Compo recipe and directions

[tonywish]

As a new member I have done a lot of research on how to make compo. I have a large container of failed results. It must be like baking a cake, in that it is not only the recipe but the technique. I am using 300 gr. of hyde glue or rabbit skin glue, 246 gr. pine rosin, 118ml of boiled linseed oil, 5 ml glycerine, 1516 gr. whiting. I heat the hyde glue ( or in the event I use rabbit skin glue mix with water to a pasty concsistency), in a double boiler I heat the rosin and boiled linseed oil until it melts into a creamy consistency, I then aded 5 ml of glycerine. I then combine the rosin mix with the gluein the double boiler stir well then on a large flat surface make a mound of whiting and pour the mix into this slowly mixing with a spatula. When cool enough I knead until my fingers hurt.I now have depending on my mixtures a ball of what looks like a cauliflower head or a big glob of rubbery chewing gum. I tried several times with a few alterations and got the same results. If you have made compo successfully would you mind sharing your recipe and or technique with me.

Tony

[vintage frames]

I'm not sure from your description what you're doing wrong but you're certainly on the right track.
Try doing it this way;
Soak 250g of hide glue in 125ml of water. Melt this in your boiler and add 20ml of glycerine and 10g of zinc oxide ( this is chinese white pigment and prevents mould growing on the compo later).
Melt 100g of rosin and add 20g of venice turpentine and 60ml of linseed oil.
Mix this into the melted glue and then pour the lot into about 600-700g of whiting.
This should then blend to a soft putty like ball and split into 3 or 4 lumps to be used as needed.
I use a microwave to re-melt the compo for use.
Good luck.

[A3DFramer]

Thanks for that description it was most informative. during a period in my working life when I was travelling the antique fairs and dealing in items of 3D framing art work, a display of butterflies on modelled modelled branch and leaves passed through my hands. These were not of the usual quality of victorian souvenir ware but, suspect a line of specialty work by a craftsman who had a supply of the cut offs from glass domes. The framing was a circular picture frame with a 15 inch diam tube, probably cut off from the trimming down of a large circular glass dome, fixed into the frame projecting forwards about 5 inches. A circular piece of glass was fixed to the open end of the tube with a very fine fillet of compo.

I have always believed that the Victorian craftsmen did not waste time, they devised ingenious and practical methods but were not afraid to spend time on practice to create procedures based on skill. Your description of compo bears out my suspicions on how the original might have been produced. ( I was able to devise a method using a home made polyester putty with metal powder content to create a sheen on the edges of a joint that was commercially practical, suitable for 2mm glass, which gave a semblance of period to framing of older objects)

I believe that compo may have been used more than surviving antiques cases suggest in various forms of 3D framing.