Nigel Watts
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- 1,779
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- London N7
Polyfilla is very sticky, but this has cons as well as pros.
Stickiness is an asset when the surface to which it is being applied has little key. I had a problem finishing off the external corners of a chimney breast where the original wooden battens were still in place under the finish coat. A thin layer of lime, even when mixed with plaster, simply wouldn't adhere strongly enough to the wood. I had to strip all the lime off and replace with pollyfilla, which worked much better, but applying multiple coats, sanding in between was pretty tiresome.
However, the stickiness makes it very difficult to shape accurately as it tends to adhere to one's tools. It can of course be sanded easily - another advantage - but this is an extra step in the process and a less accurate way of making a more complex shape. For example if I had to repair a small gap in a length of straight plaster moulding I would much prefer to use a lime/Plaster of Paris mix which I could then shape accurately and smoothly using a plasterer's joint rule. Doing the same job with pollyfilla would take longer and almost certainly be less accurate and with a poorer finish.
Stickiness is an asset when the surface to which it is being applied has little key. I had a problem finishing off the external corners of a chimney breast where the original wooden battens were still in place under the finish coat. A thin layer of lime, even when mixed with plaster, simply wouldn't adhere strongly enough to the wood. I had to strip all the lime off and replace with pollyfilla, which worked much better, but applying multiple coats, sanding in between was pretty tiresome.
However, the stickiness makes it very difficult to shape accurately as it tends to adhere to one's tools. It can of course be sanded easily - another advantage - but this is an extra step in the process and a less accurate way of making a more complex shape. For example if I had to repair a small gap in a length of straight plaster moulding I would much prefer to use a lime/Plaster of Paris mix which I could then shape accurately and smoothly using a plasterer's joint rule. Doing the same job with pollyfilla would take longer and almost certainly be less accurate and with a poorer finish.
