sources. There is evidence that amber was used in Europe, and certainly balsams, as well as products such as mastic, and even sandarac. Many of these products were used in other areas, such as with musical instuments, and furniture. Any use of sub-saharan resins in painting, post dates the time that Europeans first entered the heart of Africa. From a historical perspective, we pretty much know when that was.

As a double side issue, I would say that folks wanting to use mediums such as copal, should ask why? What is it that one is trying to achieve? Do you want to paint like the old masters? Quite frankly, if that is the case, a trip to the museum should be enough to convince anyone that it is not a special medium that makes the work. It is a creative composition, an attention to detail, and an exceptional level of patience, in addition to the materials. Mediums are not that high on the list of importance, when considering a painted work. I knew a monk who painted icons that were remarkable. They appeared to glow from within. They also looked very, very old. To place one in an Orthydox church next to another 400 year old piece, one would be hard pressed to know which is which, by sight alone. In fact, this monk did not use tempera, or any old material. Rather he used Jo Sonja's acrylic paints, water, and a modern synthetic varnish.

Jim

marielizabeth
03-02-2009, 03:40 AM
I'm glad this subject came up. I have a bottle of Garrets copal I bought a couple of years back to use with oil pastels, but I wouldn't mind using some just to make up my own mind, but what about the brushes? Do they clean up with OMS, or do you need naptha? Is it hard on your good sables? 'becca

LarrySeiler
03-02-2009, 10:32 AM
Has anyone tried products from these folks?

http://www.woodfinishingenterprises.com/varnish.html#cgocop

Not that I'd even know how to go about heating to make my own...

(Termini, every time I see a comment from you I think I learn something new. Thank you.)

I use their pumice #FFFF for my support grounds..

gunzorro
03-02-2009, 11:42 AM
marielizabeth -- It is possible to clean out most of the copal with OMS, but Mineral Spirits is better to dissolve the resin varnish. You shouldn't need to use turps for cleaning (you can!), even though that is the best thinner to use if you are mixing copal for mediums.

Let us know what you think of Garrett copal.

Termini.
03-02-2009, 12:48 PM
I'm glad this subject came up. I have a bottle of Garrets copal I bought a couple of years back to use with oil pastels, but I wouldn't mind using some just to make up my own mind, but what about the brushes? Do they clean up with OMS, or do you need naptha? Is it hard on your good sables? 'becca

Much more effective to use turpentine to clean with, if you can. Based on the way these resins affect the texture of paint, I would think that you would want to use other mediums, if you are going to paint with fine sables. That is unless you plan on using extremelly high resin varnish, which is very sticky, but acts like stand oil in a paint mix. This isn't advisable for several reasons.


Jim, I hope you are not engaging in one of those "you pound from one side, and I'll pound from the other," type deals:D

Einion
03-02-2009, 04:29 PM
It seems that those making these products should know what raw materials they have.
See next point.

Copal can refer to recent resins fresh off the tree, to very old resins hundreds of thousands of years old, and buried under quite a bit of earth.
Differing views on that very issue are what I allude to.

As I mention above there are previous threads on the subject. They highlight all the relevant points if memory serves.

...I say that even though I am in Coventry on that site.
You're in good company then :thumbsup:

Einion

Termini.
03-02-2009, 05:22 PM
See next point.
As I mention above there are previous threads on the subject. They highlight all the relevant points if memory serves.



Nothing wrong with a little reiteration. I haven't really seen any threads here which allude to definitive evidence regarding any mistaken beliefs on the part of any manufacturer, as to their raw materials. If there is such, I would think that it would be most helpful to anyone interested in these topics.



You're in good company then :thumbsup:



:smug: :D

Renilou
08-20-2010, 10:39 PM
I know this is an old thread, but I just acquired a very old 16 oz can of Grumbacher Copal painting Medium. My mother in law was an oil painter in her youth but had abandoned it in her later years. She passed away and her husband kept everything until he finally moved into assisted living. I went through things and found this near full can of medium.
I read the ingredients and it contains pure Congo Copal Resin, Linseed oil and stand oils.
Since I am a watercolorists I have no idea what all this is or how to use it.
I do want to try it but wanted to find out how toxic this can of medium is. I have found no information on it online. Do any of you know if this stuff is toxic? If so, how toxic? Would it still work well? This is a very OLD can. The cost she paid for this can of Medium is $2.35. There is no date on it so I have no clue how old it is.
I have some oil paints, M Graham and am planning to use the walnut/Alkyd medium. Should I just toss the Grumbacher Copal painting medium in the garbage?

sidbledsoe
08-21-2010, 12:09 AM
That is a semi valuable find.
It is not particularly toxic, should have some turp in it too, if it still looks good and is liquid then it probably will still work well. If so and you want to get rid of it then do not toss that in the garbage, PM me and I will give you my address and I will send you postage plus for it.
Congo copal is desirable, not cheap anymore, and not that easy to find.

Renilou
08-21-2010, 12:37 AM
That is a semi valuable find.
It is not particularly toxic, should have some turp in it too, if it still looks good and is liquid then it probably will still work well. If so and you want to get rid of it then do not toss that in the garbage, PM me and I will give you my address and I will send you postage plus for it.
Congo copal is desirable, not cheap anymore, and not that easy to find. The can looks like it literally can out of the late 50's or early 60's. It is still in good shape too. It says Grumbacher Copal painting Medium.
The actual listing of ingredients. An oil painting medium containing pure Congo Copal Resin, Linseed and Stand Oils.
It does not say anything about having turps within it. It does not smell like it either. What are stand oils?

I decided it might be worth keeping. I just needed to know if it was toxic or not. I'm still not certain about that but will research it.

Thanks for the reply!;)

For all techniques.

monkhaus
08-21-2010, 01:28 AM
Wow. What a find.

Read up on Frederic Taubes and then James Grove's site would be worth looking at too. They'll give you and idea of what you can do with it.

Renilou
08-21-2010, 01:30 AM
Thanks!!!:thumbsup::clap:

Wow. What a find.

Read up on Frederic Taubes and then James Grove's site would be worth looking at too. They'll give you and idea of what you can do with it.

sidbledsoe
08-21-2010, 01:35 AM
Yes, you should keep it and treasure using it. Copal is a natural resin. Stand oil is just linseed oil that has been heated without air. This makes it thicken and polymerize and acquire desirable qualities such as far less yellowing and produces a glossy luster upon drying and the paint film is more durable or sturdy.

Doug Nykoe
08-22-2010, 03:30 AM
An oil painting medium containing pure Congo Copal Resin


Wow what a findů meaning a throw back to a time when Grumbacher actually meant QUALITY. Ah the good old days. :rolleyes:

I also remember their Finest series of paints, those were great too. :heart:

~.~

Renilou
08-22-2010, 03:38 AM
Wow what a findů meaning a throw back to a time when Grumbacher actually meant QUALITY. Ah the good old days. :rolleyes:

I also remember their Finest series of paints, those were great too. :heart:

~.~I think all things change to comply with environmental demands. Sometimes those changes are not better and quality suffers.

Doug Nykoe
08-22-2010, 05:06 AM
I think all things change to comply with environmental demands. Sometimes those changes are not better and quality suffers.

How true, and thank goodness there are still people making those old but true and time tested traditional products like copal. I would get pretty grumpy if all we had for a choice in this nanny world we are seemingly progressing to was just the alkyds,,,you know, that one trick pony. :D


~.~

Renilou
08-22-2010, 03:35 PM
I heard the copal came from tree's, buried 1000 to 1 million years old beneath the ground. Now that the environmentalist have taken a stand, one cannot dig holes in the ground anymore. LOL!
I'm all for saving our beautiful world, but I also think some take it to extremes and interfere with nature to much by trying to control it.
I did a little research the past couple of days and found the copal is forbidden out of their country's now by government so this is why we cannot get it.
I have no clue about this as fact. It is just what I read. But whatever the case may be, I want to keep the copal and my husband says I should sell it. Leave it to a man! LOL!:rolleyes: No offense to any gents out there. :wink2:

monkhaus
08-22-2010, 03:48 PM
Ahh, let the bidding war on WC begin. Though you should give your friends in WA State first dibs (hint, hint).

Honestly, though, keep it and use it. If you don't like it then sell it or give it away in a year or three but don't do so before you have the chance to paint with it.

Renilou
08-22-2010, 04:14 PM
Oops..I better update my profile. I since moved back to my Home State of Oregon. :wave: My husbands Moms place was always Oregon too.
1st bid for Oregonians:lol:. But I think I'll keep it. I may be a watercolorists but I have always wanted to try oils. I have some. I just have to get going on it.
My problem now is not enough space.

Renilou
08-22-2010, 04:23 PM
Well, I cannot figure out how to do it so I give up. There is every option there except how to update my home state.:cool:

sidbledsoe
08-22-2010, 06:15 PM
Well, I cannot figure out how to do it so I give up. There is every option there except how to update my home state.:cool:
Click on - My WC
then - edit profile
then - location (where you live)
update the info
then - save changes

Renilou
08-22-2010, 06:21 PM
Click on - My WC
then - edit profile
then - location (where you live)
update the info
then - save changesThanks! I guess I did not scroll down far enough the 1st time.:)