diff --git a/.hgignore b/.hgignore
index 47c82bab..7ceb7ef3 100644
--- a/.hgignore
+++ b/.hgignore
@@ -4,4 +4,6 @@ last-change
 dashboard/coordinator/buildongce/client-*.dat
 dashboard/coordinator/buildongce/token.dat
 dashboard/coordinator/coordinator
+dashboard/env/linux-x86-base/*.tar.gz
+dashboard/env/linux-x86-nacl/*.tar.gz
 
diff --git a/dashboard/coordinator/buildongce/create.go b/dashboard/coordinator/buildongce/create.go
index 005e2928..9b3666d4 100644
--- a/dashboard/coordinator/buildongce/create.go
+++ b/dashboard/coordinator/buildongce/create.go
@@ -25,8 +25,9 @@ var (
 	proj     = flag.String("project", "symbolic-datum-552", "name of Project")
 	zone     = flag.String("zone", "us-central1-a", "GCE zone")
 	mach     = flag.String("machinetype", "n1-standard-16", "Machine type")
-	instName = flag.String("instance_name", "go-builder", "Name of VM instance.")
+	instName = flag.String("instance_name", "go-builder-1", "Name of VM instance.")
 	sshPub   = flag.String("ssh_public_key", "", "ssh public key file to authorize. Can modify later in Google's web UI anyway.")
+	staticIP = flag.String("static_ip", "", "Static IP to use. If empty, automatic.")
 )
 
 func readFile(v string) string {
@@ -110,6 +111,25 @@ func main() {
 	storageService, _ := storage.New(oauthClient)
 	_ = storageService // TODO?
 
+	natIP := *staticIP
+	if natIP == "" {
+		// Try to find it by name.
+		aggAddrList, err := computeService.Addresses.AggregatedList(*proj).Do()
+		if err != nil {
+			log.Fatal(err)
+		}
+		// http://godoc.org/code.google.com/p/google-api-go-client/compute/v1#AddressAggregatedList
+	IPLoop:
+		for _, asl := range aggAddrList.Items {
+			for _, addr := range asl.Addresses {
+				if addr.Name == *instName+"-ip" && addr.Status == "RESERVED" {
+					natIP = addr.Address
+					break IPLoop
+				}
+			}
+		}
+	}
+
 	cloudConfig := baseConfig
 	if *sshPub != "" {
 		key := strings.TrimSpace(readFile(*sshPub))
@@ -135,7 +155,7 @@ func main() {
 				InitializeParams: &compute.AttachedDiskInitializeParams{
 					DiskName:    *instName + "-coreos-stateless-pd",
 					SourceImage: imageURL,
-					DiskSizeGb:  100,
+					DiskSizeGb:  50,
 				},
 			},
 		},
@@ -154,8 +174,9 @@ func main() {
 			&compute.NetworkInterface{
 				AccessConfigs: []*compute.AccessConfig{
 					&compute.AccessConfig{
-						Type: "ONE_TO_ONE_NAT",
-						Name: "External NAT",
+						Type:  "ONE_TO_ONE_NAT",
+						Name:  "External NAT",
+						NatIP: natIP,
 					},
 				},
 				Network: prefix + "/global/networks/default",
diff --git a/dashboard/env/linux-x86-base/Dockerfile b/dashboard/env/linux-x86-base/Dockerfile
index 6abf6eba..4aa6dacb 100644
--- a/dashboard/env/linux-x86-base/Dockerfile
+++ b/dashboard/env/linux-x86-base/Dockerfile
@@ -24,7 +24,7 @@ RUN apt-get install -y --no-install-recommends gcc libc6-dev
 RUN apt-get install -y --no-install-recommends libc6-dev-i386 gcc-multilib
 
 # For interacting with the Go source & subrepos:
-RUN apt-get install -y --no-install-recommends mercurial git-core subversion
+RUN apt-get install -y --no-install-recommends mercurial git-core
 
 ENV GOPATH /gopath
 ENV GOROOT /goroot
@@ -36,10 +36,10 @@ ENV GO_TOOLS $GOPATH/src/code.google.com/p/go.tools
 RUN mkdir -p $GO_TOOLS
 RUN cd $GO_TOOLS $ && curl -s https://storage.googleapis.com/gobuilder/go.tools-snap.tar.gz | tar x --no-same-owner -zv
 
-RUN cd $GOROOT && hg update -C b8ff0ec2a724
+RUN cd $GOROOT && hg pull && hg update -C b8ff0ec2a724
 RUN cd $GOROOT/src && ./make.bash
 RUN mkdir -p /usr/local/bin
 
-RUN cd $GO_TOOLS && hg update -C 918b8a7e7b1e
+RUN cd $GO_TOOLS && hg pull && hg update -C f9e37a924785
 ENV GOBIN /usr/local/bin
 RUN /goroot/bin/go install code.google.com/p/go.tools/dashboard/builder
diff --git a/dashboard/env/linux-x86-base/Makefile b/dashboard/env/linux-x86-base/Makefile
index 9e8171ed..8335e248 100644
--- a/dashboard/env/linux-x86-base/Makefile
+++ b/dashboard/env/linux-x86-base/Makefile
@@ -3,7 +3,10 @@
 # license that can be found in the LICENSE file.
 
 docker: Dockerfile
+	rm -f docker-linux.base.tar.gz
 	docker build -t gobuilders/linux-x86-base .
 
-push: docker
-	docker push gobuilders/linux-x86-base
+# This gets uploaded to:
+# https://console.developers.google.com/project/apps~symbolic-datum-552/storage/go-builder-data/
+docker-linux.base.tar.gz: docker
+	docker save gobuilders/linux-x86-base | gzip > docker-linux.base.tar.gz
diff --git a/dashboard/env/linux-x86-nacl/Dockerfile b/dashboard/env/linux-x86-nacl/Dockerfile
index f7295ccb..c290c6a9 100644
--- a/dashboard/env/linux-x86-nacl/Dockerfile
+++ b/dashboard/env/linux-x86-nacl/Dockerfile
@@ -15,6 +15,8 @@ FROM ubuntu:trusty
 MAINTAINER golang-dev <golang-dev@googlegroups.com>
 
 ENV DEBIAN_FRONTEND noninteractive
+
+RUN echo cachebuster4
 RUN apt-get update && apt-get upgrade -y
 
 # For running curl to get the hg starter tarballs (faster than hg clone).
@@ -24,7 +26,7 @@ RUN apt-get install -y --no-install-recommends curl ca-certificates
 RUN apt-get install -y --no-install-recommends gcc libc6-dev
 
 # For interacting with the Go source & subrepos:
-RUN apt-get install -y --no-install-recommends mercurial git-core subversion
+RUN apt-get install -y --no-install-recommends mercurial git-core
 
 # For 32-bit nacl:
 RUN apt-get install -y --no-install-recommends libc6-i386 libc6-dev-i386 lib32stdc++6 gcc-multilib
@@ -39,11 +41,11 @@ ENV GO_TOOLS $GOPATH/src/code.google.com/p/go.tools
 RUN mkdir -p $GO_TOOLS
 RUN cd $GO_TOOLS $ && curl -s https://storage.googleapis.com/gobuilder/go.tools-snap.tar.gz | tar x --no-same-owner -zv
 
-RUN cd $GOROOT && hg update -C b8ff0ec2a724
+RUN cd $GOROOT && hg pull && hg update -C b8ff0ec2a724
 RUN cd $GOROOT/src && ./make.bash
 RUN mkdir -p /usr/local/bin
 
-RUN cd $GO_TOOLS && hg update -C 918b8a7e7b1e
+RUN cd $GO_TOOLS && hg pull && hg update -C f9e37a924785
 ENV GOBIN /usr/local/bin
 RUN /goroot/bin/go install code.google.com/p/go.tools/dashboard/builder
 
diff --git a/dashboard/env/linux-x86-nacl/Makefile b/dashboard/env/linux-x86-nacl/Makefile
index 2128361f..903ac097 100644
--- a/dashboard/env/linux-x86-nacl/Makefile
+++ b/dashboard/env/linux-x86-nacl/Makefile
@@ -3,8 +3,11 @@
 # license that can be found in the LICENSE file.
 
 docker: Dockerfile
+	rm -f docker-linux.nacl.tar.gz
 	docker build -t gobuilders/linux-x86-nacl .
 
-push: docker
-	docker push gobuilders/linux-x86-nacl
+# This gets uploaded to:
+# https://console.developers.google.com/project/apps~symbolic-datum-552/storage/go-builder-data/
+docker-linux.nacl.tar.gz: docker
+	docker save gobuilders/linux-x86-nacl | gzip > docker-linux.nacl.tar.gz