Problems varnishing oil paintings

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SarahD57 posted on 8 Jan 2009 4:16 AM

Hello everyone,

I am finally taking the plunge and varnishing my first paintings. I cleaned all of the dust off with a damp cloth and once they were dry began to varnish. It seemed to go rather well, the varnish spread evenly and thinly... until I noticed that on some parts of each one of my paintings, the varnish was 'beading', as if I was applying a water-based varnish on an oil painting. Thankfully these rejected spots are fairly small, but on some, whole areas have a weird mottled look now because the varnish beaded.  I can't think of any reason why- I am using proper dammar varnish, thinned with turps substitute, a dedicated varnish brush, and the areas of the painting where the varnish did what it was supposed, well they look great.

Help! I have a show in three weeks! Any ideas?

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Hi Sarah,

The only thing I can think of is that there was some dampness or moisture or perhaps something spilled (coffee in my case) on the surface.  It is strange that this happened on more than one painting.  On those areas, is it the same color on each painting that has beaded?  I'm trying to find something in common on each of the paintings where the beading has occured.

Also, any particular reason why you diluted the varnish?

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I did consider that maybe the paintings weren't absolutely, completely dry before I began varnishing. I would be surprised if that was the reason but I suppose that even the slightest film of humidity would cause the varnish to reject. What I did notice is that the beading mostly happened on areas of one colour on each painting, although from painting to painting there wasn't a 'common' colour where it happened.

I diluted the varnish because I have read and heard from many people that it is best to go 50/50 varnish/turps. I guess that's to help it spread more easily, evenly, thinly... Do you use your varnish straight out of the tin? Is there a disadvantage to diluting?

Thanks so much for your help,

Sarah

 

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There is no enough bonding strength on your top paint layer. This can be due to a large number of reasons.

Next time, before you start varnishing, make sure all your painting surface is of the same shine. If not use retouch varnish to make so. Again and again.

Bonding strength can be increased with resin in the medium, or slice of the onion.

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This is a really interesting response- can you list some of the reasons the top layer of my painting might not have enough bonding strength? What kind of resin do you mean for use in the medium (I assume that means either the linseed/poppy oil or a prepared medium). Also, what do you do with the onion?

 

I have another varnish-related question... yesterday someone pointed out a flaw in a painting that has already been varnished (with final varnish). I want to fix it-- So, must I remove the varnish from the whole painting, repaint, and re-varnish once it's completely dry? Or can I remove the varnish just from that small area and re-varnish with retouching varnish?

Is there anything I need to know about removing varnish other than being careful with a good rag and turps?

thanks so much for all of your help.

Sarah

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A few questions.

How long has the painting sat before appling the varnish??

What colors lifted???

 

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Sarah, what brand of varnish are you using? 

If you wish to drown, do not torture yourself with shallow water.  (Bulgarian Proverb)

http://www.danadabagia.com

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I've had this problem with two different paintings, one was finished a year before varnishing (thick paint- needed long drying time) and the other was drying for about 6 months.

The paint didn't lift, rather the varnish was 'rejected' on just a few areas, and that within an area of the same colours. The only thing I can think of is that there may have been some residual humidity left after wiping the dust off with a damp cloth- I would be really, really surprised if this really was the cause, because I let them dry next to a heater for a good half hour and the cloth I used was only just damp.

Very bizarre. Is it possible that the paint can be too dry, and have dry rejection, as sometimes happens in lithography?

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I'm in Germany, so it's probably a brand you don't know of... called Guardi. It's their generic finishing varnish, the cheapest one in the art supply store (would love to be able to afford the proper dammar varnish but it's more than double the price...)

 

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Sarah, I tried to find info on Guardi varnish and couldn't find a thing, not even a manufacturer of it.  So, I'm afraid I can't help.  But do try the onion technique.  Cut it, rub it on the area that isn't attaching to the varnish, let it dry and then try to revarnish. 

Were it mine, I'd try to remove the varnish completely and get a better grade of varnish when you can afford it.  I use nothing but GamVar made by Gamblin but don't know if it's available in Germany.  You might ask at your local art store for a good substitute.

 

If you wish to drown, do not torture yourself with shallow water.  (Bulgarian Proverb)

http://www.danadabagia.com

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It does sound like a moisture problem or possibly some film from fingers or something rubbing up against the painting.

Could the painting possibly have wax on it??

I'd give the onion a try as DanaD suggested. I've never tried it but have heard of it. Let us know either way...

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SarahD,

Yes it is possible that your oil paint was dry. By that, I mean the linseed oil used in the manufacture of the paint

had dried out .This is not really an uncommon thing it happens to oil paint.

I suggest that you "oil out" the painting. Oiling out is a term refering to returning the oil to your painting.

You can look this term up if you want to get into detail.

But, simply put, you need to place the canvas down flat ,with a clean piece of cotton rag that has been saturated with refined linseed oil, daub the cloth into the canvas. Let this oil set and dry before you varnish again.

As to the blistering you mentioned, that is something I have never seen happen.

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Suggested by Kadon

I have been following this discussion diligently.  I had a similar problem and was told to spray varnish in VERY thin even layers.

It seems to have worked so far.

 

Can never learn enough.

Blogspot: http://kadon-artwork.blogspot.com

 

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Hi everyone, I've finished varnishing the paintings and they are now hanging in the gallery. If anyone is interested, the gallery's site is www.elm75.de (in German only) and the images are on my own site www.sarahdudley.net, along with photos from the vernissage.

About the varnish- the onion trick worked wonders, and it's so easy to do. I imagine I had problems with the varnish because some of the paintings had been dry too long (over a year), and on areas of others, their wasn't enough oil in the paint (not enough used in painting, or some pigments like red and white tend to dry really quickly and therefore I'm guessing they lose their oil more, or more quickly than other colours). 

Regardless, if you have the same problem, on dry paintings, wipe the open side of a freshly-sliced onion over the problem area. I wiped enough so that I could see droplets of the juice scattered around so I knew there was actually something there. Let it dry WELL. In a warm room it took only a matter of an hour or so but I waited a while longer to be sure. Then apply the finishing or retouching varnish as usual and voila!

Thanks a million to everybody for your help and suggestions,

Sarah

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Good news Sarah.  Can you, or anyone tell me the difference between retouch varnish and/or the other final varnish (if there IS any difference of course.)

Can never learn enough.

Blogspot: http://kadon-artwork.blogspot.com

 

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