The best ways of patching holes in a skoolie floor often sparks more passionate debates than Red Sox or Yankees.
Regardless of the method, Skoolie conversion engineers need to find ways to patch rust holes and cover up the holes left by seat bolts.
Some folks love the durability of welding. Others rivet patches. Others epoxy pennies to the floor.
As in any scenario, if you’re converting a school bus, you need to identify the problem, inventory your resources, then choose the solution that works the best.
Patching Holes in a Skoolie Floor by Welding
Many folks cut out the rust and weld new pieces of metal in place. Although I recently bought a used stick welder “just in case” of the likely event that I could use one in the conversion process, I’m not good enough…yet. In practice runs with it I successfully splashed molten metal around the shop, melted holes in thin steel and got the rod stuck to the metal 972 times.
I was not ready to risk the floor of our beloved skoolie with my subpar welding skills. The floor had enough holes already.
So welding was out.
Penny Patches
Many people epoxy pennies to the floor to seal the bolt holes left by seat removal.
Cons
Others balk at this approach pointing out that the different metals of the pennies (some copper and mostly zinc) react with the floor metals (galvanized steel), thus increasing the rate of rust.
Pros
The penny patchers counter this argument saying that the epoxy gluing the penny to the floor provides a barrier that prevents the metals from reacting to each other.
I have found pennies under the floor of my car that I could barely recognize because of oxidization, so opted for yet another route.
Patching holes in a Skoolie floor with Stainless Steel Rivets
For us without welding skills, patching holes in a skoolie floor necessitated rivets. I bought a sheet of 16 gauge steel for $40. I decided that I would paint it with some sort of rust resistance coating, then use it to seal all the holes in the floor of the bus
Por 15 vs Rust Bullet
I painted the steel with two coats of Rust Bullet. I considered POR15, but I opted for the Rust Bullet because it claimed not to need as much prep. I do plan on undercoating the bus as well, but I wanted as much rust protection as I could get.
POR 15
Many forums and reviews of POR 15 spoke favorably of the product but were adamant that meticulous surface prep was critical to its success. It also was over $40 a quart.
Rust Bullet
According to the Rust Bullet website, “Rust Bullet simplifies rust prevention by eliminating the need for extensive surface preparation.”
I like the sound of that.
In addition, it is designed to “penetrate the metal surface and mix the rust. This feature helps in better rust prevention for the products and attacks rust right at the root level thus offering better protection.”
Moreover, at around $30 a quart, it’s almost $10 less expensive than POR 15.
Steel Surface Prep
I didn’t feel confident in my ability to perfectly prepare a surface. Even though I used a lot of new steel, I planned to use any leftover material to coat the floor surfaces where grinding out steel had thinned the metal. I wanted to maximize rust protection and couldn’t guarantee that it was perfectly prepped, so I went with the Rust Bullet.
I wiped each side of the steel clean with acetone, then painted one side and let it dry overnight. I came back the next day and painted the other side.
Cutting the Floor Patches
First, I tried my angle grinder. With the 16 gauge steel, I found it challenging to cut straight lines. It looked like I had taken several samples from the tequila bottle before playing with power tools.
The thicker steel chowed through cut-off blades as well. I thought I’d better try something else.
So I put my metal cutting blade on my skill saw and went with that. I clamped a straight edge to the steel to get nice straight lines. (My kindergarten teacher, Mrs. Kimball would’ve been proud!)
This worked much better, despite the dullness of my blade. I found that I had to take the grinder to the edges to smooth the out. But it worked better.
I cut the patches to the various needed sizes, (about an inch larger than the hole all the way around) then took them to my drill press and drilled 13/64 rivet holes in each corner. I planned to use 3/16″ rivets, so I wanted a hole just a whisker larger than the rivet.
Drilling Holes in the Floor
I set the patches in place over the holes, then drilled holes in floor of the bus right through the holes already drilled in the patches to line them up. After drilling each hole, I set a rivet in place (not fully riveted) just to hold in place.
I hadn’t heard about them before, but I may have considered getting a cleco kit that would have held patches in place. The rivets kept rattling out while drilling other holes!
Patching Holes in a Skoolie Floor by Wet Riveting
After pre-drilling, Julie and I got started on securing the patches in place. We donned rubber gloves to keep the high strength adhesive off our hands. We chose 3M 5400 Marine Adhesive because in several tests that I researched it performed the best.
Julie applied the sealant to the patch and used a rubber-clad finger to spread it over the entire bottom of the patch. She then handed it to me and I riveted it in place.
This is called “wet riveting” because the 3M 5400 seals not only the seam around the patch but also the rivet. We definitely don’t want water coming up into our floor insulation.
We were liberal with the adhesive, covering pretty much the entire underside of the patches with 3M 5400. I thought it would take more, but we did the entire bus with one tube.
Stainless Steel Rivets
Remember that part about different metals reacting to each other? It applies here, too. So, we used stainless steel rivets as opposed to aluminum ones.
Stainless steel rivets go in much harder than aluminum! My hands got a workout. BE SURE TO WEAR EYE / FACE PROTECTION! When the mandrel from the rivet pops out, it can go flying! One hit me right in the nose and drew blood.
Since then, I bought a pneumatic riveter. I found riveting stainless steel a royal pain and figured the money would be well spent to accelerate the process on several upcoming riveting projects.
Skoolie Floor Bolt Hole Patches
The seat bolt holes sit about an inch and a half from each other. I decided to cut patches 1 1/2 x 2 1/2″.
I cut the width first by again using a straight-edge and my skill saw.
Then I built a jig. I built a platform with guides on each side for the steel, a straightedge for the saw, and a stop to measure the length.
I would pull the steel to the stop to measure, then pull it back just a sixteenth of an inch so it wouldn’t be under tension, made the cut, and repeated.
62 times.
Or something like that. I don’t remember exactly but it was a lot.
Anyway, we used a similar process of smearing sealant on the backs, but since the patches were so small, we didn’t rivet them, just stuck them down. They appear to be holding just fine!
Checking for Holes
That night, we put a light under the bus and checked from inside to bus to locate any holes that we had missed, and marked them to patch the next day.
Painting the Floor
After the adhesive dried, I put a thick coat of Rustoleum paint on the entire floor to seal it up good! This stuff goes on well, but takes 24 hours, at least, to fully dry. It is also temperature-dependent. It should be applied with temps between 50-90 degrees. Since it was November in the Northeast when we reached this step, we found ourselves in the lower range of that spectrum!
Patching Holes in a Skoolie floor: The Final Word
The best way for patching holes in a skoolie floor will vary for everyone. For us, however, The patches appear to be holding well even without welding. While we worked on other projects none of them kicked loose. Some of the paint scratched near the entrance, though, where I dragged a heater across it, so you may want to put down a protective sheet of cardboard or plywood in high traffic areas before you put down your subfloor.
Most importantly, however…NO MORE RUST!!
To see the skoolie paint job process, check out this post here!
If you like this blog post, you’ll love our free PDF that shows you how you can save HOURS or even DAYS over the course of your build. Click here for immediate access!