Wednesday, 29 September 2010

Graffiti No. 1

This isn't about gang tags or fashionable slogans but rather looking at historic graffiti.  Things that might be hidden under modern decorations and might be a single mark or might be a whole fleet of aircraft.  I mention this because one of the most emotive pieces of graffiti I have ever seen is the silhouettes of German bombers penciled onto dado paneling of an Oxfordshire church tower.  It is always exciting to find this sort of graffiti.  It raises so many question and for me at least, becomes a direct link to an individual, a time or event.  But it also presents the problem of whether and how to preserve it.  After all, it may well have been done clandestinely and quickly covered up.  It was almost certainly never meant to last.

This curvy figure was hidden under some nasty, inappropriate and badly done matchboard.  Before that it had been partly obscured with blackboard paint.  It's not the usual builders scrawl, the chalk lines have depth and texture and the proportion and shading show some skill.  But it's not part of any design within the building and in chalk, it is probably not possible to consolidate and preserve in any way.  Does this matter?  Here, I think not.  But I would like to think that whatever happens next might allow it to survive for someone else to find.

Tuesday, 7 September 2010

Invisible Green

Invisible green is a green so dark that it renders itself invisible and appears black.  So you could call it black but that's not very poetic is it.  It's origination is attributed to Humphrey Repton for use on railings in gardens.  It was apparently used on the door to No.10 Downing Street.  Coincidently, invisible green is also used at Hughenden Manor, the home of Benjamin Disraeli, Prime Minister and resident of No.10 in 1868 and later from 1874 to 1886.

Friday, 27 August 2010

You can't hide a house behind a tree

In front of every building is a space to stand and look at the building.

Monday, 12 April 2010

A short glossary from the information sheets

See earlier posts for the information sheets.

Ashlar; Stone that is dressed with sharp square arisses (corners).
Bed/bedding; Line of mortar between courses.
Brick trowel; Large diamond shaped trowel used for placing mortar (not pointing).
Bucket trowel; Medium sized trowel, slightly tapered sides, flat end. For working out of a bucket. Good general purpose trowel.
Burning; Heating limestone to remove carbon dioxide and produce lump lime.
Carbonation; The process of absorbing carbon dioxide (in a mortar) that causes calcium hydroxide to revert to calcium carbonate.
Coarse stuff; Lime with sharp sand.
Course; A line of bedded building material (brick or stone).
Fat lime; A matured slaked lime.
Fine stuff; Lime with soft sand.
Finger trowel; Thin trowel for pointing. Width varies from 6- 24mm in 6mm increments. Also known as a tuck pointer or Frenchman.
Float; Rectangular trowel, usually metal, and used for floating plaster onto wall.
Free lime; Any uncarbonated lime (calcium hydroxide) within a set mortar.
Gauged mortar; Lime mortar with pozzolana added.
Haired mortar; Lime mortar with hair for use on laths.
Hot lime; Lump lime slaked with sand and used immediately.
Hydrated lime; Lump lime that has been partially slaked, dried, ground and bagged. Used as a plasticiser in cement mortar.
Hydraulic lime; Lime that has naturally occurring pozzolana.
Hydraulic set; The ability to set without carbon dioxide.
Lime cycle; Limestone (calcium carbonate)+heat→Lumplime (calcium oxide)+water→Lime putty (calcium hydroxide)+carbon dioxide→Limestone.
Lime mortar; A mix of aggregate and lime.
Lime putty; Slaked lumplime (calcium hydroxide).
Lumplime; Burnt limestone (calcium oxide). Also known as quick lime.
NHL; Natural Hydraulic Lime.
OPC; Ordinary Portland Cement.
Plasterers small tool; Double ended tool with leaf shape trowel at one end and rectangular trowel at other. Useful for pointing very fine joints.
Pointing trowel; A small diamond shaped trowel, best with slightly curved edges.
Pozzolana; Any material that will impart an hydraulic set in a lime mortar. Originally a fine volcanic ash from Pozzuoli near Vesuvius. Can be almost any burnt material but most commonly clay.
Putty joint; A thin bedding joint in ashlar stone or brick.
Sharp sand; Sand with broken particles.
Soft sand; Sand with rounded particles.