Epic Truck Cap project

How to get a cheap truck cap for a 3rd gen Tacoma – a cautionary tale…

Later this summer I have a road trip planned and want to take the Tacoma. With the tonneau cover on, the storage in the truck bed would be too limited, so even though I didn’t want a truck cap, having one for this trip would be a benefit. There are zero 3rd generation caps available used, and the lowest cost for a new cap, (not painted to match) would be $1800; or $2400 for the model with the features I’d want.

Being famously cheap and one of those rare sociopaths that enjoy difficult projects, I set a goal to modify a truck cap to fit the Tacoma and painted to match; for under $500. I also wanted to complete the project inside of 6 weeks (weekends only).

 

Wow..where’s the video?

 

I’ve previously sliced and diced an 8’ Ford F150 cap to fit a ’87 Dakota 6’ bed and, body work not withstanding (as I did none), it turned out great. For that project, I sprayed the outside w/ black Herculiner.

The lessons learned from the previous project dictated that I only want to modify the cap on 2 of the 3 dimensions. Some research and measuring a bunch of different caps on trucks, I found that a cap for a 2nd generation S-10 has the proper height, so the only changes needed would be on length and width. The $50 (piece of crap) Leer cap I found was for an S-10 with a 6’ bed. It was 13” too long and at the front, 2” too narrow and 1.5” too narrow at the rear.

Before I got the donor cap home, I needed the means to work on it, keep it flat and square and also be able to flip it over it to work on the inside. I scored some retired pallet rack uprights and built a large enough table and a yoke from which to pivot the cap. My shop hoist was just barely high enough to be able to rotate the cap without having the edge hit the shop floor. (Now that the project is done, I have no idea what to do with the cap flipper.). For your reference, the cap was through bolted to the flipper table.

 

if thats the "completed" photo, color me impressed!

 

It seemed to make sense to first modify the overall length. Knowing the challenge of shortening the existing side windows (and I already had a plan for glassing in the sides), I opted to make the cuts through the forward edge of the window openings. I added braces to keep the cap from collapsing and got to cutting. (FYI, I used an oscillating multi-tool to make the cuts. Not having a spinning saw blade helped minimized the dust.)

While cutting I was seeing water spurt out of the cuts. Turns out there was a layer of cardboard between the inner and outer roof (for insulation?) and water has somehow gotten in. I finished the cut and set the two halves outside to dry. Eventually, I accepted that I needed to cut the entire inner roof out and scrape out all the wet cardboard.

 

With the back half of the cap moved forward on the flipper frame and bolted down, I needed to align the cut edges of the fiberglass without having too wide of a gap. I used plastic floor tile clips and wedges to hold the edges aligned for glassing. I glassed the inside surfaces first, the removed the clips and glassed the outside. I should add that I used a small belt sander to grind a shallow bevel on the outside surfaces for someplace for the new fiberglass to fill and join the halves.

This is where I made the one big mistake of the project. Along with the floor tile clips, I clamped the outside edges to keep them aligned. I didn’t realize the S-10 cap was slightly tapered front to back so with 13.5” of length removed, the width at the cut edge of the front half was wider than the width of the rear half. As such, with the outer edges clamped, the front half was compressed and developed a hump in the middle. I didn’t notice it until I had the inside glassed. In hindsight, I should have cut it apart and started over, but I had already lost a valuable weekend due to finding the wet cardboard.

 

Cutting the sides to widen the cap took some planning, but the best way to do it was one side at a time. I knew I was going to retain and reuse the front and rear windows, so the cuts for the widening had to occur outside of the existing openings. I screwed some plywood guide blocks to the flipper base to establish the new required overall width at the front and rear. Since I was adding 1” at the front and ¾” at the rear, I made some reusable spacer blocks. After cutting the side lengthwise, I moved it against the new plywood guide blocks, inserted and attached the spacers at the cut, then re-bolted the side down to the flipper base. Since I had a large fiberglass panel cut from the inner roof, I used it as filler material to fill in the gap. As before, I used floor tile clips and wedges, glassed the inside 1st then ground and glassed the outside. I should add that when glassing the inside I used 4 layers of chop strand.

 

To fill the side window openings, I know I wanted to glass from the inside and also try to match the compound curvature of the cap. I used a piece of ¼” thick PVC compressed foam board as the mold. For your reference, the foamboard goes by the trade name “Sintra” and is typically used for signage. I just happened to have a 4’x2’ piece left over from a project in 1993.

I only had 1 piece of Sintra and would need to use it as a mold twice, so I covered one side with metalized tape **. I also painted the inside surface of the mold with PVA (Poly Vinyl Alcohol) as a release agent. I attached the Sintra to the outside of the cap using drywall screws. Being a bit flexible, the Sintra panel conformed nicely to the curvature of cap. Each side window got 6 layers of glass: 2 layers of 1.5oz chop strand, then one layer of woven cloth, another layer of chop strand, another layer of woven cloth and topped with a layer of 3/4oz chop strand. Experience building and fixing sailboats as a kid, laminating chop strand and woven yields a more stable panel. There is a newer fiberglass material called 1708 which is a combination of glued overlay strand and woven cloth, but I had enough woven cloth left over from a prior project that I only had to buy more chop strand. Each side window used a full gallon of resin. ** Turns out the metalized tape was unnecessary because neither the polyester resin with MEKP hardener or the PVA release agent had any negative effect on the Sintra PVC panel.

The filled windows turned out better than I was expecting. The outside surface was very flat and matched the curvature of the cap very well. Other than a few pits from bubbles and the horizontal lines from the metalized tape, the filled sides didn’t need much bodywork or sanding.

I repeated the belt sanding and glassing on the outsides of the filled windows, then treated the entire outside to a whole day of sanding things smooth.

 

Because among my goals was to be able to lift the cap using a garage ceiling hoist, I needed to reinforce the roof and add lifting points. I started the reinforcing by laying in 2 layers of 1.5oz chop stand and let it cure. After sanding the high points, I layed in strips of chop strand and while still wet, layed in strips of ¼” Lauan plywood. As kid, I built a 6’ skiff using Lauan plywood so I know it works well with fiberglass resin. Next, I layed in 1 layer of woven cloth and then 2 layers of 3/4oz chop strand over the whole inner roof. While the chop strand was still wet, I added 4 pieces of 8” square Lauan ply to the inside roof at the lifting points. Over these, I added 2 layers of woven cloth. At this point, all the fiberglass work was done.

 

To fill the random bubbles, I mixed up some “Rondo”. Basically, its Bondo (or in my case, Rage lightweight body filler) thinned with fiberglass resin. The end result is basically body filler thin enough to apply with a paintbrush. You have to add the correct amounts of body filler and resin hardeners, so you need to move quickly and spread the Rondo where needed. The upside to using Rondo is it spreads and fills easily. The downside is its rock hard when cured, so you’re best to sand it while it’s still a bit soft (i.e. have a lot of 40 grit paper on hand).

After Rondo and sanding, I sprayed the cap with high build gray primer (I also later sprayed the inside with white primer). For reference, it took a little more than a quart of primer for only 1 coat. After blocking, I found a bunch of pin holes, so I spot putty’d and sanded it up to 120 grit. I primed the outside again and blocked it to 220 grit…ready for paint.

 

I wanted the inside a light color, but not stark white, so I mixed a little gray and black paint (in a few moments you’ll know why I had those colors available) with oil based gloss white and sprayed the inside light “tan” gloss.

For the outside paint, I really wanted it to match the Quicksand color. Unfortunately, OEM matching auto paint would have blown my budget, so I went cheap, really cheap … Rustoleum Acrylic Enamel.

As a base color, I chose Rustoleum Gloss Sand (#7771) and experimented adding small amounts of gloss gray and gloss black to try and match the truck color. Gray was a total bust as it made the end color lighter. After experimenting adding black paint, turns out adding 25ml of black to 1 qt of Gloss Sand yielded a very close color match. To make it spray better, I thinned the paint 1/16 with Acetone and also added a paint hardener. Where as the primer took over a quart for 1 coat, I was able to spray 4 coats of color from 1.5 quarts. Turns out the color is just a hint too light, but I wasn’t aware until the first time the cap was on the truck (this past Saturday) and I’m not going to repaint it.

I let the paint cure for a week, then wet sanded up to 1500 grit. In hindsight, I should have gone up to 2500 before cut and buff. The cutting and buffing was done using Meguiar's Ultimate Compound and foam pads on an orbital buffer. I’m not happy with the shine, but I’m tired of this project and am done sanding.

 

To reinforce the 4 lifting points, I added some ¼” thick aluminum to the inside and through bolted the cargo style lifting points. There is a rubber gasket and windshield sealant under each lift point, so I’m confident it won’t leak.

Because the cap rear window was intended to overlap the tailgate on an S-10, it was too tall to fit the Tacoma. To remedy this I cut about 7/8” off the bottom of the aluminum frame. Whereas this made it fit the truck well, the gasket holder feature of rear window frame was removed. I solved this by riveting a strip of garage door seal to the inside of the rear window frame bottom and did so such that when closed, the bottom of the window frame compresses the seal against the tailgate top. I’m really pleased with the result.

I wanted lights for the inside and had some LEDs left over from adding them to the cargo area on Mrs Imagineer’s new Forester. There are 5 lights on the cap roof and I added another 7 to the bed (under the t-slot rail and front edge). All the lights are controlled by a pin switch mounted in the bed such that when the tailgate is opened, all the lights come on. I also added an LED 3rd brake light.

To be able to disconnect the cap electrical, I used a 4-wire trailer plug and socket. I also had to replace the original t-handles and gas struts.

Last, to be able to lift and remove the cap by myself, I made a lifting frame that engages the 4 lifting points on the cap roof and keeps it level while being raised for storage from the garage ceiling.

Start to finish, I have the bulk of 7 weekends and $488 into the project (including the $50 for the cap). So, do I recommend anyone attempting this epic project? Not a chance, unless you’re a frugal, introvert who gets off on completing challenging projects (like me).

 

Bravo....

 

This is insane in the best possible way. It is threads like this that make me really appreciate the creativity and ingenuity of the folks on this forum ... despite some of the nattering nabobs of negativism.

Great job.

I will say it again, there should be a hall of fame mod section. This would be in there right along with the guy who connected an AC unit and duct tape to his Tacoma camper.

Bravo ... !

 

I thought about making a YouTube video of the process, but my shop is a mess and I'm too uninspired to clean and organize...

 

whoa

 

That's pretty rad

 

Shocked. That's a tricky job and you did it well. Bravo.

 

God damn dude! That's why I come here. Good job!

 

WOW