This site shares information on efforts to build or source replacement windows and components for horse trailers.
Exiss Dropdown Head Windows
Many models of Exiss trailers built in the early 2000’s, were built with windows having wood cores. These cores rot and the disintegrated material no longer provides a secure anchor for the hinge attachment screws. This can result in the dropdown window falling off the trailer.
Replacement Issue
So far, it has not been possible to identify the original source of the windows. Hehr was the primary supplier of windows to many trailer manufacturers and it possible that it was for Exiss. However, Hehr was sold to Lippert Industries in 2017 which merged it into their Duncan Division. The range of windows has been significantly reduced and is targeted at current production trailers.
Solution
It is possible to source used windows from scrapped trailers. However, they may also have the same issue of rotten cores. Therefore, if the external components of the window including the front and rear faces, internal sliding window, and the extrusion around the window itself, are in good condition, the dropdown may be rebuildable.
We are working to provide a DIY kit for rebuilding as well as forming a small team to undertake remanufacturing from customer provided parts.
There are owners who have already undertaken their own rebuilds using treated lumber (caution with chemical compatibility with aluminum) or marine plywood. Lightening of the solid core has been accomplished by drilling holes in the core. Some effort is required to get to the correct thickness.
Our solution is to use PVC exterior building trim to frame the internals combined with EPS insulation foam. The OEM windows used styrofoam. The foam is not really a structural element but provides support between the front and rear faces of the window and prevents vibration.
For both the internal PVC framing and the EPS foam, the standard material thicknesses have to be shaved down.
The PVC may be sized using a table saw. It might be possible to use a circular saw but it might be difficult to both clamp the part and support the saw on relatively narrow parts.
A thickness planer was used to dimension the foam cores. Dust collection is important. Since the individual parts have small surface areas, sanding to the desired thickness might work with either hand sanding with block back paper or a hand held electric sander.
A 3M paper backed sheet adhesive is used to glue the components to the front and rear window faces. Construction adhesive is used between the parts. Any glue has to be tested with the foam in case it might chemically melt the foam.
Dropdown Window Hinges
The window hinges that we have worked with, have 13 aluminum leaves which attach to the frame, bars, and dropdown window.
The problem of binding and breakage typically occurs when the hinges have not been lubricated or the trailer has sat idle for a while.
The hinges use a 3/16 inch stainless steel rod which does not corrode but it is compatible with the aluminum hinge leaves. The holes through the hinge leaves are fairly close tolerance. While aluminum is corrosion resistant, it is typically protected by anodization. Where the hinge leaves rotate around the pivot rod, the anodization can be worn away. Aluminum “self-protects” by creating an oxidation layer over its surface. In the case of the pivot bores, this results in a reduction in the ID of the leaf and binding to the pin.
Penetrating oils do not work to loosen the hinge leaf. So far, we have not found an ideal solution but chemicals used to clean the exterior aluminum surfaces of the trailer exterior do seem to aid loosening. A key step seems to be heating the individual leaf with either a propane or butane torch. Plus patience. It does require the removal and disassembly of the hinge off of the trailer frame and window. Remove the caps from the end of the hinge pin and work on each leaf individually until it slides off the pin. Use screws to pin a leaf to a piece of wood to aid handling and prevent bending or breakage of the leaf. The rest of the hinge leaves and pin should be sandwiched with wood and clamped to a bench top.
Do not try to free a hinge leaf by gripping with pliers and attempting to free the part in place. We have produced our own examples of bent or broken hinge leaves.
Some owners have reported success with drilling holes in the middle of the leaf down to the hinge pin to aid lubrication.
Once removed, the id of the leaf can be cleaned by further chemical application, sanding, or careful filing. If not overdone, a drill bit can be used on a well clamped leaf. Don’t try to hold only by hand.
Grainger can source stainless steel rods inexpensively. End caps can be bought at Home Depot.
3D Printing Nylon
We have employed 3D printing to create new hinges. Because of its strength, nylon was used to make sets of hinges. After about eight months in the high altitude environment of Colorado, the UV caused yellowing and a significant reduction in strength and stiffness. Adding carbon fiber filaments increased stiffness but it still does not address the deterioration of the nylon. This would be of particular concern with heavy OEM windows. It may work as a short term solution, but we cannot offer these.
ASA is another 3D printing filament that has good UV resistance. It is difficult to use because it outgasses posionous styrene gas requiring extensive exhaust control. Modern machines can produce metal parts but are prohibitively expensive.
Metal Replacement Hinges
Reportadly, stainless steel hinges are available that have been manufactured on a custom basis. The cost is around $330. We are working on sourcing.
Acrylic Window Replacement
Many older trailers such as Circle J, used acrylic plastic (Plexiglass, Uvex), for fixed windows (curved or flat) and within sliding windows. Frequently, sand and grit blasting combined with UV exposure, results in opaque windows.
We are developing DIY instructions for replacing the windows as well identifying the part numbers for the surrounding window seals.
Additionally, we’re working with sub-contractors to find cost effective production of both standardized and custom windows using laser or water cutting fabrication.