Sculpture is a tactile art form – people love to touch sculpture, or in the case of very small pieces, actually pick them up and play with them.  There is no reason why you shouldn’t do this if the surface is protected with a cleanable and renewable finish.

Unfortunately, for those of us who love the unique character of raw steel, no clear protective finish will provide completely permanent and unobtrusive rust protection.  A number of products will provide a clear coating, but all have drawbacks.  Some highly durable products are too slick and glossy to be aesthetically pleasing on raw steel.  Some finishes require complete stripping of the old finish if repair is needed.  Some oil-based sealers tend to add a yellowish discoloration or leave a faintly sticky surface that attracts dust. 

I coat most of my pieces with several thin applications of Penetrol, a petroleum-based sealer and rust inhibitor.  I like Penetrol because it dries to a subtle, non-sticky, and non-yellowing sheen.  It is also easy to renew without having to strip the existing finish.  There is a great deal of debate about finishes among sculptors, but nobody can suggest a finish that is less obtrusive or easier to maintain.

Steel sculpture can be dusted or polished with any ordinary duster or soft cloth.  If it has been handled a great deal or seems to need more than just a wipe, don’t be afraid to wash it with hot water and dishwashing liquid.  Rinse well, and dry as quickly as possible using a hairdryer or heat gun to prevent water trapped in crevices from triggering rust.  Using waxes or polish is not recommended as they may not adhere well to the Penetrol, or may prevent subsequent coats of Penetrol from adhering properly.

Indoors, a sculpture protected with Penetrol should not need refreshing for at least several years.  If a piece is displayed outside, I would suggest refreshing the Penetrol finish about twice a year in a salty coastal environment, or once a year inland. 

A small tin or aerosol spray pack of Penetrol is available in the paint department of any hardware store.  Before applying, make sure the piece is clean by giving it a good wash as described above.  Apply the Penetrol as soon as the piece is thoroughly dry.  There is no need to remove existing Penetrol before adding another coat.

If using the tinned Penetrol, apply a little to a lint-free cloth and wipe a very thin film over the metal, rather as you would oil a piece of fine wooden furniture.  If using the aerosol spray, mist a light coat evenly over the surface, working from all directions.  Turn it over and apply a second coat the next day if any of the under surfaces may have been missed.  Make sure you apply the Penetrol very thinly, just enough to moisten the metal – you don’t want to see drips or runs.  Wipe away any drips with a clean cloth.  Protect surrounding surfaces with sheets of newspaper.

Be sure to read and follow the instructions on the Penetrol package.  Once opened, a tin of Penetrol will develop a film over the surface and may eventually become too thick to use conveniently.  If you only need small amounts, buy the smallest tin, or use the aerosol.  I prefer the aerosol spray as it is very quick and easy to waft a light, even coat over all the surfaces of a sculpture.