INTRODUCTION

Roof racks for carrying 1+ kayaks can get pretty expensive (at least $100) for a transporting a single kayak and even more additional kayaks. This Instructable will show you how to build and mount a PVC Kayak Roof Rack/Carrier to your vehicle that can carry one or two kayaks. The total cost of this in its most basic form is about $80 (as of 2013). As shown in the pictures it is about $100 (as of 2013).

DISCLAIMER: I take no credit for this design, this Kayak Roof Rack/Carrier is based on the work of Niel Santos. I am uploading this Instructable because it is an awesome design that should not be lost to the internet (I only by chance came across it myself). The original plans for this Kayak Roof Rack/Carrier used to be available on Neil's website, however the site has since been taken down. If you need the original plans, I have made a PDF of them available for download at the following link: Original PVC Kayak Rack Plans - Google Drive.

WARNING! BUILD AND USE AT YOUR OWN RISK! Built properly you will have a great piece of equipment. Built improperly, this Kayak Roof Rack/Carrier could damage your vehicle, your kayaks or create a driving hazard for you and other drivers. Be safe, if not for yourself, do it for those around you.

This Instructable assumes you already have a roof rack on your vehicle with two cross bars. If you do not have any type of roof rack, please see the original design on Neil's website for how to build and mount directly to a car roof.

We will be making a slightly modified version of Neil's original design and mounting it to a 2001 Nissan Xterra.

During this Instructable, you may be using power tools and working with PVC primer and cement. Read all instructions with the equipment/materials and always use PPE (personal protective equipment). Don't chance losing a finger, or an eye, or passing out from noxious fumes. If you don't know how to do something or use a piece of equipment, please ask somebody that knows or look it up on YouTube before going at it on your own.

MATERIALS

You will need the following materials, all PVC piping is 1.5 inch diameter and everything can be bought at a hardware store like Home Depot, Lowe's, Ace Hardware and so on.

- 2x 90 degree "street" elbows (or substitute for 45 degree street elbows, either will work). Street elbows have one male and one female end as opposed to regular elbows that have two female ends.

- 10x 90 degree elbows.

- 12x T-Junctions.

- 4x 45 degree elbows.

- 4x Caps.

- Minimum 20 feet of 1.5 inch PVC pipe. You may need more depending on your vehicle.

- PVC Primer and Cement (I found a double pack that had both together).

- 4x 3/8 inch by 4 inch long bolts with hex nuts. Depending on how thick your PVC is, the bolt length may need to be shorter or longer.

- 4x 8 foot, 200 pound rated lashing straps (not to be confused with Ratchet Tie-Downs) or U-Bolts.

- 2x 24 inch bike tire inner tubes (found at any major retailer).

OTHER MATERIALS AND TOOLS

- PPE (personal protective equipment like goggles and gloves).

- Compound miter saw (or hack saw, or PVC pipe cutter of appropriate size).

- Drill and drill bits.

- Large tarp or towel you do not mind getting stained/ruined.

- Kitchen gloves (the traditional yellow ones) or other flexible gloves (Latex, Nitrile…)

- Large, flat surface to work on in a well ventilated area (preferably outside).

Step 1: Basic Skills Review - Using PVC Primer and Cement

First you will need to know (or learn) how to use PVC primer and cement. I learned watching this video: How To Glue PVC Pipe

Here is how I glued all my PVC pipes together, complete all steps without delay:

1. One application of primer to the female side of the joint (make sure coating is fairly even).

2. One application of primer to the pipe (make sure coating is fairly even).

3. Two applications of cement to the female side of the joint. The primer and cement will mix a bit, this is fine.

4. Insert pipe into the joint and twist while pushing in.

5. Continue gently twisting until you feel it start to grip (about 90 degree turn).

6. Make fine adjustments if necessary.

The cement dries quickly (within 10 seconds of joining the pipes) but even after that you can still move it slightly if you apply enough force (30 seconds max before it is solid).

Once you finish a joint you can move on to the next joint right away, however if you are paranoid about adhesion like I was, wait a minute and then move on.

Step 2: Cut and Label Each Segment

First you will assemble Segments 1-7 (called the Main Body). Then assemble Segments 8-15. For this step we will just be cutting and labeling the PVC segments. The assembly process is in the next step.

Cut each segment of pipe first and label it appropriately (use a Sharpie marker), be sure to label the joints too. Be careful with segments 2A and 2B as they are different lengths.

1A: 90 degree street elbow.
1B: 45 degree elbow.

2A: 15-1/2 inch long pipe (this will connect to the 90 degree elbow).
2B: 14-3/4 inch long pipe (this will connect to the 45 degree elbow).

3A: T-junction.
3B: T-junction.

4A: 3 inch long pipe.
4B: 3 inch long pipe.

5A: T-junction.
5B: T-junction

6A: 8-1/4 inch long pipe.
6B: 8-1/4 inch long pipe.

7: 45 degree elbow.

8A: 3 inch long pipe.
8B: 3 inch long pipe.

9A: 90 degree elbow.
9B: 90 degree elbow.

------------------------
Consider assembling the Main Body before proceeding to cut the remaining Segments, especially 10A and 10B. The length of Segments 10A and 10B depend on how wide your vehicle is. Cut these Segments so that they do not extend beyond the max width of your vehicle when assembled to the Main Body.
------------------------

10A: Varies, between 3 and 7 inch long pipe. Mine was 8-1/2 inch long pipe, check the width of your vehicle.
10B: Varies, between 3 and 7 inch long pipe. Mine was 8-1/2 inch long pipe, check the width of your vehicle.

11A: T-junciton.
11B: T-junction.

12A: 3 inch long pipe.
12B: 3 inch long pipe.

13A: 90 degree elbow.
13B: 90 degree elbow.

14A: 5-1/2 inch long pipe.
14B: 5-1/2 inch long pipe.

15A: Cap.
15B: Cap.

Step 3: Assemble Segments 1-7 (Main Body)

Put on your gloves and lay the tarp on a large flat surface where you want to work. Be sure you are in a well ventilated area.

Part 1: Using the PVC primer and cement, assemble Segments 1-5:

- Make sure 1A and 1B join together flat or the assembly will develop a twist what will make later assembly difficult.

- Be careful because 2A and 2B are different lengths, assemble appropriately.

- 3A and 3B need to point straight upward (if you are a tiny bit off that is okay).

- 5A and 5B need to be point inward and be parallel to the ground (if you are a tiny bit off that is okay).

Part 2: Using the PVC primer and cement, assemble Segments 6 and 7:

1. First join 6A to 5A and then 6B to 5B.

2. Apply primer both sides of 7.

3. Apply primer to 6A and 6B.

4. Apply cement to both sides of 7 (be quick about it).

5. Without delay, join 7 with 6A and 6B, this will be a tight fit and you won't be able to twist it. Don't worry about stretching the assembly too far. PVC is tough and your previously glued joints will be strong by now.

6. Without delay, make sure 6A and 6B are fully seated in 7. Turn the assembly on its side and use your weight to fully seat the pipes in both sides of the joint.

Now take a quick five minute break while the Main Body sets a bit.

Step 4: Assemble Segments 8-15

Using the PVC primer and cement, assemble Segments 8-15 to the Main Body:

- Sections 9A, 9B, 11A, 11B, 13A and 13B need to be parallel to the ground.

- Both A and B sides are mirror images of each other, if you mix the parts it doesn't matter.

- Alternating between the A and B sides will allow sufficient time for the cement to fully set.

Step 5: Repeat!

Now do it all over again! Assemble a second Main Body with attached Segments 8-15.

- Consider swapping the A and B sides this time so the two ends of the Kayak Rack will be mirror images of each other. If you assemble again exactly as before, that will work too. I used the mirror image method to give a consistent appearance.

- You will be tempted to go fast. Resist the urge, you may mess up or have an assembly that contains a bit of a twist. Be patient with yourself!

Step 6: Join Both Ends of the Kayak Rack Together

Now you need to determine how long the Kayak Rack will be, this depends on your vehicle's roof rack configuration.

Part 1: Determine how long the Kayak Rack needs to be:

1. Measure the distance between the crossbars on your roof rack (center of crossbar to center of crossbar). Mine was about 29 inches.

2. The measurement result will be your starting point, cut two lengths of pipe to that dimension (29 inches for me).

3. DRY FIT both ends of the Kayak Rack together using the cut pipes inserted into Segment 3A and 3B. If you rub some wax (like from a candle) on the ends of the pipes they will be easier to remove from the T-junctions when you make sizing adjustments. Remember to clean off the wax with hot water when you're finished.

4. Put the assembled Kayak Rack on your roof rack and see how it fits. The two ends will probably be too far away from each other. Slowly shorten the pipes connecting the two sides of the Kayak Rack by 1/4 to 1/2 inch at a time until the two sides sit neatly in the middle of the roof rack's cross bars. For me this was 27-5/8 inches.

Part 2: Join the ends of the Kayak Rack together:

1. Dry fit both ends of the Kayak Rack together using the cut pipes inserted into Segment 3A and 3B. Make sure the pipes are fully seated in the segments at both ends before proceeding.

2. Turn the Kayak Rack on its side and push down with your weight to ensure the pipes are fully seated in the joints.

Part 3: Drill holes for the bolts to make the Kayak Rack collapsible:

1. Mark where you intend to drill the holes. I used the bolt head to determine how far in from the edge the hole should be (for me it was about 5/8 of an inch from the edge). Using a Sharpie, make a vertical mark.

2. Next, use the joint's "parting line" as your horizontal mark. The hole will be drilled at the intersection of the vertical and horizontal lines. Mark both sides of the joint (outside and inside) by repeating the process. Repeat again for all four corners.

2. Drill small pilot holes at each mark (I used a 1/8 inch bit for this). Only drill through one side at a time. If you do not use pilot holes you run the risk of losing control over the drill and not hitting your mark.

3. Re-drill the holes with a larger 3/8 inch bit to open the holes up to the correct size, remember only drill through one side at a time. Be careful doing this because if you don't have good control over the drill or you are not aligned properly, the drill will wander and chew up the pipe making the hole bigger (and messier) than you intended.

Part 4: Insert the bolts and secure with hex nuts.

1. Insert each bolt through the holes you just drilled so the hex nut will be on the inside of the Kayak Rack with the bolt head on the outside. The bolts should slide loosely through the holes, if they do not, open the holes up a bit wider using the drill. Again, only drill one side at a time.

2. Screw the hex nut onto the bolt and tighten by hand. Do not use tools to tighten.

Alternatively, you may skip the drilling and join the two sides using PVC primer and cement. Only do this if you want the Kayak Rack permanently assembled and not collapsible.

Step 7: Cut the Bike Inner Tubes Into Sheets

The purpose of the bike inner tubes is to protect your roof rack and prevent the Kayak Rack from sliding around while you're driving.

1. Cut the inner tube in half close to the valve so it can lie as one long tube (as opposed to a circle or torus).

2. Cut off the valve.

3. Cut one wall of the inner tube down the whole length so the inner tube can open up and lay as one long sheet of rubber.

3. Cut the now long sheet of inner tube in half along its width so you have two shorter sheets of rubber.

Repeat for the second inner tube so you have 4 sheets of rubber. Wash the pieces in warm water to remove the powder.

Step 8: Mount It to the Car

Mounting to the car is really easy. There are two methods you can use:

Method 1: Use U-Bolts

- Use this method if you have a normal roof rack with narrow crossbars.

- Wrap a section of bicycle tubing around Segments 9A and 9B. This will protect your roof rack and prevent sliding.

- Mount the U-Bolts around Segment 9A and 9B and secure tightly to the roof rack.

Method 2: Use Lashing Straps

- This is the method I used because the cross bars on the Xterra are about 4" wide, far too wide for U-Bolts.

- Wrap a section of bicycle tubing around Segments 9A and 9B. This will protect your roof rack and prevent sliding.

- Wrap the Lashing Straps around Segments 9A and 9B and pull tight. You may want to let them sit for a few minutes and then retighten to account for any stretching in the straps, especially if they are new.

You're basic Kayak Rack is ready to go! Congratulations!

Step 9: Finishing It Up and Taking It to the Next Level

End Notes

WARNING! This rack will add a significant amount of height to any car, especially an SUV. Before leaving home take a moment to measure the final height of your vehicle. You don't want to encounter a low overpass/bridge/tunnel and have it ripped off. Know the total height of your vehicle and pay attention to the clearances posted on overhangs.

- When mounting the kayaks on the rack, mount them with the opening facing inward. The first time, I mounted the kayaks with the opening facing outward and they howled while driving and created a significant amount of drag. When I changed it so the openings were towards the inside, I had no issues.

- I've used this Kayak Rack on the highway in speeds of up to 60 MPH with and without kayaks on it. It performed fine, no movement or loosening.

- On my first use of the rack I took it on fairly rough (and badly wash boarded) dirt roads in excess of 30 MPH. I did not have any issues with the rack moving or having to retighten any of my straps. Its performance surprised me a lot.

Tips For Accessorizing

- Paint it using spray paint! Be sure to get spray paint that will adhere to plastic. If the can doesn't specifically say the paint bonds to plastic, IT DOESN'T so don't buy it. I used two cans of spray paint which just barely covered everything, I recommend having three cans if you want a perfect paint finish.

- Add some pool noodle cushions to ensure your kayaks won't get scratched.

Step 10: Community Knowledge

Here is some knowledge from the community that was originally provided as comments. I selected the ones I felt needed escalation above the standard comment and are things future builders may want to consider.

When in the cold, PVC can become very brittle, break and shatter if subjected to a strong impact. During the cold winter, take your Kayak Roof Rack off your car and store it inside your home, away from the cold. You probably won't be going Kayaking in the winter anyway! This has been cautioned by at least three commenters.
Don't leave your Kayak Roof Rack on your car when not in use for extended periods of time. PVC is not UV stable and leaving it subject to the full sun can cause it to degrade over time. If you must leave it on your car, paint it with a UV blocking paint that bonds to PVC.
To increase the adhesion of paint, scuff sand the PVC with some fine grit sand paper before you paint.
Sections 11A and 11B need not be T-junctions. You can just use a straight pipe. I decided to use the T-junction because I felt that having a single straight pipe would put a lot of pressure on that arm.

Step 11: Revision History

26DEC2013: Initial release.

18JAN2014: Updated instructions in Step 7 to clarify cuts.

03MAR2014: Added Community Knowledge step; Added pictures to Step 7; Updated Step 1 to include the possible need for additional PVC pipe and varying length bolts depending on how thick your PVC is.

14JUN2015: Updated Intro to remove bad links; Added information for how to obtain PDF of original plans.

03JUL2015: Added link to download PDF of original plans.

23SEP2021: Updated link for PDF of original plans; changed revision history to dates only.