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Last time talked about having a clear plan for our builds. Once you have that, it’s time to get started putting things into play. Realize that your plan, or portions of your plan, may change as you progress with the build. That’s no big deal, but be sure you take the time to map out what the new plan is.

So, it’s time to dismantle, or demo, our trailer. Just for ease I’ve picked a recent trailer I’ve rebuilt. I’ve addressed campers as well, just no pictures to show.


I always read “floor is solid” when reading the advertisement for a trailer. But I’ve learned that “solid” is subjective. In a horse trailer, I always recommend removing the old floor, because it might be solid, but if it has been used to haul animals it’s going to have a smell to it (maybe not in the winter, but in the summer.)

Also, by removing it I give myself a clean, level slate to work with. Horse trailer flooring is generally held down with self-tapping metal screws or bolts that have rusted heads. I don’t waste even a minute trying to unscrew them. Instead, I locate all the supports holding floor and mark them with a pencil. I then use a circular saw to cut all the way through the wood between the supports. Once cut, the boards themselves can be used as levers to snap off the bolts or screws and remove the wood.

Also, in this picture take a look at the wheel well of the trailer. The new metal used to patch the rusted through original piece, was saved from the side of the trailer when it was removed for the service area. Another reason to remove the flooring can be seen in the picture on the right. If you look closely, you can see that the square tubular frame, at the rear of the trailer, has rusted completely through, and the tubing is filled with wet shavings. This wasn’t exposed until the floor was removed and can be catastrophic if left as is and is certainly a costly repair.


When removing metal, tin, or wooden walls or beams, a demolition saw is a very good option. The tool is easy to handle and relatively safe to operate. A side note…do yourself a favor and buy the very best blades you can afford (and buy lots of them). And lastly, change them out frequently. It makes a huge difference in the ease and quality of the cut, as well as your safety. You can purchase blades at any big box store, but I’ve found a company named Fastenal is often cheaper and has higher quality items. 

Because I’ve taken the time to make plans for layout, plumbing, and electrical, I will cut all the holes for these items as well.  If there is a bad section of wall, or metal angle, that needs to be replaced, I will mark these areas and cut them out as well. A useful tool to cut aluminum siding is a right-angle grinder with a cut off blade. A useful tool, but they can be extremely dangerous (mine has been dubbed “Satan”)!

Wheel wells on horse trailers are a common spot for rust. In this case using a plasma cutter or demolition saw, I would cut from the outside and follow the shape of the wheel well.  

This trailer had extensive rust damage along the entire left side. I generally will strike a level line only as high up the side as it takes to reach sound metal. In this case it was as high as the wheel well. These areas were cut out and replaced with metal salvaged from the service side of the trailer.

You can be creative when patching areas.  The owner of this trailer wanted the non-service side window removed and covered on the inside. Instead of just patching that area we turned it into a “window frame”, with an awning over it, where they can put a logo or permit numbers etc.

Cutting through tin walls on campers is rather straight forward, and can be accomplished with tin snips, electric shears, or large roofing shears. The best cut will come from using electric shears, which can be purchased from store like Northern Tools for approximately $50.00. If you will be cutting a lot of tin, aluminum, or metal, shears are well worth the price. Removing metal that has been riveted is straight forward as well. Using a 1/8” or 3/16” “metal” bit, drill down the center of the rivet until the head pops off. As with blades, buy good drill bits (made from cobalt), and buy at least five to have around. Like a horse trailer, I will remove, and discard, all plywood, insulation, or wiring that I don’t anticipate needing for the reconstruction phase. Be confident of your cuts on an older camper as sourcing matching siding can be extremely difficult.

Removing Windows and Trim

This process is rather straight forward. It does help to decide before removing the trim and windows which ones will be re-installed on the trailer. On older trailers, there can be numerous layers of caulk and mastic around windows and under trim. If an item, such as a window, isn’t going back on the trailer, then feel free to use a hammer and pry bar to remove these items. Otherwise, care needs to be taken not to bend or break these items. In the case of older trailers, it can be near impossible to find replacement window parts. Do yourself a favor and mark where each piece of trim came off the trailer, and where each window came from. It makes the reassembly much easier. 

This is also the time to remove any loose paint or caulking and repair small areas with Bondo or fiberglass. Caulking can be tough to remove, but it helps to use a heat gun to make the caulk soft and then remove it with a sharp putty knife, or oscillating saw. If the Bondo is sound (is not chipping, or cracked), it can be left in place. A random orbital sander works well on chipping and cracked paint. I generally start with a lower grit paper and then work my way to a higher grit. If your plan is to have your trailer professionally painted then discuss with your painter what preparation they will be responsible for. 

When all is said and done, your trailer should look something like the picture below.  If you’re working on a camper, the inside will probably be gutted to the aluminum exterior walls. At this point, this trailer was ready for fabrication of the service areas, and replacing the damaged areas of the walls. This trailer was slated for a three-compartment sink so we cut a “door” and “pass-through” window through the tack room wall. The sink will be hidden from the public, behind the knee wall. Because I considered this wall “structural,” we reinforced this area during fabrication. The entire right side of the trailer has been removed for the service opening, and the rear ramp was removed in preparation of the rear service area. The metal laying on the undercarriage was salvaged from the service side of the trailer, saving money, and the environment.

Next month we will start to outline the reconstruction phase of the build. If you have any questions about this build or other topics you can reach me though my website here.