diff --git a/radiant/csg.cpp b/radiant/csg.cpp
index 14c2e44e..c797b3d0 100644
--- a/radiant/csg.cpp
+++ b/radiant/csg.cpp
@@ -77,11 +77,11 @@ public:
 	// true = exclude by axis strategy, false = m_excludeSelectedFaces by 'selected' property
 	bool m_excludeByAxis;
 	Vector3 m_exclusionAxis;
-	double m_mindot;
-	double m_maxdot;
+	mutable double m_mindot;
+	mutable double m_maxdot;
 	// true = exclude selected faces, false = exclude unselected faces
 	bool m_excludeSelectedFaces;
-	std::vector<DoubleVector3> m_exclude_vec; // list of excluded normals per brush
+	mutable std::vector<DoubleVector3> m_exclude_vec; // list of excluded normals per brush
 
 	bool m_caulk;
 	bool m_removeInner;
@@ -94,33 +94,28 @@ public:
 			return std::find( m_exclude_vec.begin(), m_exclude_vec.end(), face.getPlane().plane3().normal() ) != m_exclude_vec.end();
 		}
 	}
-};
-
-
-class FaceExcludeByAxis {
-	HollowSettings& m_settings;
-public:
-	FaceExcludeByAxis( HollowSettings& settings ) : m_settings( settings ) {
+	void excludeFaces( BrushInstance& brushInstance ){
+		if( m_excludeByAxis ) {
+			m_mindot = m_maxdot = 0;
+			Brush_forEachFace( brushInstance.getBrush(), *this );
+		}
+		else{
+			m_exclude_vec.clear();
+			Brush_ForEachFaceInstance( brushInstance, *this );
+		}
 	}
 	void operator()( Face& face ) const {
-		double dot = vector3_dot( face.getPlane().plane3().normal(), m_settings.m_exclusionAxis );
-		if( dot < m_settings.m_mindot ) {
-			m_settings.m_mindot = dot;
+		const double dot = vector3_dot( face.getPlane().plane3().normal(), m_exclusionAxis );
+		if( dot < m_mindot ) {
+			m_mindot = dot;
 		}
-		else if( dot > m_settings.m_maxdot ) {
-			m_settings.m_maxdot = dot;
+		else if( dot > m_maxdot ) {
+			m_maxdot = dot;
 		}
 	}
-};
-
-class FaceExcludeSelected {
-	HollowSettings& m_settings;
-public:
-	FaceExcludeSelected( HollowSettings& settings ) : m_settings( settings ) {
-	}
 	void operator()( FaceInstance& face ) const {
-		if( m_settings.m_excludeSelectedFaces == face.isSelected() ) {
-			m_settings.m_exclude_vec.push_back( face.getFace().getPlane().plane3().normal() );
+		if( m_excludeSelectedFaces == face.isSelected() ) {
+			m_exclude_vec.push_back( face.getFace().getPlane().plane3().normal() );
 		}
 	}
 };
@@ -208,10 +203,8 @@ public:
 					Winding& winding = face.getWinding();
 					TextureProjection projection;
 					TexDef_Construct_Default( projection );
-					for( Winding::iterator j = winding.begin(); j != winding.end(); ++j ) {
-						std::size_t index = std::distance( winding.begin(), j );
-						std::size_t next = Winding_next( winding, index );
-
+					for( std::size_t index = 0; index < winding.numpoints; ++index ){
+						const std::size_t next = Winding_next( winding, index );
 						m_out.back()->addPlane( winding[index].vertex,
 												winding[next].vertex,
 												winding[next].vertex + face.getPlane().plane3().normal() * m_settings.m_offset,
@@ -240,29 +233,27 @@ public:
 						newFace->planeChanged();
 					}
 
-					Winding& winding = face.getWinding();
+					const Winding& winding = face.getWinding();
 					TextureProjection projection;
 					TexDef_Construct_Default( projection );
-					for( Winding::iterator i = winding.begin(); i != winding.end(); ++i ) {
-						std::size_t index = std::distance( winding.begin(), i );
-						std::size_t next = Winding_next( winding, index );
+					for( std::size_t index = 0; index < winding.numpoints; ++index ){
+						const std::size_t next = Winding_next( winding, index );
 						Vector3 BestPoint;
 						float bestdist = 999999;
 
-						Face* parallel_face = 0;
-						for( Brush::const_iterator j = m_brush.begin(); j != m_brush.end(); ++j ) {
-							if( vector3_equal_epsilon( face.getPlane().plane3().normal(), ( *j )->getPlane().plane3().normal(), 1e-6 ) ){
-								parallel_face = ( *j );
+						const Face* parallel_face = nullptr;
+						for( const Face* f : m_brush ) {
+							if( vector3_equal_epsilon( face.getPlane().plane3().normal(), f->getPlane().plane3().normal(), c_PLANE_NORMAL_EPSILON ) ){
+								parallel_face = f;
 								break;
 							}
 						}
 
-						if( parallel_face ){
-							Winding& winding2 = parallel_face->getWinding();
+						if( parallel_face != nullptr ){
+							const Winding& winding2 = parallel_face->getWinding();
 							float bestdot = -1;
-							for( Winding::iterator k = winding2.begin(); k != winding2.end(); ++k ) {
-								std::size_t index2 = std::distance( winding2.begin(), k );
-								float dot = vector3_dot(
+							for( std::size_t index2 = 0; index2 < winding2.numpoints; ++index2 ){
+								const float dot = vector3_dot(
 												vector3_normalised(
 													vector3_cross(
 														winding[index].vertex - winding[next].vertex,
@@ -278,11 +269,10 @@ public:
 							}
 						}
 						else{
-							for( Brush::const_iterator j = m_brush.begin(); j != m_brush.end(); ++j ) {
-								Winding& winding2 = ( *j )->getWinding();
-								for( Winding::iterator k = winding2.begin(); k != winding2.end(); ++k ) {
-									std::size_t index2 = std::distance( winding2.begin(), k );
-									float testdist = vector3_length( winding[index].vertex - winding2[index2].vertex );
+							for( const Face* f : m_brush ) {
+								const Winding& winding2 = f->getWinding();
+								for( std::size_t index2 = 0; index2 < winding2.numpoints; ++index2 ){
+									const float testdist = vector3_length( winding[index].vertex - winding2[index2].vertex );
 									if( testdist < bestdist ) {
 										bestdist = testdist;
 										BestPoint = winding2[index2].vertex;
@@ -332,16 +322,8 @@ public:
 			Brush* brush = Node_getBrush( path.top() );
 			if( brush != 0
 					&& ( Instance_isSelected( instance ) || Instance_isSelectedComponents( instance ) ) ) {
+				m_settings.excludeFaces( *Instance_getBrush( instance ) );
 				brush_vector_t out;
-				m_settings.m_exclude_vec.clear();
-				m_settings.m_mindot = m_settings.m_maxdot = 0;
-
-				if( m_settings.m_excludeByAxis ) {
-					Brush_forEachFace( *brush, FaceExcludeByAxis( m_settings ) );
-				}
-				else {
-					Brush_ForEachFaceInstance( *Instance_getBrush( instance ), FaceExcludeSelected( m_settings ) );
-				}
 
 				if( m_settings.m_hollowType == ePull ) {
 					if( !m_settings.m_removeInner && m_settings.m_caulk ) {
@@ -1366,14 +1348,7 @@ public:
 	}
 	void operator()( BrushInstance& brush ) const {
 		if( brush.isSelected() || brush.isSelectedComponents() ){
-			m_settings.m_mindot = m_settings.m_maxdot = 0;
-			m_settings.m_exclude_vec.clear();
-			if( m_settings.m_excludeByAxis ) {
-				Brush_forEachFace( brush, FaceExcludeByAxis( m_settings ) );
-			}
-			else {
-				Brush_ForEachFaceInstance( brush, FaceExcludeSelected( m_settings ) );
-			}
+			m_settings.excludeFaces( brush );
 			Brush_forEachFace( brush, FaceOffset( m_settings ) );
 		}
 	}