Intro: Jku Tonneau Cover
I made a tonneau cover for my 2016 Jeep Wrangler unlimited black bear. Some fellow jeepers requested me to make a guide. So here’s everything that I think may be useful. Thanks for looking!
Step 1: Making a Template
Go to your local hardware store buy a cheap sheet of plywood 3/8” thick at the least, so it does not flex a lot. I had them cut it for me so it would fit in my jeep. 64” on the long end. Then cut that 64” piece down the middle 19”,so you end up with 2 64” pieces. I used the factory cut sides of the plywood for the center seam,because I don’t have a table saw. I then used card board to make a template for where the roll bar hole would be. I made the piece closest to the rear gate first, so I could measure from the center seam to the back seat and know where to cut the piece that is closest to the rear seat. You can use the rear soft top window bar as a guide to trace a line where the piece will line up well. Remember to make all the cuts and measurements with the rear window bar and the plastic pieces in if you want to be able to use your soft top as you normally would. If your first template isn’t close enough to what you want your final project to be make another or make notes with arrows while it is installed. I made a second template out of 1/8” particle wood to get the roll bar holes as close as possible and trying to keep a uniform gap around it. This wood is flimsy, so I just put it on top of the first template while making adjustments while on the jeep. You can use a pencil along the bottom of the plywood and trace along the body lines for reference once you get the rough cuts made for the seat and roll bar. I rolled small pieces of paper towel and put them in the hard top mounting holes, then put a little paint on them - this way I can gently place the pieces on to get a general idea of where the mounting holes should be drilled.
Step 2: Using the Template
Go to your local reputable lumber supplier NOT Home Depot or Lowe’s. Nothing against them but you want Baltic or Russian birch 3/4”. 4 x 8 plywood. Do not buy white birch which is what Home Depot and Lowe’s sales I did this with my first version I started and the wood began to warp half way through my project. Then I did the research about plywood very exciting stuff if you have the time. Have then cut the same dimensions as the first piece, so you can put it in your jeep and drive home. I used the factory cut edges for the seam again and traced my template on to the Russian birch taking account any notes I made on the template where I refined my roll bar holes (this was the most difficult part so take your time and make notes so you’re happy with your project). Now get to cutting with your jig saw *tip - do not cut on the lines as the jigsaw does not cut perfectly straight - you’re going to sand every thing straight afterwards. You may want to practice on the spare piece of birch so you don’t mess up - my Russian birch cost me $100 not cheap to make any mistakes from this point on. I used a circular saw to make the long cut along the back seat. I would recommend making a template with the spare piece of birch for all your round edges around the rear seat so all of your edges are uniform. This is where a hand held router with a guide bit will come into play with the template you just made. Sand all the edges so that everything is square do this with both pieces clamped together as if it was installed on the jeep, so that your seams on the fender sides are even. If you want rounded edges like I did (highly recommend this) I used a 3/8” quarter round over router bit with a guide wheel in the router I borrowed and go around the perimeter of the whole thing while clamper together as if it was installed on the jeep. You need to be sure all your edges are square before doing so because the router bit guide wheel is going to follow the lower perimeter of your project. Set you router depth and make sure it’s setup properly on your spare plywood so you don’t make any mistakes. I also put a 3/4” piece of angle iron under each part and a 1.5” flat steel in between the two pieces to make sure it stays uniform. Drill your mounting holes for the screws and your ready for the next step.
Step 3: Prepare for Paint
This is where you want to abandon this project ship if you’re not dedicated to sanding for hours and hours on end living in a dust cloud like Pig Pen from Peanuts. You may be tired of this project and just throw some rhino lining type product on. I considered this too. Here we go. Get the body filler out I used bondo as it was easily available, but you might want to research a more user friendly product. Here is where you fill all the edges all the way around sealing them up and any imperfections the might not be filled be high build primer. Sand all the bondo smooth. Reevaluate the situation and apply more bondo - sand and repeat. I heard you should wait before covering body filler to allow any shrinkage that may occur. I waited a week. Blow off the project. Wipe down with a tack cloth. I used 2k urethane high build primer that I bought from English color. I was lucky enough to have a cool as f*** boss that let me come in on a couple of Saturday’s to use the paint booth (I am not a painter and this is my first time doing any of this - youtube is very helpful). I bought a hvlp paint gun at harbor freight for like $60 with a coupon. Not the purple one! There’s a two pack one that comes in a carrying case that has a detail small gun (didn’t use that at all) and a regular size one that has 2 spraying nozzles a 1.4 and a 1.8. Use the 1.8 for the primer spraying. Spray the primer according to the data sheet available online with the recoat time, overlap, humidity and weather parameters. Now use a long block sander and sand away - youtube it. I used a flexible sanding backing pad for the perimeter and the roll bar holes. You may find you need a second pass with the primer - I did. Second coat. So I continued sanding. Once you’re satisfied and everything is smooth you're on to the next step.
Step 4: Paint
I used a 2k primer sealer with the 1.4 spay tip following the online data available for that product. I then stayed the hot rod satin black after the sealer flashed off. Wait for the recoat time to expire and repeat. Here’s where you can add a clear coat if want. I didn’t but it would make cleaning a lot easier on you in the long run as well as add protection.
Step 5: Installation
The best part. I ordered some adhesive rubber stripping from amazon and installed in on the underside to help protect the paint where it is sitting on. Then installed the bolts for the flat iron underneath joining the 2 pieces. Then I just bolted it down using rubber washers under the bolts. I also installed some of that car door edge rubber protector to the angle iron on the underside to protect my jeep and me from scratches.