Home Forums Explore Media Oil Painting The Technical Forum For Gigalot: oiling out with Synvar

Viewing 15 posts - 1 through 15 (of 28 total)
  • Author
    Posts
  • #472126
    MrsSellers
    Default

        Alex, you said in this post that Synvar could be used for oiling out:

        https://www.wetcanvas.com/forums/showthread.php?t=1402527&page=2

        There is another post which I can’t find anymore that suggested using Synvar as an isolation layer.

        But what about the 6-12 month drying period before varnishing? Or is Synvar like Gamvar in that respect? Can Synvar be applied over uncured paint? I don’t see any information about this on the product page.

        #816140
        Gigalot
        Default

            since oiling out is non-removable varnishing process, you do not need to wait 6 months to cure oil paint. 1-2 months of curing time should be enough for that. However, you must completely wipe all excessive synvar from the painting surface. The advantage over Galkyd oiling out is, that synvar is completely non-yellowish stuff. Do not use OMS to dilute synvar, it needs strong white spirit or turpentine for that.

            #816152
            RomanB
            Default

                Synvar is an acrylic varnish made of poly(n-butyl methacrylate). It will turn grey and attract all the possible dust. Also it is barely removable.

                #816155
                Richard P
                Default

                    I thought varnishes turned yellow, not grey?

                    #816141
                    Gigalot
                    Default

                        Synvar is an acrylic varnish made of poly(n-butyl methacrylate). It will turn grey and attract all the possible dust. Also it is barely removable.

                        Hope you understand the difference between oiling out and varnishing.

                        #816134
                        Don Ketchek
                        Default

                            Hope you understand the difference between oiling out and varnishing.

                            Which is why it isn’t always a good idea to oil out with a varnish (Synvar is a varnish). Yes, it is done, as many folks use a retouch varnish for the same purpose as oiling out. It is important to note that if you want to use varnish to oil out, that it is considerably thinned. Gamvar, for example, is often used as a retouch varnish and the instructions are to thin with additional OMS. Hopefully, if you intend to use Synvar as a retouch varnish (or oil out) there are instructions as to what and how much to thin with.

                            Or, as it is called oiling out, you use an oil to oil out.

                            Don

                            #816137
                            Anonymous

                                Oiling out with an oil does not cause any more yellowing than the binding oil in the paint that is already there, so yellowing is not a factor.
                                Oiling out replenishes the binding oil that has gone missing, it has shrunken, and has been absorbed down into the layer(s) of paint.
                                It is binding oil inside that is missing, not varnish.
                                So if you use varnish instead of oil, then you introduce acrylic plastic varnish into your painting layer(s) which is another variable factor into the paint layer as it ages and cracks and deteriorates.
                                The binding oil of paint will cure and undergo dimensional changes over a period of months and years. The acrylic plastic varnish will not undergo the same flux and thus will be different from the rest of your paint layers.
                                You could also oil out with Super Glue, Titebond, Mop and Glo, or Thompson’s Water Seal, and it may seem to work ok, just not in my studio.

                                #816153
                                RomanB
                                Default

                                    I thought varnishes turned yellow, not grey?

                                    Acrylic varnishes turn grey. Here is an interesting photo: several Soviet varnishes used for oil painting, test swatches were applied in 1986 and were photographed in 2016, after 30 years of natural ageing on a wall.
                                    Labels are, from left to right:
                                    Mastic varnish, Damar varnish, Siberian Pine Balsam varnish, PBMA varnish, Amber varnish.

                                    #816148
                                    contumacious
                                    Default

                                        Alex, you said in this post that Synvar could be used for [B]oiling out[/B]:

                                        [url]https://www.wetcanvas.com/forums/showthread.php?t=1402527&page=2[/url]

                                        There is another post which I can’t find anymore that suggested using Synvar as an [B]isolation layer[/B].

                                        But what about the 6-12 month drying period before varnishing? Or is Synvar like Gamvar in that respect? Can Synvar be applied over uncured paint? I don’t see any information about this on the product page.

                                        Are you wanting to use it as a true oiling out product, where you only apply it in the areas you are going to paint over that day, or as an overall sheen unifying / isolation layer – or both in different instances?

                                        #816157
                                        MrsSellers
                                        Default

                                            I was considering it as an isolation layer over some areas I didn’t want disturbed if I had to scrape off the new paint. I rarely oil out, but if I do, I use oil.

                                            #816149
                                            contumacious
                                            Default

                                                I have had good results using Galkyd Lite as a PERMANENT isolation layer. It holds up to well to OMS and rubbing with rags either dry or soaked with OMS. As for scraping, I don’t think there are many materials that will hold up to heavy scraping with a metal tool, but a heavier layer of Galkyd gives a pretty tough surface. The color doesn’t change over time like raw oils. What you see now will be what you will see years down the road. It is a bit darker than some other materials, but the layer is so thin it doesn’t make a noticeable change to my eyes. It is pretty shiny and slippery. If you find it too slippery, I have read that you can add transparent matting agents to give it more tooth, such as finely ground silica and perhaps other materials. I have not yet had any beading up problems with a thinly applied layer.

                                                You may have already seen the discussion on this where I gave links where someone at Gamblin said it is OK to use it this way. If you can’t find it, I will post a link to it. The key word here is PERMANENT, but if you are going to be painting over the Soluvar, that would also be basically a permanent solution as well. If the paint is dry to the touch and doesn’t lift appreciably when wiped with a rag saturated with Galkyd I proceed with adding the isolation layer. You can use Galkyd or Galkyd Lite – I dilute them with 50% Gamsol and brush it on thinly and evenly. I will sometimes wipe it after brushing, depending no how it looks, but I don’t do that every time. The thinnest layer that does what you want is where you want to be.

                                                #816158
                                                MrsSellers
                                                Default

                                                    Thanks, good advice. I used Liquin for this once but was concerned that the parts that didn’t get painted over might change color.

                                                    #816150
                                                    contumacious
                                                    Default

                                                        Thanks, good advice. I used Liquin for this once but was concerned that the parts that didn’t get painted over might change color.

                                                        You are welcome, I would assume that the current formulation of Liquin doesn’t darken very much over time, though my rather old bottle has darkened quite a bit. I have never used Liquin that way before since I did not see any recommendations to do so by the folks who make it.

                                                        #816142
                                                        Gigalot
                                                        Default

                                                            Acrylic synvar is more flexible than any alkyds and more chemically stable, than both, oil and alkyds. Also, synvar is partially reversible. If any, you can wipe fresh synvar with mineral spirit, while oils and alkyds are non-reversible.

                                                            You do not need to wait much time to apply galkyd oiling out because it will eventually polymerize. But you must wait more, if you like to use synvar because excessive oil from non-dried surface can make it tacky, while pure synvar layer itself is solid like Plexiglas.

                                                            #816135
                                                            AnnieA
                                                            Default

                                                                This seems to me to be a related question:
                                                                If there is yellowing of the oils typically used for oiling out, then wouldn’t it make sense, if one wants to do actual oiling out with oil, to choose an oil that has minimal yellowing? For example, to use safflower instead of linseed oil for oiling out, even if the painting was done using linseed oil?

                                                                [FONT=Arial]C&C always welcome ©[/I] [/font]
                                                                [FONT=Palatino]
                                                                “Life is a pure flame and we live by an invisible sun within us.” ― Sir Thomas Browne [/size][/font]

                                                                http://s3.amazonaws.com/wetcanvas-hdc/Community/images/29-Jul-2007/85002-sig-thumbnail_composite_2.jpg]/img]

                                                              Viewing 15 posts - 1 through 15 (of 28 total)
                                                              • You must be logged in to reply to this topic.