SEALING THE CANVAS
I mixed up five litres of solution for this job. I did not need five litres. In reality I only used just under two and a half litres for the 12ft x 9ft. canvas on the previous page. But I had more than one cloth to seal and also I did not want to run out of sealer before I was finished.
DON'T RUN OUT If you do run out before finishing then you have to make up some more and, inevitably, you will make a different strength and the canvas will dry and contract differently at that point.
Friends of mine "helped" me once by laying a new canvas on a floor (Did not stretch it at all); put on a big blow heater; and then ran out of sealer half way through so had to make up some more. The cloth was 25 feet long by 12 feet wide. But when it dried, one end was one and half feet narrower than the other!

PROPORTIONS TO MAKE THE SEALANT.
To make up five litres of sealant I used the following:-
  • 5 litres of cheap white vinyl emulsion paint
  • One cupful approximately of PVA glue
  • One cup full approximately of water
  • One spoon full of red vinyl emulsion paint.

The red paint is there for several reasons. It enables me to ensure this concoction is thoroughly mixed when the whole turns an even pink colour. When applying the sealant the colour helps me see what I have painted so far. The pink colour when on the canvas enables me to see the subsequent charcoal marks easier. And a pink base livens blue skies and seas when applied over it.

Mix the solution and prepare to put it on the new canvas. By the way you only need to do this sealing business once. Cloths which have been painted do not need to be sealed again.

I have a ritual when preparing to seal a cloth. And some of these are quite large. The game is - once started - don't stop, or else the cloth dries unevenly. So first task is to turn off the heat in the place I am working to let the cloth dry slower. I then have a cuppa, go to the loo, stick on my MP3 headphones and (starting in the top left hand corner ) away I go. I am right handed so find painting from left to right on the cloth is most convenient for me. You may have an alternative solution.

I use a four inch brush as I feel a brush gets into the weave of the canvas more satisfactorily than a roller.

I paint a band of sealant about four feet deep all along the top. Then, starting again from the left, repeat the four foot band with a slight overlap below the top (still wet) band. This is a boring uninteresting job (hence listening to music). A big cloth, say 25 feet wide could take up to an hour and a half to seal. The cloth which I sealed on the small 12 ft. by nine ft. frame (see previous page) took me exactly three quarters of an hour.

DRIPS One problem to be aware of is drips. Watch out for drips below the area you are sealing. If these are not mopped up and brushed out straight away then any drip will solidify into an immoveable lump. By brushing out I mean running the dry brush across the drip to disperse it. No need to use water to get rid of the drip. You'll be sealing over it in any case in the near future.
DRY OVERNIGHT Now leave to dry overnight. There's nothing more you can do to this cloth now.
When you return the next day your cloth should have tightened like a drum. A lovely surface to paint on.
 
 
THAT ENDS THIS "LECTURE" ON BUILDING A FRAME, STRETCHING A CANVAS AND SEALING IT.
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