diff --git a/experiments/2024-12-09/src/model.rs b/experiments/2024-12-09/src/model.rs
index b73f67ebb..b6dde918d 100644
--- a/experiments/2024-12-09/src/model.rs
+++ b/experiments/2024-12-09/src/model.rs
@@ -2,7 +2,7 @@ use crate::{
     geometry::{AnyOp, Sketch},
     math::{Bivector, Plane, Point, Vector},
     storage::Stores,
-    topology::{Face, Solid},
+    topology::Solid,
 };
 
 pub fn model() -> AnyOp {
@@ -30,20 +30,11 @@ pub fn model() -> AnyOp {
 
     let [bottom, top] = [bottom, top].map(|face| stores.faces.insert(face));
 
-    let side_faces = bottom
-        .half_edges()
-        .zip(top.half_edges())
-        .map(|([q, r], [t, s])| {
-            let surface = stores.surfaces.insert(Plane::from_points(
-                [q, r, s].map(|vertex| vertex.point),
-            ));
-            let face =
-                Face::new(surface, [q, r, s, t].map(|vertex| vertex.clone()));
-            stores.faces.insert(face)
-        })
-        .collect::<Vec<_>>();
-
-    let solid = Solid::new([bottom, top].into_iter().chain(side_faces));
+    let solid = Solid::connect_faces(
+        [bottom, top],
+        &mut stores.surfaces,
+        &mut stores.faces,
+    );
 
     AnyOp::new(solid)
 }
diff --git a/experiments/2024-12-09/src/topology/solid.rs b/experiments/2024-12-09/src/topology/solid.rs
index 6a6634db0..3ea3951b8 100644
--- a/experiments/2024-12-09/src/topology/solid.rs
+++ b/experiments/2024-12-09/src/topology/solid.rs
@@ -1,4 +1,8 @@
-use crate::geometry::{AnyOp, Handle, Operation, TriMesh};
+use crate::{
+    geometry::{AnyOp, Handle, Operation, TriMesh},
+    math::Plane,
+    storage::Store,
+};
 
 use super::Face;
 
@@ -12,6 +16,29 @@ impl Solid {
             faces: faces.into_iter().collect(),
         }
     }
+
+    pub fn connect_faces(
+        [a, b]: [Handle<Face>; 2],
+        surfaces: &mut Store<Plane>,
+        faces: &mut Store<Face>,
+    ) -> Self {
+        let side_faces = a
+            .half_edges()
+            .zip(b.half_edges())
+            .map(|([q, r], [t, s])| {
+                let surface = surfaces.insert(Plane::from_points(
+                    [q, r, s].map(|vertex| vertex.point),
+                ));
+                let face = Face::new(
+                    surface,
+                    [q, r, s, t].map(|vertex| vertex.clone()),
+                );
+                faces.insert(face)
+            })
+            .collect::<Vec<_>>();
+
+        Solid::new([a, b].into_iter().chain(side_faces))
+    }
 }
 
 impl Operation for Solid {