Letter: Letters: Corny quicksand

From ALEC VANS

Re the letter from Keith Farnish (4 September) on inverse thixotropic
substances. When I want to strip paint I make a mixture of ordinary household
washing soda dissolved in water in a bucket, to which I add ordinary builder’s
lime till the mixture reaches the consistency of thick custard. Applied
evenly over the paint surface this will fetch off several layers of paint.

It is best to use only lukewarm water, as if you use hot water the mixture
will suddenly seize up and become stiff and unusable. It can be brought
back to custard consistency by stirring it as best you can vigorously, but
even so the mixture after that will tend to have lumps in it, which, of
course, do the application process no good at all.

So this mixture is an example of an inverse thixotropic substance followed
by a thixotropic mode.

DIY enthusiasts among your readers might like to try this mixture. Wear
gloves though as it makes sore places sting and turns fingers brown, and
will eventually eat the top skin away.

Alec Vans Newnham, Gloucestershire